Control of hypertension, labile or fixed, systolic or diastolic, at any age, in either sex appears to be central to prevention of atherothrombotic brain infarction (ABI). Prospectively, hypertension proved the most common and potent precursor of ABI's. Its contribution was direct and could not be attributed to factors related both to stroke and hypertension. Asymptomatic, causal "hypertension" was associated with a risk of ABI about four times that of normotensives. The probability of occurrence of an ABI was predicted no better with both blood pressure measurements or the mean arterial pressure than with systolic alone. Since there was no diminishing impact of systolic pressure with advancing age, the concept that systolic elevations are, even in the aged, innocuous is premature. Comparing normotensives and hypertensives in each sex, women did not tolerate hypertension better than men.

https://jamanetwork.com/journals/jama/articlepdf/409700/jama_276_15_040.pdf

Epidemiologic Assessment of the Role of Blood Pressure in Stroke: The Framingham Study

Blood Pressure and Risk of Coronary Heart Disease: The Framingham Study

Embolization from or decreased flow through cervical carotid and vertebral arteries causes ischemic stroke syndromes. Specific pathologic findings were studied in 50 symptomatic patients who underwent 69 carotid endarterectomies. Detailed analyses of their carotid plaques included correlations between photographs of gross specimens, microscopic findings, angiograms, preoperative symptoms and long-term postoperative follow up. Carotid plaques were primarily fibrous with significant (greater than 70%) stenoses encountered in 70% of the arteries. Stenoses were due to simple fibrous thickening in only 20%; the remainder due to intraplaque hemorrhage, atheromatous debris and, least often, luminal thrombus with or without ulceration. Intramural hemorrhage was frequent in plaques associated with focal neurologic symptoms and may have preceded localized collections of atheromatous debris. Ulceration occurred in 1/3 of all plaques, symptomatic or not. It is concluded that the carotid plaques start as fibrointimal thickening evolving to symptomatic stages by the occurrence of one or more of a number of pathologic changes, intraplaque hemorrhage being prominent. A single rational therapeutic regimen seems impossible until patients can be classified according to their pathologic changes diagnosed non-invasively.

The carotid bifurcation plaque: pathologic findings associated with cerebral ischemia.

Flow through a converging-diverging tube and its implications in occlusive vascular disease — I

The distribution of fatty streaks, fibrous plaques, complicated lesions, and calcified lesions were determined for each of five segments in the common carotid arteries, each of five segments of internal carotid arteries, and for each of seven segments of vertebral arteries in specimens from 961 autopsied cases in Oslo, Norway, and Guatemala. The pattern of distribution of the lesions along the length of the arteries is characteristic for the different arteries. This pattern seems to be independent of sex, age group, type of lesions, and geographic location. Fatty streaks and fibrous plaques have the same pattern of distribution within each artery at all ages. This close topographic association is consistent with the hypothesis that fibrous plaques are derived from fatty streaks. The early atherosclerotic lesions are located at the same sites where stenotic and occlusive lesions have been reported. Thus, it is likely that the early atherosclerotic lesions and the stenotic or occlusive lesions are pathogenetically closely associated with each other.

Localization and Sequence of Development of Atherosclerotic Lesions in the Carotid and Vertebral Arteries

This report identifies the inception and progressive pathology of atherosclerosis resulting from the effects of hydraulic forces inherent in the circulatory system. 1 Vascular dynamics relates the effect of hydraulic forces to the biological response of blood vessels. The forces and principles involved are directly comparable to those which prevail in all hydraulic systems with due regard to local conditions of flow and hydraulic characteristics. 2 The laws of fluid mechanics are fully applicable to the hydrobiological conditions found in the human circulatory system, and the composite effects of their operation are both prerequisite and conducive to atherosclerosis. Previous reports 3,4 have correlated atherosclerotic lesions found at autopsy with their localization in the circulatory system as determined by hydraulic forces. Rigid and flexible model hydraulic systems built to simulate the specifications of human blood vessels with respect to pulsatile flow, volumetric flow, velocity of flow, and anatomical geometry confirm the

The role of vascular dynamics in the development of atherosclerosis.

