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Asymptomatic myocardial ischemia following cold provocation
American Heart Journal
|September 1, 1987
Summary
Cold exposure causes more silent myocardial perfusion abnormalities in stable angina patients than exercise. These silent perfusion changes are not always indicated by chest pain or ECG changes, highlighting a critical aspect of coronary disease management.
Area of Science:
- Cardiology
- Nuclear Medicine
- Physiology
Background:
- Cold exposure is known to provoke angina in coronary disease patients.
- Potential mechanisms include increased myocardial demand or coronary vascular resistance.
Purpose of the Study:
- To compare the effects of cold pressor stimulation and exercise on regional myocardial perfusion.
- To assess if cold exposure induces asymptomatic perfusion abnormalities in stable angina.
Main Methods:
- Positron emission tomography (PET) with rubidium-82 was used to assess regional myocardial perfusion.
- 35 patients with stable angina and coronary disease and 10 normal subjects were studied.
- Cold pressor stimulation and symptom-limited supine bicycle exercise were employed.
Main Results:
- Cold pressor stimulation caused significant perfusion abnormalities in 24/35 patients, often without angina or ST depression.
- Supine exercise induced perfusion abnormalities in all 29 patients who underwent it, with angina in 27/29 and ST depression in 25/29.
- Cold exposure led to more frequent asymptomatic regional myocardial perfusion disturbances compared to exercise.
Conclusions:
- Cold exposure frequently causes asymptomatic regional myocardial perfusion abnormalities in patients with stable angina and coronary disease.
- These abnormalities may be underestimated by traditional indicators like chest pain or ECG changes.
- Cold pressor testing can reveal subclinical myocardial ischemia in coronary disease patients.