BACKGROUND: Susceptibility to ventricular arrhythmias and sudden cardiac death can be reduced by modulation of autonomic tone. Spinal cord stimulation (SCS) presumably affects autonomic tone and reduces myocardial ischemia. OBJECTIVE: The purpose of this study was to investigate whether SCS could reduce myocardial ischemia, infarct size, and ventricular arrhythmias as well as repolarization alterations in a porcine ischemia-reperfusion model. METHODS: Anesthetized common Landrace pigs were randomized to SCS (n = 10) or sham treatment (n = 10) before, during, and after 45 minutes of coronary occlusion. Area at risk, infarct size, and spontaneous ventricular arrhythmias were analyzed. Continuous three-dimensional vectorcardiograms was recorded and analyzed with respect to ECG intervals, ST-segment, and T-vector and T-vector-loop morphology. RESULTS: SCS was associated with significantly (P <.04) fewer episodes of nonsustained ventricular tachycardia (NSVT) and sustained ventricular tachycardia (SVT), particularly during mid-left anterior descending artery (LAD) occlusion (SCS vs non-SCS; NSVT, mid- and proximal LAD: 0 vs 22 and 45 vs 72; SVT, mid- and proximal LAD: 3 vs 15 and 5 vs 5). No difference in ventricular fibrillation episodes was observed. The SCS group had significantly less ST elevation (P <.03) but similar area at risk, infarct size, and ratio of infarct size/area at risk. Ischemia induced increases of T(amplitude) and T(area) suggesting increased repolarization gradients, which were significantly reduced by SCS (P <.01 for both). CONCLUSION: SCS appears to have an antiarrhythmic effect on spontaneous NSVT and SVT during ischemia-reperfusion in association with a reduction of repolarization alterations. Vectorcardiography signs of myocardial ischemia were reduced by SCS, but this intervention was not accompanied by any effect on infarct size.
BACKGROUND: Susceptibility to ventricular arrhythmias and sudden cardiac death can be reduced by modulation of autonomic tone. Spinal cord stimulation (SCS) presumably affects autonomic tone and reduces myocardial ischemia. OBJECTIVE: The purpose of this study was to investigate whether SCS could reduce myocardial ischemia, infarct size, and ventricular arrhythmias as well as repolarization alterations in a porcine ischemia-reperfusion model. METHODS: Anesthetized common Landrace pigs were randomized to SCS (n = 10) or sham treatment (n = 10) before, during, and after 45 minutes of coronary occlusion. Area at risk, infarct size, and spontaneous ventricular arrhythmias were analyzed. Continuous three-dimensional vectorcardiograms was recorded and analyzed with respect to ECG intervals, ST-segment, and T-vector and T-vector-loop morphology. RESULTS: SCS was associated with significantly (P <.04) fewer episodes of nonsustained ventricular tachycardia (NSVT) and sustained ventricular tachycardia (SVT), particularly during mid-left anterior descending artery (LAD) occlusion (SCS vs non-SCS; NSVT, mid- and proximal LAD: 0 vs 22 and 45 vs 72; SVT, mid- and proximal LAD: 3 vs 15 and 5 vs 5). No difference in ventricular fibrillation episodes was observed. The SCS group had significantly less ST elevation (P <.03) but similar area at risk, infarct size, and ratio of infarct size/area at risk. Ischemia induced increases of T(amplitude) and T(area) suggesting increased repolarization gradients, which were significantly reduced by SCS (P <.01 for both). CONCLUSION: SCS appears to have an antiarrhythmic effect on spontaneous NSVT and SVT during ischemia-reperfusion in association with a reduction of repolarization alterations. Vectorcardiography signs of myocardial ischemia were reduced by SCS, but this intervention was not accompanied by any effect on infarct size.
Authors: E Marie Southerland; David D Gibbons; S Brooks Smith; Adam Sipe; Carole Ann Williams; Eric Beaumont; J Andrew Armour; Robert D Foreman; Jeffrey L Ardell Journal: Auton Neurosci Date: 2012-04-11 Impact factor: 3.145
Authors: Marmar Vaseghi; Jean Gima; Christopher Kanaan; Olujimi A Ajijola; Alexander Marmureanu; Aman Mahajan; Kalyanam Shivkumar Journal: Heart Rhythm Date: 2013-11-28 Impact factor: 6.343