Heart Murmurs and Valvular Heart Disease (USMLE Step 1)

★ High-yield tip #1

Classic signs of aortic regurgitation

Aortic regurgitation has a classic set of signs. Besides the wide pulse pressure, look for head bobbing with each heartbeat, called the de Musset sign, and bounding pulses. The pulse has a brisk upstroke followed by a sudden downstroke, as blood rushes back into the ventricle. This bounding, collapsing pulse is called a water-hammer or Corrigan pulse.

★ High-yield tip #2

Causes of aortic regurgitation

Aortic regurgitation is seen in connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome, the same disorders linked to mitral valve prolapse. But one of the most important causes on the USMLE is aortic dissection. The dissection can spread backward toward the aortic root, dilate it, and make the aortic valve leak.

★ High-yield tip #3

Mitral regurgitation

Mitral regurgitation gives a holo-systolic murmur best heard at the apex. In developed countries the most common cause is degenerative valve disease such as mitral valve prolapse, and ischemic heart disease is another common cause. But on the USMLE, the most important cause is papillary muscle rupture: a new holo-systolic murmur with shortness of breath a few days after a myocardial infarction. Acute rheumatic fever also causes mitral regurgitation, while mitral stenosis develops years to decades later.

★ High-yield tip #4

Aortic stenosis versus regurgitation

Aortic stenosis gives a mid-systolic murmur at the upper right sternal border. A bicuspid aortic valve, as in Turner syndrome, is a big risk factor, and it can also be simple age-related calcification. The exam mainly wants you to contrast it with aortic regurgitation. Aortic stenosis gives slow-rising pulses, pulsus parvus et tardus. Aortic regurgitation gives bounding pulses, a brisk upstroke with a sudden downstroke, head bobbing, and a wide pulse pressure.

★ High-yield tip #5

Mitral stenosis

Mitral stenosis classically gives an opening snap followed by a mid to late rumbling diastolic murmur, in someone who had rheumatic heart disease as a child. Some questions leave out the opening snap but make the childhood rheumatic heart disease obvious, with a loud rumbling diastolic murmur. So a rumbling diastolic murmur after childhood rheumatic heart disease means mitral stenosis.

★ High-yield tip #6

Mitral stenosis in pregnancy and the right heart

Mitral stenosis can first show up in pregnancy, because the increased plasma volume raises the pressure behind the narrowed valve. Rarely, pressure backs up through the lungs into the right heart, stiffens the right ventricle, and causes a right-sided S4.

★ High-yield tip #7

To-and-fro and the PDA murmur

Strictly, a to-and-fro murmur is a systolic murmur plus a separate diastolic murmur, as in tetralogy of Fallot with an absent pulmonary valve. A patent ductus arteriosus, or PDA, classically gives a continuous, machinery-like murmur that begins in systole and runs on past S₂. Still, exams sometimes use to-and-fro loosely for a PDA. One offline NBME form for Step 2 CK hinges on that link and catches most students off guard, so know both descriptions.

★ High-yield tip #8

Grading murmurs

Murmurs are graded from 1 to 6. 1/6 is so faint it can be heard only with special effort. 2/6 is faint, but you hear it right away. 3/6 is moderately loud, with no thrill. 4/6 is loud with a thrill, a murmur you can feel; a heave is different, the chest wall pushing outward during systole. 5/6 can be heard with just the rim of the stethoscope. 6/6 can be heard with the stethoscope lifted just off the chest.

★ High-yield tip #9

Know your murmurs

Murmurs are fair game. Step 1 expects you to know what each murmur sounds like and what causes it. Step 2 builds these same descriptions into longer vignettes and expects you to work out more from them, so know your murmurs well if you want a strong score.

★ High-yield tip #1

The aortic stenosis murmur

Aortic stenosis gives a late-peaking systolic murmur, which can also be described as a mid-systolic, or crescendo-decrescendo, murmur. They don’t have to tell you the location, but it classically radiates to the carotids. Its ejection click is not the same as the mid-systolic click of mitral valve prolapse. An ejection click points to aortic stenosis.

★ High-yield tip #2

S4 versus S3

On the USMLE, an S4 basically always means diastolic dysfunction, as in hypertrophic cardiomyopathy. An S3 on its own almost always means systolic dysfunction with a decreased ejection fraction, and dilated cardiomyopathy may give you one. Think of an S4 as going with afterload, and an S3 as going with preload. So remember: S4, diastolic dysfunction; S3, systolic dysfunction.

★ High-yield tip #3

Diastolic heart failure

Diastolic heart failure can come from increased afterload, as in systemic hypertension or aortic stenosis. Hypertrophic and restrictive cardiomyopathies can cause it too. The heart simply can’t relax and fill as easily as it should, but it still pumps fine, with a normal or preserved ejection fraction. That is what the exam wants you to know.

★ High-yield tip #4

Concentric versus eccentric hypertrophy

With an S4 and increased afterload, as in aortic stenosis, the sarcomeres are laid in parallel. That is concentric hypertrophy. Volume, or preload, goes with an S3 and eccentric hypertrophy, with sarcomeres laid in series. That can be seen in aortic regurgitation, or as physiologic hypertrophy in athletes.

★ High-yield tip #5

Dilated cardiomyopathy

Diffuse four-chamber dilatation with a reduced ejection fraction is dilated cardiomyopathy. In theory, aortic stenosis might lead to it in some cases, but not for the USMLE. Systemic hypertension, of course, can lead to any type of heart failure, including dilated cardiomyopathy.

★ High-yield tip #6

Causes of dilated cardiomyopathy

Know the ABCD causes. A, alcohol. B, beriberi, which is thiamine deficiency. C, Chagas disease, cocaine, and Coxsackie B virus. D, doxorubicin, also called Adriamycin. Other causes include pregnancy, as peripartum cardiomyopathy, and hemochromatosis.

