Open AccessCoronary Flow Reserve Is Impaired in Subclinical Hypothyroidism
Author(s) -
Baycan Semra,
Erdogan Dogan,
Caliskan Mustafa,
Pamuk Baris Onder,
Ciftci Ozgur,
Gullu Hakan,
Yildirir Aylin,
Guvener Nilgun D.,
Muderrisoglu Haldun
Publication year - 2007
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.20132
Subject(s) - medicine , coronary flow reserve , cardiology , subclinical infection , diastole , thyroid , hormone , dipyridamole , blood pressure , thyroid function , coronary circulation , hemodynamics , blood flow , body mass index , endocrinology
Objective Although the cardiovascular system is highly sensitive to thyroid hormones, the cardiovascular effects of subtle thyroid dysfunction such as subclinical hypothyroidism (SHT) remain unclear. Therefore, we investigated coronary flow reserve (CFR) reflecting coronary microvascular function in patients with SHT. Methods Fifty subjects with SHT and 30 control subjects with normal serum thyroid hormones and TSH levels were included in this study. Coronary diastolic peak flow velocities were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocity. Results Age, gender, diastolic and systolic blood pressure, body mass index (BMI), serum lipid parameters, and thyroid hormone levels were similar between the groups. Heart rate was significantly lower in the SHT group. Left ventricular diastolic filling parameters were significantly different in the SHT group while other echocardiographic parameters were similar. CFR values were significantly lower in subjects with SHT than in the control group (2.38 ± 0.44 vs. 2.98 ± 0.47, p < 0.0001). Conclusions These findings suggest that CFR, which reflects coronary microvascular function, is impaired in patients with SHT. Copyright © 2007 Wiley Periodicals, Inc.