Let us listen at the apex. The timing device will be the apical movement, and once we know when systole begins, then we will use the bell of the stethoscope, listening carefully, and that bell will bring out low-frequency sounds. Let’s listen together.

And what did we hear? We heard “lubdub-errr,” “lubdub-errr,” “lubdub-errr,” “lubdub-errr.” Heart sounds? S1 was a bit diminished and what was most impressive was the diastolic “errr,” that rumbling sound in diastole. And when you hear that rumbling sound in diastole, what do you consider? Well, mitral stenosis can do that, can’t it? A narrowing of the mitral valve with rumbling across that valve during diastole. But then again, you have regurgitation, for instance, of the mitral valve or a shunt lesion. Well, you can have so much blood coming back across that valve in diastole, that you can also generate a low-frequency rumble - “lubdub-errr,” “lubdub-errr.” And finally, there is a phenomenon called the austin-flint murmur, wherein a patient with aortic regurgitation, as blood leaks back into that ventricle, the pressure rises and tends to push close the mitral valve, and you almost have a mitral stenosis that’s physiologic, therefore, and you still hear the same thing, “lubdub-errr.” You must consider all these possibilities and refine our thinking to distinguish one from the other.