Impairment of coronary microvascular function in patients with neurally mediated syncope.
Pacing Clin Electrophysiol
; 26(2 Pt 1): 605-12, 2003 Feb.
Article
em En
| MEDLINE
| ID: mdl-12710321
ABSTRACT
Recent evidence suggests that myocardial ischemia may occur in patients with neurally mediated syncope and normal coronary angiograms. This study was conducted to evaluate if coronary microvascular function is impaired in such patients. Coronary hemodynamic studies and head-up tilt table tests (HUTs) were performed on 30 consecutive patients with normal coronary angiograms and recurrent syncope. Another ten subjects with atypical chest pain and no evidence of myocardial ischemia or syncope served as a control. Great cardiac vein flow (GCVF) and coronary sinus flow (CSF) were measured by the thermodilution method at baseline and after dipyridamole infusion (0.56 mg/kg i.v. for 4 minutes). Coronary flow reserve (CFR), derived from CSF and GCVF, was significantly lower in the 15 patients with positive HUT than in the other 15 patients with negative HUT (1.75 +/- 0.48 vs 2.64 +/- 0.8, P < 0.01 and 2.29 +/- 0.45 vs 3.07 +/- 0.63, P < 0.01, respectively). Ischemic-like ECG was noted during treadmill exercise test in 40% of the former and in 7% of the latter group (P = 0.01). There was no significant difference in CFR between patients with negative HUT and control subjects. Coronary microvascular function was impaired in syncopal patients with positive HUT and relatively preserved in those with negative HUT, suggesting the possible linkage between coronary microvascular dysfunction and the development of neurally mediated syncope.
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Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Síncope Vasovagal
/
Circulação Coronária
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
Limite:
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Pacing Clin Electrophysiol
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
China