[The risks involved in the heart catheter examination. A retrospective evaluation of the complications after 700 examination. III. Irregularities of heart (author's transl)].

Disturbances of heart rhythm, observed during 700 heart catheterizations in infants and children, are discussed. Paroxysmal supraventricular tachycardia has been observed in 25 investigations (3,6%), sinus bradycardia in 18 (2,6%), junctional rhythm in 10 (1,4%), second degree AV-block in 9 (1,3%), ventricular fibrillation in 8 (1,1%), sinus tachycardia in 7 (1%), complete block in 7 (1%), asystole and atrial flutter in 2 (0,3%) each, and ventricular tachycardia in 1 (0,15%). Supraventricular tachycardia occurred equally in all ages without preference of a special malformation. The two patients with WPW-syndrome, however, showed this disorder in each of three catheterizations. Propranolol and verapamil succeeded in terminating the attacks. Junctional rhythm and sinus tachycardia presented equal behavior and benignity. Sinus bradycardia, second and third degree AV-block, and especially ventricular fibrillation occurred mostly in neonates and infants, many of them cyanotic and suffering from complex malformations and therefore needing multiple catheter manipulations. Bradycardia was in two, asystole in one of the very sick neonates associated with subsequent death within 24 hours. Once asystole resulted in immediate death after pulmonary angiography in a child with severe pulmonary hypertension. Ventricular fibrillation could be terminated promptly by DC countershock in all patients, but three of the children died subsequently. Complete block occurred only in children with systemic right ventricular pressure, 4 of the 7 patients having pulmonary hypertension, too. In two instances the block subsided spontaneously, the rest could successfully be treated with orciprenaline (Alupent R). Life threatening arrhythmias became less frequent as a consequence of earlier investigation, if severe heart disease was suspected, and by closer control of cyanosis, acidosis and temperature before, during, and after catheterization.