Clinical aspects of preconditioning and implications for the cardiac surgeon

Transient ventricular asystole using adenosine during minimally invasive and open sternotomy coronary artery bypass grafting

BACKGROUND

The emergence of minimally invasive coronary artery bypass grafting and recent off-pump open sternotomy clinical reports have refocused attention on the technical aspects and outcome of grafting on the beating heart.

METHODS

To optimize the surgical field we report a method using adenosine for induction of controlled intervals of ventricular asystole to produce a transiently still cardiac field that facilitates anastomotic accuracy.

RESULTS

Adenosine was used in 57 patients, 31 included off-pump coronary artery bypass grafting (27 by minimally invasive technique, 4 by open sternotomy). In a further 26 patients adenosine pauses were used for suture placement to control anastomotic bleeding after cardiopulmonary bypass. Average adenosine boluses per anastomosis were 9 (6-14), mean dose of adenosine per bolus (mg/kg) was 0.24 (0.15-0.35), mean duration of pause (seconds) was 6 (3-19), and mean time for arterial blood pressure (mean) to return to baseline (seconds) was 35 (13-48). Presence of repolarization arrhythmias was noted in 1 patient. There were no deaths. Two patients had recurrent myocardial ischemia shown on angiography to be the result of technical problems.

CONCLUSIONS

This report describes our experience with the emerging procedure of minimally invasive coronary operations and off-pump grafting with the adenosine technique. The method also includes mechanical devices and other pharmacological therapy to optimize the surgical field, and the technique has now become a standard component of our off-pump revascularization methods.