★ High-yield tip #7

Mitral stenosis

On the USMLE, mitral stenosis is nearly always due to rheumatic heart disease; the two are basically synonymous. Rheumatic heart disease can sometimes affect the aortic valve too, but for the exam, think of the mitral valve. Mitral stenosis can be described simply as a rumbling diastolic murmur. Or the question can be very buzzy and describe an opening snap followed by a mid to late diastolic rumble.

★ High-yield tip #8

Rheumatic heart disease

In rheumatic heart disease, a child first has a Strep pyogenes infection. A type II hypersensitivity follows: antibodies against the M protein of group A strep cross-react with heart tissue, including the mitral valve. Acutely, in childhood, that causes mitral regurgitation, a holosystolic murmur. Years later the valve scars over and becomes stenotic.

★ High-yield tip #9

The wedge pressure

The pulmonary capillary wedge pressure reflects left atrial pressure. In aortic stenosis, pressure backs up into the left atrium, so left atrial pressure and the wedge pressure rise. That backs up into the lungs, raises pulmonary capillary pressure, and pushes fluid out, causing pulmonary edema. Know that the wedge pressure is normal in cor pulmonale, which is right heart failure due to a lung cause.

★ High-yield tip #10

Pulsus paradoxus

Pulsus paradoxus means a drop in systolic blood pressure of more than 10 mm Hg with inspiration. Nearly always it points to cardiac tamponade, and rarely to something like severe asthma. The USMLE can be slick and write it as paradoxical pulse, so recognize both names.

★ High-yield tip #11

Cardiac tamponade

Cardiac tamponade is a pericardial effusion that compresses the heart and causes low blood pressure. You get Beck’s triad: hypotension, jugular venous distension, and muffled or distant heart sounds. Pulsus paradoxus may or may not be present; maybe a third of questions mention it.

★ High-yield tip #1

The diastolic murmurs

When a murmur sits in diastole, ask yourself which diastolic murmurs you know. The two left-sided ones are aortic regurgitation and mitral stenosis. The right-sided ones, pulmonic regurgitation and tricuspid stenosis, are close to nonexistent on the USMLE; tricuspid stenosis is under 1% of valve disease. There are other unusual sounds, like a tumor plop from an atrial myxoma, or a venous hum.

★ High-yield tip #2

Describing the aortic regurgitation murmur

Aortic regurgitation is described as an early diastolic, decrescendo murmur, and sometimes as a decrescendo holodiastolic murmur. That last term can be confusing, because a holodiastolic murmur should fill all of diastole. Still, both descriptions mean the same murmur: aortic regurgitation.

★ High-yield tip #3

Mitral stenosis versus aortic regurgitation

Mitral stenosis sounds different. There is an opening snap shortly after S₂, followed by a mid-to-late diastolic rumble. So the sound sits in the later part of the space between S₂ and S₁, not right after S₂. Aortic regurgitation, by contrast, starts right at S₂ and then fades.

★ High-yield tip #4

Spotting a wide pulse pressure

Look for any blood pressure with a big gap between the two numbers, like 120/40 or 150/50. In aortic regurgitation the diastolic number can fall extremely low. Whenever you see that gap, think of a leaky aortic valve.

★ High-yield tip #5

Causes of aortic regurgitation

A bicuspid aortic valve is a common cause of both aortic stenosis and aortic regurgitation. For aortic regurgitation, the cause the exam most wants you to know is aortic dissection. Hypertension or cocaine use can cause a dissection that spreads backward toward the aortic root, causing aortic root dilation so the valve can no longer close properly. Dissection causes aortic regurgitation, not aortic stenosis.

★ High-yield tip #6

Aortic stenosis

Angina and pulsus parvus et tardus are both classic for aortic stenosis. Aortic stenosis is a mid-systolic, crescendo-decrescendo murmur, so it sits between S₁ and S₂, not between S₂ and S₁. Remember SAD: syncope, angina and dyspnea. Pulsus parvus et tardus means a weak, slow-rising pulse, and the murmur radiates to the carotids.

★ High-yield tip #7

Cannon A waves

When students don’t know an answer, they often pick the strange-sounding option. You hardly need the jugular venous pulse curve for the USMLE. Cannon A waves happen when the right atrium contracts against a closed tricuspid valve. This occurs with AV dissociation, such as third-degree heart block, when the atria and ventricles are no longer in sync. The pressure bounces back up into the jugular vein.

★ High-yield tip #8

Myxomatous degeneration

On the USMLE, myxomatous degeneration is the buzzword for mitral valve prolapse, which gives a mid-systolic click. It is the term used for how connective tissue disorders like Marfan syndrome and Ehlers-Danlos affect the mitral valve. These disorders can also raise the risk of dissection and aortic regurgitation, but the exam ties myxomatous degeneration to mitral valve prolapse, not aortic regurgitation.

★ High-yield tip #1

The aortic regurgitation murmur

Aortic regurgitation is an early diastolic, decrescendo murmur, and it can also be described as holodiastolic, meaning present throughout diastole. Pulmonic regurgitation can sound similar, but it is virtually nonexistent on the USMLE, so an early diastolic, decrescendo murmur on the exam is far more likely to be aortic regurgitation.

★ High-yield tip #2

The hidden murmur in aortic dissection

The exam won’t make this easy. You might get a long, twelve-line vignette about a dissection that simply mentions a diastolic murmur and nothing else. Students recognize the dissection but miss the murmur. That diastolic murmur is aortic regurgitation.

★ High-yield tip #3

Mitral valve prolapse syndrome

Most people with mitral valve prolapse have no symptoms. A minority do, called mitral valve prolapse syndrome, with atypical chest pain that the exam describes as fleeting chest pain on the left. A Step 2 CK question might describe a 30-year-old woman with about 30 such episodes, whose father died of a heart attack. The answer is reassurance, with no specific treatment needed. Mitral valve prolapse gives a mid-systolic click between S₁ and S₂.

