MAPIISG1 - Cardiac Muscle Dysfunction/Heart Failure Flashcards
(32 cards)
What is Cardiac Muscle Dysfunction / Heart Failure?
pathophysiological state in which abnormality of cardiac function is responsible for failure of heart to pump blood at a rate sufficient to meet metabolic demands of body
What are clinical manifestations of heart failure?
Exercise intolerance, SOB, chronic fatigue, decline in functional status, QOL (quality of life)
What are the Etiologies (causes) of heart failure?
Intrinsic myocardial disease: CAD –> CHD or coronary myopathy due to virus, infection, congenital)
Myocardial damage: chemotherapy, radiation, drugs
Excess workload: HTN, aortic stenosis
What are measurements of heart function?
- Ejection Fraction (LVEF): normal 55-75%
- What is Cardiac Output (blood moved in 1 minute : normal 4-8L/min
- LVEDV (or LVEDP)
- Ecocardiogram
- Exercise Stress Test
Pathophysiology of heart failure - abnormal stroke volume due to (3)
- Impaired ventricular filling
- Increase afterload
- impaired ventricular filling
What is increase in afterload?
resistance encoutered by blood ejected during systole; due to increase in arterial resistance leads to increase in myocardial O2 consumption and decrease stroke volume
What affect does increase in afterload have on stroke volume of a normal heart?
increase in afterload has little effect on SV
What is impaired contractility?
due to decrease in intercellular Ca2+ –> decrease in force of contractility and stroke volume
What are the three types of cardiomyopathy?
Dialted: heart chamber enlarges, muscle fibers stretch
Hypertopic: heart walls thicken, espcially in LV; some athelets
Restrictive: hypertropic and ventricle walls stiffen resulting in loss of flexibility
What are the 4 types of Systolic dysfunction?
- Loss of contractility
- Dilated ventricle
- Increase LVEDV
- Decreased LVEF
What is 1 type of Diastolic dysfunction?
- Impaired filling due to hypertrophy or decreased filling, may result from HTN or aortic stenosis
Classify the type of Heart Failure: Dialated Cardiomyopathy
- LVEDP: Increase or Decrease
- Force of Muscle Contraction: Increase or Decrease
- Systolic or Diastolic
Classify the type of Heart Failure: Dialated Cardiomyopathy
- LVEDP: Increase
- Force of Muscle Contraction: Decrease
- Systolic
Classify the type of Heart Failure: Restrictive Cardiomyopathy
- LVEDP: Increase or Decrease
- Force of Muscle Contraction: Increase or Decrease
- Systolic or Diastolic
Classify the type of Heart Failure: Restrictive Cardiomyopathy
- LVEDP: Decrease
- Force of Muscle Contraction: Increase
- Diastolic
What causes right-sided heart failure?
increase in pulmonary resistance
What are symptoms of Right-sided heart failure?
Venous Congestion
- peripheral pitting edema
- weight gain
- hepatomeglary
- jugular venous distension
What causes left-sided heart failure?
loss of myocardial tissue (decrease in force of contraction and increase in afterload)
What are symptoms of Left-sided heart failure?
- Dyspnea: rales/crackles, pulmonary edema
- Orthopnea: SOB > lying down vs. sitting up
- Paroxysmal nocturnal dyspnea
- S3 heart sound
- Excessive weight gain (>2lbs/day)
- Decrease in exercise tolerance
How do neromal neurohormonal compensatory mechansims tend to exacerbate HF?
- Purpose of NCMs (SNS stimulation, RAAS) is to maintain levels of CO, BP that allow for adequate perfusion of brain, heart
- Body senses decrease in cardiac output, but blood pressure isn’t able to identify cause as HF so compensatory adaptations decompensate heart function
What is a diagnostic marker of heart failure?
B-type natriuretic peptide (BNP) if CO decreased, BNP increases
BNP >100pg/ml is diagnostic for chronic heart failure
What are the New York Heart Association Classification of HF?
Class I: no limitation of physical activity
Class II: slight limitation of physical activity; dyspnea, fatigue with moderate PA
Class III: dyspnea with minimal physical activity
Class IV: symptoms at rest
Control of HF - How is preload corrected?
Control of salt and water retention - low sodium diet or diuretics
Control of HF - How is contractility improved
Increase FOC:
Digitalis (Glycosides)
Ionotropic Meds (Digoxin)
Decrease Workload: Ace Inhibitors (decease afterload) B-blockers (decrease HR) pacemaker Diuretics (decrease volume)
Control of HF - How is Afterload improved?
reduce peripheral resistance
lower blood pressure
ACE inhibitors (decrease afterload)
What is the HF triple cocktail?
Medications to decrease cardiac workload
ACE Inhibitors
Diuretics
Beta-blockers