The hemodynamic concept of atherosclerosis considers the laws of fluid dynamics as the primary factor in the pathogenesis of atherosclerosis. The laws of fluid mechanics can account for the localization, progressive development, and varied pathologic appearance of atherosclerotic lesions at specific areas of predilection. These are areas characterized by curvature, bifurcation, branching, tapering, or external attachment. Such locations are subject to a relative decrease in local lateral pressure in accordance with the laws of fluid mechanics. The contributing atherogenic influence of other factors, such as sex, race, diet, nutritional status, habitus, lipid metabolism, drugs, hormones, associated diseases, hypertension and stress, requires further evaluation. It appears that these are secondary factors which may modify the primary hemodynamic mechanism. The Hemodynamic Mechanism Model hydraulic systems based upon specifications of actual autopsy specimens demonstrate that sites of relative decrease in lateral pressure are sites of predilection. The incidence and degree of atherosclerosis at

https://jamanetwork.com/journals/jamasurgery/articlepdf/558328/archsurg_80_1_006.pdf

The Hemodynamic Concept of Atherosclerosis: The Experimental Production of Hemodynamic Arterial Disease

Previous reports 1-4 have presented the primary relation of hemodynamics to the inherent pathology of atherosclerosis. The hemodynamic concept of atherosclerosis considers the laws of fluid dynamics as the primary factor in the pathogenesis of atherosclerosis. The laws of fluid mechanics can account for the inception, the progressive changes, and the varied pathologic appearances of arterial occlusive disease in the aorta and coronary arteries as well as in arteries of the viscera and extremities. The absence or lesser degree of atherosclerosis in the pulmonary artery and in veins is also accounted for on the basis of hemodynamics. The hemodynamic concept of atherosclerosis was developed by correlating atherosclerotic lesions found at autopsy with their localization as determined by hydraulic principles. It was then demonstrated with the aid of model hydraulic systems built to the precise specifications of blood vessels obtained at autopsy. Flow in these models, as well as in the

Experimental production of arterial lesions. Furthering the hemodynamic concept of atherosclerosis.

Fifty per cent of esophageal hiatal hernias are probably asymptomatic. Of patients with hiatal hernias, 38% have cholelithiasis, whereas approximately 25 per cent have duodenal ulcers. Only approximately one-third of patients with hernias have the characteristic symptom complex of regurgitant peptic esophagitis. Massive upper gastrointestinal hemorrhage in the presence of a sliding hernia is frequently associated with a low lying gastric or duodenal ulcer. These facts suggest that transabdominal approach for the repair of hiatal hernia is necessary for proper exploration of the abdomen. Satisfactory repair can be performed by this approach. Eight case reports illustrate the problems encountered which favor transabdominal approach, as well as the manner in which the difficult complications of this entity—such as peptic esophagitis with stricture—can be dealt with.

Case for transabdominal repair of esophageal hiatal hernia.

The frequency of abdominal aortic aneurysm has been increasing. The varying clinical manifestations and resulting difficulties in diagnosis and treatment are illustrated by 10 case histories. Among 43 patients treated by elective resection of such aneurysms in 5 years, there were only 2 hospital deaths. This is in marked contrast to the high mortality rate of 50% within 2 years in 53 patients not treated surgically. In the last 44 consecutive elective resections performed by the authors there were but 2 operative deaths. Elective resection is therefore advocated for all patients with abdominal aortic aneurysm who are good surgical risks. It is recommended that, when other serious abdominal conditions are also present, priority be given to the aneurysm.

Anthony M. Imparato

Papers

The role of vascular dynamics in the development of atherosclerosis.

The Hemodynamic Concept of Atherosclerosis: The Experimental Production of Hemodynamic Arterial Disease

Experimental production of arterial lesions. Furthering the hemodynamic concept of atherosclerosis.

Case for transabdominal repair of esophageal hiatal hernia.

The abdominal aortic aneurysm. Its importance to the internist.