L4: Pathophysiology of Heart Failure

What is inotropy?

contractily strength

What is chronotropy?

heart rate

What is dromotropy?

conduction velocity

What is lusitropy?

elastance

What is preload?

ventricular load immediately prior to contraction

What is afterload?

load ventricle works against

What is contractility?

intrinsic force generated during contraction

What is the primary determinant of preload?

end-diastolic volume

What is stroke volume?

volume of blood ejection (EDV-ESV)

What is cardiac output?

SV x HR

What is ventricular performance proportional to?

preload to a point

True or False: contractility does not equal contractile strength.

True: contractile is dependent on other factors while contractility is independent

What is heart failure?

inability of cardiovascular system to maintain adequate organ perfusion

What is compensated heart failure?

activation of compensatory mechanisms to maintain cardiac output and perfusion

What is decompensated heart failure?

end stage of many heart diseases; low output heart failure or congestive heart failure

What is concentric hypertrophy?

increased pressure; hypertension

What is eccentric hypertrophy?

increased volume; mitral regurgitation

What are natriuretic peptides?

oppose effects of the renin angiotensin aldosterone system (RAAS); however, this system is overwhelmed during heart failure: NA+ and H2O retention dominate

What are the stimulants of natriuretic peptides?

increase right atrial and ventricular stretch and pressure (stress)

What is congestive heart failure?

end stage of heart failure that increases the venous and capillary hydrostatic pressure causes fluid and protein to accumulate in interstitial spaces, overwhelming lymphatic system

What is left sided congestive heart failure?

increased pressure in pulmonary veins and capillaries

What is right sided congestive heart failure?

increased pressure in systemic veins and capillaries