How do clinicians tell one cardiac dysrhythmia from another. Seems too complicated.?

Question

How to tell apart ventricular fibrillation, ventricular tachycardia, atrial fibrillation, and atrial flutter when you're actually listening to the heart sounds? Gosh, any insight will be helpful here.

Answer 1

Ok. There's some confusion here.

Most of the dysrhymia s are detected by EKG, some of the ones you mention are actually life threatening (v-fib, unstable v-tach) and the patient will likely be pulseless or in extremis at best.

A-fib can be detected with a fair degree of certainty by feeling or hearing a very irregular pulse. This is confirmed by EKG. A-flutter often presents as tachycardia and prompts an EKG, otherwise you are very unlikely to detect it.

When you listen or auscultate the heart, you are listening for valvular or ventricular (e.g. S3 in an MI) dysfunction which manifests itself as changes in the sounds heard.

The normal healthy person has an S1 and an S2 heart sound.

Abnormalities include friction rubs, gallops (S3 and S4), murmurs, and clicks. The actual interpretation of these is a little too complex to detail here so see the second source (which also has some detailed explanations).

Answer 2

Some can be distinguished clinically. For example atrial fibrillation/flutter can be distinguished from ventricular tachycardia because not every atrial contraction gets transmitted through the AV node, so the pulse will be different from the heart sounds. VFib usually won't have any heart sounds because there isn't enough of an organized contraction to open or close the valves. But in general, an EKG is necessary to tell exactly what's going on.

Answer 3

First of all, you can't do it from heart sounds. You need an EKG tracing. Atrial fib sounds like normal sinus with PAC's/PVC's. Tachycardia is fast - you can't tell by listening where it originates. All you can tell by listening is rate.

On the EKG, you need to look at a number of things:

Is the rate too fast (tachycardia) or too slow (bradycardia)?

Are there p waves? (if no, think a fib/flutter)

What is the relationship of the p waves to the QRS? (looking for heart block, 1st, 2 types of 2nd or 3rd degree)

Is the QRS narrow or wide? (where does the impulse originate - narrow = supraventricular, wide = ventricular)

Look at the shape of the QRS (is there a bundle branch block?)

Hope that helps.

Answer 4

well, they do sound different. But auscultating a heart dysrythmia is not the best/most accurate way, and in fact, not the usual way to diagnose a cardiac arrhythmia.

EKG is the tool of choice.

the EKG machine itself can even give a preliminary diagnosis.