Localize systolic murmurs by timing, chest position, radiation, and maneuvers, then recognize the exceptions that require echocardiography and urgent care.
A systolic murmur reaches the apex. Does that make it mitral regurgitation? It makes the mitral valve worth investigating. The diagnosis comes from the sound's timing, distribution, response to loading, and the rest of the examination. A listening area is a starting point, not a valve label.
Use the map to organize what you hear, then ask what pressure difference could produce it. The same lower sternal location can carry a tricuspid leak, a ventricular septal jet, or dynamic outflow obstruction. Their mechanisms predict different sounds.
Place the sound on the patient's chest
The apex is lateral to the sternum, usually near the left fifth intercostal space at the midclavicular line in an adult. The tricuspid listening area lies near the lower left sternal edge, commonly the fourth or fifth interspace. They are not separated by a fixed two-inch distance. Cardiac enlargement, body habitus, and position can shift where a sound is loudest.
Anterior listening map. Patient's right is on the reader's left.
Patient's right
Patient's left
Patient's rightUpper sternal edge Aortic area Second interspace
Patient's leftUpper sternal edge Pulmonic area Second interspace
Patient's rightContinue listening across the chest.
Patient's leftLower sternal edge Tricuspid area Fourth or fifth interspace
Patient's rightThe apex lies toward the patient's left.
Patient's leftLower and farther lateral Mitral area at the apex Usually fifth interspace, midclavicular line
These are listening areas, not the anatomical positions of the valves. Compare upper versus lower and parasternal versus lateral. A murmur may occupy more than one area. [1]
Use the diaphragm for the higher-pitched systolic sounds and clicks. The bell, applied lightly, helps with lower-pitched accompanying sounds such as an apical S3. Find S1 and S2 before naming a murmur. Gentle palpation of one carotid pulse can help identify systolic ejection; never compress both carotids together.
Radiation describes where the sound remains audible. Aortic stenosis often transmits toward the neck and carotids. Mitral regurgitation often transmits toward the axilla. The blood jet helps generate the vibrations, but the chest wall also transmits them. Axillary radiation does not mean blood travels into the axilla, and an eccentric mitral jet can have a different distribution. Listen beyond the standard four areas. [1]
Try it here · Checkpoint 1 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 1
Show answer and explanations for case 1
A. Tricuspid regurgitation (Why this does not fit)
TR can also fill systole, but a lower parasternal maximum, inspiratory increase and systemic venous findings would support it. This lateral apical and axillary distribution favors the mitral valve.
B. Mitral regurgitation (Best answer)
The apical maximum, full systolic duration and axillary transmission together support MR. The progressive exertional symptoms warrant echocardiographic assessment of the leak and its consequences.
C. Aortic stenosis (Why this does not fit)
AS may reach the apex, but its typical murmur grows and fades during ejection. A carotid-radiating upper sternal murmur with delayed pulses would be more supportive.
D. Pulmonary valve stenosis (Why this does not fit)
PS generally produces an ejection murmur near the left second interspace, not this persistent apical jet.
Takeaway: Use timing and distribution together; holosystolic alone does not separate MR from TR.
S1 marks atrioventricular valve closure near the start of ventricular systole. S2 contains aortic closure, A2, and pulmonic closure, P2. Systole includes isovolumetric contraction before the semilunar valves open; ventricular pressure does not exceed arterial pressure throughout the entire S1-to-S2 interval.
Read timing before interpreting shape. The ejection peak can occur later with greater obstruction. In pulmonary stenosis, the murmur can extend beyond A2 but still end before delayed P2. [1][3]
A holosystolic, or pansystolic, jet persists because ventricular pressure exceeds pressure in the receiving chamber throughout systole. Think mitral regurgitation, tricuspid regurgitation, or a ventricular septal defect. An ejection murmur follows forward flow through an outflow tract. It grows and fades as flow changes. Stenosis is one cause; increased flow through a structurally normal valve is another.
A midsystolic click followed by a late systolic murmur suggests mitral valve prolapse. The click arises as the prolapsing valve apparatus abruptly tenses, and the murmur represents regurgitation. An early ejection click just after S1 belongs to a different mechanism, often an abnormal but mobile semilunar valve. Do not collapse all clicks into prolapse. [3]
Normal S2 splitting widens with inspiration. A wide split that changes little with respiration supports an atrial septal defect in the appropriate examination. Pulmonary stenosis can delay and soften P2; severe aortic stenosis can soften A2 or produce paradoxical splitting. S2 is supporting evidence, not a stand-alone diagnosis. [11]
Three persistent jets, three destinations
Mitral regurgitation sends blood from LV to LA
The classic sound is a blowing holosystolic murmur strongest at the apex, often reaching the axilla. A soft S1 may accompany it. Chronic regurgitation can enlarge the left atrium and ventricle; an S3 suggests increased ventricular filling and volume loading. Neither an S3 nor left atrial enlargement identifies the valve by itself.
