CARDIAC-RHYTHM STRUCTURE IN PATIENTS WITH ISCHEMIC-HEART-DISEASE AND VENTRICULAR ARRHYTHMIAS

ECG at rest and at exercise (veloergometer), 24 hour ECG (Holter) and transesophageal cardiac pacing were performed in 60 patients with ischemic heart disease and stable angina (mean age 55,4+/-8, 5 years). 18 patients had ventricular premature beats and 12 - ventricular tachicardia. Autonomic regulation of the heart was assessed by mathematical analysis of 100 or more consequtive RR intervals recorded at rest. The following parameters of dispersion analysis were calculated: coefficient and amplitude of variation, mode and amplitude of mode. Spectral characteristics of rhythm were used for calculation of two secondary parameters - index of stress and index of centralisation. Results of this study show that in patients with ischemic heart disease and ventricular premature beats mathematical analysis of rhythm at rest reveals increased variability of cardiac rhythm and enhanced centralisation of its control. In patients with ventricular tachycardia such analysis reveals a shift of autonomic nervous system balance towards its sympathetic part.