Clinical investigation is a fundamental component of the activities of the Electrophysiology Service. A computerized database which includes clinical and electrophysiologic data on over 5800 patients is maintained and has been of invaluable assistance to faculty and fellows performing prospective and retrospective clinical investigations. The Electrophysiology Service has participated in a number of NIH and industry sponsored clinical trials including: MUSTT, AFFIRM, MOST, TOVA, and Companion, as well as trials to evaluate antiarrhythmic drugs. Other investigations in the EP lab involve modalities that may improve the safety and efficacy of radiofrequency ablation. The clinical EP faculty members are well-versed with the use of intracadiac ultrasound catheter for AF ablation and are in the process of evaluating 3-dimensional intracardiac echo technology. Finally, Dr. Joseph Akar is interested in examining clinical outcomes of patients with implantable devices. As member of the Yale-New Haven Hospital Center for Outcomes Research and Evaluation (YNHH/CORE), Dr. Akar is investigating the determinants of use of device remote monitoring technology and its effect on long-term morbidity and mortalit. He is also leads the analytic team for the MADIT-CRT Post-market Approval Study from within YNHH/CORE.

On a more basic clinical level, Dr. Rachel Lampert has explored the physiologic links between psychological stress and arrhythmias. Following a recent investigation of the effects of mental stress on arrhythmias in patients with monomorphic ventricular tachycardia, a study of the electrophysiologic and nervous system mechanisms of these effects is underway. The prognostic import of mental stress testing, including a possible role in risk-assessment, is also under evaluation. A second related area of interest involves heart rate variability, a non-invasive measure of autonomic nervous system function, which may provide a measure of the physiologic impact of stress. Studies correlating socioeconomic status and heart rate variability, and examining the predictive value of changes in heart rate variability with stress, are ongoing. The influences of gender on arrhythmias are also under investigation.

Finally, basic mechanisms of arrhythmogenesis are actively investigated. Using molecular imaging targeted to matrix metalloprotease activity, the development of atrial structural remodeling is being non-invasively imaged and correlated with the development of the arrhythmogenic substrate. This novel and exciting approach holds great potential for a better understanding of arrhythmogenesis.