Separate primary disease of the leaflets, chordae, or papillary muscles from secondary regurgitation caused by altered ventricular or atrial geometry. Prolapse, rheumatic damage, endocarditis, and papillary muscle rupture are relevant causes. The posteromedial papillary muscle usually has one arterial supply, from the RCA or circumflex system depending on dominance; the anterolateral muscle usually has dual supply. This helps explain the post-infarction rupture pattern. [6] Dilated cardiomyopathy can prevent adequate leaflet coaptation without primary leaflet destruction. Prolapse is not the universal most common cause in every population. [4]
Tricuspid regurgitation sends blood from RV to RA
A lower left parasternal holosystolic murmur with inspiratory augmentation supports tricuspid regurgitation, the Carvallo sign. Large jugular systolic c-v waves, a pulsatile liver, and edema connect the sound to systemic venous congestion. Pulmonary hypertension and right ventricular dilation commonly produce secondary TR; infection, device-lead interference, and carcinoid valve disease can damage or restrict the apparatus. [10][13]
A missing inspiratory increase does not exclude TR, particularly with severe right ventricular failure. Marked right ventricular enlargement may also shift the audible murmur toward the apex. Use the venous examination and echocardiogram when the map is less tidy. [1]
A ventricular septal defect sends blood between ventricles
With low pulmonary vascular resistance, systolic flow usually runs from LV to RV. A restrictive defect can preserve a substantial pressure gradient and generate a harsh lower sternal murmur with a thrill, even in a thriving child. A larger defect can produce greater pulmonary flow and heart failure despite a less impressive sound. Feeding difficulty, tachypnea, and poor weight gain may emerge weeks after birth as pulmonary resistance falls. [7]
Loudness is not a ruler for defect size. Tiny muscular defects may close functionally during contraction and produce a short early systolic murmur. Advanced pulmonary hypertension can reduce the LV-to-RV gradient and diminish the murmur; shunt reversal can cause cyanosis. A quiet murmur in a symptomatic patient is not reassuring. [1]
The distinction to retain is the receiving chamber. LA loading supports MR. RA and venous pulsations support TR. An interventricular jet and pulmonary overcirculation support VSD. A palpable thrill signals substantial vibration, not a particular shunt volume.
Compare a fixed outlet with a changing ventricle
Aortic stenosis
A harsh ejection murmur at the right upper sternal edge that reaches the carotids suggests aortic stenosis. A small, delayed carotid upstroke is pulsus parvus et tardus. Later peaking and diminished A2 support more advanced obstruction. Calcific disease is common in older adults; a bicuspid valve can become obstructed earlier, without a fixed age gap. Exertional syncope, angina, or dyspnea makes assessment more urgent. The three symptoms need not all be present. [1][4]
Aortic sclerosis can cause a similar murmur without significant obstruction. Aortic stenosis can also transmit a musical component to the apex, the Gallavardin phenomenon, and low forward flow can make severe stenosis quiet. Doppler echocardiography determines the severity; location and decibels do not. [1][4]
Pulmonary stenosis and increased pulmonary flow
Pulmonary valve stenosis produces an ejection murmur near the left second interspace, often with a right ventricular heave, thrill, or delayed P2. Inspiratory augmentation may support its right-sided origin. Radiation toward the shoulder or back is variable and is not required. An ejection click may become softer during inspiration even when the murmur becomes louder. Increased right ventricular filling can partly open a mobile stenotic valve before ejection, leaving less excursion to generate the click. [1][3]
Carcinoid heart disease can affect both the tricuspid and pulmonary valves, producing regurgitation more often than stenosis. [17] An ASD can produce a pulmonary flow murmur through a normal pulmonary valve. Fixed wide S2 splitting and right heart volume loading distinguish this from isolated valvar stenosis. Noonan syndrome is associated with dysplastic pulmonary valves and can also include HCM. In tetralogy of Fallot, obstruction may be infundibular as well as valvar. Congenital rubella classically associates with peripheral pulmonary artery stenosis and PDA, so do not assume every pulmonary-region murmur originates at the valve. [9][15][8]
Obstructive hypertrophic cardiomyopathy
The ejection murmur often lies along the left sternal edge toward the apex. A smaller ventricular cavity can intensify dynamic left ventricular outflow tract obstruction. Septal hypertrophy and systolic anterior motion of the mitral valve can cooperate to narrow the outlet; associated MR can add a separate apical regurgitant sound. HCM does not always cause obstruction or an audible murmur. [18] Lack of carotid radiation supports the classic distinction from AS but cannot rule either diagnosis in or out. [1][5]
Mitral valve prolapse
Listen at the apex for a click followed by late systolic regurgitation. Reducing LV volume brings prolapse earlier, lengthening the murmur; increasing volume usually delays the click. Listen for timing, not merely greater loudness. Some patients have a click without significant regurgitation, while established severe MR may be holosystolic. MVP can be associated with connective tissue disease, but it also occurs without a distinctive body habitus or a connective tissue syndrome. [3][14]
Try it here · Checkpoint 2 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 23
Show answer and explanations for case 23
A. Aortic stenosis with transmission of its musical ejection sound to the apex (Why this does not fit)
Aortic stenosis can transmit to the apex, but its transmitted component retains ejection timing. The separate holosystolic sound and mitral displacement favor MR.
