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[Circadian variation of ischaemic ST lowering in exercise ECG (author's transl)]
Insights
Circadian rhythms influence myocardial ischaemia detection. ST lowering, a marker for coronary heart disease, showed minimal expression at 11:00 AM, suggesting diurnal variations impact cardiac drug efficacy assessments.
Area of Science:
- Cardiology
- Chronobiology
- Pharmacology
Background:
- Coronary heart disease (CHD) diagnosis and treatment efficacy can be influenced by various physiological factors.
- Understanding diurnal variations in cardiac events is crucial for accurate patient assessment and drug evaluation.
Purpose of the Study:
- To investigate the circadian variation of ischaemic ST lowering in patients with coronary heart disease.
- To assess the impact of diurnal variations on the evaluation of cardiac drug efficacy, specifically molsidomine.
Main Methods:
- Utilized the placebo phase of a randomized, double-blind ergometry study involving 10 patients with CHD.
- Monitored ST lowering during ergometry, analyzing data for circadian patterns and correlation with the pressure-frequency product.
Main Results:
- Observed non-significant tendencies and minimal expression of ST lowering around 11:00 AM.
- Found no dependency between ST lowering and changes in the pressure-frequency product.
- Identified one case where ischaemic reactions were not diagnosed at 11:00 AM but were detectable at other times.
Conclusions:
- Diurnal variations in circadian rhythms may lead to errors in evaluating the duration and extent of cardiac drug action.
- The time of day must be considered in control investigations for cardiac drug studies to ensure accurate results.
Abstract:
The circadian variation of ischaemic ST lowering was investigated in 10 patients with coronary heart disease. The placebo phase of a randomised double blind ergometry study on the extent and duration of the action of molsidomine was used for this purpose. Non-significant tendencies with minimal expression of ST lowering were seen at 11.00 a. m. There was no dependency on changes of the pressure frequency product. In one patient ischaemic reactions recognizable at other times would not have been diagnosed at 11.00 a. m. A retrospective analysis of data gives evidence for errors in evaluation of duration and extent of action of cardiac drugs caused by diurnal variation. Consideration of time of day must be included in control investigations.