Created by Jinda Chai
almost 10 years ago
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Question | Answer |
Systolic dysfunction (heart contracting) | Cardiac muscle contracts weakly and the chambers cannot empty properly. |
Diastolic dysfunction (heart is relaxed) | Muscle cannot relax sufficiently to permit ventricular filling. |
Heart Failure aka CHF | Heart unable to pump blood at a sufficient rate to meet metabolic demands of tissues (or can only do so at an elevated filling pressure(?)) *Need O2 from blood to make ATP for organ function. |
Forward (complication) | inadequate cardiac output (decreased organ perfusion) In physiology, perfusion is the process of a body delivering blood to a capillary bed in its biological tissue. " |
Backward (complication) | Passive congestion of organs (back up of flow bc of blockage or bc of inadequate cardiac output)... |
Chronic causes of CHF | valvular disease, hypertension, ischemic heart disease |
Sudden/acute causes of CHF | acute hemodynamic stresses (fluid overload, acute valvular dysfunction, large myocardial infarction) |
Frank Starling Mechanism | Adaptive mech: increased filling volumes dilate the heart and thereby increase functional cross-bridge formation within sarcomeres, enhancing contracility. |
Myocardial adaptation | Adaptive Mech: hypertrophy with or without cardiac chamber dilation. |
Neurohumoral systems | Adaptive Mech: 1) released of norepinephrine via autonomic NS (increases HR) 2) activation of renin angiotensin aldosterone system (elevate BP) 3) release of atrial natriuretic peptide (BV dilation) |
Systolic Left HF | L. ventricle cannot pump enough blood into circulation |
Diastolic LS HF | L. ventricle cannot relax to allow blood filling. |
Etiology of LSHF | Ischemic HD, hypertension, myocardial disease, aortic or mitral valve disease. |
Consequence | Increased heart weight, left ventricular hypertrophy and dilation, heavy edematous lungs. |
Mechanism of LS Heart Failure | 1) Left side heart fails 2) Right side of heart still functional 3) R ventricles continue to pump blood into lungs 4) Blood not recirculated into body by left heart 5) Final result - Increased blood volume in pulmonary circulation. |
2 major problems in LS HF | 1) Pulmonary vascular congestion 2) Pulmonary edema |
Compensated Heart Failure | Acute = Sympathetic stimulation (30s-1min) Chronic = Renal fluid retention and recovered cardiac output (?) (hours to weeks) |
Decompensated Heart Failure | Heart is too weak to have enough cardiac output for kidneys to excrete necessary amount of fluid. Causes: 1) Fluid retention --> overstretched sarcomeres 2) Edema of heart muscle 3) Longitudinal tubules of sarcoplasmic reticulum fail to accum enough Ca2+ 4) NE in sympathetic nerves decreases |
Morphological changes of LS HF | - Heavy edematous lungs -pulmonary cap. congestion -alveolar edema -intra-alveolar hemosiderin-laden macrophages (heart failure cells) <-- see one note for explanation |
Clinical manifestations of LS HF | -Reduced exercise tolerance/fatigue -Cough, dyspnea at rest/ordinary exertion/middle of night - orthopnea -A fib (irreg/rapid pulse) -urination at night -fluid retention weight gain -azotemia (impaired renal excretion of nitrogens) - hypoxic encephalopathy --> irritability, restless, stupor, coma) |
Etiology of RS HF | 1) LS HF (increased pressure in pulmonary circ burdens RS) Pure right sided heart failure (mostly assos./w lung disorders): - pulmonary heart disease: assos/w parenchymal disease of lung - disorders that affect pulmonary vasculature (primary pulmonary hypertension) - pulmonary thromboembolism |
Mechanism of RS HF | *Usually occurs as a result of LS HF Right atrial pressure may increase bc of: - volume over load (tricuspid insufficiency) -tricuspid valve stenosis - elevated right ventricular filling pressures |
Morphology of RS HF | Often caused by lung disease. Hypertrophy and dilation of R A and V mostly common presentations. |
Clinical features of isolated RS HF | Congestive hepatomegaly and splenomegaly. |
Management of CHF | 1) Relieve fluid overload via diuretics 2) block renin-angiotensin system (ACE inhibitors) 3) lower adrenergic tone (beta blockers) |
Azotemia | nitrogen in blood. occurs in kidney damage. measured via BUN and creatinine |
Uremia | Urine in blood |
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