Let's now return to the lower left sternal edge. We shall correlate the acoustic events we have heard with our patient's precordial movements in this area.
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We also have movement at the mid and lower left sternal edge and, by definition, that is abnormal. Normally, there is no movement at the parasternal edge and, when there is, it is due to the right ventricle when it is in this area. We palpate that movement and we not only find it is present, but it is multiple. Let's time the contour of this movement and see what we can conclude. Again we use the carotid vessel to time systole, we place a cotton swab also on this parasternal movement and we observe there is not just one movement or two but, again, three movements at the lower left sternal edge. Let's time those carefully. [Cut-away]
When we time those movements we see clearly that we have, again, a presystolic impulse, a sustained systolic impulse and an early diastolic impulse. The sustained systolic impulse tells us that this is a dilated and possibly even hypertrophied right ventricle; and the impulses in presystole and in early diastole, they tell us that this is a patient who has a palpable equivalent of a fourth sound and a third sound. In presystole, the atrium in the right side contracts pushing blood into the right ventricle, a non compliant right ventricle decelerates that blood causing vibrations that can be felt at the bedside and heard as an S4. Similarly, the early diastolic movement is also due to blood flowing into that non compliant ventricle in early diastole, the deceleration of blood that occurs because of the non compliance, vibrations set up that you can hear as an S3 or palpate as an early diastolic movement.