Effect of right ventricular pacing on cardiac apex rotation assessed by a gyroscopic sensor.
To quantify cardiac apex rotation (CAR), the authors recently proposed the use of a Coriolis force sensor (gyroscope) as an alternative to other complex techniques. The aim of this study was to evaluate the effects of right ventricular (RV) pacing on CAR. A sheep heart was initially paced from the right atrium to induce a normal activation sequence at a fixed heart rate (AAI mode) and then an atrioventricular pacing was performed (DOO mode, AV delay = 60 ms). A small gyroscope was epicardially glued on the cardiac apex to measure the angular velocity (Ang V). From AAI to DOO pacing mode, an increase (+9.2%, p < 0.05) of the maximum systolic twisting velocity (Ang VMAX) and a marked decrease (-19.9%, p < 0.05) of the maximum diastolic untwisting velocity (Ang VMIN) resulted. RV pacing had negligible effects (-3.1%, p = 0.09) on the maximum angle of CAR, obtained by integrating Ang V. The hemodynamic parameters of systolic (LVdP/dtMAX) and diastolic (LVdP/dtMIN) cardiac function showed slight variations (-3.8%, p < 0.05 and +3.9%, p < 0.05, respectively). Results suggest that cardiac dyssynchrony induced by RV pacing can alter the normal physiological ventricular twist patterns, particularly affecting diastolic untwisting velocity.
Marcelli
Emanuela
E
Surgery and Transplantation Department, University of Bologna, Italy.
Cercenelli
Laura
L
Parlapiano
Mario
M
Fumero
Roberto
R
Bagnoli
Paola
P
Costantino
Maria Laura
ML
Plicchi
Gianni
G
D000818:Animals; D003971:Diastole / Q000502:physiology; D005260:Female; D006321:Heart / Q000502:physiology*; D006334:Heart Function Tests / Q000295:instrumentation*; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles; D020007:Implants, Experimental; D010138:Pacemaker, Artificial; D012756:Sheep; D013599:Systole / Q000502:physiology