TY - JOUR T1 - Ambulatory electrocardiographic monitoring in 100 healthy teenage boys. JF - British Heart Journal JO - Heart SP - 179 LP - 183 DO - 10.1136/hrt.51.2.179 VL - 51 IS - 2 AU - D F Dickinson AU - O Scott Y1 - 1984/02/01 UR - http://heart.bmj.com/content/51/2/179.abstract N2 - Ambulatory monitoring of the electrocardiogram in 100 healthy 14 to 16 year old boys showed heart rates ranging from 45 to 200 beats/minute during the day and from 23 to 95 beats/minute during sleep. Sinus arrhythmia was present in all cases and was the only variation noted in 17%. Sudden variations in the PP interval occurred in 41%, but a precise diagnosis of the mechanism was usually impossible; 15% had changes compatible with sinus arrest or temporary complete sinoatrial block, and one boy had a pattern compatible with type II second degree sinoatrial block. Escape rhythms were noted in 26%, first degree atrioventricular block in 12%, and second degree atrioventricular block (Mobitz type I) in 11%. Mobitz type II second degree atrioventricular block was seen on one occasion in one boy. Ventricular extrasystoles seen in 41% were of uniform morphology in 75% and multiform in 25%. Short episodes of ventricular tachycardia were recorded in 3%. ER -