Systolic vs. Diastolic Heart Failure

What is the difference between systolic and diastolic heart failure in terms of pathophysiology clinical presentation and management?, How does ejection fraction help differentiate the two conditions and why do treatment strategies vary based on this classification?

Systolic vs. Diastolic Heart Failure

Pathophysiology:

• Systolic Heart Failure (HFrEF – Heart Failure with Reduced Ejection Fraction):
  • The heart’s left ventricle loses its ability to contract effectively, reducing cardiac output.
  • Common causes include ischemic heart disease, myocardial infarction, and dilated cardiomyopathy.
  • Leads to increased left ventricular end-diastolic volume and pressure, causing pulmonary congestion.
• Diastolic Heart Failure (HFpEF – Heart Failure with Preserved Ejection Fraction):
  • The left ventricle has impaired relaxation and reduced compliance, leading to inadequate ventricular filling.
  • Common causes include hypertension, left ventricular hypertrophy, and restrictive cardiomyopathy.
  • Leads to increased left atrial pressure and pulmonary congestion despite normal systolic function.

Clinical Presentation:

• Systolic Heart Failure:
  • Symptoms: Dyspnea, orthopnea, paroxysmal nocturnal dyspnea, fatigue, and reduced exercise tolerance.
  • Signs: Pulmonary rales, S3 heart sound, and reduced ejection fraction (≤40%).
• Diastolic Heart Failure:
  • Symptoms: Similar to HFrEF (dyspnea, fatigue), but often with preserved exercise tolerance.
  • Signs: Pulmonary congestion, S4 heart sound, and normal or mildly reduced ejection fraction (≥50%).

Ejection Fraction (EF) Role:

• EF differentiates the two conditions:
  • HFrEF: EF ≤40% indicates reduced contractility.
  • HFpEF: EF ≥50% with normal contraction but impaired relaxation.

Management Strategies:

• Systolic Heart Failure:
  • Medications: ACE inhibitors, ARBs, beta-blockers, aldosterone antagonists, SGLT2 inhibitors, and diuretics for symptom relief.
  • Devices: Implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) in select patients.
• Diastolic Heart Failure:
  • Focus on blood pressure control (ACE inhibitors, ARBs, calcium channel blockers).
  • Diuretics for congestion, but over-diuresis should be avoided to prevent reduced preload.
  • Lifestyle modifications, such as sodium restriction and exercise, play a crucial role.

Despite different mechanisms, both types require optimal volume management, risk factor control, and lifestyle interventions. APA