Left heart failure with a normal ejection fraction: identification of different pathophysiologic mechanisms

Area of Science:

• Cardiology
• Internal Medicine
• Physiology

Background:

• Heart failure with normal ejection fraction (HFNEF) is clinically heterogeneous.
• Diastolic dysfunction is often cited as the sole cause of HFNEF.
• This study investigates potential differing pathophysiologic mechanisms within HFNEF.

Purpose of the Study:

• To identify distinct pathophysiologic subgroups within HFNEF patients.
• To differentiate mechanisms in hypertensive HFNEF versus non-hypertensive HFNEF.
• To analyze cardiac contractility and volume dynamics in HFNEF subgroups.

Main Methods:

• Utilized freehand 3-dimensional echocardiography to assess left ventricular volumes.
• Measured end-systolic and end-diastolic pressures via Doppler and sphygmomanometry.
• Calculated pressure-volume loops and end-systolic pressure-volume relationship slope (Ees,sb) as a measure of contractility.

Main Results:

• Non-hypertensive HFNEF patients required high end-diastolic pressures for normal volumes, with normal systolic function.
• Hypertensive HFNEF patients showed increased end-diastolic pressure and volumes.
• Two hypertensive HFNEF subgroups emerged: one with high Ees,sb (elderly women, small body size, concentric remodeling) and one with normal Ees,sb (volume overload characteristics).

Conclusions:

• HFNEF comprises subgroups with distinct pathophysiologies, not solely diastolic dysfunction.
• Hypertensive HFNEF patients can be further categorized based on systolic function and cardiac remodeling.
• These findings challenge the monolithic view of HFNEF and highlight the need for personalized therapeutic approaches.