Abstract 13943: Alterations in Left Ventricular Twist Mechanics and Regional Strain by Speckle Tracking Echocardiography During Cardiac Sympathetic Stimulation
Background— Left ventricular (LV) twist mechanics and regional strain during cardiac sympathetic efferent activation are poorly understood. The purpose of this study was to compare the effects of stimulation of the left and right stellate ganglia (LSG and RSG) on cardiac twist mechanics and regional radial strain.
Methods and Results— In nine pigs, simultaneous echocardiographic imaging and LV pressure-volume measurements were performed before and during either LSG or RSG stimulation. Both LSG and RSG stimulation significantly augmented LV end systolic pressure 36% and 46%, respectively (P<0.01), dP/dtmax 235% and 256% (P<0.01), and time constant of LV relaxation 21% and 50% (P<0.01). RSG stimulation resulted in a greater chronotropic response than LSG stimulation (RSG 68% vs. LSG 12%, P<0.01). Both LSG and RSG stimulation increased global apical systolic twist and diastolic untwisting rate, and reduced apical time to peak twist and time to peak untwisting rate. However, LSG stimulation increased radial strain in LV posterior, inferior, and septal regions, whereas RSG stimulation increased radial strain in anterior septal and anterior regions (see table).
Conclusions— Both LSG and RSG stimulation can alter LV systolic and diastolic function and cardiac twist mechanics; however, LSG and RSG stimulation result in specific regional strain patterns, suggesting nerves originating from LSG control posterior, inferior, and septal regions of LV, whereas RSG controls anterior septal and anterior regions. These findings provide a better understanding of regional myocardial innervations from the left and right stellate ganglia.
- © 2011 by American Heart Association, Inc.