Differentiating Murmurs of Aortic Stenosis and Mitral Regurgitation

One of the questions I was asked at the recent IBC Dubai PACES course was how would one differentiate the systolic murmurs of aortic stenosis from mitral regurgitation.
This is a good question. Most often it is very easy to make out whether it is aortic stenosis or mitral regurgitation but sometimes the features are not clear and then the differentiation can become exceedingly difficult.
The answer is not to depend on the characteristics of the murmur but to take into account all the other information gleaned on clinical examination.
To start with mitral valve disease is more likely in a female and aortic stenosis if the patient is a male (these are genralisations and not to be regarded as rules).
On general examination one may note a very pale appearance in association with aortic stenosis (Dresden doll appearance ACES for PACES page 180)
Elfin facies is associated with aortic stenosis ACES for PACES page 182
A malar flush would be in keeping with mitral valve disease and pulmonary hypertension ACES for PACES page 186
High arched palate may occur in supravalvular aortic stenosis ACES for PACES page 187
Atrial fibrillation more likely mitral valve disease ACES for PACES page 193
Low volume, slow rising pulse in aortic stenosis ACES for PACES page 193,194
Brachio-radial delay aortic stenosis ACES for PACES page 196
Displaced apex beat mitral regurgitation ACES for PACES page 202
Thrusting apex mitral regurgitation ACES for PACES page 202
Heaving apex aortic stenosis ACES for PACES page 202
Apical thrill mitral regurgitation ACES for PACES page 203
Thrill 2nd right intercostal space aortic stenosis ACES for PACES page 203
Soft 1st heart sound mitral regurgitation ACES for PACES page 205
Soft 2nd heart sound aortic stenosis ACES for PACES page 206
Pan systolic murmur radiating to the axilla inferior angle of scapula mitral regurgitation ACES for PACES page 211,213 (remember mitral regurgitation can also cause ejection systolic murmurs ACES for PACES page 211)
Ejection systolic murmur radiating to the neck aortic stenosis ACES for PACES page 210,213

This exercise in differentiating murmurs is a good illustration of the importance of following each step of the clinical examination, focussing one’s mind on the findings and analysing the findings before moving on to the next step (i.e. following the elephant’s footstep ACES for PACES preface)

History Taking, Communication and Ethics for MRCP PACES

Many candidates and unfortunately many from outside the UK do not do well in these two stations.
One of the main reasons for this is failure to ask and take into account the patient’s, or in the case of a scenario in the communication skill station, the relation or carer’s perspective.
This may be due to the fact that this has not been standard teaching or standard practice when taking histories. Indeed many clinical skills books do not give a structure or framework for asking about the patient’s perspective.
It is essential to include the patient’s perspective in standard history taking. This is the only way in which one will do this naturally rather than in an artificial way in exams.
In order to do so it is vital to have a structure of framework for doing so.
In ACES for PACES I have provided such a structure (see chapters 4 and 18)
I have also provided an acronym as an aid to memorising this structure
It is I PASSED By Employing ACES, which stands for :
Identification and Introduction
Purposefully
Analyse
Symptoms
Systems
Elicit
Details
Beliefs
Expectations
Anxieties (regarding)
Causes
Effects
Survival