Atrial volume and function during exercise in health and disease

Area of Science:

• Cardiovascular Physiology
• Medical Imaging
• Pulmonary Hypertension Research

Background:

• Atrial function is prognostically significant in cardiovascular diseases.
• Exercise-induced changes in atrial function have not been previously assessed.
• Understanding atrial behavior during exercise is crucial for diagnosing and managing cardiovascular conditions.

Purpose of the Study:

• To evaluate left atrial (LA) and right atrial (RA) volume and function during incremental exercise.
• To compare these changes in healthy non-athletes, athletes, and patients with chronic thromboembolic pulmonary hypertension (CTEPH).
• To determine the clinical significance of exercise-induced atrial remodeling.

Main Methods:

• Multi-slice real-time cardiovascular magnetic resonance imaging (CMR) was used.
• Assessments were performed at rest and during supine bicycle exercise.
• Simultaneous invasive hemodynamic measurements were obtained in 15 healthy non-athletes, 15 athletes, and 15 CTEPH patients.

Main Results:

• Athletes exhibited larger indexed maximal RA and LA volumes at rest compared to CTEPH patients and non-athletes.
• CTEPH patients showed reduced RA and LA emptying function (EmF) at rest and impaired exercise-induced increases in RAEmF and LAEmF.
• Peak exercise RAEmF and indexed minimal LA volume (iLAVmin) were independent predictors of peak oxygen consumption (VO2peak) in CTEPH patients.

Conclusions:

• Normal physiology involves increased RAEmF and LAEmF with exercise, which is impaired in CTEPH patients.
• Exercise-induced changes in atrial volumes and function better distinguish physiological from pathological remodeling than resting measures.
• Peak exercise RAEmF serves as a valuable marker for assessing the functional status in CTEPH patients.