The electrocardiogram of man in semistarvation and subsequent rehabilitation.

Abstract 1.1. In thirty-two normal subjects, electrocardiograms were taken at regular intervals during a control period of three months, during a semistarvation period of six months in which a 24 per cent weight loss was produced, and during a controlled rehabilitation period of twelve weeks. In twenty subjects, electrocardiograms were taken also after thirty-two weeks of rehabilitation, the last twenty weeks being on a freely chosen diet. 2.2. During semistarvation, statistically highly significant changes occurred in most electrocardiographic items, and the electrocardiograms became clinically abnormal in the majority of subjects. 3.3. There was pronounced slowing of the heart rate, and its variability range decreased both relatively and absolutely so that the heart rate was more regular in semistarvation. These changes reached their maximum at the twelfth week of semistarvation, and recovered slowly during rehabilitation. 4.4. Q T interval and mechanical systole duration increased during semistarvation and shortened again during rehabilitation, but these changes lagged behind the simultaneous changes of the cycle length in both directions, so that K Q-T and K SYST changed accordingly. 5.5. The amplitudes of all deflections (P wave, QRS complex, and T wave) decreased continuously and very considerably during semistarvation and recovered slowly during rehabilitation. 6.6. During semistarvation, there was a marked right axis shift of the QRS axis and even more so of the T axis, so that the angle between both axes was diminished. During rehabilitation, both QRS axis and T axis moved to the left, overshooting the original prestarvation position at the thirty-second week of semistarvation. 7.7. Most electrocardiographic items were only partially recovered during twelve weeks of rehabilitation, but were back to the control values within thirty-two weeks, several functions (heart rate, R 1 , Σ T , QRS axis, T axis) overshooting the control values subsequently. 8.8. There was a discrepancy in the time course of changes between interval and amplitude changes, and between QRS complex and T-wave changes. 9.9. There was no correlation between QRS axis changes and anatomic axis changes, or between QRS axis and T axis, although all changed in the same direction. 10.10. A statistically significant differentiation of the groups receiving different caloric levels during rehabilitation was obtained in the following items: systole duration, K QT , R 1 , R 2 , Σ QRS , T 1 , T 2 , Σ T , and T axis. 11.11. Before semistarvation, voluntary maximal inspiration produced an initial acceleration of the heart rate in all subjects, which was followed by a late retardation in eighteen subjects. 12.12. During semistarvation, the effect of maximal inspiration was diminished in respect to both initial acceleration and late retardation. During twelve weeks of rehabilitation, only the late retardation was restored. 13.13. The decrease of K QT and K SYST in the late phase of maximal inspiration was significantly less pronounced at the end of semistarvation, and this effect was, to a certain degree, independent of the changes in the heart rate. 14.14. While the slow heart rate in semistarvation, as a rule, was due to sinus bradycardia, in two subjects nodal rhythm was observed; this was temporarily restored to sinus rhythm during maximum voluntary inspiration.