Clinical studies of the partial atrial electrical standstill : electrophysiological, hemodynamic and pathological study

Seven out of 363 cases that received electrophysiological study were found to have partial atrial electrial standstill. The clinical and pathological features of the 7 cases were examined. The results were as follows. 1) Of the seven patients, there were three with cardiomyopathy, two with sick sinus syndrome, one with mitral stenosis and regurgitation, and one with mitral regurgitation. 2) Six of the patients complained of exertional dyspnea, three complained of dizziness and syncope and one complained of palpitation. 3) On the surface electrocardiogra, the atrial acrivity had a tendency to be low and narrow. 4) The region that received the most injury was the higt right atrium, while the region near the coronary sinus was left almost intact. 5) The right ventricular endocardial biopsy was performed upon five patients. The pathological examinations of the right ventricular endocardium revealed abnormal findings in all five patients. The pathological region may extend not only to the atrial myocrdium but also to the ventricular myocardium. The present study showed that partial atrial electriacl staudstill had severe symptoms Further examinations and more detailed information for this disease is needed.