B. Restrictive ventricular septal shunting with systolic flow from LV to RV (Why this does not fit)
A restrictive VSD may cause a harsh holosystolic sound, usually lower sternal with a thrill. It does not explain the imaged mitral displacement as well as MR.
C. Myxomatous mitral prolapse causing primary regurgitation into the LA (Why this does not fit)
Prolapse can produce MR, but imaging shows systolic anterior displacement with intact leaflets rather than prolapse into the LA.
D. MR from failed coaptation during systolic anterior mitral motion (Best answer)
Anterior displacement can narrow the LV outlet and prevent effective mitral closure. HCM can therefore produce both an ejection murmur and a separate regurgitant component.
Takeaway: HCM can produce both dynamic outflow obstruction and MR; describe each component.
Compare the same listening site before and during a maneuver. Describe what actually changed. Maneuvers modify probability; they do not confirm valve anatomy. Published bedside testing demonstrates that individual responses have imperfect sensitivity and specificity. [2]
Inspiration increases right heart filling
Spontaneous inspiration lowers intrathoracic pressure and generally increases systemic venous return. An increase in a lower sternal regurgitant murmur supports TR. Left-sided sounds may be easier to hear in expiration, but this is not an absolute loudness rule. Keep the pulmonary ejection click exception separate from the murmur.
Standing and sustained Valsalva strain reduce filling
Reduced venous return usually decreases forward-flow murmur intensity. Dynamic LV outflow obstruction commonly becomes louder; the MVP click occurs earlier and its murmur becomes longer. Specify the strain phase. Valsalva release restores filling and can reverse the response, so “during Valsalva” is incomplete documentation.
Squatting increases filling and systemic resistance
The larger LV cavity usually softens obstructive HCM and delays the MVP click. More forward flow often augments AS, and MR may intensify as loading increases. Squatting combines preload and afterload effects; it is not identical to handgrip.
Handgrip raises systemic vascular resistance
Increased afterload often makes MR more audible and can augment a left-to-right VSD jet. The AS murmur may soften or remain similar; obstructive HCM commonly softens. Responses depend on flow, pressure, and lesion physiology. For MVP, handgrip can delay the click and shorten the late systolic murmur. Document this timing response separately from amplitude, especially when established MR is also present. A percentage loudness bar cannot express all these findings. [1][2][3]
Describe amplitude and timing separately. “Earlier click with a longer murmur” conveys more than “louder.” “No change with handgrip” is an observation, not an exclusion test for AS.
Finish with a clinical decision
A soft short systolic murmur with otherwise normal findings can reflect increased flow during pregnancy, anemia, fever, or hyperthyroidism. A holosystolic murmur, thrill, abnormal S2, concerning symptoms, or evidence of chamber loading warrants assessment for structural disease. Transthoracic echocardiography links the examination to valve morphology, ventricular function, and Doppler measurements. Also listen after S2. A separate high-pitched early diastolic decrescendo murmur with a wide pulse pressure suggests aortic regurgitation, which can coexist with a systolic flow murmur. [1][19][12][4]
For concordant severe high-gradient AS, the 2025 ESC/EACTS criteria include peak velocity at least 4.0 m/s, mean gradient at least 40 mmHg, and valve area at most 1.0 cm². Discordant or low-flow findings need further assessment. In severe primary MR, an LVEF of 54% is not reassuring merely because it exceeds 50%; regurgitant emptying can mask LV dysfunction. These are reasons to interpret the full study with a valve specialist. [4][16][20]
Suspected HCM warrants echocardiography. A peak LV outflow gradient of at least 30 mmHg indicates obstruction; 50 mmHg is a different threshold used in further assessment and treatment decisions. When the resting gradient is below 50 mmHg, bedside provocative assessment is recommended. In symptomatic HCM without a resting or bedside-provoked gradient of at least 50 mmHg, exercise echocardiography is recommended to detect and quantify dynamic obstruction. A quiet resting examination cannot exclude it. [5][18]
Sudden pulmonary edema or shock after myocardial infarction changes the task. Papillary muscle rupture can cause severe acute MR with a short, soft, or absent murmur because LA and LV pressures rapidly approach each other. A normal-sized LA does not exclude an acute leak. Septal rupture can follow anterior or inferior infarction. Obtain urgent bedside echocardiography and specialist care; do not delay for provocative maneuvers. TEE may be needed when TTE is nondiagnostic. [6]
Establish S1 and S2 and classify the systolic timing.
Find maximal intensity, then listen for radiation.
Compare pulses, S2, jugular waves, and congestion.