★ High-yield tip #4

Respiration and tricuspid regurgitation

Left-sided murmurs increase with expiration, and right-sided murmurs increase with inspiration. The exam uses this: a holosystolic murmur that increases with inspiration is tricuspid regurgitation. Causes include IV drug use, which leads to tricuspid vegetations, and carcinoid syndrome. Cor pulmonale, or pulmonary hypertension, also causes it: the right ventricle expands and dilates the tricuspid annulus.

★ High-yield tip #5

Ischemia and mitral regurgitation

Papillary muscle rupture after a heart attack is the highest-yield cause of mitral regurgitation on the USMLE, though it is not the most common cause in real life. Ischemic remodeling after a heart attack also causes it, and dilated cardiomyopathy stretches the mitral annulus, which also causes mitral regurgitation.

★ High-yield tip #6

Myxomatous degeneration

In Marfan syndrome and Ehlers-Danlos, histology can show a thickened, proteoglycan-rich valve extracellular matrix, called myxomatous degeneration. The exam ties it to mitral valve prolapse, with its mid-systolic click. Marfan syndrome can cause aortic regurgitation through aortic root dilation, or through cystic medial necrosis leading to aortic dissection. Myxomatous degeneration is the histology for mitral valve prolapse, not aortic regurgitation.

★ High-yield tip #1

Tricky wording for mitral stenosis

Be ready for tricky wording. A question may not mention an opening snap at all and just describe a rumbling diastolic murmur. That is also mitral stenosis. So when you read about a rumbling murmur in diastole, think of mitral stenosis even without the snap.

★ High-yield tip #2

Rheumatic heart disease, regurgitation then stenosis

Rheumatic heart disease changes the mitral valve over time. A child who gets rheumatic heart disease first develops mitral regurgitation. Over years, the valve scars and becomes stenotic. So a 12-year-old with acute rheumatic heart disease has mitral regurgitation, and years later, mitral stenosis.

★ High-yield tip #3

Other causes of mitral stenosis

Rheumatic heart disease is not the only cause of mitral stenosis. In developed countries, calcification of the mitral annulus in older adults is also a common cause. Rarer causes include lupus, which affects the valves through Libman-Sacks endocarditis.

★ High-yield tip #4

The aortic regurgitation murmur

Aortic regurgitation is an early diastolic murmur, also called a decrescendo holodiastolic or pan-diastolic murmur. It starts right at S₂, the very beginning of diastole. So a murmur diagram with a silent start of diastole argues against aortic regurgitation.

★ High-yield tip #5

Aortic dissection and aortic regurgitation

For the USMLE, know that an aortic dissection can spread backward toward the aortic root, disrupting the aortic annulus and causing aortic regurgitation. It is the highest-yield cause of aortic regurgitation on the exam. Dissection can come from hypertension, cocaine use, or connective tissue disorders like Marfan syndrome and Ehlers-Danlos. In Marfan, the lesion behind it is cystic medial necrosis.

★ High-yield tip #6

Aortic stenosis and tricuspid regurgitation

A calcified bicuspid aortic valve points to aortic stenosis. That is a mid-systolic, crescendo-decrescendo murmur, with syncope, angina and dyspnea. Intravenous drug use classically causes tricuspid regurgitation, which is a holosystolic murmur that increases with inspiration. Both are systolic murmurs, heard between S₁ and S₂.

★ High-yield tip #7

Myxomatous degeneration

Myxomatous degeneration goes with mitral valve prolapse and its mid-systolic click. It describes the histology of proteoglycan deposits in the valve’s extracellular matrix, and it is seen with Marfan syndrome and Ehlers-Danlos. In one of these patients with a mid-systolic click, the answer is myxomatous degeneration.

★ High-yield tip #8

Telling them apart

If a patient with Marfan syndrome or Ehlers-Danlos instead has an aortic dissection, with sudden, severe, tearing chest or back pain, the answer is cystic medial necrosis. Mitral valve prolapse is the most common valve abnormality, so know it well: a mid-systolic click. Mitral stenosis is an opening snap in diastole, followed by a mid-to-late diastolic rumble.

★ High-yield tip #1

How rheumatic heart disease causes mitral stenosis

Rheumatic heart disease follows strep throat in childhood, caused by Streptococcus pyogenes, which is group A strep. The immune system makes antibodies against the bacterium’s M protein, and these cross-react with mitral valve antigens. This is molecular mimicry. In the child, the acute result is mitral regurgitation, a holosystolic murmur. Over the years the valve scars, and later in life it becomes mitral stenosis.

★ High-yield tip #2

Causes of mitral stenosis

Rheumatic heart disease is the predominant cause of mitral stenosis worldwide, and on the exam you should link the two almost every time. Much rarer causes of mitral valve disease include Libman-Sacks endocarditis in lupus, with vegetations on both sides of the valve, and nonbacterial thrombotic endocarditis, also called marantic endocarditis, which can occur with cancer.

★ High-yield tip #3

Bicuspid valve in children

A bicuspid aortic valve does not have to show up as a valve that calcifies early in middle age. The exam can give you a child with aortic stenosis from a bicuspid valve, which throws some students off. For example, a three-month-old with a grade 4/6 mid-systolic murmur. The answer is still bicuspid aortic valve. It does not have to be an adult.

★ High-yield tip #4

Aortic stenosis

For aortic stenosis, remember SAD: syncope, angina and dyspnea. The stiffened left ventricle can sometimes produce an S₄ heart sound. The pulse is pulsus parvus et tardus, a weak, slow-rising pulse, so the carotid pulse has a delayed upstroke.

★ High-yield tip #5

Carcinoid syndrome

Carcinoid syndrome means a carcinoid tumor, classically of the appendix or small bowel, that secretes serotonin. In some patients this leads to fibrous, plaque-like thickening of the tricuspid valve and tricuspid regurgitation. Picture a patient with flushing, a fast heart rate and diarrhea, with raised urine 5-HIAA, the main test used to diagnose carcinoid syndrome.

