PRECORDIAL LEADS QRST TIME INTEGRALS FOR EVALUATION OF RIGHT-VENTRICULAR OVERLOAD IN CHILDREN WITH CONGENITAL HEART-DISEASES

It was previously shown that body surface QRST isointegral maps of the anterior chest were abnormal in patients with right ventricular overl oad and that the abnormalities varied with hemodynamic status. The QRS T isointegral maps were first characterized by using a departure index map for normal controls. The study group consisted of 14 patients wit h pulmonary stenosis (PS), 20 with tetralogy of Fallot, (TOF) and 43 w ith atrial sep:al defect (ASD). The QRST isointegral maps of these thr ee groups were compared with the data on 23 to 65 age-matched normal c hildren. In mean departure index maps, the patients with right ventric ular pressure overload (PS or TOF) showed an increase in departure ind ex on the anterior midchest, while those of right ventricular volume o verload (ASD) showed two maxima on the anterior and left lateral chest , with a trough-like negative area between them. Since the abnormal fi ndings were seen on the anterior chest, we evaluated the diagnostic us efulness of QRST time integral values for precordial leads of the rout ine electrocardiogram (EGG) in a second part of this study. The precor dial QRST time integral values from 9 patients with PS and 11 with TOF (0-2 years of age, mean 1.1 years) and 22 ASD patients (6-15 years, m ean 10.1 years) were compared with those of the age-matched control ch ildren. The QRST time integral values of the precordial leads in right ventricular pressure overload were significantly increased in the rig ht precordial leads (V-1, V-2) In right ventricular volume overload, t he QRST time integral values of the V-1, V-2, V-4, and V-6 leads demon strated a significant deviation from those of the control group. There fore, a discrimination formula was constructed by using the values of these leads, and the criteria derived from this formula revealed good (98%) diagnostic accuracy. In detection of right ventricular overload, the QRST time integral values of the precordial lead EGG, if confirme d in a larger data set, may be useful as a simple screening method.