If the patient is stable, use a loading maneuver that separates the leading possibilities.
Use echocardiography to resolve discordance and grade disease. Escalate immediately when symptoms indicate instability.
Try it here · Checkpoint 3 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 15
Show answer and explanations for case 15
A. Papillary muscle rupture with acute MR (Why this does not fit)
MR can cause pulmonary edema and shock after inferior infarction, but does not produce an oxygen saturation step-up from RA to RV.
B. LV free-wall rupture with tamponade (Why this does not fit)
Free-wall rupture can cause sudden shock, but blood entering the pericardium does not create an oxygenated interventricular shunt.
C. RV infarction with secondary TR (Why this does not fit)
RV infarction can cause hypotension and TR, but TR recirculates right-sided blood and does not explain this RV oxygen saturation step-up.
D. Ventricular septal rupture (Best answer)
A new LV-to-RV shunt explains the lower sternal thrill and increased RV oxygen saturation. Septal rupture can follow inferior as well as anterior infarction and needs urgent specialist treatment.
Takeaway: An inferior infarction can produce septal rupture as well as papillary muscle rupture.
A. Increased systemic vascular resistance during inspiration (Why this does not fit)
Handgrip primarily tests systemic resistance. The respiratory response and hepatic pulsations here instead identify changing right-heart filling.
B. Earlier prolapse of a mitral leaflet as LV volume falls (Why this does not fit)
MVP is identified by an apical click and its timing. This lower sternal regurgitant murmur with hepatic pulsations supports a right-sided lesion.
C. Increased venous return to the right heart (Best answer)
Spontaneous inspiration increases systemic venous return. More filling can augment regurgitant flow through an infected tricuspid valve, producing the Carvallo sign.
D. Increased forward flow through a stenotic aortic valve (Why this does not fit)
Aortic stenosis has ejection timing and usually an upper sternal maximum with carotid radiation. It does not explain this venous congestion pattern.
Takeaway: Inspiratory augmentation supports TR by testing right-heart filling.
The outflow timing, neck transmission, delayed carotid pulse and diminished A2 form a coherent AS pattern. Symptoms require prompt assessment of severity.
B. Mitral valve prolapse (Why this does not fit)
MVP would favor an apical click and late regurgitant murmur. It does not account for the delayed carotid upstroke and reduced A2.
C. Obstructive hypertrophic cardiomyopathy (Why this does not fit)
HCM can cause exertional syncope and an ejection murmur, but this delayed weak pulse and aortic distribution favor fixed valvar obstruction.
D. Isolated tricuspid regurgitation (Why this does not fit)
TR produces a regurgitant systolic murmur and venous findings, not the impaired aortic ejection pattern documented here.
Takeaway: Delayed carotid rise and altered A2 strengthen the localization to the aortic outlet.
A. Persistent LV-to-RV flow through a restrictive septal defect (Why this does not fit)
A restrictive VSD usually causes a persistent systolic jet. Reduced filling generally does not intensify its murmur in this characteristic positional pattern.
B. Fixed obstruction at a congenitally abnormal aortic valve (Why this does not fit)
A bicuspid aortic valve can obstruct in a young adult, but reduced filling on standing usually lowers its flow murmur. The opposite positional response favors dynamic LV outflow obstruction.
C. Mitral leaflet prolapse earlier in systole (Why this does not fit)
MVP also changes with LV volume, but the expected apical click and late murmur are absent. The ejection contour favors dynamic outflow obstruction.
D. Dynamic LV outflow narrowing as the cavity shrinks (Best answer)
Standing reduces LV filling, which can increase obstruction involving the septum and systolic anterior mitral motion. Squatting restores filling and usually reduces the obstruction.
Takeaway: A louder ejection murmur with lower filling suggests dynamic LV outflow obstruction and needs imaging.
A. Pulmonary valve stenosis (Why this does not fit)
Its click is an early ejection sound near the upper left sternal border. That is different from an apical click whose timing shifts substantially with posture.
B. Mitral valve prolapse (Best answer)
Reduced LV volume allows the leaflet apparatus to prolapse and tense earlier. The earlier click and longer late systolic murmur are the discriminating findings.
C. Bicuspid aortic valve with an ejection click (Why this does not fit)
A mobile bicuspid aortic valve can produce an early systolic ejection click, sometimes audible at the apex. Its early timing differs from the mid-to-late systolic click that shifts toward S1 as LV filling decreases.
D. Rheumatic mitral stenosis (Why this does not fit)
Mitral stenosis typically produces a diastolic rumble, often with an opening snap after S2. This event is between S1 and S2.
Takeaway: In MVP, track the click's position within systole.
An ASD typically produces a pulmonary ejection flow murmur and fixed wide S2 splitting. Neither fits the persistent lower sternal jet described here.
B. Innocent Still murmur (Why this does not fit)
A Still murmur is generally vibratory and systolic, but a holosystolic contour and thrill require investigation for structural disease.
