Curious lessons in clinical cardiology : Auscultate your ejection fraction !
Posted Jan 01 2012 5:37am
How to rapidly diagnose significant LV dysfunction at the bed side ?
Exertional LV S3
Often inconspicuous apical impulse
If all these signs are present EF is likely to be less than 35 % with 90 % specificity . If this is accompanied by true cardio-megaly in X-ray chest, LV dysfunction can be diagnosed with a precision reaching almost 100% .
Note the sluggish motion of mitral leaflets and how closely the LV contractility is related to AML movement.This man had a soft S1 and his EF was 30 %
* Tachycardia may be a non specific finding . Further ,base line tachycardia may not be present in all cases of LV dysfunction . When there is a sudden surge in HR even with minimal exertion , it suggests severe LV dysfunction.
** The above clues may not apply in valvular heart disease , and isolated right heart disease as multiple factors may impact S1 intensity .
*** LV failure must be distinguished from LV dysfunction (Vide infra)
Similarly , a patient can not have significant LV dysfunction if one detects any of the following.
If the first heart sound is loud
If he feels chest thumping as palpitation.(A fluttering and audible mitral AML has 100 % predictive value for normal LV function )
If you here an aortic ejection sound (Vascular clicks ) . Ejection clicks need significant force for it’s generation.
The most mobile structure of the heart is anterior mitral leaflet . Fortunately it’s closure is well heard as S1 . Mind you, the most important determinant of S1 intensity is LV contractility. If your ear is sharp , and if you are able to rule out other reasons for soft S1 (Like obesity, pericardial effusion ) we are fairly justified in suspecting significant Left ventricular dysfunction.
Further reading :
***What is the difference between LV dysfunction and LV failure ?
Both these terms are often perceived to convey the same meaning . But it can never be used synonymously .Cardiac failure is a clinical entity while LV dysfunction is a derived technical parameter by and large an echocardiographic entity. Cardiac failure is defined classically as a clinical syndrome .(elevated jvp, edema * S 3 rales etc) Neuro hormonal activation can occur with both.
A patient with LV dysfunction when destabilsed develops LV failure and after stabilisation of LV failure he is brought back to the baseline LV dysfunction.