Women are far more likely than men to suffer from Raynaud's disease. The purpose of this study was to determine whether there are gender differences in local or central control of cutaneous blood flow that could account for the increased incidence of Raynaud's disease in women. To assess cutaneous blood flow, hand blood flow (HBF), finger blood flow (FBF), or skin perfusion (SP) was measured by fluid plethysmography, mercury strain-gauge plethysmography, or laser Doppler spectroscopy, respectively, in 47 volunteers. Basal HBF in men exceeded that of women (12.1±2.0 versus 6.2±1.5 mlU100 ml/min). Likewise, FBF in men surpassed that of women (19.5±4.1 versus 7.7±1.8 ml/100 mlVmin). Similarly, SP in men was greater than that of women (270±42 versus 81±16 perfusion units). However, after total body warming (to induce a thermal sympatholysis), HBF in women exceeded that of men, suggesting that the lower basal HBF in women was due to increased sympathetic outflow to the extremities. Mental stress and deep inspiration reduced HBF and SP in men. Paradoxically, both of these maneuvers increased HBF and SP in women. To determine whether these paradoxical responses in women were due to the women's elevated basal sympathetic tone, these experiments were repeated after total body cooling in men to increase sympathetic tone and after total body warming in women to reduce sympathetic tone. Total body cooling reduced HBF and SP in men. Under these conditions, mental stress and deep inspiration induced vasodilation. In women, total body warming for 10 minutes increased HBF. Under these conditions, mental stress and deep inspiration induced vasoconstriction. In conclusion, basal cutaneous blood flow is reduced in women. This appears to be due to a basal increase in sympathetic tone rather than to a local structural or functional difference in the cutaneous circulation. In addition, a paradoxical vasodilation in response to mental arithmetic and deep inspiration is unmasked at high levels of sympathetic tone. The gender differences in cutaneous blood flow may account for the increased incidence of Raynaud's disease in young women. (Circulation 1990;82:1607-1615
The prognostic importance of coronary artery disease at the time of elective abdominal aortic aneurysmectomy was evaluated among 131 residents of Olmsted County, Minnesota who underwent elective aneurysmectomy from 1971 to 1987 and were followed up to 1988 for death and cardiac events (cardiac death, myocardial infarction, coronary bypass surgery and angioplasty). Before aneurysmectomy, 75 patients (Group 1) had no clinically recognized coronary disease, 47 patients (Group 2) had suspected or overt uncorrected coronary artery disease (history of prior myocardial infarction, angina or a positive stress test) and 9 patients (Group 3) had undergone coronary artery bypass grafting or coronary angioplasty. The 30 day operative mortality rate was 3% (2 of 75) in Group 1 and 9% (4 of 47) in Group 2 (p = 0.15). According to Kaplan-Meier analysis, estimated survival 8 years after aneurysmectomy was 59% (expected rate 68%, p = 0.29) in Group 1 versus 34% (expected rate 61%, p = 0.01) in Group 2. The cumulative incidence rate of cardiac events at 8 years was 15% and 61%, respectively, for patients without and with suspected/overt coronary artery disease (p less than 0.01). Using multivariable proportional hazards analysis, uncorrected coronary artery disease was associated with a nearly twofold increased risk of death (hazard ratio 1.79, 95% confidence interval 1.06 to 3.00) and a fourfold increased risk of cardiac events (hazard ratio 3.71, 95% confidence interval 1.79 to 7.69). These population-based data support an aggressive life-long approach to the management of coronary artery disease in patients undergoing abdominal aortic aneurysmectomy.
Plethysmography can be used to detect and assess venous incompetence in the lower extremities. The authors recently evaluated a new device designed for this purpose that uses strain gauges to determine changes in lower extremity circumference occurring with (and immediately after) exercise. The device plots a curve of volume against time for each limb and automatically calculates key values such as the volume of blood expelled from the lower limb veins during exercise and the time required for the veins to refill following exercise. The apparatus was incorporated into their noninvasive vascular laboratory and used (along with other standard tests) to study patients referred for suspected venous incompetence. They observed the following: (1) A shortened postexercise refilling time accurately identified limbs with venous incompetence. (2) The clinical severity of venous incompetence was inversely related to the refilling time. (3) Exercise-induced changes in lower extremity volume correlated well with simultaneously determined changes in venous pressure. (4) Valvular incompetence could be localized to the deep or superficial veins based upon the improvement in refilling times seen following placement of elastic tourniquets around the lower limb. (5) The type of exercise performed (knee bends while the patient was standing versus ankle reflexes while sitting) had little effect on results. The authors conclude that exercise venous plethysmography is a useful noninvasive tool for assessing lower limb venous incompetence.
The records of 66 necropsied cases of periarteritis nodosa in which there was no associated collagen disease were reviewed with reference specifically to the heart. Clinically, congestive heart failure and its manifestations were the most important cardiac findings. Congestive heart failure developed some time during the illness in 57 per cent of the patients, and 44 per cent died as a direct result of this cardiac condition. Myocardial infarction was diagnosed clinically in only three cases. The electrocardiogram was abnormal in 35 of 41 cases but was diagnostic of left ventricular hypertrophy in only six cases and of acute myocardial infarction in only three cases; in the other cases the changes were of a nonspecific nature. Pathologically, 41 of the 66 hearts had evidence of necrotizing arteritis of the coronary arteries; in 39 of these the arteritis had been acute, and in two it had healed. Forty-one of the 66 hearts exhibited myocardial infarcts. Evidence of acute pericarditis was found in 22 hearts; nine of these cases were attributed to uremia, one was due to transmural myocardial infarction, three could not be classified, and the remaining nine were attributed directly to the periarteritis nodosa. Forty-one of the 64 hearts that had been weighed were hypertrophied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.