[Changes in sinoatrial node function in ischemic heart disease]

Seventy-nine patients with ischemic heart disease were examined. Weakness of the sinus node was suspected in 32 patients according to the clinical findings and the ECG; diagnostic atrial stimulation was conducted. Sinoatrial node potential was registered in the form of a spike in patients with ischemic heart disease. Direct stimulation from the region of the sinoatrial node was performed. The stimulator impulse was followed by a distinct potential of the sinoatrial node in the form of a spike which was continuous with the wave of atrial depolarization. The time of sinoatrial conduction (from the onset of the sinoatrial) node potential to the first atrial spike) was determined in 47 patients with ischemic heart disease. It was determined that under the effect of nitroglycerin the time of sinoatrial conduction becomes significantly shorter (reduced from 29 +/- 10.6 to 20 +/- 8.3 msec).