C. Restrictive ventricular septal defect (Best answer)
A substantial LV-to-RV pressure difference can generate a harsh jet and thrill despite little hemodynamic burden. Normal growth does not exclude a small VSD.
D. Patent ductus arteriosus (Why this does not fit)
A PDA often produces continuous flow audible through S2 into diastole near the left infraclavicular area. This murmur is localized lower and confined to systole.
Takeaway: A loud restrictive VSD may coexist with normal growth; loudness does not measure shunt burden.
A. Preserved LV performance because LVEF exceeds 50% (Why this does not fit)
A generic 50% cutoff misses dysfunction in severe primary MR, where regurgitant emptying can keep total LVEF deceptively high.
B. Mild MR because LVEF has not fallen below 40% (Why this does not fit)
LVEF describes total ventricular emptying and cannot downgrade MR that has been graded severe by integrated imaging.
C. Normal forward stroke volume inferred from a total LV ejection fraction of 54% (Why this does not fit)
Total ejected volume includes blood entering the LA. LVEF alone cannot establish adequate forward output.
D. LV dysfunction in severe primary MR; prompt valve-team assessment (Best answer)
In severe primary MR, LVEF at or below 60% indicates LV dysfunction. Her symptoms and confirmed severity also warrant prompt assessment; the Heart Team determines intervention suitability.
Takeaway: Interpret LVEF in the physiology of severe MR, not as an isolated percentage.
Its usual single arterial supply, from the RCA or circumflex system depending on dominance, makes it vulnerable after inferior or lateral infarction. Rupture can cause a flail leaflet and abrupt severe MR.
B. Anterolateral papillary muscle (Why this does not fit)
This also supports the mitral valve and can rupture, but its usual dual arterial supply makes ischemic rupture less common than posteromedial rupture.
C. Mitral annulus (Why this does not fit)
Annular dilation can cause secondary MR, but usually produces inadequate coaptation rather than sudden loss of leaflet support with a flail segment.
D. Primary mitral chordae from degenerative valve disease (Why this does not fit)
Chordal rupture can produce a flail leaflet and acute MR. The close temporal relationship to inferior infarction favors ischemic papillary muscle rupture.
Takeaway: Use demonstrated anatomy to distinguish post-infarction mechanical complications.
A. Standing suddenly from a seated position (Why this does not fit)
Standing reduces venous return and often reduces the intensity of a chronic MR murmur. It is more useful for provoking dynamic outflow obstruction or earlier prolapse.
B. Sustained Valsalva strain (Why this does not fit)
The sustained strain phase reduces ventricular filling and usually makes chronic MR less audible. Release has a different hemodynamic effect.
C. Sustained isometric handgrip (Best answer)
Handgrip raises systemic resistance and often augments MR. More resistance to forward ejection can favor regurgitant flow.
D. Quiet inspiration alone (Why this does not fit)
Inspiration is more useful for testing a right-sided murmur such as TR. It is not the best maneuver to augment this established mitral leak.
Takeaway: Use handgrip as supportive evidence for MR, alongside timing and anatomy.
An ASD may cause an upper left sternal flow murmur, but fixed wide splitting with right-sided volume loading would be more characteristic than this obstructive heave, thrill and soft delayed P2.
B. Pulmonary valve stenosis (Best answer)
The location and ejection contour identify the right ventricular outlet. A thrill, RV pressure-loading findings and delayed soft P2 support obstruction.
C. Mitral regurgitation (Why this does not fit)
MR favors a persistent apical jet with left-sided loading. It does not explain the upper left sternal ejection profile.
D. Aortic stenosis (Why this does not fit)
AS can produce a harsh ejection murmur, but carotid transmission and altered A2 or carotid upstroke would be more supportive than this pulmonary component abnormality.
Takeaway: Use the affected component of S2 and chamber loading to refine an ejection murmur.
A. Aortic sclerosis without significant stenosis (Why this does not fit)
Sclerosis does not produce the substantial transvalvular velocity and gradient reported here.
B. Moderate aortic stenosis (Why this does not fit)
A soft murmur can underestimate disease. Velocity 4.3 m/s, mean gradient 46 mmHg and area 0.8 cm² are all in the severe range.
C. Severe low-flow, low-gradient aortic stenosis (Why this does not fit)
This category requires a low gradient and evidence of reduced flow. Her mean gradient is already 46 mmHg; a preserved LVEF alone does not define flow status.
D. Severe high-gradient aortic stenosis (Best answer)
The velocity, mean gradient and valve area satisfy concordant severe high-gradient criteria. Her symptoms warrant prompt valve assessment irrespective of murmur grade.
Takeaway: Grade stenosis with integrated Doppler findings, not murmur loudness.
A. Atrial left-to-right shunting increases pulmonary valve flow (Best answer)
The fixed wide split and pulmonary ejection murmur support an ASD with increased right-sided flow. Echocardiography should establish the anatomy.