★ High-yield tip #6

Tricuspid regurgitation

Tricuspid regurgitation gives a holosystolic murmur that gets louder with inspiration. Besides carcinoid syndrome, it can come from endocarditis in people who inject drugs. But the highest-yield cause is pulmonary hypertension, or cor pulmonale. Pressure backs up into the right ventricle, which dilates and stretches the tricuspid annulus. So a patient with COPD and a holosystolic murmur that increases with inspiration has tricuspid regurgitation from pulmonary hypertension.

★ High-yield tip #7

Dissection and aortic regurgitation

An aortic dissection can extend backward toward the aortic root, disrupt the aortic annulus, and cause aortic regurgitation. That gives an early diastolic, decrescendo murmur that begins right at S₂. Dissection is a high-yield cause of aortic regurgitation, for example with Marfan syndrome, Ehlers-Danlos syndrome, cystic medial necrosis of the aorta, or cocaine use.

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Signs of aortic regurgitation

In aortic regurgitation, look for head bobbing, bounding pulses and a wide pulse pressure, a big gap between systolic and diastolic pressure, such as 160/50. The diastolic pressure collapses because blood falls back from the aorta into the left ventricle.

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The click versus the snap

Myxomatous degeneration refers to mitral valve prolapse, which gives a mid-systolic click. When you first learn this, it is easy to mix up the mid-systolic click and the opening snap. The click is mitral valve prolapse. The opening snap is mitral stenosis. Also, mitral valve prolapse is not the same thing as mitral regurgitation.

★ High-yield tip #10

Marfan and the mitral valve

We said Marfan syndrome and Ehlers-Danlos syndrome can cause dissection with aortic regurgitation. They can also cause proteoglycan buildup in the mitral valve’s extracellular matrix, which leads to mitral valve prolapse. Myxomatous degeneration is a buzzword for mitral valve prolapse, not for aortic regurgitation. The exam may simply describe a man who is six foot nine, with long hands and flat feet, and a mid-systolic click.

★ High-yield tip #11

Mitral valve prolapse on the exam

Mitral valve prolapse is very common, found in about 2 to 3% of people, and most patients have no symptoms. When you see Marfan features and a mid-systolic click, the answer is simply myxomatous degeneration.

★ High-yield tip #1

Carcinoid tumors and the liver

Carcinoid tumors occur in the GI tract, such as the small bowel and appendix, and in the lungs as bronchial carcinoids. They secrete serotonin, and its urine breakdown product, 5-HIAA, is high yield. The liver normally breaks these hormones down. If the tumor spreads to the liver, the hormones reach the circulation directly, and that is when the right-sided valves get damaged, most often the tricuspid.

★ High-yield tip #2

Inspiration and right-sided murmurs

A holosystolic murmur that increases with inspiration is tricuspid regurgitation, and you have to know that. Right-sided murmurs get louder with inspiration because inspiration increases venous return to the right heart. If a holosystolic murmur is loudest at the apex and radiates to the left axilla, and the question does not mention inspiration, think mitral regurgitation instead.

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Causes of tricuspid regurgitation

It sounds odd, but the exam wants you to know that carcinoid tumors can cause tricuspid regurgitation. Other causes include right-sided endocarditis in people who inject drugs, and cor pulmonale. In pulmonary hypertension, pressure backs up into the right heart and stretches the tricuspid annulus, so the valve can no longer close.

★ High-yield tip #4

Aortic regurgitation

An early diastolic murmur points to aortic regurgitation. Technically it could be pulmonic regurgitation, since both are described as early diastolic, decrescendo murmurs. For aortic regurgitation, think head bobbing, bounding pulses and a wide pulse pressure, a big gap between systolic and diastolic pressure. A high-yield cause is a type A aortic dissection that extends back to the aortic root and damages the valve.

★ High-yield tip #5

Mid-systolic murmurs and carcinoid

A mid-systolic murmur means aortic stenosis, or possibly pulmonic stenosis. Pulmonic stenosis can occur with carcinoid tumors, but it is less likely than tricuspid regurgitation. If the exam wants pulmonic stenosis, it describes a mid-systolic murmur that increases with inspiration.

★ High-yield tip #6

Aortic stenosis

Aortic stenosis gives a crescendo-decrescendo murmur. Look for pulsus parvus et tardus, a slow-rising pulse with a delayed carotid upstroke, and SAD: syncope, angina and dyspnea. A bicuspid aortic valve is a high-yield cause. Congenital aortic stenosis does not need heavy calcification, and it can present in children too, which confuses students who assume it has to be an adult.

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Mitral stenosis

An opening snap with a diastolic murmur is mitral stenosis, and on the exam, mitral stenosis means a history of rheumatic heart disease. In young people, rheumatic heart disease most often shows up as mitral regurgitation. Over the following decades the valve scars and can become stenotic. So the classic finding is an opening snap followed by a low-pitched diastolic rumble.

★ High-yield tip #8

Mitral stenosis in pregnancy

The exam can also give a pregnant woman with a diastolic murmur and shortness of breath from the second trimester onward. That is mitral stenosis becoming symptomatic. Plasma volume rises by about 45 to 55% in pregnancy, and hemodynamic demands peak in the second trimester. Stenosis that was silent before now causes symptoms. The cause is still a history of rheumatic heart disease. Pregnancy simply unmasks it.

★ High-yield tip #9

To-and-fro versus continuous murmurs

A to-and-fro murmur is a systolic murmur plus a separate diastolic murmur, as when aortic stenosis and aortic regurgitation occur together. Don’t confuse it with a continuous, machinery-like murmur, which begins in systole and continues past S₂. Neither one is the classic murmur of carcinoid heart disease, which most often causes tricuspid regurgitation.

★ High-yield tip #10

PDA wording on the exam

Exam questions sometimes use to-and-fro loosely for a PDA, whose classic murmur is continuous and machinery-like. One offline NBME form for Step 2 CK reportedly gives congenital rubella syndrome with a to-and-fro murmur, meaning a PDA, so know that rubella causes it. Continuous murmurs can also come from outside the heart, such as an arteriovenous fistula at the arterial puncture site after cardiac catheterization, which gives a continuous bruit.

