Heart Failure Part 1 Flashcards
Epidemiology of Heart Failure
- ~2-2.5 % of Americans with HF or ~ 6.7 million people: Age related increase: 5% (60-69); 7% (70-79); 10% (80+)
- Lifetime risk is ~24%
- ~ 1 million new cases are diagnosed and approximately
284,000 people die from HF each year - Increase in the number of hospital admissions for HF, ~1 million patients annually.
- HF is the most common hospital discharge for patients >65 years of age.
- Management in 2012 cost an estimated $ 39 billion, with ~1/10 associated with drug costs!
- Prognosis: Survival rates: 5 years: ~50 %
Definitions of Heart Failure
- Although heart failure can be readily described as a clinical syndrome……..an abnormality of myocardial function is responsible for the failure of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues
- Not a single disease state but the final common pathway for CV diseases: CAD, HTN, valvular Dz, cardiomyopathies (intrinsic diseases of the heart)
Pathogenesis of Heart Failure
CAD, HTN, cardiomyopathy, valvular disease –> left ventricular dysfunction –> remodeling –> decrease EF –> death (from arrhythmia + pump failure)
non-cardiac factors: endothelial dysfunction, neurohormonal activation, vasoconstriction, Na retention –> symptoms –> chronic heart failure
Types of HF
HFreEF - HF with reduced ejection fraction, HF sx with EF < 40% (w/o sxs… asymptomatic reduced EF)
HFpEF - HF with preserved ejection fraction, HF sx with EF > 50%
Impairment in cardiac function
HFrEF: Systolic Dysfunction - Decreased contractility; HFpEF: Diastolic dysfunction - Impairment in ventricular relaxation/filling
Causes of HF
HFrEF: Dilated Ventricle -
* Ischemic Dilated CM (~70% of cases)
* Non-Ischemic Dilated CM
* (HTN, Thyroid Dz, Obesity, Stress, Cardiotoxins, Myocarditis, Idiopathic, Tachycardic, Peripartum)
HFePF: Recognized as the 1o disturbance in many patients with HF. Many patients have a combination of systolic and diastolic dysfunction.
HTN is most common cause (>60%)
Determinants of Left-Ventricular Performance (meaure using Stroke Volume)
- Preload: Venous return; LV end-diastolic volume
- Myocardial contractility: Force generated at any given LVEDV
- Afterload: Aortic impedance and wall stress
Cardiac and Heart Failure Hemodynamics
heart failure: can’t fill it anymore w/o it causing pulmonary congestion; preload increase –> stroke volume increase
Heart Failure Pathophysiology
cardiac output decreases –> decrease in BP and organ perfusion –> activates and causes increase in SNS, RAAS, vasopressin, ANP/BNP –> CM hypertrophy, cell death, fibrosis, arrhythmias
Compensatory Response
increased preload due to Na/water retention
vasoconstriction
tachycardia and increased contractility (SNS activation)
ventricular hypertrophy and remodeling
beneficial and detrimental effects of compensation - increased preload due to Na/water retention
beneficial: Optimize stroke volume via Frank-Starling mechanism
detrimental:
* Pulmonary/systemic congestion and edema
* Increased MVO2
Beneficial and detrimental effects of compensation - vasoconstriction
beneficial:
* Maintain BP in face of reduced CO
* Shunt blood from nonessential tissues to the heart
detrimental:
* Increased MVO2
* Increased afterload
decreases SV and further activates the compensatory responses
Beneficial and detrimental effects of compensation - tachycardia and increased contractility (SNS activation)
beneficial: maintain CO
detrimental:
* Increased MVO2
* Shortened diastolic filling time
* b-receptor downregulation and decreased responsiveness
* Ventricular arrhythmias
* Increased risk of myocardial cell death
Beneficial and detrimental effects of compensation - ventricular hypertrophy and remodeling
beneficial:
* Maintain CO
* Reduce myocardial wall stress
Decreases MVO2
detrimental:
* Diastolic and systolic dysfunction
* Risk of myocardial cell death and ischemia
* Risk of arrhythmias
* Fibrosis
Drug-Induced Heart Failure
Antiarrhythmics: (disopyramide, flecainide)
β-blockers: (atenolol, propranolol, metoprolol)
Calcium channel blockers: (verapamil, diltiazem)
Itraconazole
NSAIDs and COX-2 inhibitors
Clinical Presentation of HF
SOB, swelling of feet and legs, chronic lack of energy, difficulty sleeping at night due to breathing problems, swollen or tender abdomen with loss of appetite, cough with frothy sputum, increased urination at night, confusion and or impaired memory
Major Signs/Symptoms of Pulmonary Congestion
- Exertional dyspnea (DOE)
- Orthopnea
- Paroxysmal nocturnal dyspnea (PND)
- Rales
- Pulmonary edema
- Bendopnea
Major Signs/Symptoms of Systemic Venous Congestion
- Peripheral edema
- Jugular venous distension (JVD)
- Hepatojugular reflux (HJR)
- Hepatomegaly, ascites
Other Major Non-specific Findings
- Fatigue, weakness and exercise intolerance
- Nocturia
- Cardiomegaly