L5.10: Ventricular hypertrophy

Question 1

What are concentric and eccentric hypertrophy due to?

Answer 1

Pressure and volume overload respectively.

Concentric leads to sarcomeres in parallel.

Eccentric leads to sarcomeres in series.

Question 2

True or false? Eccentric hypertrophy can be linked to hypertension (pressure overload)

Answer 2

True.

Question 3

What is increased in hypertrophy?

Answer 3

Cell size, mitochondria, myofibrils, SR.

Question 4

What are some causes of concentric and eccentric hypertrophy?

Answer 4

Concentric: Hypertension, aortic stenosis. Due to pressure overload, high afterload.

Eccentric: Mitral/aortic regurgitation, due to volume overload, high preload.

Question 5

What is diastolic dysfunction due to?

Answer 5

Thick stiff muscle. Increased LVEDP required to achieve the same LVEDV due to low compliance.

Increase in LA and pulmonary vein subsequently occurs and we get pulmonary congestion.

Question 6

What is Hypertrophic cardiomyopathy?

Answer 6

Genetic condition in which interventricular septum hypertrophy is markedly distinct. Has variable penetrance.

Due to mutation in cardiac troponin, myosin binding protein, myosin heavy chain.

Question 7

What is the pathenogenesis of hypertrophic cardiomyopathy? Clinical signs?

Answer 7

Myocyte disarray, diastolic dysfunction and ventricular arrhythmias - sudden death.

Clinical signs can show outflow obstruction, SOB, heart failure, syncope.
Most common cause of death in young athletes.

Question 8

True or false? In athlete’s heart, or dilated cardiomyopathy, eccentric hypertrophy occurs but can regress overtime if athlete de-conditions (stops exercising).

Answer 8

False. It doesn’t regress at all. This is due to a cytoskeletal defect in the heart itself.