A 70-year-old male with edema and congestive heart failure has diastolic dysfunction characterized by decreased ventricular filling due to reduced ventricular muscle compliance. Which one of the following proteins determines the normal stiffness of ventricular muscle?
A) Calmodulin
B) Troponin
C) Tropomyosin
D) Titin
E) Myosin light chain kinase

Question

Quizplus · Accepted Answer

Titin is a protein that plays a crucial role in determining the elasticity and stiffness of muscle fibers, including those in the heart. In the context of diastolic dysfunction, where there is decreased ventricular filling due to reduced compliance of the ventricular muscle, the properties of titin are particularly relevant. This protein helps to maintain the structural integrity and proper function of the myocardium, influencing its ability to stretch and recoil, which are essential for normal cardiac filling and function.

A 70-Year-Old Male with Edema and Congestive Heart Failure Has