Endothelium-Dependent Dilation of the Coronary Arteries in Syndrome X: Effects of the Cold Pressor Test

Abstract

The coronary flow reserve is abnormal in syndrome X, but the response to the cold pressor test, which in normals produces flow-mediated endothelium-dependent epicardial coronary dilation, has not been studied. In this study, in 12 patients with typical syndrome X and angiographically normal coronary arteries, the response to the cold pressor test was abnormal with a mean fall in diameter (10 ± 8%) in 6 patients, no change in 1, and a minimal increase (4 ± 2%) in 5 patients (normal increase 12 ± 1%). The coronary blood flow fell slightly during the cold pressor test, and the coronary vascular resistance increased significantly (from 2.4 ± 1.1 to 3.2 ± 1.7 mm Hg/cm-s^-1mm²; p = 0.05), both abnormal responses. This study confirms that in syndrome X patients there is coronary endothelial dysfunction which is apparent in response to physiological stimuli induced by the cold pressor test.

Blood Pressure in Young Adulthood and the Risk of Type 2 Diabetes in Middle Age

“…Fifth, the BP response to the cold pressor test may not have been an adequate assessment of endothelial function so early in the course of the prediabetic state, which might explain our finding of a lack of association between the cold pressor response and incident diabetes. The cold pressor test, however, is still used to measure coronary artery vasomotion, and an abnormal response to this test (i.e., coronary artery vasoconstriction) has been demonstrated in individuals with the metabolic syndrome (considered to be a prediabetic state) (26), hypertension (9,11), and atherosclerosis (10,27).…”

Brachial Artery Flow-Mediated Vasodilation in Patients With Cardiac Syndrome X

“…2 In addition, one of the causes of microvascular dysfunction in CSX is ED, which is believed to be caused by impaired NO release and/or activity and a decreased coronary flow response to acetylcholine, atrial pacing, cold suppressor test, and other endothelium mediated vasodilator stimuli. [3][4][5][7][8][9][10] Instead of presenting adequate vasodilatation and flow increase after EDVD stimuli as in normal controls, CSX patients tend to have vasoconstriction and decreased coronary flow. In contrast, after endothelial-dependent stimuli, such as injections of nitroglycerin, papaverine, or adenosine, both control and CSX patients show adequate vasodilatation reactions.…”

Methods to investigate coronary microvascular function in clinical practice

“…Recently, the cold pressor test (CPT) 19 has been used to assess endothelium-dependent coronary vasodilator function. CPT is a simple test that can be applied noninvasively.…”

“…The normal increase of CBF in response to CPT has poorly been investigated, and significantly variable results have been reported in different studies, although it is lower than that seen with adenosine. 19 Test standardization…”