Congestive Heart Failure Flashcards
Congestive heart failure definition
Condition where the hearts oxygen demand out weighs the oxygen supply, which begins cardiac ischemia
- common end point for many forms of cardiac disease
- usually progressive condition w/ poor prognosis but can be acute
Rates are 5 million per year w/ 1 million hospitalizations
Is heart failure resulting from systolic or diastolic?
Can be either systolic or diastolic
- systolic = caused from inadequate myocardial contractile function
1) caused by ischemic heart disease or HTN
- diastolic = caused by from inability of the heart to adequately relax and fill
1) caused by massive LVH, myocardial fibrosis, amyloid deposition or constrictive pericarditis
Other causes not related to systolic/diastolic dysfunction
Valve dysfunction
Endocarditis
Rapid increases blood volume/pressure
Heart failure physiologic effects
Increases in:
- EDV volume
- EDV pressures
- venous pressures
Forward failure
Heart failure caused by inadequate cardiac output
Backward failure
Heart failure caused by poor venous circulation
Mechanisms the cardiovascular system uses to attempt to compensated for reduced myocardial contractility/increased hemodynamic burden
Frank starling mechanism
Neurohurmoral systems
Myocardial structural changes (hypertrophy and dilation)
Frank starling mechanisms
Increased EDV = dilation of the heart through eccentric hypertrophy
- increases cardiac myofiber stretching allowing for increased CO
- increases wall tension
Increases oxygen demands of the myocardium
note if this is present the patient is in compensated heart failure
Activation of neuro humoral systems STEPS
1) Releases large amounts of NE
- increases HR and vascular resistance
- augments myocardial contractility
2) Activates the renin-angiotensin-aldosterone system
- increases water and salt retention
- increases vascular tone
3) release of atrial natriuretic peptides
- balances the renin-angiotensin- aldosterone system effects by
- relaxing smooth muscle
- increasing diuresis
Myocardial structures changes during CHF
Increases hypertrophy through concentric or eccentric means
Increases oxygen demands
Stenosis causes what hypertrophy
Concentric hypertrophy through new sarcomeres being added in parallel
- causes thickness of the wall rather than stretching of the wall
Volume overload/regurgitation causes what hypertrophy?
Eccentric hypertrophy through adding sarcomeres in series with existing sarcomeres
Increases wall length by dilating the heart
Increases heart weight, not wall thickness
Left-sided heart failure
Most common causes are
- ischemic heart disease
- systemic HTN
- mitral/aortic valve diseases
- amyloidosis
Clinical effects:
- diminished systemic perfusion
- pulmonary backflow
- pulmonary edema
- pleural effusion
- coughing
- tachycardia w/ possible S3 sound
- nocturnal dyspnea (only chronic)
- dyspnea (earliest sign of left heart failure)
- increased pulmonary pressures
Signs/symptoms
- left ventricle is hypertrophied and dilated (except in mitral valve stenosis and RCM)
Hemosiderin-laden alveolar macrophages
Breakdown of red blood cells and hemoglobin that is commonly found in chronic left sided heart failure
- a result of previous pulmonary edema episodes
Ventricular dilation caused by left sided heart failure is unique why?
Causes mitral regurgitation and a unique “snap-systolic” murmur
- also causes increased atrial fibrillation rates*
- reduces ventricular stroke volume
- causes increased stasis in the atria that leads to thrombus formation within the atria
