[Evaluation of the ECG recording in abnormal positions of the heart in the thorax].

Abnormal localization of the heart in the chest is a rare congenital developmental disorder (1,10). Even if the heart is in these instances normally developed, its abnormal position leads in case of its affection by disease to diagnostic and therapeutic difficulties, in particular when an invasive procedure must be used. With regard to the entirely different position of individual cardiac departments it is necessary to differentiate carefully between dextrocardia and dextroversion (15). Dextroposition is only a marginal problem. A very satisfactory diagnostic method in these anomalies is the ECG tracing, where we encounter quite typical pictures. Dextrocardia and dextroversion are characterized by a similar mirror image reversed tracing in the leads from the extremities. It differs, however, fundamentally in the chest lead tracings. In dextrocardia during tracing of standard thoracic leads we follow the predominant negative QRS complex in all leads; when including the dextrolateral thoracic leads the curve "becomes normal". In dextroversion, with regard to the anterior position of the left ventricle the dominating finding is a high R wave in all leads from the left and right side of the chest.