Change in right ventricular function during off-pump coronary artery bypass graft surgery

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Critical Care Medicine

Background:

• Off-pump coronary artery bypass graft (OPCAB) surgery aims to reduce myocardial injury by avoiding cardiopulmonary bypass.
• Hemodynamic instability during OPCAB may be linked to right ventricular (RV) dysfunction.
• Accurate assessment of RV function is vital for managing patients undergoing OPCAB.

Purpose of the Study:

• To evaluate right ventricular (RV) function and hemodynamic alterations during off-pump coronary artery bypass graft (OPCAB) surgery.
• To determine the impact of heart displacement for anastomosis on RV performance.
• To assess the utility of a thermodilution pulmonary artery catheter for continuous monitoring.

Main Methods:

• Prospective study of 30 patients undergoing OPCAB.
• Continuous monitoring of cardiac output (CO), right ventricular ejection fraction (RVEF), and RV volume using a thermodilution pulmonary artery catheter.
• Hemodynamic variables measured at baseline, during coronary anastomosis, and post-sternal closure.

Main Results:

• No significant changes in RVEF or cardiac index during left anterior descending and right coronary artery anastomoses.
• Significant reduction in RVEF, increased RV afterload, and decreased CO during obtuse marginal artery anastomosis.
• Increased right atrial pressure observed during all coronary anastomoses; RV volumes remained stable.

Conclusions:

• Displacement of the beating heart for obtuse marginal artery anastomosis significantly impairs RV function and reduces CO.
• Continuous monitoring with a thermodilution catheter effectively tracks changes in RV function and volume during OPCAB.
• This monitoring aids in managing potential hemodynamic derangements during OPCAB surgery.