★ High-yield tip #1

Who gets a bicuspid aortic valve

Most people with a bicuspid aortic valve do not have Turner syndrome. It can occur on its own or run in families, where the pattern can be autosomal dominant.

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Bicuspid valve in children

Symptoms of stenosis from a bicuspid valve typically begin between ages 50 and 70, but many students wrongly learn that a bicuspid valve only causes trouble in adulthood. The exam will happily give you a bicuspid valve in children, even in an infant a few months old, and almost everyone is surprised.

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Valsalva and murmurs

Valsalva sharply raises intrathoracic pressure and reduces preload, so less blood fills the heart. Whenever a vignette mentions Valsalva, think less volume in the heart. With less volume, most murmurs, aortic stenosis included, get softer. The point is that they do not get louder, so a murmur that does not change fits too. The exceptions are HOCM and mitral valve prolapse, which get worse. Going from lying down to standing works the same way.

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Splitting of S2

B, an atrial septal defect, would be described with fixed splitting of S2. Some students ask why vignettes don’t always say wide fixed splitting. Wide splitting means the pulmonic valve closes late, as with right-sided overload. Paradoxical splitting means the aortic valve closes late, as with left bundle branch block or severe aortic stenosis. So the key word for an atrial septal defect is fixed, and vignettes may simply say fixed splitting.

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Cystic medial necrosis

Cystic medial necrosis describes degenerative changes in the wall of the aorta, classically in Marfan syndrome, though it also occurs with hypertension. It sets the stage for aortic dissection, and a dissection reaching the aortic root causes aortic regurgitation, a diastolic murmur.

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Aortic regurgitation versus stenosis

The murmur of aortic regurgitation is a decrescendo diastolic murmur, which can be holodiastolic. It is loudest right after S2, so it is also called early diastolic. One important cause of aortic regurgitation is aortic dissection reaching the aortic annulus. Look for bounding pulses, head bobbing, and a wide pulse pressure. Aortic stenosis instead gives pulsus parvus et tardus, slow-rising pulses, and its murmur can radiate to the carotids.

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Myxomatous degeneration

E, myxomatous degeneration, is the valve change behind mitral valve prolapse. It can occur on its own or with connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome. You would expect a mid-systolic click, and the murmur gets louder with Valsalva.

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Vague murmur locations

Exam questions can be vague about murmur location and may not say right or left. Sometimes they place an aortic valve murmur at the left sternal border, second intercostal space, which is technically the pulmonic area, not the aortic area.

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How the aortic regurgitation murmur is described

Know the different ways a question can describe the aortic regurgitation murmur. It can be called a decrescendo holodiastolic murmur, an early diastolic murmur, or a murmur loudest immediately after S₂, because diastole begins after S₂. All of these wordings point to aortic regurgitation.

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Signs and causes of aortic regurgitation

The classic signs of aortic regurgitation are a wide pulse pressure, head bobbing, and bounding pulses. One important cause is aortic dissection spreading back toward the aortic root, for example with hypertension, Marfan syndrome or Ehlers-Danlos syndrome. A question does not have to give a cause; the wide pulse pressure alone can be enough.

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Pulmonic regurgitation

Pulmonic regurgitation would in theory give the same kind of murmur, but it would be described as getting louder with inspiration, like other right-sided murmurs. Its classic form, the Graham Steell murmur, comes from pulmonary hypertension stretching the pulmonic valve ring.

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Mitral stenosis and rheumatic heart disease

Mitral stenosis gives an opening snap shortly after S₂, then a mid-to-late diastolic rumble. Worldwide, it is most often due to rheumatic heart disease. In young people, rheumatic heart disease most often shows up as mitral regurgitation, while symptoms of rheumatic mitral stenosis typically begin in the third or fourth decade.

★ High-yield tip #5

Mitral stenosis in pregnancy

Another classic vignette is a pregnant woman in her second or third trimester who becomes short of breath and has a diastolic murmur. That is mitral stenosis. Mild mitral stenosis may first cause symptoms in pregnancy, because plasma volume and cardiac output rise, and cardiac output peaks by mid-pregnancy.

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Causes of tricuspid regurgitation

Tricuspid regurgitation gives a holosystolic murmur that increases with inspiration. Its most common cause is secondary, from a right ventricle enlarged by pressure or volume overload, as in pulmonary hypertension and cor pulmonale, so lung disease can lead to it. A loud P2 is usually the first exam finding of pulmonary hypertension. Infective endocarditis in people who inject drugs is a primary cause.

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Mitral valve prolapse

Mitral valve prolapse gives a mid-systolic click and is one of the most common valve abnormalities. Most cases are primary, with no underlying connective tissue disease, although it can come with Ehlers-Danlos syndrome or Marfan syndrome. Most patients have no symptoms.

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Symptomatic mitral valve prolapse

Some patients do have symptoms, such as atypical chest pain or palpitations, without significant regurgitation. Picture a young woman with fleeting left-sided chest pain and a mid-systolic click. Once other causes are ruled out, management focuses on reassurance, lifestyle changes and treating symptoms, not on fixing the valve.

★ High-yield tip #9

Ejection click versus mid-systolic click

Do not confuse two different clicks. An ejection click is not the same thing as the mid-systolic click of mitral valve prolapse. An ejection click can be described in aortic stenosis vignettes, together with a mid-systolic murmur.

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Aortic stenosis

Aortic stenosis can cause syncope, angina and dyspnea, and pulsus parvus et tardus, meaning slow-rising pulses, also described as a slow carotid upstroke. Contrast aortic regurgitation, with bounding pulses, head bobbing and a wide pulse pressure. In patients under 70, the most common cause of aortic stenosis is a bicuspid aortic valve, which can run in families in an autosomal dominant pattern.

