Dr.S.Venkatesan MD

How to rapidly  diagnose  significant LV dysfunction  at the bed side ?

Look for

1. Tachycardia*
2. Exertional LV  S3
3. Muffled S1
4. Weak carotids
5. 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.

Final message

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.