B. A restrictive LV-to-RV jet across a ventricular septal defect (Why this does not fit)
A restrictive VSD usually produces a harsh lower sternal holosystolic jet, often with a thrill, rather than this pulmonary flow pattern.
C. Ejection through a stenotic pulmonary valve (Why this does not fit)
Pulmonary stenosis can share this location, but an ejection click, thrill and delayed soft P2 would support obstruction more than a relatively fixed wide split with a mild flow murmur.
D. Systolic RV-to-RA flow through an incompetent tricuspid valve (Why this does not fit)
TR favors holosystolic timing at the lower sternal edge, inspiratory augmentation and venous systolic pulsations. The ejection contour points to pulmonary outflow.
Takeaway: A pulmonary-region murmur can reflect extra flow through a normal valve.
A. Cardiac MRI to define the mitral apparatus (Why this does not fit)
MRI can characterize cardiac structure in stable patients, but transport and acquisition time make it unsuitable as the immediate next test in this unstable patient.
B. Urgent bedside transesophageal echocardiography (Best answer)
TEE can identify partial papillary muscle rupture or other mitral failure when TTE is nondiagnostic. It should be coordinated with airway and hemodynamic stabilization and urgent specialist care.
C. Right-heart catheterization to look for large wedge-pressure V waves (Why this does not fit)
Hemodynamics may assist shock management, but V waves do not directly identify papillary or leaflet anatomy. TEE more directly resolves the nondiagnostic mitral study.
D. CT pulmonary angiography to assess pulmonary embolism (Why this does not fit)
PE can cause post-hospitalization shock, but abrupt pulmonary edema and a new apical murmur after MI make a mechanical left-sided complication a priority for bedside imaging.
Takeaway: Severe acute MR can be acoustically unimpressive; the clinical deterioration drives urgent imaging.
A. A nonrestrictive opening permits high shunt volume with a relatively small LV-to-RV systolic gradient (Best answer)
The large opening can carry considerable flow without the high-velocity jet of a restrictive defect. Symptoms and pulmonary overcirculation, not acoustic amplitude, establish burden.
B. Fixed high pulmonary vascular resistance has already reversed the shunt (Why this does not fit)
Reversal would favor cyanosis and reduced pulmonary flow. The reported pulmonary overcirculation and age favor a large left-to-right shunt as postnatal resistance falls.
C. The septal opening closes completely in late systole (Why this does not fit)
Transient muscular closure can explain a brief murmur in a tiny defect. It does not explain the large opening and substantial pulmonary overcirculation here.
D. Critical pulmonary valve stenosis is restricting the pulmonary circuit (Why this does not fit)
Severe RV outflow obstruction reduces pulmonary flow and may promote right-to-left shunting. That conflicts with the documented pulmonary overcirculation.
Takeaway: In infant VSD, assess feeding, growth and pulmonary flow rather than ranking severity by volume of sound.
A. Pulmonary vascular disease equalizes ventricular pressures (Why this does not fit)
That can soften a VSD murmur, but normal estimated RV pressure and an asymptomatic child make it a poor explanation here.
B. Rapid LV-to-LA pressure equalization during acute mitral regurgitation (Why this does not fit)
Severe acute MR can produce a short systolic murmur, but it would not explain an asymptomatic child with a tiny muscular VSD and no reported mitral lesion. Muscular narrowing during contraction fits the identified defect.
C. Muscular narrowing stops shunt flow before systole ends (Best answer)
A tiny muscular defect can functionally close during contraction. Its murmur may therefore be early systolic rather than holosystolic.
D. A large nonrestrictive opening equalizes ventricular pressures (Why this does not fit)
The defect is tiny and the chambers and RV pressure are normal. The physiology of a large nonrestrictive defect does not fit.
Takeaway: Some tiny muscular VSDs produce early systolic rather than holosystolic murmurs.
A. Progressive severe RV outflow obstruction causing right-to-left shunting (Why this does not fit)
RV outflow obstruction can promote cyanosis in a patient with VSD, but it usually produces an outflow ejection murmur and a soft or delayed P2. The loud P2 and fading septal murmur favor elevated pulmonary arterial pressure.
B. Rising pulmonary vascular resistance with reduced or reversed interventricular shunting (Best answer)
Advanced pulmonary vascular disease can reduce the LV-to-RV pressure gradient, soften the jet and permit right-to-left shunting with cyanosis.
C. A newly restrictive small defect with increased left-to-right velocity (Why this does not fit)
A larger pressure difference across a restrictive opening does not explain this pattern of worsening cyanosis and pulmonary hypertension.
D. LV systolic dysfunction with increased pulmonary venous pressure (Why this does not fit)
LV failure can cause exercise limitation and pulmonary congestion, but it does not directly explain chronic cyanosis and clubbing from a ventricular shunt. The loud P2 and quieter VSD jet favor advanced pulmonary vascular disease with right-to-left flow.
Takeaway: A fading VSD murmur with cyanosis may indicate pulmonary vascular disease, not recovery.
HCM can cause an apical or parasternal ejection sound, but delayed small carotid pulses and the upper right sternal component favor fixed aortic obstruction.
B. Primary mitral regurgitation (Why this does not fit)
MR commonly radiates from apex to axilla, but the ejection contour and delayed carotid upstrokes argue against interpreting this as a pure mitral jet.
C. Aortic sclerosis without significant obstruction (Why this does not fit)
Sclerosis can cause an ejection murmur but generally preserves the carotid upstroke. The delayed pulses suggest stenosis that needs Doppler grading.
D. Aortic stenosis with musical apical transmission (Best answer)
The Gallavardin phenomenon explains different sound qualities from the same aortic lesion. Echocardiography should also assess any coexisting mitral disease.
Takeaway: An apical maximum or musical quality does not exclude aortic stenosis.
A. Increased forward flow through structurally normal outflow valves (Best answer)
Anemia can increase cardiac output and produce a systolic ejection murmur. The normal valves and absent shunt support this mechanism.
B. Dynamic subaortic obstruction from systolic anterior mitral motion (Why this does not fit)
Dynamic obstruction requires compatible anatomy and loading behavior; it is not the default explanation for an anemia-associated flow murmur with normal imaging.
C. Systolic backward flow from LV to LA (Why this does not fit)
That is MR and would require mitral regurgitant flow on imaging. The soft ejection contour and normal valves favor increased forward flow.
D. Increased pulmonary ejection from an atrial left-to-right shunt (Why this does not fit)
ASD can produce a similar flow murmur but usually adds fixed S2 splitting and demonstrable right-sided volume loading or a shunt, absent here.
Takeaway: Ejection timing describes flow and does not automatically establish stenosis.
MRI can define hypertrophy and scar, but it does not directly test the LV outflow gradient during the exertion that triggers symptoms.
B. Exercise echocardiography (Best answer)
In symptomatic HCM without a resting or bedside-provoked gradient of at least 50 mmHg, exercise TTE is recommended to detect and quantify dynamic LV outflow obstruction.
C. Ambulatory ECG monitoring (Why this does not fit)
Monitoring is useful for rhythm assessment in HCM, but an ECG cannot measure the outflow gradient during exercise.
D. Transesophageal echocardiography at rest (Why this does not fit)
TEE may clarify uncertain valve anatomy. Resting anatomy is already defined, and the question requires physiologic provocation of the LV outflow gradient.
Takeaway: Dynamic obstruction may require physiologic provocation to become measurable.
A. Greater inspiratory RV filling partially opens the valve before ejection (Best answer)
In a stiff RV with a mobile stenotic valve, increased filling can raise late-diastolic pressure enough to partially open the valve. Less subsequent excursion produces a softer click.
B. Reduced inspiratory RV filling decreases forward flow (Why this does not fit)
Spontaneous inspiration generally increases systemic venous return. Reduced right-sided flow would also fail to explain the louder ejection murmur.
C. Inspiratory delay of pulmonary valve closure changes P2 intensity (Why this does not fit)
P2 is a closure sound at the end of systole. The described click occurs near the start of ejection and reflects opening of the valve.
D. Earlier mitral prolapse reduces the intensity of an apical click (Why this does not fit)
MVP produces a mid-to-late systolic apical event whose timing changes with LV volume. The early upper sternal click accompanies a demonstrated pulmonary lesion.
Takeaway: Separate the pulmonary ejection click from the accompanying ejection murmur.
A. Valvar pulmonary stenosis (Why this does not fit)
A valvar lesion can produce a pulmonary-region murmur, but congenital rubella particularly associates with narrowing of the peripheral pulmonary arteries and PDA. Imaging should locate the obstruction.
B. Supravalvar aortic stenosis (Why this does not fit)
This is a congenital outflow lesion, but it is not the characteristic rubella association; the upper chest and back transmission favors a pulmonary arterial lesion.
C. Peripheral pulmonary artery stenosis (Best answer)
Congenital rubella is associated with branch or peripheral pulmonary artery stenosis and PDA. The syndrome and systolic murmur distribution make peripheral pulmonary narrowing the best option.
D. Coarctation of the aorta (Why this does not fit)
Coarctation may produce a back murmur, but would be supported by upper-to-lower limb pulse or pressure differences. It is not the characteristic rubella cardiovascular association.
Takeaway: Specify the artery, not just 'pulmonary stenosis,' when recalling the rubella association.
Noonan syndrome can include HCM, but an RV heave and abnormal P2 localize the leading concern to the right ventricular outlet.
B. Pulmonary valve stenosis (Best answer)
Dysplastic pulmonary valve stenosis is a common Noonan cardiac lesion. The upper left sternal thrill and RV pressure-loading findings support it.
C. ASD with a pulmonary flow murmur (Why this does not fit)
An ASD can share the upper left sternal location, but a fixed wide split and volume-loading pattern would be more typical than this thrill and soft delayed P2.
D. Mitral valve prolapse (Why this does not fit)
MVP can produce a systolic murmur, but an apical click with late regurgitation would be expected rather than this pulmonary outflow examination.
Takeaway: Syndrome associations guide attention; imaging establishes the level of obstruction.
A. Mitral valve stenosis with diastolic inflow obstruction (Why this does not fit)
Mitral stenosis primarily impairs diastolic LA-to-LV flow and does not produce this right-sided regurgitant pattern.
B. Isolated aortic valve stenosis with systolic outflow obstruction (Why this does not fit)
An aortic ejection murmur and delayed carotid pulse would be more characteristic. The jugular and hepatic systolic findings favor TR.
C. A small restrictive VSD with systolic interventricular flow (Why this does not fit)
A VSD could give a harsh lower sternal murmur, but it does not account as well for this inspiratory response and prominent systemic venous systolic pulsations.
D. Tricuspid regurgitation from carcinoid valve disease (Best answer)
Carcinoid can restrict right-sided valve tissue. RV-to-RA systolic leakage explains the murmur and venous pulsations.
Takeaway: Combine carcinoid context with the direction of congestion and the murmur's respiratory response.
A. Mechanical interference from the pacing lead (Best answer)
The focal leaflet abnormality at the lead crossing and preserved chamber geometry support direct device-associated failure of closure.
B. Pulmonary hypertension with RV dilation and leaflet tethering (Why this does not fit)
This is a common functional TR mechanism, but the preserved RV and annular geometry do not support it as the cause of this focal lesion.
C. Atrial functional TR from annular dilation (Why this does not fit)
Atrial functional TR involves annular enlargement, often with atrial fibrillation. A normal annulus and focal lead-related restriction favor direct interference.
D. Infective leaflet destruction (Why this does not fit)
Device infection can cause TR, but the afebrile course and localized closure interference without described tissue destruction favor a mechanical mechanism.
Takeaway: TR can result from mechanical interference with coaptation, not only pulmonary hypertension or infection.
A. Pulmonary regurgitation from pulmonary hypertension (Why this does not fit)
PR can cause an early diastolic decrescendo murmur, but usually accompanies pulmonary hypertension findings such as loud P2. The wide systemic pulse pressure favors AR.
B. Mitral stenosis with increased pulmonary flow (Why this does not fit)
MS produces a low-pitched apical diastolic rumble, often after an opening snap. It does not fit this high-pitched early diastolic sound and wide pulse pressure.
C. Aortic regurgitation with an accompanying systolic flow murmur (Best answer)
The early diastolic decrescendo and wide pulse pressure support AR. Increased forward systolic flow can generate an additional ejection murmur; echo assesses severity and coexisting stenosis.
D. Patent ductus arteriosus (Why this does not fit)
PDA can widen pulse pressure and produce systolic and diastolic sound, but typically has a continuous murmur across S2 near the left infraclavicular region rather than these separate contours.
Takeaway: Find S1 and S2 before applying a systolic localizer; more than one sound may be present.
A. Ventricular septal defect (Why this does not fit)
A VSD can produce a lower sternal holosystolic murmur, but jugular systolic waves and a pulsatile liver favor direct RV-to-RA regurgitation.
B. Tricuspid regurgitation (Best answer)
Advanced RV failure can blunt inspiratory augmentation. The venous systolic pulsations and murmur remain strongly supportive of TR and warrant echocardiographic assessment.
C. Mitral regurgitation (Why this does not fit)
MR can cause secondary pulmonary hypertension and RV failure, but the described lower sternal sound and systemic venous systolic pulsations point more directly to TR.
D. Pulmonary valve stenosis (Why this does not fit)
PS produces an ejection murmur with RV pressure loading. It does not explain a blowing holosystolic sound and systolic back-transmission into systemic veins as well as TR.
Takeaway: An absent Carvallo sign does not exclude TR in advanced RV failure.
A. Across the large ventricular septal opening (Why this does not fit)
A nonrestrictive VSD permits near-equal ventricular systolic pressures, so its jet often contributes little to the murmur in tetralogy with substantial outflow obstruction.
B. Backward across the tricuspid valve (Why this does not fit)
TR generates a regurgitant holosystolic sound and venous pulsations rather than the ejection contour characteristic of obstructed pulmonary outflow.
C. Across the aortic valve into the overriding aorta (Why this does not fit)
An overriding aorta receives blood from both ventricles but does not itself establish aortic valvar stenosis. In this cyanotic tetralogy pattern, RV outflow obstruction is the leading murmur source.
D. Through the narrowed RV outflow tract toward the pulmonary artery (Best answer)
Substantial RV outflow obstruction generates the ejection murmur and limits pulmonary blood flow. Narrowing can occur below the pulmonary valve as well as at the valve.
Takeaway: In tetralogy, localize obstruction across the RV outflow tract rather than assuming isolated valvar PS.
