The college, for some anachronistic reason, still has profound fondness for the physical act of human examination. The candidates are expected to be expert at auscultating cardiac murmurs and distinguishing between them. The following past paper questions have involved heart sounds, murmurs, and cardiovascular examination findings in a broader sense:
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In order to improve this situation, I wanted a one-page summary of all the possible clinical signs that one may be asked about the significance of.
And here it is.
Respiratory variation |
Timing in cardiac cycle |
Characteristic features |
Murmur |
Causes of this valve pathology |
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Louder on inspiration |
Systolic |
Large pulsatile liver; |
Tricuspid regurgitation |
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Split of P2 varies with respiration; |
Pulmonic stenosis |
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Fixed split P2 |
Atrial septal defect |
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Diastolic |
Left sternal edge |
Tricuspid stenosis |
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Signs of pulmonary hypertension |
Pulmonic regurgitation |
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Louder on expiration |
Systolic |
Louder with Valsalva
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S4 is present |
HOCM |
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No S4 |
Mitral prolapse |
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Quieter with Valsalva
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Radiates to carotids Quieter with isometric hand grip |
Aortic stenosis |
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Loud S3 Louder with isometric hand grip |
Mitral regurgitation |
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Diastolic |
Quiet S1 |
3rd, 4th left intercosdtal space |
Aortic regurgitation |
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Loudest at apex |
Austin Flint murmur |
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Loud S1 |
Mitral stenosis |
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Rules of thumb:
- Right sided murmurs become louder on INspiration
- Left sided murmurs become louder on EXpiration
- The only murmurs louder with Valsalva are HOCM and mitral prolapse
The timing of murmurs within the cardiac cycle
This is my attempt to graphically represent the timing of murmurs.
Murmurs which are best heard with the bell of the stethoscope
Generally speaking, low pitched sounds are meant to be auscultated with the bell.
- Mitral stenosis
- third heart sound
Murmurs which are louder on inspiration (increased preload)
Right-sided murmurs are usually louder with inspiration; left sided murmurs are usually softer (this is one way of distinguishing between them)
- Tricuspid regurgitation
- Tricuspid stenosis
- Pulmonic regurgitation
- Pulmonic stenosis
Murmurs which are louder on expiration (decreased preload)
Left sided murmurs are usually louder with expiration. Right-sided ones are quieter.
- Aortic regurgitation
- Aortic stenosis
- Mitral regurgitation
- Mitral stenosis
Murmurs which are louder on leaning forward with deep expiration
This manoeuvre brings the left side of the heart closer to the chest.
- Aortic regurgitation and stenosis are heard best in this position
- Pericardial friction rub is also most audible in this way
Murmurs which are louder with the Valsalva manoeuvre (decreased preload)
One could write an entire monograph on the four phases of the Valsalva manoeuvre. Let us limit ourselves to discussing what happens in Phase 2 (during "straining") with decreased preload the prevalent condition.
- The systolic murmur of hypertrophic cardiomyopathy (HOCM) becomes louder
- Mitral prolapse murmurs get louder
- All other murmurs become quieter because less blood is available in the heart
Murmurs which are quieter with squatting (increased preload)
Suddenly squatting from a standing position increased preload and afterload; the increased blood in the chambers increases the loudness of all murmurs, except...
- The systolic murmur of hypertrophic cardiomyopathy (HOCM) becomes quieter
- All other murmurs become louder because more blood is available in the heart
Murmurs which are louder with the isometric hand grip (increased afterload)
- All murmurs become louder EXCEPT aortic stenosis and HOCM
Distinguishing pansystolic murmurs
Which pan-systolic murmur is it? It could be mitral regurgitation, tricuspid regurgitation, a VSD or an aortopulmonary shunt of some sort.
Inspiration and expiration
- Mitral regurgitation and VSD will be louder on expiration;
- however MR is best heard at the apex and in the left lateral position, whereas the VSD is loudest along the sternal border
- Tricuspid regurgitation will be louder on inspiration.
- The aortopulmonary shunt, though most audible in systole, is in fact a continuous murmur (it just so happens that the diastolic component is quiet).
Distinguishing midsystolic crescendo-decrescendo murmurs
Which ejection systolic murmur is it? It could be aortic stenosis, pulmonic stenosis, ASD or the LVOT obstruction of HOCM.
First: is it right-sided or left-sided?
