Left Atrial Function Dynamics During Exercise in Heart Failure: Pathophysiological Implications on the Right Heart...

Area of Science:

• Cardiology
• Cardiopulmonary Exercise Testing
• Echocardiography

Background:

• Left atrial (LA) function is crucial for heart failure hemodynamics (HFrEF and HFpEF).
• LA dynamics are primarily studied at rest, limiting understanding of exercise-related changes.

Purpose of the Study:

• To investigate the hypothesis that impaired LA dynamics during exercise contribute to right ventricular-pulmonary circulation (RV-PC) uncoupling and ventilation inefficiency.
• To assess LA strain and RV-PC coupling during exercise in heart failure patients and healthy controls.

Main Methods:

• Prospective enrollment of 49 HFrEF patients, 20 HFpEF patients, and 32 healthy controls.
• Cardiopulmonary exercise testing with echo-Doppler assessment of LA strain and RV-PC coupling at rest, during exercise, and recovery.
• Measurement of LA strain, LA strain rate, and RV-PC coupling ratio (pulmonary arterial systolic pressure/tricuspid annular peak systolic excursion).

Main Results:

• Healthy controls showed increased LA strain during exercise and recovery.
• HFpEF patients had some LA strain increase, while HFrEF patients showed no change.
• Impaired LA strain and RV-PC uncoupling correlated significantly with ventilation inefficiency (VCO2 slope) across all groups.

Conclusions:

• Impaired LA strain response during exercise is a key factor in RV-PC uncoupling and ventilation inefficiency in heart failure (HFpEF and HFrEF).
• LA dynamics during exercise represent a potential therapeutic target for improving exercise capacity in heart failure.