[the Electrocardiogram in the Tetralogy of Fallot].

The features of the standard limb lead electrocardiogram in the tetralogy of Fallot were described by Baker et al. (1949). In all except the earlier cases at Guy's Hospital unipolar limb and chest leads have also been recorded. The purpose of this paper is to present their characteristics in 52 cases in which the diagnosis was well established. In 15 cases the diagnosis has been confirmed by post-mortem examination: some of these and all the others were operated on by Mr. R. C. Brock with either a systemic-pulmonary anastomosis, a pulmonary valvulotomy, or an infundibular resection, and most were investigated by cardiac catheterization or angiocardiography before operation. The ages of the patients were 3-10 years in 32, 11-20 years in 18, 24 years in 1, and 34 years in the last. All the records were taken with the Sanborn visocardiette direct-writing electrocardiograph. In 38 cases the unipolar leads comprised aVR, aVL, aVF, and VI to V6, while in the remaining 14 aVL, aVF, VI, Y3 and V5 were recorded. In 7 cases leads were also taken to the right of VI. P Wave. As has already been noted by Baker et al. (1949), tall pointed P waves are a striking feature in the standard leads, especially in lead II (Fig. 1). In these 52 cases Pll varied from 1 mm. to 5 mm. in height, with an inversion of 2 mm. in one case. In 35 per cent the height was of 2-5 mm. or more (Table I).