Heart Failure for PA
Heart Failure for the Physician Assistant Licensing Exam
- Definition: Heart failure (HF) is a clinical syndrome in which the heart cannot effectively pump blood to meet the body’s needs. It is classified based on ejection fraction (EF):
- Heart Failure with Reduced Ejection Fraction (HFrEF): EF ≤40%, primarily due to systolic dysfunction.
- Heart Failure with Preserved Ejection Fraction (HFpEF): EF ≥50%, primarily due to diastolic dysfunction.
- Heart Failure with Mid-Range Ejection Fraction (HFmrEF): EF 41-49%, combining characteristics of both HFrEF and HFpEF.
Pathophysiology
- Systolic Dysfunction (HFrEF):
- Occurs when the heart muscle cannot contract adequately, reducing stroke volume and ejection fraction.
- Often caused by ischemic heart disease, chronic hypertension, and dilated cardiomyopathy.
- Diastolic Dysfunction (HFpEF):
- Characterized by impaired ventricular relaxation, leading to reduced filling and increased filling pressures.
- Associated with conditions like chronic hypertension, aging, and left ventricular hypertrophy.
- Compensatory Mechanisms:
- Renin-Angiotensin-Aldosterone System (RAAS) activation and Sympathetic Nervous System stimulation temporarily support cardiac output but eventually contribute to worsening HF through fluid retention, vasoconstriction, and fibrosis.
Clinical Presentation
- Left-Sided Heart Failure:
- Symptoms: Dyspnea, orthopnea, paroxysmal nocturnal dyspnea (PND).
- Signs: Pulmonary rales, S3 heart sound, and possible pleural effusion.
- Right-Sided Heart Failure:
- Symptoms: Peripheral edema, ascites, and abdominal discomfort.
- Signs: Jugular venous distention (JVD), hepatomegaly, and hepatojugular reflux.
Diagnostic Evaluation
- BNP and NT-proBNP: Biomarkers elevated in HF, useful in diagnosis and severity assessment.
- Echocardiography: Key imaging for assessing ejection fraction, ventricular size, and wall motion.
Management
Heart Failure with Reduced Ejection Fraction (HFrEF)
- Medications:
- ACE Inhibitors/ARBs: First-line for reducing afterload and improving survival.
- Beta-Blockers: Reduce mortality and prevent remodeling.
- Diuretics: Relieve symptoms of volume overload.
- Aldosterone Antagonists: For advanced HF to decrease mortality and hospitalization.
Heart Failure with Preserved Ejection Fraction (HFpEF)
- Management:
- Focuses on symptom control, including diuretics for volume management.
- Comorbidity management (e.g., hypertension, diabetes) is crucial for HFpEF patients.
Key Points
- Heart Failure Types:
- HFrEF involves systolic dysfunction, HFpEF involves diastolic dysfunction.
- HFmrEF has mixed characteristics, with EF 41-49%.
- Clinical Signs:
- Left-sided HF causes pulmonary congestion, while right-sided HF leads to systemic congestion.
- Diagnostics:
- BNP and echocardiography are essential in diagnosing and assessing HF.
- Management:
- HFrEF is treated with ACE inhibitors, beta-blockers, and diuretics.
- HFpEF management focuses on symptom relief and controlling comorbidities.