In which cardiomyopathy does increased outflow tract obstruction occur post-prandially?

In hypertrophic cardiomyopathy (HCM), there is an abnormal thickening of the heart muscle, particularly affecting the interventricular septum. This abnormal thickening can lead to left ventricular outflow tract obstruction, especially after meals. The mechanism behind the increased obstruction post-prandially relates to a few physiological responses. After eating, blood flow is redirected to the gastrointestinal tract for digestion, which can lead to lower preload and subsequently alter the dynamics of the heart. In HCM patients, this change in blood volume can exacerbate the outflow tract obstruction due to altered hemodynamics.

It is notable that the pattern of obstruction in hypertrophic cardiomyopathy is dynamic and can be influenced by several factors, including body position, hydration status, and, as mentioned, post-meal changes in blood volume distribution. This distinguishes HCM from other types of cardiomyopathy where such post-prandial effects on outflow tract obstruction are not observed. For example, restrictive cardiomyopathy primarily results from diastolic dysfunction without significant outflow tract obstruction, while dilated cardiomyopathy typically features inadequate contractility rather than obstruction. Arrhythmogenic right ventricular dysplasia primarily leads to arrhythmias and does not display this characteristic post-prand