Heart Failure: Etiology, Classification, Stages, Pathophysiology, Pathology, and Complications

Heart failure (HF) is a chronic, progressive condition where the heart's ability to pump blood effectively is compromised. It is a major global health concern, leading to significant morbidity and mortality.

Etiology

Heart failure can result from various conditions, including coronary artery disease, hypertension, valvular heart disease, and cardiomyopathies.

Classification

Heart failure is broadly classified into:

• Heart Failure with Reduced Ejection Fraction (HFrEF): EF ≤40%
• Heart Failure with Preserved Ejection Fraction (HFpEF): EF ≥50%
• Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF): EF 41-49%

Stages of Heart Failure: ACC/AHA and NYHA Classification

ACC/AHA Stages

• Stage A: High risk but no structural heart disease.
• Stage B: Structural heart disease but no symptoms.
• Stage C: Structural heart disease with symptoms.
• Stage D: Advanced heart failure with severe symptoms.

NYHA Functional Classification

• Class I: No symptoms with ordinary physical activity.
• Class II: Mild limitation of physical activity.
• Class III: Marked limitation of physical activity.
• Class IV: Symptoms at rest.

Pathophysiology

Heart failure arises from the inability of the heart to maintain adequate cardiac output. Mechanisms include neurohormonal activation, ventricular remodeling, and fluid retention.

Pathology

Common pathological findings include myocyte hypertrophy, fibrosis, and chamber dilation in HFrEF, while diastolic dysfunction predominates in HFpEF.

Complications

• Pulmonary edema
• Arrhythmias
• Renal dysfunction
• Thromboembolism

Conclusion

Early diagnosis and management of heart failure improve outcomes. Optimizing treatment strategies based on patient characteristics remains essential.