Arterial dysfunction in syndrome X: results of arterial reactivity and pulse wave propagation tests

Objective: To assess arterial distensibility using pulse wave velocity (PWV) measurements and its relation with endothelium dependent vasodilatation (EDV) in patients with cardiological syndrome X. Methods: The study group consisted of 92 patients: 52 with syndrome X (34 women, 18 men, mean (SD) age 45 (3) years) and 40 healthy volunteer controls (27 women, 13 men, mean (SD) age 41 (2) years) without risk factors of atherosclerosis and with negative ECG exercise test and normal proximal coronaries on transoesophageal echocardiography. Patients with arterial hypertension, diabetes mellitus, valvar disease, or cardiomyopathy were excluded. PWV measured by a Complior Colson device was calculated for each patient. EDV was assessed from two dimensional Doppler measurement using an Acuson Sequoia with 8 MHz linear transducer at rest, during postischaemic-reactive hyperaemia, and after an oral dose of 400 mug of glyceryl trinitrate. Results: PWV was significantly higher in patients with syndrome X than in healthy subjects (9.3 (0.7) m/s v 8.2 (0.9) m/s, respectively, p < 0.001). Baseline brachial artery;diameter was similar in the syndrome X and control groups (4.0 (0.6) mm v 4.08 (0.64) mm, NS). EDV was impaired in patients with syndrome X compared with controls (6.6 (3.0)% v 11.1 (3.9)%, p < 0.001). Endothelium syndrome X there was a posi-independent vasodilatation was similar in both groups. In patients with syndrome correlation between PWV and the degree of EDV (r = 0.864, p < 0.001). The cut off value for PWV was 8.5 m/s, with a sensitivity of 62% and a specificity of 91 %. Conclusions: EDV but not glyceryl trinitrate induced vasodilatation is decreased in patients with syndrome X. There is a strong correlation between PWV and the degree of endothelial dysfunction of peripheral arteries in patients with syndrome X. PWV assessment may be useful to identify abnormal vascular physiology in these patients.