[Evaluation of left ventricular diastolic function during coronary artery bypass grafting by color M-mode Doppler...

Area of Science:

• Cardiology
• Cardiac Surgery
• Echocardiography

Background:

• Left ventricular diastolic dysfunction is a critical concern in patients with coronary artery disease.
• Coronary artery bypass graft surgery (CABG) involves cardiopulmonary bypass (CPB) and cardioplegic arrest, potentially impacting cardiac function.
• Understanding the effects of CABG on diastolic function is crucial for patient outcomes.

Purpose of the Study:

• To evaluate the impact of CABG and cardioplegic arrest on left ventricular diastolic function.
• To assess changes in diastolic parameters before and after CPB.
• To investigate the relationship between specific Doppler-derived measurements and diastolic function.

Main Methods:

• Transesophageal Doppler echocardiography was used in 10 patients with coronary artery disease.
• Key measurements included peak early filling velocity (peak E), peak atrial contraction velocity (peak A), and the E/A ratio.
• Color M-mode Doppler assessed the rate of propagation of peak early filling flow velocity (FPV).
• Measurements were taken pre-sternotomy, post-sternotomy, post-CPB, and post-sternal closure.

Main Results:

• The E/A ratio significantly decreased after sternotomy and did not recover to pre-CPB levels.
• The FPV significantly increased after CPB.
• A significant correlation was found between FPV and E/A ratio both pre- and post-CPB.
• After adjusting for heart rate, the corrected E/A value showed a significant increase post-CPB compared to pre-CPB.

Conclusions:

• Coronary artery bypass graft surgery, specifically after cardiopulmonary bypass, appears to improve left ventricular diastolic function.
• The observed increase in FPV and heart-rate-corrected E/A suggests enhanced diastolic filling post-CABG.
• These findings highlight a potential positive effect of the surgical procedure on diastolic mechanics.