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Aortic stenosis in children

A bicuspid valve is not only about Turner syndrome, and it absolutely occurs in children. A pediatrics question might show a three-month-old with a mid-systolic murmur and an ejection click, and many students skip aortic stenosis because they think a bicuspid valve must be an adult problem. It does not have to calcify later in life first. Aortic stenosis can be the answer in a child.

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Connective tissue disorders

Mitral valve prolapse and aortic regurgitation are both seen in connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome. In a patient with Marfan features, the type of murmur tells you which lesion is present.

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The click versus the opening snap

Do not confuse a midsystolic click with an opening snap. An opening snap is heard in diastole and points to mitral stenosis. Think of it when a patient has a history of rheumatic fever. Most mitral stenosis is a late result of rheumatic heart disease from rheumatic fever in childhood.

★ High-yield tip #3

The Marfan trap, aortic regurgitation

Because aortic regurgitation is also seen in Marfan syndrome and Ehlers-Danlos, it is a tempting trap when a question describes Marfan features. That link is true, but aortic regurgitation would not cause a midsystolic click. It causes a high-pitched, blowing decrescendo murmur that starts in early diastole.

★ High-yield tip #4

Bicuspid aortic valve

A bicuspid aortic valve points to aortic stenosis, which gives a midsystolic, crescendo-decrescendo ejection murmur, not a midsystolic click. A bicuspid aortic valve is classic for Turner syndrome, but it can also simply run in families, sometimes in an autosomal dominant pattern.

★ High-yield tip #5

Mitral regurgitation after a heart attack

Rupture of the chordae tendineae causes mitral regurgitation. The classic exam link is a myocardial infarction: ischemia damages the papillary muscles that anchor the chordae, and papillary muscle rupture causes acute mitral regurgitation. That gives a holosystolic murmur that classically radiates to the axilla, not a midsystolic click.

★ High-yield tip #1

The diastolic murmurs

The word blowing is not the critical part. When you see diastolic, ask how many things it can be: aortic regurgitation, pulmonic regurgitation, or in theory mitral or tricuspid stenosis. The right upper sternal border is the aortic area, so a diastolic murmur there means aortic regurgitation, a decrescendo murmur that can last through diastole.

★ High-yield tip #2

Bounding pulses and pulse grading

Pulse grading is subjective. On the 0 to 4 scale used by StatPearls, 3+ is a normal, easily felt pulse and 4+ is bounding, so when a question gives 3+ as a clue, lean on the murmur, not that number. Aortic regurgitation classically gives a bounding, water-hammer pulse and can widen the pulse pressure, such as 120/40.

★ High-yield tip #3

Pressure overload versus volume overload

D, left ventricular pressure overload, is high yield. It points to aortic stenosis, and it can also mean systemic hypertension or the outflow obstruction of hypertrophic obstructive cardiomyopathy. Remember the pair: pressure overload, aortic stenosis; volume overload, aortic regurgitation. Aortic stenosis would give a midsystolic, crescendo-decrescendo systolic murmur, not a diastolic one.

★ High-yield tip #4

Don’t pigeonhole

Some students get thrown off by the word blowing because they expected a different description. The lesson is not to pigeonhole. Do not read one description in a textbook and decide a disease must always present that way. Many exam questions are not textbook, and if one is, consider yourself lucky.

★ High-yield tip #1

Mitral versus tricuspid regurgitation

A holosystolic murmur that gets louder with expiration is mitral regurgitation. If the question instead said a holosystolic murmur that gets louder with inspiration, that would be tricuspid regurgitation.

★ High-yield tip #2

The three classic VSD presentations

A ventricular septal defect is also a holosystolic murmur. On exams it shows up in three classic ways, each a holosystolic murmur at the left sternal border: first, with a palpable thrill; second, with a diastolic rumble; third, with left atrial enlargement, a sign of a large shunt. That is how a VSD appears in vignettes.

★ High-yield tip #3

Aortic and pulmonic regurgitation

Pulmonic regurgitation and aortic regurgitation are both diastolic murmurs, heard in diastole, not systole. The aortic valve is on the left side of the heart, so aortic regurgitation gets louder with expiration. The pulmonic valve is on the right side, so pulmonic regurgitation gets louder with inspiration.

★ High-yield tip #1

How the aortic regurgitation murmur is described

A question may call the aortic regurgitation murmur a holodiastolic murmur loudest in early diastole, or simply a holodiastolic murmur. Classically it is decrescendo, loudest in early diastole and then fading. Any of these descriptions should make you think of aortic regurgitation.

★ High-yield tip #2

Murmur location is not always textbook

The classic aortic listening area is the second intercostal space at the right sternal border. A question does not have to say that. Some questions say the murmur radiates down the left or the right sternal border. Murmur questions are not always textbook.

★ High-yield tip #3

Radiation patterns

There are classic radiation patterns, such as mitral regurgitation radiating to the axilla or aortic stenosis radiating to the carotids, but a question need not mention them.

★ High-yield tip #4

Bounding pulses

Bounding pulses and head bobbing are characteristic of aortic regurgitation. A wide pulse pressure matters for aortic regurgitation, but it is not limited to it. Bounding pulses also occur with arteriovenous fistulas and sometimes with patent ductus arteriosus.

★ High-yield tip #5

Do not overlook the blood pressure

So remember: aortic regurgitation, wide pulse pressure, bounding pulses, a big gap between systolic and diastolic pressure. Some questions give a blood pressure like 160/60. Students often overlook it until someone points out the large difference between the two numbers.

★ High-yield tip #6

Three ways to describe a VSD

Exam questions describe a VSD with a holosystolic murmur at the left sternal border, or lower left sternal border, plus one of three extras: a palpable thrill, a diastolic rumble, or left atrial enlargement from a large shunt.

★ High-yield tip #7

Aortic stenosis

A narrow aortic valve orifice means aortic stenosis. It obstructs outflow from the left ventricle and gives a systolic crescendo-decrescendo murmur at the right upper sternal border, often radiating to the carotids.

