Detection of intraoperative myocardial dysfunction by accelerometer during aortic valve replacement

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Myocardial dysfunction is a potential complication during weaning from cardiopulmonary bypass (CPB).
• Epicardial accelerometers have shown promise in monitoring myocardial ischemia during cardiac surgery.

Purpose of the Study:

• To investigate the utility of an accelerometer in detecting myocardial dysfunction during the weaning from CPB process.
• To compare accelerometer-based detection of myocardial dysfunction with established methods like echocardiography and pulmonary artery catheterization.

Main Methods:

• A three-axis accelerometer was attached to the left ventricle in 23 patients undergoing aortic valve replacement (AVR).
• 3D velocity, peak early systolic velocity (Vsys), and velocity at aortic valve closure (Vavc) were calculated.
• Measurements were taken before aortic cross-clamping and after cross-clamp removal, with myocardial dysfunction defined as Vsys < Vavc.

Main Results:

• The accelerometer identified myocardial dysfunction in 56% of patients during weaning from CPB, compared to 11% before cross-clamping.
• Patients with normal function showed improved left ventricular (LV) stroke work and systolic velocity post-AVR, unlike those with dysfunction.
• Accelerometer classification of normal function correlated with increased echocardiographic systolic velocity (r = 0.63, P < 0.01).

Conclusions:

• Epicardial accelerometers can effectively detect myocardial dysfunction during weaning from CPB.
• The accelerometer's findings align with those from echocardiography and pulmonary artery catheter measurements.
• This technology provides a valuable tool for continuous monitoring of cardiac function in critical surgical scenarios.