Arrhythmias in Primary Pulmonary Hypertension

Through the examination of 171 electrocardiograms (ECG) of 101 patients with primary pulmonary hypertension (PPH), the following conclusions were obtained. Arrhythmias were found in 27 (26.7%) of the 101 patients. Among the surviving cases, arrhythmias were found in 8 (17.8%) out of 45 patients, but among the decreased cases, the figure was higher, 19 (33.9%) out of 56. There were instances of more than one kind of arrhythmias in the same patient and a total of 34 types of arrhythmias were noted. The main types of arrhythmias were sinus tachycardia (13 cases), sinus bradycardia (6 cases), and first degree A-V block (5 cases), which accounted for 70% of the total. Sinus tachycardia was observed in only 2 of the survivors but in 11 of the decreased cases, which showed a significant difference (p less than 0.05). First A-V block were all induced by digitalis. Wenckebach type of second degree A-V block was noted in only 1 case and it was also induced by digitalis. Since severe attacks of ventricular arrhythmias were very rare in these cases with PPH, it is difficult to consider the Adams-Stokes syndrome as the cause of syncopal attacks or sudden death. However, it is necessary to further investigate nodal functions by means of continuous ECG monitoring, the overdrive suppression test and His bundle ECGs.