Right ventricular systolic function during exercise with and without significant coronary artery disease

Area of Science:

• Cardiology
• Physiology
• Exercise Science

Background:

• Right ventricular (RV) systolic function is crucial for overall cardiac performance.
• The impact of coronary artery disease (CAD) on RV function during exercise is not fully understood.
• Assessing RV systolic function provides insights into cardiac adaptation to stress.

Purpose of the Study:

• To evaluate the effects of exercise and coronary artery disease on right ventricular (RV) systolic function.
• To differentiate the impact of CAD severity on RV response to exercise.
• To identify the underlying mechanisms responsible for changes in RV function during exercise in CAD patients.

Main Methods:

• Rest and exercise biplane RV angiograms were recorded in 20 patients undergoing cardiac catheterization.
• Thirteen patients with analyzable angiograms were divided into two groups based on CAD severity.
• RV systolic pressure, pulmonary resistance, and RV ejection fraction were measured at rest and during exercise.

Main Results:

• RV systolic pressure increased significantly in both groups during exercise.
• Pulmonary resistance increased significantly in the significant CAD group but not in the mild CAD group.
• RV ejection fraction decreased significantly in the significant CAD group during exercise (73% to 58%), correlating with increased pulmonary resistance.

Conclusions:

• Significant coronary artery disease leads to a decline in right ventricular ejection fraction during exercise.
• The observed reduction in RV ejection fraction is primarily attributed to increased afterload (pulmonary resistance), not direct RV ischemia.
• These findings highlight the importance of assessing RV function in patients with CAD undergoing exercise stress.