Heart rate‐independent prolongation of QTc interval in women with syndrome X
| Autor: | R. Schwartzman, Carmelo Mammana, Oscar A. Salomone, Josef Kautzner, Juan Carlos Kaski |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Sympathetic nervous system
medicine.medical_specialty QT interval Electrocardiography Heart Rate Internal medicine Cardiac syndrome X Heart rate Medicine Humans cardiovascular diseases Clinical Investigation Microvascular Angina medicine.diagnostic_test business.industry Confounding Case-control study General Medicine Middle Aged medicine.disease Autonomic nervous system medicine.anatomical_structure Endocrinology Case-Control Studies Cardiology cardiovascular system Female Cardiology and Cardiovascular Medicine business |
| Popis: | Background: Cardiac syndrome X is usually diagnosed in the presence of typical exertional chest pain, a positive response to exercise testing, and normal coronary angiograms. The underlying pathogenic mechanisms are speculative, but myocardial ischemia and increased sympathetic activity have been implicated. Hypothesis: The present study examined whether QTc interval is prolonged in women with syndrome X when confounding factors such as heart rate, gender, and environmental conditions are accounted for. Methods: Maximum QTc interval and its relationship to clinical and exercise variables were evaluated in 32 women with syndrome X (exertional chest pain, positive exercise testing, and completely normal coronary arteries) and 34 normal controls. Results: Patients with syndrome X had significantly longer QTc interval (440 ± 24 ms) than normal subjects (410 ± 26 ms, p |
| Databáze: | OpenAIRE |
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