★ High-yield tip #8

Hypertension and the S4

Systemic hypertension puts afterload on the left ventricle, and long-standing hypertension is better linked to an S₄ heart sound. An S₄ means the left ventricle is stiff. The thickened ventricle fills poorly in diastole, and the atrium contracting against it produces the S₄. That diastolic dysfunction is classic for advanced hypertension.

★ High-yield tip #9

The tricuspid murmur

Tricuspid insufficiency would be a holosystolic murmur, classically at the left sternal border. The tricuspid listening area is the fourth intercostal space at the lower left sternal border.

★ High-yield tip #1

Caplan syndrome and the lungs in RA

Caplan syndrome is rheumatoid arthritis plus pneumoconiosis. Rheumatoid arthritis itself can cause restrictive lung disease, called rheumatoid lung. Methotrexate, the first-line DMARD for rheumatoid arthritis, can also injure the lungs and cause interstitial lung disease.

★ High-yield tip #2

Pneumoconiosis

Pneumoconiosis means lung disease from workplace dust, such as coal workers’ pneumoconiosis, silicosis and berylliosis. These are usually restrictive. So a person with rheumatoid arthritis who also has a dust exposure, such as working in a stone quarry with silica, fits Caplan syndrome. Caplan is spelled with a C.

★ High-yield tip #3

Felty syndrome

Felty syndrome is rheumatoid arthritis plus neutropenia plus splenomegaly. You don’t need to know why the three go together, only the combination. It looks low yield, but it does show up on Step 2 CK questions, where the answer is simply Felty syndrome.

★ High-yield tip #4

Heyde syndrome

Heyde syndrome is aortic stenosis plus bleeding from angiodysplasia. Angiodysplasia means dilated, tortuous small vessels in the wall of the bowel. It causes painless rectal bleeding in older adults, and it is one of the common causes in this age group, along with diverticular bleeding and colorectal cancer.

★ High-yield tip #5

Why aortic stenosis bleeds

Why the link? High shear stress across the narrowed aortic valve breaks up large von Willebrand factor multimers, so the fragile vessels bleed more easily. On Step 2 CK, a vignette may describe an older man who gets chest pain while arguing with his wife and also has a history of rectal bleeding. That is Heyde syndrome.

★ High-yield tip #6

Leriche syndrome

Leriche syndrome is atherosclerosis of the aortoiliac vessels in someone with advanced disease. It causes claudication in the buttocks and thighs, which reflects that high level of blockage, plus erectile dysfunction in men. If a man only gets calf pain when he walks, the disease is lower down, so that is not Leriche syndrome.

★ High-yield tip #7

Leriche syndrome on the exam

A classic question describes a man with advanced diabetes, a major risk factor for atherosclerosis, who has erectile dysfunction and no nocturnal erections. Absent nocturnal erections point to a physical cause rather than a psychological one, which fits Leriche syndrome.

★ High-yield tip #1

Concentric hypertrophy

Concentric hypertrophy classically comes from systemic hypertension or aortic stenosis, and the wall is also thick in hypertrophic obstructive cardiomyopathy. The sarcomeres are laid down in parallel, which thickens the left ventricular wall and makes it stiffer. That causes diastolic dysfunction and an S4 heart sound.

★ High-yield tip #2

Aortic stenosis

Remember SAD for aortic stenosis: syncope, angina and dyspnea. The murmur is a mid-systolic, crescendo-decrescendo murmur that classically radiates to the carotids. The pulse is pulsus parvus et tardus, a weak pulse with a slow upstroke.

★ High-yield tip #3

Aortic regurgitation

Aortic regurgitation gives a decrescendo diastolic murmur. It causes eccentric hypertrophy, with sarcomeres laid down in series and a dilated left ventricle, sometimes with an S3. It also gives bounding pulses: a wide pulse pressure, such as 120/40 or 160/60, with a brisk upstroke and a sudden fall.

★ High-yield tip #4

Mitral regurgitation

Mitral regurgitation is a holosystolic murmur that classically radiates to the axilla. Ischemic heart disease is a common cause, and after a heart attack, papillary muscle rupture can cause it suddenly. In developed countries, the most common cause is degenerative valve disease with mitral valve prolapse, which connective tissue disorders like Marfan and Ehlers-Danlos syndromes make more likely.

★ High-yield tip #5

Mitral stenosis

Mitral stenosis is classically caused by rheumatic heart disease, which is still a leading cause worldwide. It gives an opening snap followed by a diastolic murmur in mid to late diastole. Sometimes the question simply calls it a diastolic rumble.

★ High-yield tip #6

Rheumatic fever and the mitral valve

This trips students up. A 12-year-old with strep pharyngitis who develops a new murmur during acute rheumatic fever has mitral regurgitation, not mitral stenosis. Mitral stenosis appears 10 to 20 years later, in adult life.

★ High-yield tip #7

Pulmonic regurgitation

Pulmonic regurgitation is seldom the answer on the exam. It is mostly seen after repair of congenital heart disease or with pulmonary hypertension. Its murmur is a blowing, decrescendo diastolic murmur, so it can sound similar to the murmur of aortic regurgitation.

★ High-yield tip #8

Pulmonic stenosis

Pulmonic stenosis is classic for tetralogy of Fallot, which is linked to DiGeorge syndrome. Tetralogy has four parts: pulmonic stenosis, right ventricular hypertrophy, an overriding aorta and a ventricular septal defect. Pulmonic stenosis is also associated with Noonan syndrome and congenital rubella syndrome, which are less likely to be tested here.

★ High-yield tip #9

Right-sided murmurs

Pulmonic stenosis sounds like aortic stenosis, a mid-systolic murmur. But instead of the right upper sternal border, second intercostal space, it is heard at the left upper sternal border, second intercostal space. Right-sided murmurs get louder with inspiration, because lower pressure in the chest increases venous return.

