Clinical examination of a 35 year old man who is short of breath reveals a pansystolic murmur. Outline the salient clinical features and investigations which will help you distinguish between mitral regurgitation, tricuspid regurgitation and a ventricular septal defect in this setting.
College Answer
This question lends itself to answering with table. An example of the sort of information that could
be provided is included in the following example table:
|
MR |
TR |
VSD |
|
|
Symptoms |
Paroxysmal |
Pedal oedema, |
Chest Pain, Short |
|
Pulse |
Commonly AF |
May be AF |
Usually Sinus |
|
JVP |
May be raised |
V waves |
Prominent a waves |
|
Precordium |
Systolic Thrill +/- |
Systolic Thrill +/- |
Systolic Thrill +/- |
|
Murmur |
Apical to axilla |
Left Sternal Border, |
Left Sternal |
|
Other systemic |
Basal crepitations |
Pulsatile liver |
Other congenital |
|
Chest X-Ray |
Straight Left heart |
Enlarged Right |
Nil specific |
|
Echocardiogram |
Classic features |
Classic features |
Classic features |
|
Pulmonary Artery |
Pulmonary |
Pulmonary |
Step up in O2 |
Discussion
To answer this, I have referred again to my own tabulated summary of heart murmurs.
One can do little to improve on the table presented in the college answer.
The MR and TR are easy to tell apart. TR gets louder on inspiration, and causes a pulsatile liver.
MR gets louder on expiration, and causes pulmonary oedema.
The VSD is a little more tricky, and apart from occasionally causing pulmonary hypertension its murmur is difficult to distinguish from the others.
Both VSD and MR will be loudest on expiration, but VSD will be most audible at the left sternal border, whereas the MR is best heard near the apex.
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 anywhere.