Inspiration and expiration
- Pulmonic stenosis and ASD will both be louder with inspiration
- Aortic stenosis and the LVOT murmur of HOCM will be louder with expiration.
Louder with inspiration: must be either pulmonic stenosis or ASD, but which is it?
The atrial septal defect creates an ejection systolic murmur by causing greater flow across the pulmonic valve. To differentiate between them, one needs to examine the S2 split in inspiration and expiration.
S2 splitting with inspiration and expiration
- Pulmonic stenosis and ASD will both cause a widely split P2.
- In pulmonic stenosis, the P2 split is greater with inspiration.
- In ASD with P2 split is fixed: i.e. inspiration and expiration will not alter the timing of the P2 split (because the pressure equalises between the atria via the ASD)
Louder with expiration: must be either AS or HOCM, but which is it?
Valsalva manoeuvre to distinguish between AS and HOCM
- AS is quieter with Valsalva
- HOCM LVOT obstruction is usually the only other murmur which is LOUDER with Valsalva
Radiation into the neck
- Aortic stenosis is usually the only one that radiates to the carotids.
Distinguishing end-systolic murmurs
These are basically murmurs of the faulty mitral valve, regurgitating into the left atrium during systole. Typically, mitral prolapse is a murmure of late systole, which ends with the second heart sounds. But lets say you suck at timing murmurs. How do you tell a mitral prolapse murmur from an aortic stenosis or any other mid-systolic murmur?
Well.
- Mitral prolapse starts with a mid-systolic click. Nothing else can click like that.
- Mitral prolapse, like HOCM, is the only other murmur which gets louder with the Valsalva manoeuvre.
How can you differentiate mitral prolapse from HOCM?
- The hand grip manoeuvre, which increases afterload, helps tell these two apart.
- In HOCM, the murmur gets quieter with increased afterload
- In mitral valve prolapse, the murmur gets louder.
Distinguishing diastolic murmurs
These could be damn near anything. Diastolic murmurs are hard enough to hear, let alone time according to whether they are late middle or early.
Really, there are 4 left-sided murmurs one should be familiar with, and two right-sided murmurs.
Louder on expiration
- Aortic regurgitation
- Mitral stenosis
- Austin Flint murmur of aortic regurgitation
- Carey Coombs murmur of acute rheumatic fever
Louder on inspiration
- Pulmonary regurgitation
- Tricuspid stenosis
Distingusihing between the left-sided diastolic murmurs:
- Mitral stenosis is best heard with the bell, and is low pitched
- With mitral stenois, there is usually an opening snap shortly after S2
- With mitral stenosis, there is usually a loud S1
- Aortic regurgitation is best heard with the diaphragm, and is high-pitched.
- There is no opening snap and the S1 is soft with aortic regurgitation
Distinguishing between pulmonary regurgitation and tricuspid stenosis
- Tricuspid stenosis is freakishly rare; typicaly its a diastolic murmur heard best at the left sternal edge. .
- Unlike pulmonic regurgitation, tricuspid stenosis causes a presystolic pulsation of the liver, which is caused by the forceful contraction of the atrium against a stenotic valve.
- Pulmonic regurgitation is also freakishly rare; they call it the Graham Steell murmur. It is typically the result of pulmonary artery dilatation in the context of pulmonary hypertension. If there is no sign of pulmonary hypertension, you may be listening to an aortic regurgitation instead.
Clinical and echosonographic features of right heart failure
Features if the RV which can be assessed on TTE:
- RV size: LV size on apical 4-chamber view
- RV diameter
- RV wall thickness
- Tricuspid annular plane systolic excursion (TAPSE) or S-PRIME on apical 4-chamber view
- Right ventricular systolic pressure gradient to right atrium using tricuspid regurgitation (TR) jet. Ventricular septal motion (D-shaped septum) that can indicate pressure or volume overload
- Tissue Doppler and E/E’ ratios
Clinical features:
- Elevated Jugular venous pressure
- Right ventricular heave
- Right ventricular third heart sound
- Pleural effusion
References
Clinical Examination of the Critically Ill Patient, 3rd edition by L.I.G. Worthley - which can be ordered from our college here.
Clinical Examination: whatever edition, by Talley and O'Connor. Can be acquired any damn where.
Flint, Austin. Compendium of Percussion & Auscultation, and of the Physical Diagnosis of Diseases Affecting the Lungs and Heart. W. Wood & Company, 1870.
Chapter 27 by Sylvia Crawley of Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition