[Comparison of 24 hours ambulatory electrocardiography and endocavitary recording in the diagnosis of heart rate disorders].

Ninety symptomatic patients aged between 16 and 90 years were investigated by ambulatory continuous 24 hour electrocardiography. 75 of these patients underwent endocavitary exploration of atrioventricular conduction and sinus node function within 48 hour of ambulatory electrocardiography. Symptoms occurred during the recording in 30% patients, enabling the mechanism of the malaise to be determined. Every time that abnormalities in the zone surrounding the Tawara node were demonstrated by endocavitary recordings, the 24 hour electrocardiogramme showed the symptoms to be due to other causes than complete heart block. In 70% patients no symptoms were experienced but 58% of them had cardiac arrhythmias and particularly sinus node dysfunction (24 out of 37 patients) on the 24 hour electrocardiogramme. Comparing the results of these two methods of investigation, continuous electrocardiography appears to be a better technique for the diagnosis of sinus node dysfunction but endocavitary study of sinus node function would seem more suited to determine its severity. Endocavitary recordings seem more reliable in the investigation of paroxysmal atrioventricular blocks. These results demonstrate the complementary nature of these two methods in determining the causes of syncope and dizziness.