Electrocardiogram PR Interval Is a Surrogate Marker to Predict New Occurrence of Atrial Fibrillation in Patients with Frequent Premature Atrial Contractions

The clinical significance of prolonged PR interval has not been evaluated in patients with frequent premature atrial contractions (PACs). We investigated whether prolonged PR interval could predict new occurrence of atrial fibrillation (AF) in patients with frequent PACs. We retrospectively analyzed 684 patients with frequent PACs (> 100 PACs/day) who performed repeated 24-hour Holter monitoring. Prolonged PR interval was defined as longer than 200 msec. Among 684 patients, 626 patients had normal PR intervals (group A) and 58 patients had prolonged PR intervals (group B). After a mean follow-up of 59.3 months, 14 patients (24.1%) in group B developed AF compared to 50 patients (8.0%) in group A (P < 0.001). Cox regression analysis showed that prolonged PR interval (hazard ratio [HR], 1.950; 95% CI, 1.029-3.698; P = 0.041), age (HR, 1.033; 95% CI, 1.006-1.060; P = 0.015), and left atrial (LA) dimension (HR, 1.061; 95% CI, 1.012-1.112; P = 0.015) were associated with AF occurrence. Prolonged PR interval, advanced age, and enlarged LA dimension are independent risk factors of AF occurrence in patients with frequent PACs.

Two Cases of Neonatal Arrhythmia Observed by Fetal Echocardiography / 대한주산의학회잡지

M-mode, pulsed Doppler and Doppler color flow mapping, in addition to two-dimensional echocardiography, have greatly improved imaging of the fetal heart through identification of abnormal cardiac anatomy and rhythm in utero. The early detection of cardiac disturbance in utero permits alteration in obstetric management such as delivery in a high-risk center for optimal neonatal care and/or decision in optimal delivery time. We report two cases of the neonatal arrhy-thmia which were observed by fetal echocardiography. In the first case, female baby showed neonatal arrhythmias including tachycardia and brady-cardia until 3 days after birth, and then turned to bradyarrhythmia due to non-conducted atrial bigeminy. These events lead us to review the fetal echocardiographs of the patient carefully. Premature atrial contractions were observed in her fetal echocardiography. At 2 months after birth, the patient's electrocardiogram showed normal sinus rhythm. Severe neonatal bradycardia of the second case was due to congenital complete heart block, identified clearly by electrocardiogram after birth. This case also showed complete heart block in her fetal echocardiography. After insertion of the temporary pacemaker, cardiomegaly was improved. Both the neonate and the mother had positive anti-SSA/Ro autoantibody. But any other symptoms and signs of neonatal lupus did not appear in the neonate. Patient's mother also did not show any symptoms and signs of systemic lupus erythematosus. Since the prognosis depends upon the cause of bradyarrhythmia in fetus and neonates, differential diagnosis is important in obstetric management and optimal neonatal treatment.