Ventricular Hypertrophy Flashcards
What is the definition of ventricular hypertrophy?
It is a compensatory change related to alterations in pressure and/or volume imposed on the wall of the ventricle
What are the basic changes that occur in result to increased stess on the wall?
The stress causes changes in gene expression that leads to duplication of sarcomeres
In what way do cells duplicate to cause hypertophy in response to hypertrophy?
They duplicate parallel to the long axis of the cells causing indicidual muscle fibres to be thicker
What are the causes of left ventricular hypertrophy due to increased afterload?
Essential hypertension
Aortic stenosis
Hypertrophic cardiomyopathy
What are the causes of right ventricular hypertrophy due to increased afterload?
Pulmonary hypertension
Pulmonary valve stenosis
What changes occur to the heart with increased preload?
Dilation and eccentric hypertrophy of the ventricular wall (sarcomeres duplicate in series)
What can cause increased preload and eccentric hypertrophy in the left ventricle?
Mitral or aortic valve regurgitation
Septal defects causing left to right shunting of blood
What can cause increased preload and eccentric hypertrophy in the right ventricle?
Tricuspid or pulmonary valve regurgitation
Why does regurgitation in the AV valves cause increased ventricular preload?
As some of the blood from the ventricles returns to the atria with systole in diastole the atria will pump the larger volume of blood into the ventricle increasing preload
What are the 4 main consequences of ventricular hypertrophy?
left and right sided heart failure
Angina pectoris with exercise
S4 heart sound is commonly heard with LVH or RVH
S3 heart sound is heard with blood entering left or right sided eccentric hypertophy
Why does ventricular hypertrophy cause heart failure?
The increased work imposed on the ventricles is caused by increased preload or afterload leading to failure
Why is angina pectoris with excercise caused by ventricular hypertrophy?
Due to the hypertrophy the muscle wall is thickened. This means that when exercising and there is less time for the cardiac arteries to fill then the subendocardial tissue recieves low levels of O2 causing angina
Why is an S4 heart sound heart in ventricular hypertrophy?
This is the sound produced by blood entering a non compliant ventricle. This occurs at the atrial contraction in late diastole. It can occur in concentric or eccentric hypertrophy
Why is an S3 heart sound heard in ventricular hypertrophy?
This only occurs in eccentric hypertrophy and is the sound produced from blood entering a volume overloaded chamber
