Left ventricular diastolic function and cardiac performance during exercise in patients with acromegaly

Area of Science:

• Cardiology
• Endocrinology
• Physiology

Background:

• Patients with acromegaly often exhibit exercise-induced impairment of left ventricular (LV) ejection fraction despite normal resting systolic function.
• The role of diastolic dysfunction in this abnormal exercise response remains unclear.

Purpose of the Study:

• To investigate the contribution of diastolic dysfunction to impaired cardiac adaptation during exercise in acromegaly patients.
• To identify factors influencing left ventricular ejection fraction at peak exercise.

Main Methods:

• Forty-eight active acromegaly patients underwent LV radionuclide angiography (rest and exercise) and Doppler echocardiography.
• Diastolic function was assessed using mitral and pulmonary flow velocity curves, including Delta duration.
• LV mass index was also evaluated.

Main Results:

• LV ejection fraction at peak exercise correlated with rest ejection fraction, peak filling rate, LV mass index, and Delta duration.
• Stepwise regression identified rest ejection fraction and Delta duration as independent predictors of peak exercise ejection fraction.
• Impaired LV diastolic function, indicated by Delta duration, was crucial for exercise performance.

Conclusions:

• Diastolic dysfunction plays a critical role in exercise cardiac performance in acromegaly patients with normal resting systolic function.
• Combined analysis of pulmonary vein and mitral flow velocity curves effectively identifies impaired LV diastolic function in this population.