What are the characteristic findings of diastolic heart failure?

Characteristic Findings of Diastolic Heart Failure

The two findings most characteristic and specific to diastolic heart failure are preserved ejection fraction (>50%) and pulmonary congestion without cardiomegaly.

Definition and Diagnostic Criteria

Diastolic heart failure is characterized by:

• Preserved left ventricular ejection fraction (LVEF >45-50%) 1, 2
• Signs and symptoms of heart failure
• Evidence of abnormal left ventricular diastolic function 1

Key Diagnostic Findings

Primary Diagnostic Features:

1. Preserved ejection fraction (>45-50%)

   • Essential criterion that distinguishes it from systolic heart failure 1, 2
   • Normal or only mildly abnormal LV systolic function

2. Pulmonary congestion without cardiomegaly

   • Characteristic radiographic finding 1
   • Reflects elevated filling pressures despite normal chamber size

Additional Diagnostic Features:

• Abnormal LV filling patterns on echocardiography:

  • Impaired relaxation pattern (Grade I): Decreased E/A ratio (<1) 1
  • Pseudonormalized filling pattern (Grade II): Normal-appearing E/A ratio but abnormal when assessed with tissue Doppler 1
  • Restrictive filling pattern (Grade III): Elevated E/A ratio (>2) with short deceleration time 1

• Elevated E/e' ratio on tissue Doppler imaging:

  • E/e' >15 indicates high LV filling pressures 1, 3
  • Values between 8-15 require additional confirmation 3

• Left ventricular hypertrophy:

  • Common finding due to underlying conditions like hypertension 4
  • Increased LV mass index (>95 g/m² in women, >115 g/m² in men) 1

• Elevated natriuretic peptide levels:

  • BNP or NT-proBNP elevation suggests diastolic dysfunction 1, 5
  • Cannot distinguish between systolic and diastolic heart failure 2

Contrasting with Systolic Heart Failure

Diastolic heart failure differs from systolic heart failure in several key ways:

• Ejection fraction:

  • Diastolic HF: Preserved (>50%)
  • Systolic HF: Reduced (<40%) 1

• Ventricular size:

  • Diastolic HF: Normal or small LV cavity
  • Systolic HF: Dilated LV with increased end-diastolic volume 1

• Cardiac sounds:

  • Diastolic HF: S4 gallop (atrial contraction against stiff ventricle)
  • Systolic HF: S3 gallop (rapid filling of dilated ventricle) 1

• Demographics:

  • Diastolic HF: Higher prevalence in elderly women, especially with hypertension 1
  • Systolic HF: Higher prevalence in males 1

Pathophysiology

The primary abnormalities in diastolic heart failure include:

• Delayed ventricular relaxation
• Increased myocardial stiffness
• Decreased ventricular compliance 6
• Increased left ventricular end-diastolic pressure despite normal volume 1

These changes lead to elevated left atrial pressure, pulmonary venous congestion, and symptoms of heart failure despite normal contractile function.

Common Pitfalls in Diagnosis

• Relying solely on ejection fraction without assessing diastolic parameters
• Failing to recognize that pulmonary congestion can occur without cardiomegaly
• Not considering diastolic heart failure in elderly patients with heart failure symptoms
• Overlooking the importance of tissue Doppler imaging in diagnosis 5

Understanding these characteristic findings helps distinguish diastolic heart failure from other cardiac conditions and guides appropriate management strategies.