- Laplace's law is as follows: T = (P × R)/M where T is the tension in the walls, P is the pressure difference across the walls, R is the radius of the vessel and M is the thickness of the wall.
- In dilated cardiomyopathy, after prolonged increases in afterload (in the setting of hemodynamic stress such as hypertension), the heart becomes distended and the radius of the ventricle increases.
- To create the same pressure during ejection of the blood, much larger wall tension has to be developed by cardiac muscle and the ventricular wall thickens.
- The dilated hypertrophic heart requires more energy (and oxygen consumption) to pump the same amount of blood as compared to the heart of normal size.
- Dilated cardiomyopathy causes increases in the risks of ischemia and arrhythmias.