[Effect of dipyridamole on the functional state of the atrioventricular node]

Effect of dipyridamole on sinoatrial node function was evaluated in 24 patients during invasive cardiac electrophysiological examination. 3 multipolar USCI electrodes were inserted into the heart through femoral veins using Seldinger's method. Intracardiac potentials (A, H, V) and ecg tracings (I, II, III, aVR leads) were recorded during sinus rhythm and right atrial stimulation - continous, with gradually increasing pacing frequency and during extrastimulation, with gradually shortening of coupling interval. 0.5 mg/kg b.w. of dipyridamole (Curantyl, Germed, GDR) was intravenously administrated. During the initial examination and 5 minutes after the end of a drug injection following parameters were estimated: sinus cycle length (SCL), sinoatrial conduction time using Narula's and Strauss's methods (respectively SACTN, SACTS), maximal, corrected and standardized sinus node recovery time (respectively SNRTmax, SNRTcor, SNRTnorm) and maximal second postimulation pause (II pause max). Statistically significant (p less than 0.01) shortening of SCL by 26%, SACTN by 17%, SACTS by 13% SNRT max by 21%, II pause max by 26% was observed after dipyridamole administration. Only in the patient with sinoatrial node dysfunction dangerous bradycardia occurred.