Coronary artery constriction caused by the cold pressor test in human hypertension.

Abstract

Hypertensive patients with angiographically normal coronary arteries may have myocardial ischemia when metabolic demand increases. Abnormal epicardial coronary artery vasomotion in response to sympathetic stimulation may contribute to ischemia in such patients. We studied the vasomotor response of smooth coronary arteries to a cold pressor test in 10 hypertensive patients without other risk factors and in 9 control subjects. Vessel dimensions were measured by quantitative angiography, and blood flow was calculated using an intracoronary Doppler catheter in the left anterior descending coronary artery. In response to cold pressor stimulation, arteries of control subjects dilated 13.0±5.9% (P<.001), and they constricted 8.2±8.5% in hypertensive patients (P<.001). Rate-pressure product increased from 9466±1677 to 12 547±2367 beats per minute (bpm) • mm Hg in control subjects (P<.001) and from 13 720±1823 to 17 353±2037 bpm • mm Hg in hypertensive A ngina-like chest pain or thallium defects consis-/\ tent with myocardial ischemia can occur in _Z A. patients with hypertension and angiographically normal coronary arteries. 1 -2 Abnormal maximal coronary vasodilator reserve 13 and/or disturbances of coronary vasomotion 4 -5 may constitute mechanisms responsible for myocardial ischemia in these patients. The vascular endothelium, by releasing relaxing and constricting factors, 67 and the sympathetic nervous system are major regulators of vascular tone. Furthermore, endothelium is a modulator of the contractile agonist effects of sympathetic activation. In experimental hypertension, morphological changes develop in arterial endothelial cells. 8 In hypertensive rats, endothelial destruction is associated with increased constriction of large vessels in response to norepinephrine infusion. 910 In isolated pig and dog coronary arteries, norepinephrine is a more powerful vasoconstrictor in the absence of endothelium.11 In hypertensive patients (HTN patients), impairment of endothelium-dependent dilation of coronary epicardial and resistance vessels has been evidenced, The aim of the present study was to assess the effects of sympathetic stimulation on vasomotion of epicardial coronary arteries in HTN patients with angiographically normal coronary arteries. We studied the response to a cold pressor test, which activates the sympathetic nervous system and induces dilation of angiographically normal coronary arteries in control subjects. 15 We measured coronary artery diameters by quantitative angiography and used intracoronary Doppler to measure blood flow velocity. Methods Patient SelectionTen HTN patients and 9 control normotensive subjects undergoing diagnostic coronary angiography for evaluation of chest pain were studied. Control subjects had a supine systolic blood pressure lower than 140 mm Hg and a diastolic blood pressure lower than 90 mm Hg. All HTN patients had a well-established history of elevated blood pressure higher than 140/90 mm Hg, with at least four sets of readings taken at 1-week intervals. Hyper...

Prognostic Value of Epicardial Coronary Artery Constriction to the Cold Pressor Test in Type 2 Diabetic Patients With Angiographically Normal Coronary Arteries and No Other Major Coronary Risk Factors

“…Recently, coronary endothelial dysfunction, evidenced by intracoronary acetylcholine, has been demonstrated to be an independent predictor of cardiovascular events (CVEs) in patients with coronary artery disease (6 -8) and patients with coronary risk factors (8). The cold pressor test (CPT), which activates the sympathetic nervous system, induces dilation of coronary arteries in control subjects and constriction of atherosclerotic coronary arteries (6,9,10). In diabetic patients, CPT has been shown to induce coronary artery constriction (5), which may reflect endothelial dysfunction.…”

Cold stimulation induces different responses of ophthalmic artery blood flow velocity depending on baseline blood pressure and gender

“…For example, in the smooth coronary arteries of normotensive controls arteries dilated (13%) to cold stimulation, whereas in hypertensive patients arteries constricted (À8%). 26 However, the CPT was shown to cause vasoconstriction in the retinal arterioles of healthy volunteers. 23 Third, blood pressure-related analysis was carried out depending on the bBP and did not consider long-term damage of endothelial cells.…”

Abnormal myocardial perfusion and contractile recruitment during exercise in type 1 diabetic patients

“…The cold pressor test, which activates the sympathetic nervous system, induces dilation of coronary arteries in normal subjects and constriction of atherosclerotic coronary arteries. 22,23 In diabetic patients, the cold pressure test has been shown to induce coronary artery constriction, 24 which may reflect endothelial dysfunction. Increased myocardial metabolism leads to an enhanced dilation and flow of epicardial coronary arteries, which is mainly determined by endothelium-derived nitric oxide.…”