The study was designed to elucidate the wave structure of heart rhythm variability (HRV) for the assessment of vegetative regulation of pacemaker activity of the sinoatrial node in 362 patients with coronary heart disease. The results were compared with the data of routine cardiologic examination. Sinus node dysfunction and weakness were shown to be accompanied by differential autonomous dysregulations that may be used as additional symptoms for the diagnosis of arrhythmias. Precision analysis of HRV permits to evaluate the arrhythmogenic events behind vegetative regulation of the sinus node, hemodynamic significance of arrhythmic episodes, and dependence of sinoatrial blockade on the degree of autonomous dysregulation. Autonomous cardioneuropathy syndrome is distinguished, its association with necrobiotic changes in the sinus node is demonstrated by electron microscopy.