Using near-infrared spectroscopy myocardial oximetry to monitor myocardial oxygen balance in a swine model of cardiac surgery: a descriptive study.

Monitoring of the adequacy of myocardial protection with cardioplegia is nearly non-existent in clinical cardiac surgical practice and instead relies on well-defined protocols for delivery of cardioplegia often resulting in inadequate protection. We hypothesized that Near Infrared Spectroscopy technology could be useful in the monitoring of the myocardial oxygen state by attaching the monitors to the epicardium in a porcine model of cardiac surgery. The experiments were conducted with 3 different protocols of 2 pigs each for a total of 6 pigs. The objective was to induce episodic, oxygen supply-demand mismatch. Methods for decreased supply included decreasing coronary blood flow, coronary blood hypoxemia, coronary occlusion, hypovolemia, and hypotension. Methods for increase demand included rapid ventricular pacing and the administration of isoproterenol. Changes in myocardial tissue oximetry were measured and this measurement was then correlated with blood hemoglobin saturations of oxygen from coronary sinus blood samples. We found that decreases in myocardial oxygen supply or increases in demand due to any of the various experimental conditions led to decreases in both myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood with recovery when the conditions were returned to baseline. Correlation between myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood was moderate to strong under all tested conditions. This may have translational applications as a monitor of adequacy of myocardial protection and the detection of coronary occlusion.

Multimodal neuromonitoring in pediatric cardiac anesthesia.

Despite significant improvements in overall outcome, neurological injury remains a feared complication following pediatric congenital heart surgery (CHS). Only if adverse events are detected early enough, can effective actions be initiated preventing potentially serious injury. The multifactorial etiology of neurological injury in CHS patients makes it unlikely that one single monitoring modality will be effective in capturing all possible threats. Improving current and developing new technologies and combining them according to the concept of multimodal monitoring may allow for early detection and possible intervention with the goal to further improve neurological outcome in children undergoing CHS.

Rapid ventricular pacing: a novel technique to decrease cardiac output for giant basilar aneurysm surgery.

A case of a 49 year old man with a giant basilar artery aneurysm requiring rapid ventricular pacing is presented. Rapid ventricular pacing decreased aneurysm size and increased operative exposure, which aided surgical decision making. It also provided decreased wall tension in the aneurysm.

A case of severe SAM following a David procedure.

We report a case of hemodynamically significant systolic anterior motion of the mitral valve following a David procedure. Although systolic anterior motion of the mitral valve has been reported following mitral valve repair or replacement and aortic valve replacement, it has not been previously described following isolated ascending aortic surgery.