EFFECT OF ATRIOVENTRICULAR SEQUENTIAL PACING ON LEFT-VENTRICULAR FLOWDYNAMICS IN A PATIENT WITH MID-VENTRICULAR OBSTRUCTION

The effect of dual chamber atrioventricular sequential pacing on the i ntraventricular pressure gradient was tested using Doppler echocardiog raphy in a patient with hypertrophic mid-ventricular obstruction. Atri oventricular sequential pacing with relatively short atrioventricular delays reduced in the left ventricular pressure gradient at the mid-ve ntricular level. Also, atrioventricular sequential pacing affected the degree and profile of the isovolumetric relaxation flow. These result s suggest that atrioventricular sequential pacing affects both systoli c and diastolic left ventricular flow dynamics in mid-ventricular obst ruction.