The contour of our patient's apical impulse is distinctly abnormal. We didn't just find one impulse, or even two, there were three impulses at the apex. Let's time that movement against that single impulse that is the carotid vessel by again using the cotton swab and you will clearly see that there are three impulses at the apex. Let's observe together. [Cut-away, note that one of them occurs just before systole, one is sustained during systole and, finally, there is one in early diastole.]

We certainly learned a lot from the evaluation of our patient's apical precordial movement. To begin with, the impulse was inferolaterally displaced and enlarged, and that tells us that this is a dilated left ventricle. And the contour? Three movements in the contour, a presystolic movement, a sustained systolic movement and an early diastolic movement. Now, the presystolic movement is the equivalent of the audible fourth heart sound. When the left atrium contracts and pushes blood into the ventricle and when that ventricle is poorly compliant, then blood decelerates more rapidly than normal and you palpate this as a presystolic impulse. And then, of course, the sustained systolic impulse again confirms this is an enlarged, dilated left ventricle. And even more compelling than the palpable presystolic movement is the early diastolic movement we palpated. That confirms fully that this is a poorly compliant left ventricle, that this left ventricle when blood enters it in early diastole, decelerates the blood more rapidly because of that poor compliance and you feel this as an early diastolic impulse and that may be heard as a third heart sound as well.