What are the different types of heart failure?

Types of Heart Failure

Heart failure is classified into several distinct types based on timing (acute vs. chronic), ejection fraction (reduced, mid-range, or preserved), and anatomical/hemodynamic patterns (left vs. right, systolic vs. diastolic). 1, 2

Primary Classification by Timing

Acute Heart Failure (AHF)

• Acute heart failure refers to rapid onset or worsening of heart failure symptoms requiring urgent treatment, including de novo heart failure (new onset) or acute decompensation of chronic heart failure. 1, 3
• AHF presents with severe respiratory distress, pulmonary congestion, pulmonary edema, or cardiogenic shock. 1, 4
• The Forrester classification divides acute heart failure (particularly in myocardial infarction) into four hemodynamic categories based on perfusion and pulmonary capillary wedge pressure, with mortality ranging from 2.2% (normal perfusion/normal pressure) to 55.5% (poor perfusion/high pressure - cardiogenic shock). 1

Chronic Heart Failure (CHF)

• Chronic heart failure is the persistent state of heart failure, often punctuated by acute exacerbations, representing the most common form of heart failure. 1, 2
• CHF is defined as a syndrome with symptoms of heart failure (breathlessness, fatigue, ankle swelling) plus objective evidence of cardiac dysfunction at rest. 1, 2

Classification by Left Ventricular Ejection Fraction (LVEF)

The European Society of Cardiology classifies heart failure into three categories based on LVEF, which has critical treatment implications:

Heart Failure with Reduced Ejection Fraction (HFrEF)

• LVEF <40% represents systolic dysfunction with reduced pumping capacity. 2, 5
• Most heart failure is associated with left ventricular systolic dysfunction, though diastolic impairment commonly coexists. 1

Heart Failure with Mid-Range Ejection Fraction (HFmrEF)

• LVEF 40-49% represents an intermediate category with features of both systolic and diastolic dysfunction. 2

Heart Failure with Preserved Ejection Fraction (HFpEF)

• LVEF ≥50% indicates diastolic heart failure where symptoms occur despite normal ejection fraction. 2, 6
• Diastolic heart failure is more common in elderly patients and women, particularly those with systolic hypertension and myocardial hypertrophy with fibrosis. 1, 2
• This represents 40-50% of all heart failure patients with similar mortality to systolic heart failure. 7

Classification by Anatomical Pattern

Left Heart Failure

• Left heart failure presents predominantly with pulmonary venous congestion including dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and pulmonary rales. 1, 4
• The term does not necessarily indicate which ventricle is most severely damaged. 1

Right Heart Failure

• Right heart failure presents predominantly with systemic venous congestion including peripheral edema, hepatomegaly, jugular venous distension, and ascites. 1
• Fluid overload is managed with diuretics including spironolactone. 1

Additional Descriptive Classifications

Forward vs. Backward Failure

• Forward failure manifests as reduced tissue perfusion with weakness, confusion, cold extremities, hypotension, and oliguria, potentially progressing to cardiogenic shock. 1
• Backward failure presents with venous congestion either pulmonary (left-sided) or systemic (right-sided). 1

High-Output vs. Low-Output Failure

• These descriptive terms have limited clinical utility for determining modern treatment approaches, as they provide no etiological information. 1

Severity Classification

NYHA Functional Classification (for Chronic Heart Failure)

• Class I: No limitation of physical activity; ordinary activity does not cause symptoms. 8
• Class II: Slight limitation; comfortable at rest but ordinary activity causes fatigue, palpitation, or dyspnea. 8
• Class III: Marked limitation; comfortable at rest but less than ordinary activity causes symptoms. 8
• Class IV: Unable to carry on any physical activity without discomfort; symptoms present even at rest. 8

Killip Classification (for Acute MI-Related Heart Failure)

• Stage I: No heart failure signs (mortality 2.2%). 1, 4
• Stage II: Rales in lower half of lung fields, S3 gallop, pulmonary venous hypertension (mortality 10.1%). 1, 4
• Stage III: Frank pulmonary edema with rales throughout lung fields (mortality 22.4%). 1, 4
• Stage IV: Cardiogenic shock with hypotension <90 mmHg, peripheral vasoconstriction, oliguria, cyanosis (mortality 55.5%). 1, 4

ACC/AHA Staging System

The American College of Cardiology/American Heart Association staging system identifies patients earlier in the disease continuum:

• Stage A: At high risk for heart failure but without structural heart disease or symptoms. 8
• Stage B: Structural heart disease without symptoms (requires ACE inhibitors and beta-blockers to prevent progression). 8
• Stage C: Structural heart disease with current or prior heart failure symptoms (encompasses NYHA Classes I-IV). 8
• Stage D: Refractory heart failure requiring specialized interventions. 8

Critical Clinical Caveat

Heart failure should never be the only diagnosis - the underlying cause must always be identified, as specific etiologies require targeted treatments beyond standard heart failure management. 1, 2 Common causes include coronary artery disease, hypertension, valvular disease, cardiomyopathy (30% genetic), and diabetes mellitus. 2, 7