NURS 203 Lecture Notes - Pulmonic Stenosis, Mitral Valve Stenosis, Aortic Stenosis
Document Summary
Concentric (thick) hpy"d heart vs. dilated hpy heart: 2 different etiologies, and they involve work. It requires a lot of work to contract and push blood thru a stenotic aortic valve, or increased tpr from htn. These will cause an increased afterload = concentric hpy. If you have a valvular problem, and have excess volume of blood in the ventricles increased preload = increased work. Therefore, the frank starling goes into effect b/c stretching and increasing preload in there, and you have to work harder to increase the force of contraction this produces dilated hpy. Therefore, concentric hpy = afterload problem; dilated hpy = volume overload = preload problem (increased volume) S1 heart sound = beginning of systole = mitral and tricuspids close (mitral closes before the tricuspid b/c higher pressures) S2 heart sound = beginning of diastole = pulmonic and aortic close (variation with respiration as diaphragm goes down they increase the intrathoracic pressure.
