[Serum levels of beta-methyldigoxin and contractile efficiency of the myocardium evaluated with systolic polygraphy and determination of cardiac output].

0.3 mg/day betamethyldigoxin was given per os in three daily administrations to 8 healthy subjects, and 8 compensated and 8 decompensated heart patients. Prior to the treatment, and 6 hr after the last administration, blood digoxin values were determined radio-immunologically, together with cardiac output, systolic stroke volume, cardiac index (dilution of indocyanine green), and systolic time intervals, by simultaneous recording of the ECG, carotid pulse, and the phonocardiogram. No significant change in output, stroke volume and cardiac index was noted in the healthy subjects, whereas these parameters were distinctly improved in the decompensated patients. Changes in the systolic intervals after treatment were significant in all cases though there was no significant correlation with the blood digoxin levels reached. In particular, the healthy and compensated subjects displayed a reduction in the corrected electromechanical systole (delta Q-S2), the corrected pre-ejection period (delta PEP), the corrected left ventricular ejection time (delta LVET), and their ratio (PEP/LVET), whereas in the decompensated patients the picture differed to the extent that the LVET increased owing to an augment-systolic stroke volume, the other parameters being reduced. In the healthy subjects, the polygraphic data were normal prior to the treatment, while in the compensated patients delta PEP and the PEP/LVET ratio were enhanced, and the delta LVET was less than in the normal subjects. It is felt that recording of the systolic intervals may be regarded as a sound method, owing to its simplicity and its ability to demonstrate latent cardiac failure before haemodynamic changes appear. Simultaneous determination of serum digoxin and the polygraphic data, therefore, opens the way to the commencement of appropriate, safe and timely management of as yet non-decompensated heart patients.