HF Pt1 Flashcards
(92 cards)
What percentage and total number of Americans have HF?
2-2.5% (6.7 million people)
What is the prognosis of HF?
Survival rate of about 50% in 5 years of HF
What is the definition of HF?
Failure of the heart to pump blood at a rate commensurate with requirements of metabolizing tissues
What is the impairment in cardiac function with HFrEF?
Systolic dysfunction: decreased contractility
What is the definition of HFrEF?
HF sx with EF <40%
What is HFrEF without Sx?
Asymptomatic reduced EF
What are the causes of HFrEF?
Dilated ventricle:
- Ischemic dilated CM
- Non-ischemic dilated CM
- HTN, obesity, stress, etc
What is the impairment in cardiac function of HFpEF?
Diastolic dysfunction: impairment in ventricular relaxation/filling
What is the definition of HFpEF?
HF Sx w EF >50%
What is the most common cause of HFpEF?
HTN
What is the definition of HFmrEF (mildly reduced)?
HF with EF 41-49%
What is the definition of HFimpEF (improved)?
HF w EF >40% and previously had HFrEF
What are the determinants of LV performance?
- Preload
- Myocardial contractility
- Afterload
What are the compensatory mechanisms of HF?
- Increased preload due to Na/water retention
- Vasoconstriction
- Tachycardia and increased contractility (SNS activation)
- Ventricular hypertrophy and remodeling
What is the beneficial effect of increased preload due to Na/water retention?
Optimize stroke volume via Frank-Starling mechanism
What are the detrimental effects of compensation of increased preload due to Na/water retention?
- Pulmonary/systemic congestion and edema
- Increased MVO2
What are the beneficial effects of vasoconstriction?
- Maintain BP in face of reduced CO
- Shunt blood from nonessential tissues to heart
What are the detrimental effects of vasoconstriction?
- Increased MVO2
- Increased afterload: decreases SV and further activates the compensatory responses
What is the beneficial effect of tachycardia and contractility?
Maintain CO
What are the detrimental effects of tachycardia and contractility?
- Increased MVO2
- Shortened diastolic filling time
- B-receptor downregulation and decreased responsiveness
- Ventricular arrhythmias
- Increased risk of myocardial cell death
What are the beneficial effects of ventricular hypertrophy and remodeling?
- Maintain CO
- Reduce myocardial wall stress: decreases MVO2
What are the detrimental effects of ventricular hypertrophy and remodeling?
- Diastolic and systolic dysfunction
- Risk of myocardial cell death and ischemia
- Risk of arrhythmias
- Fibrosis
What are some precipitating factors of HF in resource-limited hospitals?
- Lack of compliance
- With diet, drugs
- Uncontrolled HTN
What are the precipitating factors of HF in “richer” hospitals?
- Non-compliance with drug or diet
- Cardiac ischemia
- Inadequate therapy