What is a hyper dynamic Left Ventricular Ejection Fraction (LVEF)?

Hyperdynamic Left Ventricular Ejection Fraction (LVEF)

A hyperdynamic LVEF is defined as a greater than normal proportion of blood within the left ventricular cavity being ejected during systole, typically characterized by an ejection fraction above 70%. 1

Definition and Characteristics

• According to the American College of Cardiology/American Heart Association/American Society of Echocardiography guidelines, hyperdynamic LVEF is a qualitative description of left ventricular systolic function where:
  • A greater than normal proportion of blood is ejected from the left ventricle during systole 1
  • Quantitatively, this typically means an LVEF exceeding 70% 2
  • It represents increased contractility of the left ventricle beyond normal parameters

Pathophysiology

Hyperdynamic LVEF can occur due to several mechanisms:

• Increased contractility: Hypercontractile state of the myocardium 3
• Reduced afterload: Decreased systemic vascular resistance leading to easier ejection 4
• Altered ventricular geometry: Smaller ventricular size with higher relative wall thickness 2

Clinical Significance

Despite appearing "super-normal," a hyperdynamic heart is not a normally functioning heart and has important clinical implications:

• Associated with diastolic dysfunction: 78% of patients with hyperdynamic LVEF demonstrate diastolic dysfunction 2
• Worse outcomes: Patients with hyperdynamic LVEF have reduced survival compared to those with normal EF (hazard ratio 1.56) 2
• Impaired ventriculo-arterial coupling: Patients with LVEF >60% may demonstrate a hypercontractile state with excessive LV afterload and diminished preload reserve 3

Common Causes

1. Hypertension: Leading to compensatory increased contractility
2. Volume depletion: Causing smaller ventricular volumes
3. High output states:
   • Sepsis (particularly with decreased systemic vascular resistance) 4
   • Anemia
   • Hyperthyroidism
4. Chronic diseases:
   • Chronic liver disease (independent risk factor) 4
   • Cancer (independent risk factor) 4

Clinical Associations

Patients with hyperdynamic LVEF often present with:

• Older age
• Female predominance
• Higher prevalence of hypertension, diabetes, and obesity
• Smaller ventricular size with higher relative wall thickness
• Higher heart rate
• Evidence of diastolic dysfunction (higher LV mass, larger left atrial volume, reduced relaxation, higher E/e' ratio) 2

Prognostic Implications

• In sepsis patients, hyperdynamic LVEF is associated with higher 90-day mortality (59.1%) compared to normal LVEF (24.9%) or low LVEF (32.5%) 4
• The mortality risk is positively correlated with vasoactive drug dose and negatively correlated with systemic vascular resistance 4

Clinical Pitfalls

• Mistaking hyperdynamic LVEF as a sign of excellent cardiac health, when it often represents a pathological state
• Failing to evaluate for underlying diastolic dysfunction in patients with hyperdynamic LVEF
• Not recognizing that a hyperdynamic heart may be a compensatory mechanism for an underlying disease process

A hyperdynamic LVEF should prompt thorough evaluation for underlying causes rather than being dismissed as a positive finding, as it often signals pathophysiological alterations that may require intervention.