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Chronotherapy in coronary heart disease: comparison of two nitrate treatments
1Medical University Clinic II, University Erlangen-Nürnberg, Germany.
Insights
This study found that coronary heart disease patients experience worsening ischemia and hemodynamic changes throughout the day. Nitrates significantly reduced these effects, showing a clear circadian rhythm in cardiovascular responses.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Circadian Rhythms
Background:
- Coronary heart disease (CHD) poses a significant global health burden.
- Understanding daily hemodynamic variations in CHD patients is crucial for effective management.
- Circadian influences on cardiovascular function in CHD are not fully elucidated.
Purpose of the Study:
- To evaluate the ischemic burden and hemodynamic alterations during daily activities in patients with coronary heart disease.
- To assess the impact of nitrate therapy on these daily changes.
- To investigate the circadian phase dependency of cardiovascular effects in CHD.
Main Methods:
- Three exercise tests were conducted at 10:00 a.m., 2:00 p.m., and 6:00 p.m.
- Measurements included ST-segment depression, pulmonary artery pressure, pulmonary wedge pressure, cardiac output, heart rate, and systemic blood pressure.
- Data were collected under both placebo and nitrate therapy conditions.
Main Results:
- A progressive increase in ischemia and preload, alongside a decrease in cardiac output, was observed throughout the day under placebo.
- Nitrate therapy significantly reduced both preload and ST depression.
- Cardiovascular effects demonstrated a marked circadian phase dependency.
Conclusions:
- Daily activities induce significant ischemic burden and hemodynamic changes in CHD patients.
- Nitrate therapy can effectively mitigate these daily variations.
- The cardiovascular effects of nitrates in CHD exhibit a notable circadian rhythm, influencing treatment strategies.
Abstract:
The purpose of this study was to assess the ischemic burden and the hemodynamic changes during daily activities in patients with coronary heart disease. Three exercise tests were performed during the day (10:00 a.m., 2:00 p.m., 6:00 p.m.), recording ST-segment depression, pulmonary artery pressure, pulmonary wedge pressure, and cardiac output as well as heart rate and systemic blood pressure during placebo and nitrate therapy. With placebo as well as nitrate therapy there was a gradual increase of ischemia and preload and a decrease of cardiac output during the day. High nitrate concentrations led to a significant reduction of both preload and ST depression with a marked circadian phase dependency of cardiovascular effects.