Transient ischemic attacks associated with hypotension in hypertensive patients with carotid artery stenosis.

Abstract

SUMMARY In a group of 132 patients with transient ischemic attacks (TIAs) 7 patients (4 men, 3 women, ages 64 to 81) had TIAs preceded by hypotension. The average fall of mean blood pressure during an attack was 26.4 ± 5.5 mm Hg (SD). Only one of these patients had a TIA which was not preceded by hypotension. This episode occurred during a paroxysm of coughing. All 7 of these patients had hypertension, and cerebral arteriography performed in 4 of the 7 revealed hemodynamically significant carotid artery stenosis. Each of the 4 patients developed hypotension and a TIA after the procedure. Twenty of the other patients bad hypotensive episodes but did not develop focal neurological deficits. None of these patients had carotid artery stenosis. This study suggests that hypertensive patients with carotid artery stenosis may be at risk to develop focal cerebral ischemia during acute hypotensive episodes. Stroke, Vol 12, No 3, 1981THE ROLE of hypotension in the etiology of transient ischemic attacks (TIAs) and stroke is controversial. Denny-Brown and colleagues suggested that hypotension could induce focal neurological deficits in patients with carotid artery stenosis. 1 -' More recently, several authors have stated that hypotension rarely, if ever, causes TIAs or stroke.' 1 * We sought to determine if a sub-population of patients with TIAs is susceptible to hypotensive episodes. We have found that the acute lowering of blood pressure resulting from antihypertensive medications, postural change, or cerebral angiography was associated with transient focal neurological deficits in hypertensive patients with hemodynamically significant carotid artery stenosis. MethodsThe study group consisted of 132 patients admitted to the New York Hospital-Cornell Medical Center between 1975 and 1980 with a clinical diagnosis of TIA which met the following requirements: 1) the clinical syndrome in each case satisfied established criteria for TIA;" 2) each patient was evaluated by a staff neurologist who formulated or agreed with the diagnosis; and 3) each was studied with a lumbr puncture and computed tomography which showed no evidence of a mass lesion, cerebral infarction, or hemorrhage. Eighty-nine of these patients had aortic arch studies (87 of these were believed to have ischemia in those parts of the brain supplied by the carotid artery). Carotid artery stenosis with greater than 85% reduction of the minimal common or internal carotid artery diameter was considered hemodynamically significant." Blood pressure, assessed by sphygmomanometry, and heart rate, determined by palpation of the peripheral pulse, were determined every 2-4 hours. The measurement interval was

Mechanism of in-hospital cerebral ischemia.

“…Although Torvik and Skullerud 12 did not find that cerebral infarction after cardiac arrest was correlated with the location and degree of cerebral atherosclerosis, hypertensive patients with ca- rotid artery stenosis may be more susceptible to focal cerebral ischemia in the presence of acute hypotension. 14 There is a tendency for cerebral infarction, associated with systemic hypotension, to occur in a distal field distribution, 15 but this pattern was not observed in our patients. In one study, 16 16 of 208 patients with ischemic cerebral infarction (7.7%) had hypotension at the onset of symptoms, often because of antihypertensive therapy.…”

Orthostatic hypotension in older adults. The Cardiovascular Health Study. CHS Collaborative Research Group.

“…tFrom an independently measured supine ankle-arm blood pressure measurement a series of 132 patients admitted for evaluation of TTAs and observed with serial BP measurements, 20% had documented hypotensive episodes (decrease in mean BP of 20 mm Hg or greater within 4 hours), associated with either antihypertensive therapy, cerebral arteriography, or postural changes. 4 In another series of 80 consecutive patients seen within 2 weeks of a TIA, 16% were found to have OH, and in 9% an OH-concurrent TIA was observed. 3 These clinical studies do not suggest a higher rate of OH among TIA patients than is found in the CHS cohort overall.…”

Occurrence of stroke in a nonhuman primate model of cerebrovascular disease.

“…Jackson et al 14 reported six hypertensive patients who were admitted to the hospital in a coma following rapid reduction of blood pressure to normotensive values; one had residual deficit. Ruff et al 15 noted, in a study of 132 patients with transient ischemic attacks, that in 7 patients the ischemic attacks occurred during hypotension; all 7 had hypertension, and 4 of these 7 had significant carotid stenosis. Rosenfeld et al 16 noted in 208 consecutive ischemic strokes that 16 could be attributed totally or partially to hypotension, usually iatrogenic; 12 of these 16 patients were known to be hypertensive prior to the strokes.…”