Potentiation of right ventricular function at a reduced workload: a potential pitfall in assessing right ventricular...

Area of Science:

• Cardiology
• Nuclear Cardiology
• Exercise Physiology

Background:

• Right ventricular ejection fraction (RVEF) assessment is vital for detecting exercise-induced RV dysfunction.
• Patient limitations in achieving peak cardiac workloads can complicate exercise RVEF studies.
• The impact of reduced exercise workloads on RVEF remains understudied compared to its effect on LV function.

Purpose of the Study:

• To investigate the effect of sub-peak exercise workloads on RVEF in normal individuals and patients with coronary artery disease (CAD).
• To determine if RVEF changes at reduced post-peak exercise levels and its implications for interpreting exercise RV studies.

Main Methods:

• Supine exercise radionuclide ventriculography was performed on 26 participants (9 normal, 17 CAD).
• Gated RVEF was measured at rest (R), peak exercise (P), and a reduced post-peak workload (PP) approximately 40% below peak.
• Sequential left anterior oblique views were utilized for RVEF acquisition.

Main Results:

• In normal subjects, RVEF increased from rest (27%) to peak (38%) and post-peak (44%).
• In CAD patients, RVEF increased from rest (31%) to peak (35%) and post-peak (39%).
• RVEF showed improvement from rest to PP levels in both groups and from P to PP levels in normals.

Conclusions:

• RVEF demonstrates improvement at reduced post-peak exercise workloads in both healthy individuals and those with CAD.
• These findings necessitate consideration of sub-peak exercise effects when interpreting exercise RV studies for CAD detection.
• Understanding RVEF response to varying exercise intensities enhances diagnostic accuracy in cardiovascular assessments.