U01.07.047 Heart failure

Heart failure (HF) is a clinical syndrome characterized by cardiac pump dysfunction, leading to both congestion and low perfusion. It manifests through symptoms and signs that vary depending on the type of heart failure (systolic vs. diastolic) and whether it involves the right or left side of the heart.

Key Symptoms and Signs of Heart Failure:

Symptoms:
- Dyspnea
- Orthopnea
- Fatigue
Signs:
- S3 heart sound
- Rales
- Jugular venous distention (JVD)
- Pitting edema

Types of Heart Failure

1. Systolic Dysfunction

Characteristics:
- Reduced ejection fraction (EF)
- Increased end-diastolic volume (EDV)
- Reduced contractility, often secondary to ischemia, myocardial infarction (MI), or dilated cardiomyopathy.

2. Diastolic Dysfunction

Characteristics:
- Preserved EF
- Normal EDV
- Reduced compliance (increased end-diastolic pressure, EDP), commonly seen in myocardial hypertrophy.

Heart Failure Classification

Type	Characteristics	Etiology
Left Heart Failure	– Pulmonary congestion and edema	– Often due to ischemic heart disease, MI, or hypertensive heart disease.
Right Heart Failure	– Peripheral edema, hepatomegaly (nutmeg liver), jugular venous distention (JVD)	– Most often results from left heart failure; may also be due to cor pulmonale (isolated right HF from pulmonary causes).

Left Heart Failure (LHF)

Symptoms:
- Orthopnea: Shortness of breath when supine due to increased venous return and pulmonary congestion.
- Paroxysmal Nocturnal Dyspnea: Breathlessness upon awakening from sleep, caused by redistribution of blood and reabsorption of peripheral edema.
Signs:
- Pulmonary Edema: Increased pulmonary venous pressure leads to transudation of fluid, manifesting as fluid in the lungs.
- Hemosiderin-laden Macrophages (“HF cells”): Indicative of chronic pulmonary congestion.

Right Heart Failure (RHF)

Symptoms:
- Hepatomegaly (Nutmeg Liver): Result of increased central venous pressure and resistance to portal flow, occasionally leading to “cardiac cirrhosis.”
- Peripheral Edema: Fluid accumulation due to increased venous pressure.
- Jugular Venous Distention (JVD): Caused by elevated venous pressure.

Pathophysiology and Mechanisms of Heart Failure

Condition	Systolic Heart Failure (HFrEF)	Diastolic Heart Failure (HFpEF)
LV Contractility	Decreased	Preserved
Compliance	Decreased (low compliance)	Decreased (low compliance)
Pulmonary Edema	Present due to elevated pulmonary venous pressure	Present due to elevated pulmonary venous pressure
Peripheral Edema	Present due to poor cardiac output	Present due to poor cardiac output
Compensatory Mechanisms	Increased RAAS and sympathetic activity	Increased RAAS and sympathetic activity
Renal Fluid Retention	Increased sodium and water retention	Increased sodium and water retention

Management of Heart Failure

Pharmacologic Interventions:
- ACE Inhibitors or Angiotensin II Receptor Blockers (ARBs): Reduce mortality in both systolic and diastolic heart failure.
- Beta-Blockers: Used for chronic management (except in acute decompensated HF).
- Spironolactone: Reduces mortality, especially in systolic heart failure.
- Loop and Thiazide Diuretics: Primarily for symptomatic relief of edema.
- Hydralazine and Nitrate Therapy: Beneficial for improving both symptoms and mortality in select patients.
Surgical or Device-Based Interventions:
- Implantable Cardioverter-Defibrillators (ICDs) for patients with severe systolic dysfunction.
- Cardiac Resynchronization Therapy (CRT) in cases of severe heart failure with conduction abnormalities.

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