Is hypertension a left ventricular afterload or preload?
Jun 09, 2023
Source: Cainiu Health
Dr. Tian Hongbo
Introduction
In general, hypertension involves both the preload and afterload of the left ventricle. Preload refers to the resistance the left ventricle must overcome before contraction, typically represented by the volume of blood returning via veins to the left atrium and the filling volume during left ventricular diastole. In patients with hypertension, elevated arterial pressure increases the force required by the heart to pump blood throughout the body.
Generally, hypertension affects both the preload and afterload of the left ventricle. The details are as follows:
1. Preload
Preload refers to the resistance the left ventricle must overcome before contraction, typically represented by the volume of blood returning via veins to the left atrium and the filling volume during left ventricular diastole. In patients with hypertension, elevated arterial pressure requires the heart to exert greater force to pump blood throughout the body, thereby increasing the left ventricular preload.
2. Afterload
Afterload refers to the resistance the left ventricle must overcome during contraction, usually represented by aortic pressure and vascular resistance. In hypertensive patients, increased arterial pressure leads to higher pressure within the aorta, thus increasing the left ventricular afterload.
It should be noted that long-term hypertension can lead to myocardial hypertrophy and chamber dilation, eventually impairing cardiac function. Therefore, patients with hypertension should actively manage their condition through dietary modifications, regular physical activity, weight reduction, smoking cessation, and limiting alcohol intake, as well as adhering to medical therapy as prescribed by their physician.
