Why there is pulsus biseriens in HOCM ?
Hypertrophic Obstructive Cardiomyopathy (HOCM) is a cardiac condition characterized by abnormal thickening of the heart muscle, especially the left ventricle, which can lead to various hemodynamic changes and clinical manifestations. One of the unique features associated with HOCM is the presence of pulsus bisferiens, which refers to a double-peaked arterial pulse.
Here’s why pulsus bisferiens can occur in individuals with HOCM:
- Outflow Tract Obstruction: In HOCM, the hypertrophied septum can cause dynamic left ventricular outflow tract (LVOT) obstruction. During systole, the hypertrophied septum obstructs the outflow of blood from the left ventricle into the aorta, leading to an initial sharp peak in the arterial pulse.
- Relief of Obstruction: After this initial sharp peak, there may be a momentary decrease in obstruction due to the blood being forced through the narrowed area, causing a small dip or trough in the pulse wave.
- Ejection of Blood: Following the trough, as more blood is ejected from the left ventricle and encounters less obstruction due to the widened area, there’s a second peak in the arterial pulse.
- Characteristic Arterial Pulse: This pattern of a sharp peak followed by a dip and then another peak in the arterial pulse is what defines pulsus bisferiens. It’s often felt in the radial artery.
The presence of pulsus bisferiens in HOCM is due to the interplay between the hypertrophied septum, dynamic outflow tract obstruction, and the ejection of blood from the left ventricle. It’s a distinctive clinical finding and can be indicative of the underlying cardiac pathology in individuals with HOCM.