[Hybrid ECG and its clinical significance for the detection of coronary heart disease]. / Das Hybrid-Ekg und seine klinische Bedeutung für die Erfassung der koronaren Herzkrankheit.

451 male patients with typical or atypical angina pectoris syndrome were examined and on account of the degree of severity of the coronary stenosis are subdivided into four groups. With the help of the discriminance analysis of a hybrid ECG (conventional and body surface ECG after Frank) the patients were coordinated to these four groups, in order to test its clinical valency for the recognition of the coronary heart disease. It was stated that in a scalar interpretation of the body surface ECG in every case the conventional leads V3 and/or II after Einthoven must additionally be registered and evaluated. In a scalar and vectorial interpretation of the body surface ECG a significant gain of information was possible only by taking into consideration a great number of scalar parameters of the conventional ECG. The result of the discriminance analysis with the optimum quantity (p = 88) of scalar and vectorial parameters of the two derivation systems contained a correct classification rate of 84.1%, in which case 88.6% of the post-infarction ECG were classified correctly. Neither by means of the conventional nor by means of the body surface ECG after Frank an equivalent result could be yielded. When a computer technology is existing (automatic statement of measuring values with following discriminance analysis) therefore in specialized clinics such a hybrid ECG should be used.

[Clinical significance of the corrected orthogonal ECG (Frank) in comparison with conventional ECG for the detection of coronary heart disease]. / Die klinische Bedeutung des korrigierten orthogonalen Ekg (Frank) im Vergleich zum konventionellen Ekg für die Erfassung der koronaren Herzkrankheit.

The clinical evidence of the two derivation systems is of the same value concerning the recognition of the coronary heart disease. Their information range does not significantly differ from each other statistically, when scale and vectorial parameters of the corrected orthogonal ECG after Frank are taken into consideration. But in individual cases clear differences may be present, such as the insufficient representation of localized precordial potential losses in the corrected orthogonal ECG. With the help of the discriminance analysis the high number of falsely negative findings of the ECG after resting can be reduced from about 45% to 15% to 20%. Within a diagnostic stage programme from the recognition and care of particularly endangered patients with coronary heart disease the corrected orthogonal ECG is suited, when a discriminance-analytic valuation with scale and vectorial parameters is made. In contrast to the conventional ECG it has the advantage that it is more rapidly and less expensively to be evaluated by computers.