Ventricular Hypertrophy

Question 1

What is ventricular hypertrophy?

Answer 1

Increased pressure/ volume in the ventricle>stresses ventricle wall>compensatory change (hypertrophy)

Question 2

Sustained pressure in the ventricles leads to increased wall stress. How does wall stress alter gene expression in cardiac muscle?

Answer 2

Wall stress>Increase gene controlled sarcomere duplication

Question 3

What is afterload?

Answer 3

Resistance ventricle contracts against to eject blood in systole

Question 4

How does increased afterload affect the ventricular wall?

Answer 4

Increased afterload>Sarcomeres duplicate parallel to long axis>muscle gets thicker>CONCENTRIC ventricular hypertrophy (walls thicken and volume diminishes)

Question 5

What causes LVH d/t increased afterload?

Answer 5

1. HTN (most common)2. AV stenosis3. Hypertrophic cardiomyopathy

Question 6

What causes RVH d/t increased afterload?

Answer 6

1. Pulmonary hypertension2. PV stenosis

Question 7

What is preload?

Answer 7

The volume of blood the ventricle must expel during systolePreload = LVEDV and RVEDVIncreased preload= increased stroke volume

Question 8

How does increased preload affect the ventricular wall?

Answer 8

Increased preload>sarcomeres duplicate in series>muscle fibers longer/wider>DILATION and ECCENTRIC hypertrophy (Ventricle walls dilate increasing volume)

Question 9

What causes eccentric hypertrophy of the LV d/t increased preload?

Answer 9

1. MV or AV regurgitation2. L to R shunting (VSD)

Question 10

What causes eccentric hypertrophy of the RV d/t increased preload?

Answer 10

Tricuspid valve and PV regurgitaiton

Question 11

What is the difference between cocentric and eccentric hypertrophy?

Answer 11

Concentric= increased afterload (sarcomeres duplicate in parallel along the long axis; muscle is THICKER) Eccentric= increased preload (Sarcomeres duplicate in series: muscle fibers longer/wider)

Question 12

What are the consequences of ventricular hypertrophy?

Answer 12

1. Left and right sided heart failure2. Angina pectoris with exercise3. S4 heart sound d/t RVH or LVH4. Pathologic S3 heart sound d/t RV or LV eccentric hypertrophy

Question 13

How does ventricular hypertrophy cause L/R sided heart failure?

Answer 13

Increase in preload/afterload>ventricles have to do extra work>heart failure

Question 14

How does ventricular hypertrophy lead to angina with exercise?

Answer 14

If the muscle is concentrically thickened >Subendocardial tissue doesn’t recieve enough 02>chest painALSOExercise>Increase in HR>Decreases time for diastole>decreased filling of coroanry arteries>Less blood/O2 to myocardium

Question 15

What is an S4 heart sound?

Answer 15

Atrial gallop- correlates with atrial contraction during diastole

Question 16

How does ventricular hypertrophy lead to an S4 heart sound?

Answer 16

Blood endtering a NONCOMPLIANT ventriclet’s kind of like eating pumpkin pie for desert when the stomach is already full of turkey.Coccentric/eccentric hypertrophpy>noncompliant ventricle>ventricles are volume overloaded and resist receiving more blood in late diastole

Question 17

Name 4 ways an S4 heart sound can be produced.

Answer 17

1. Concentric LVH in essential HTN or AV stenosis2. Concentric RVH in PH or PV stenosis3. Volume overload in MV or TV regurgitation4. Volume overload in AV or PV regurgitation

Question 18

What causes an S4 heart sound?

Answer 18

Blood entering a volume OVERLOADED ventricle in diastole.1. volume overload in MV, TV, AV or PV regurge