Cardio III - Heart Failure

Cardio III - Heart Failure - CARDIOVASCULAR III HEART...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CARDIOVASCULAR III HEART FAILURE Heart failure = the heart cannot pump an adequate supply of blood to meet the demands of the body. Cardiac output falls, leading to decreased tissue perfusion. - the kidneys shut down, decreased perfusion to the brain (decrease LOC, confusion, tired) - heart failure itself is not a disease, it is secondary to other diseases (i.e., CAD, hypertension) - important labs to monitor for heart failure BNP, creatinine .Atherosclerosis (blockage, decreased tissue perfusion) and hypertension (increased after load, vasoconstriction, increased muscle size hypertrophy) are the most common causes of heart failure. PHYSIOLOGY AND REVIEW 1. Cardiac output the amount of blood ejected from the left ventricle each minute. (5 L/min) - cardiac output= stroke volume x heart rate - any changes in cardiac output lead to decreased ventricular function and resultant manifestations of heart failure 2. stroke volume the amount of blood ejected with each heartbeat. (70 mL) 3. Preload volume of blood in the ventricle at the end of diastole. (Frank-Starling law which states that the force of the ventricle is related to the stretch in the muscle fibers.) - the heart can’t pump what it doesn’t get - increased preload = increased stretch 4. After load force that the ventricle must exert to eject blood into circulation - vasoconstriction hypertension 5. Contractility ability of the muscle fibers to shorten during systole. Contractility is necessary to overcome after load and eject blood during systole. Poor contractility affects CO. 6. Ejection Fraction percentage of the end-diastolic volume in the ventricle an indication of the amount of blood that was ejected and also tells the contractile ability of the ventricle. - how strong or weak the heart is - an echocardiogram can give a preliminary ejection fraction (not accurate; can’t base diagnosis on this number) - less than 18% ejection fraction candidate for heart transplant Common Causes of Heart Failure: 1) Hypertension 2) Coronary artery disease (atherosclerosis) 3) Cardiomyopathy(CM) heart muscle disease that can affect structural and functional ability of myocardium a. Dilated CM enlargement of the heart’s chambers i. Inflammation causes rapid degeneration of myocardial fibers that 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
cause ventricular dilation and decreased contractile function (alcohol-induced, genetic, hypertension) b. Hypertrophic CM thickening of heart muscle and ineffective pump (hypertension, genetic) c. Restrictive CM least common; impairs diastolic filling and stretch (idiopathic, neoplastic tumors, ventricular thrombosis 4) Substance abuse 5) Valvular disease 6) Congenital defects 7) Cardiac infections and inflammations (myocarditis) increased oxygen and metabolic demand ****Considerations for older adults: The use of certain drugs can also lead to heart failure (HF), especially in older adults. Long-term use of NSAIDS such as Motrin cause sodium and water retention. PATHOPHYSIOLOGY
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/04/2008 for the course NURS 130 taught by Professor Dupuy during the Spring '08 term at Lady of the Lake.

Page1 / 8

Cardio III - Heart Failure - CARDIOVASCULAR III HEART...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online