[Deep Q waves in the ECG of children--an electro-, vector- and echocardiographic study].

Out of 9557 children we found 120 children (1,26%), who showed deep Q-waves of greater than or equal to 0.4 mV in 3 consecutive ECG's at least in one of the leads I, aVL, V4, V5 and V6. 70 children were investigated additionally by echocardiography, 45 by vectorcardiography according to Frank. Echocardiography revealed an increased septal thickness in 5 patients, a borderline thickness in 8, an increased septal/posterior wall ratio in 4. In the vectorcardiogram 51,1% of the patients had no Q-waves in lead y, mostly in combination with deep Q-waves in a VL or left axis deviation. Q-waves in lead y were combined with Q-waves in V 5/6. The determination of the main axis coincided in 80% of ECG and VCG. Looking for the various heart diseases, 30% of the children with Q-waves had a ventricular septal defect, 23,3% an endocardial cushion defect, 10,8% a patent ductus arteriosus, 3,3% a bradycardia, 2,5% a Bland-White-Garland syndrome and 1,6% a hypertrophic cardiomyopathy. 17,5% of the children had an innocent heart murmur, 5,8% no cardiac symptoms. Other diseases were found in 5%. The most frequent cause of Q-waves in children were volume-overload of the left ventricle (35%) and left axis deviation (33,3%), whereas myocardial infarction and septal hypertrophy (3,3 and 4,1%) were of minor importance. In healthy children (23,3%) we could not find any pathomechanism.