What does a cardiac ejection fraction (EF) of 78% indicate about heart health?

Cardiac Ejection Fraction of 78%

An ejection fraction of 78% is hyperdynamic (above the normal range of 50-70%) and paradoxically indicates potential underlying cardiac pathology rather than superior heart health—this finding warrants comprehensive evaluation for diastolic dysfunction and associated conditions. 1, 2

Classification and Definition

• 78% EF falls into the hyperdynamic category (>70%) according to American College of Cardiology/American Heart Association guidelines 1, 2
• Normal LVEF ranges from 50-70% with a midpoint of 60% 1, 2
• For young adults specifically, the European Association of Cardiovascular Imaging establishes normal range for men as 57-77% by cardiac MRI, though 78% still exceeds this upper limit 3

Clinical Significance: The "Super-Normal" Paradox

A hyperdynamic heart is not a normally functioning heart. 4 The most recent high-quality research demonstrates:

• Patients with hyperdynamic EF (>70%) have significantly reduced survival compared to those with normal EF (50-70%), with a hazard ratio of 1.56 after adjustment (p<0.001) during median 9-year follow-up 4
• 78% of subjects with hyperdynamic hearts have diastolic dysfunction defined by abnormal functional or structural parameters 4
• These patients demonstrate higher LV mass, larger left atrial volume, reduced relaxation (smaller mitral e'), longer deceleration time, and higher LV end-diastolic pressures 4

Associated Clinical Characteristics

Patients with hyperdynamic EF typically present with: 4

• Older age and female predominance
• Higher prevalence of hypertension, diabetes, and obesity
• Smaller ventricular cavity size with highest relative wall thickness
• Higher resting heart rate
• 20% have diagnosed heart failure despite elevated EF

Specific Conditions Associated with Hyperdynamic EF

• Hyperdynamic circulation states: Patients with cirrhosis typically have EF >70-75% due to their hyperdynamic circulation 2
• Athletic heart: Up to 15% of trained athletes may have physiologically elevated EF as an adaptive response, though this represents a distinct population from typical clinical patients 3
• Heart failure with preserved ejection fraction (HFpEF): Enlarged left atrial volume, reduced left atrial strain, and global longitudinal strain abnormalities together with LV hypertrophy support this diagnosis even with supranormal EF 5

Critical Pitfalls and Caveats

• EF >70% should never be dismissed as "excellent cardiac function"—it demands investigation for underlying pathology 4
• EF is load-dependent and cannot distinguish between preload, afterload, and intrinsic contractility, particularly problematic in pressure overload conditions 1
• Single EF measurements have 5-7% inherent variability due to technical factors; borderline hyperdynamic values warrant serial assessment 1, 2
• EF measurement varies between imaging modalities; the specific method should be documented 1, 2

Recommended Evaluation Approach

When encountering EF of 78%, assess for: 4

1. Diastolic dysfunction parameters:

   • Left atrial volume index
   • Mitral E/e' ratio (elevated indicates increased filling pressures)
   • Mitral e' velocity (reduced indicates impaired relaxation)
   • Deceleration time

2. Structural abnormalities:

   • LV mass and relative wall thickness
   • Chamber dimensions (typically smaller in hyperdynamic states)

3. Global longitudinal strain: Values <-16% indicate dysfunction even when EF appears preserved 1

4. Clinical context: Symptoms, comorbidities (hypertension, diabetes, obesity), and functional capacity 4

Prognostic Implications

• The hyperdynamic state confers worse prognosis than normal EF, contradicting the intuitive assumption that higher EF equals better outcomes 4
• Diastolic dysfunction is the primary mechanism underlying adverse outcomes in this population 4
• Left atrial strain <18% is associated with increased LV filling pressure and adverse events, particularly relevant in patients with preserved or hyperdynamic EF 5