★ High-yield tip #10

Tricuspid regurgitation

So a 2/6 holosystolic murmur that gets louder with inspiration is tricuspid regurgitation, not mitral regurgitation. Tricuspid regurgitation is very high yield with pulmonary hypertension and cor pulmonale. Step 2 CK questions often describe one of these patients with that murmur. Don’t be thrown: pulmonary hypertension can cause it.

★ High-yield tip #11

More causes of tricuspid regurgitation

Severe mitral stenosis can also cause tricuspid regurgitation, as pressure backs up through the lungs to the right heart. Carcinoid syndrome is another cause. A neuroendocrine tumor, usually of the small bowel, sometimes the appendix or bronchi, secretes serotonin. Diagnose it with 5-HIAA in the urine. Patients can have flushing with a fast heart rate.

★ High-yield tip #12

IV drug use

Tricuspid regurgitation is also classic for intravenous drug use. Staphylococcus aureus causes acute endocarditis of the tricuspid valve, so a new murmur plus fever in someone who injects drugs points to tricuspid regurgitation.

★ High-yield tip #13

Tricuspid stenosis

Tricuspid stenosis is rare and very rarely tested. It would sound similar to mitral stenosis, with a diastolic rumble, and an opening snap may be heard. Like other right-sided murmurs, it gets louder with inspiration.

★ High-yield tip #1

The aortic regurgitation murmur

The murmur is a decrescendo diastolic murmur, loudest in early diastole. It starts at the aortic area and is heard down the left sternal border. In severe aortic regurgitation, it can last through all of diastole.

★ High-yield tip #2

Other causes of bounding pulses

Bounding pulses can also occur with a patent ductus arteriosus, because blood runs quickly from the aorta into the pulmonary trunk. Look for a continuous machinery murmur through systole and diastole. Arteriovenous fistulas also cause bounding pulses, as in Paget disease of bone or in a patient on dialysis.

★ High-yield tip #3

Aortic regurgitation versus aortic stenosis

Aortic regurgitation causes eccentric hypertrophy from volume overload, while aortic stenosis causes concentric hypertrophy from pressure overload. Aortic stenosis is a mid-systolic, crescendo-decrescendo murmur at the aortic area that radiates to the carotids. It classically presents with SAD: syncope, angina and dyspnea, though a question need not include all three.

★ High-yield tip #4

Angina and sudden death in aortic stenosis

Angina is the interesting one. The pressure overload on the left ventricle raises its oxygen demand, so it is prone to ischemia. So if a patient in their 50s or older dies suddenly and the stem is vague, think of aortic stenosis as a possibility.

★ High-yield tip #5

Bicuspid aortic valve

A bicuspid aortic valve is a classic cause of aortic stenosis. It can run in families, sometimes in an autosomal dominant pattern, and it is classic for Turner syndrome. The murmur can be present even in childhood. Bicuspid valves cause stenosis earlier, while people with normal valves classically get senile calcification in their 70s or 80s.

★ High-yield tip #6

Aneurysms and pulsations

Aneurysm questions like to mention a pulsation. A thoracic aneurysm may be described as a suprasternal pulsation, just above the manubrium, and an abdominal aortic aneurysm as a pulsatile mass in the abdomen.

★ High-yield tip #7

Aortic dissection risk factors

Aortic dissection creates a false lumen in the aortic wall. The most common risk factor is hypertension, including hypertension from cocaine use. Connective tissue disorders such as Marfan and Ehlers-Danlos syndromes raise the risk. Rare familial conditions exist too, such as an MYH11 mutation causing familial thoracic aortic aneurysm, but that is beyond the exam.

★ High-yield tip #8

Treating aortic dissection

A bonus point: an intravenous beta blocker such as labetalol is the first medication in aortic dissection. It lowers heart rate and blood pressure, which reduces shearing forces on the aorta. An ascending dissection needs surgery plus the beta blocker. An uncomplicated descending dissection is managed medically.

★ High-yield tip #9

The mitral regurgitation murmur

Mitral regurgitation is a holosystolic murmur, usually at the left mid-clavicular line, that can radiate to the axilla and gets louder with expiration. Ischemic heart disease is a common cause. A patient with heart failure from ischemia may have a 2/6 holosystolic murmur, and you don’t need a connective tissue disorder to explain it.

★ High-yield tip #10

Causes of mitral regurgitation

In developed countries, the most common cause is degenerative disease with mitral valve prolapse, which connective tissue disorders make more likely. Mitral regurgitation can also appear acutely, typically 2 to 7 days after a heart attack, when an ischemic papillary muscle ruptures. Expect sudden shortness of breath with pulmonary edema. The murmur may be holosystolic, but it can be soft or even absent.

★ High-yield tip #11

Mitral stenosis

Mitral stenosis is classically due to past rheumatic fever. It gives an opening snap shortly after S2, followed by a mid to late diastolic rumble. Step 2 CK can be tricky: one question described an adult with rheumatic heart disease and a 4/6 rumbling diastolic murmur, but stated there was no opening snap. It was still mitral stenosis.

★ High-yield tip #12

Mitral stenosis in pregnancy

Mitral stenosis appears years after rheumatic heart disease, and pregnancy often unmasks it. Plasma volume rises by about half during pregnancy, climbing fastest in the second trimester. So a 32-year-old in her second trimester with new shortness of breath may have mitral stenosis. If asked what she likely had as a child, the answer is mitral regurgitation.

★ High-yield tip #13

Rheumatic fever, regurgitation first

Students often get this backward. A 12-year-old with a sore throat, fever and a new murmur during acute rheumatic fever has mitral regurgitation, not stenosis. Mitral stenosis comes 10 to 20 years later.

★ High-yield tip #14

Libman-Sacks endocarditis

Lupus is a rare cause of mitral valve disease through Libman-Sacks endocarditis. It forms small, sterile, wart-like vegetations that can sit on both sides of the valve, most often the mitral valve, and unlike bacterial endocarditis they are not caused by infection. It is classically linked to antiphospholipid antibodies, such as the lupus anticoagulant.