[Evaluation of left ventricular function by external methods. Comparative study of systolic intervals and...

In a number of conditions characterised by major disturbance of myocardial contractility (15 cases of thyrotoxicosis, 18 of hypokinetic cardiomyopathy and 9 of hypertrophic cardiomyopathy), the authors have compared the results of measuring the systolic intervals as derived from the quotient PPE/TE with an analysis of the upstroke of the apex electrocardiogram derived from measurement of the t-da/dt interval and from the quotient da/dt/A. The quotient PPE/TE is markedly lowered in the hypokinetic cardiomyopathies. On the other hand this quotient does not differentiate between normal subjects and patients with thyrotoxicosis or hypertrophic cardiomyopathy. By contrast the measurements derived from the electrocardiogram, and especially the quotient da/dt/A, differentiate very clearly between the various pathological conditions.