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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results of surgery for occlusive coronary artery disease were studied in 600 consecutive, unselected patients who underwent aortocoronary bypass grafting between Jan. 1, 1977 and Dec. 31, 1982. Forty (7%) of these patients had diabetes mellitus, requiring medication. Sixteen of the 40 patients were insulin-dependent, the remainder required oral hypoglycemic agents. The frequency of previous myocardial infarction, hypertension and peripheral vascular disease in the groups of nondiabetic and diabetic patients was 38% and 62.5%, 12% and 22.5%, and 10.5% and 25% respectively. There was no significant difference in the rate of unstable angina, triple-vessel disease, emergency surgery, left ventricular dysfunction, myocardial infarction perioperatively and hospital morbidity or mortality in the two groups. On coronary angiography, 82% of coronary arteries in diabetic patients were graded as being small or moderate in size (less than 2 mm in diameter); at operation, 62% of these arteries were found to be 2 mm or more in diameter. At a mean follow-up of 3.9 years and 3.7 years in the nondiabetic and diabetic patients respectively (range from 1 to 6 years), no significant difference was noted with regard to relief of symptoms or survival in the two groups. It is concluded that diabetic patients with coronary artery disease can be offered bypass surgery with good short-term and medium-term results.
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PMID:Surgery for coronary artery disease in patients with diabetes mellitus. 387 80

The purpose of this study was to focus on the clinical and angiographic characteristics of 113 patients with crescendo angina (Group I) as compared to 187 patients with angina of new onset (Group II), selected from a series of 474 consecutive subjects, admitted to our clinic between January 1976 and July 1983 because of recurrent episodes of spontaneous angina, who underwent cardiac catheterization and coronary angiography within one month of hospitalization. Group I patients showed a greater incidence of prior transmural myocardial infarction (p less than 0.01), arterial hypertension (p less than 0.01), multivessel disease (p less than 0.01) and a lower value of left ventricular ejection fraction (p less than 0.01) than Group II patients. In the latter group of patients anginal episodes were more frequently associated with S-T segment elevation than with S-T segment depression (p less than 0.001), while the opposite was found in patients with crescendo angina. Survival curves up to five years showed that medically treated patients with crescendo angina had a worse long-term prognosis than patients with unstable angina of new onset (p less than 0.01). On the contrary no difference was found between the surgically treated patients of the two groups. Our data suggest that the more diffuse involvement of the coronary tree associated with a more depressed left ventricular function may result in an unfavorable long-term prognosis in patients with crescendo angina as compared to those with unstable angina of new onset. Such a difference between the two groups was abolished by surgical treatment.
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PMID:[Different clinical and prognostic aspects of angina pectoris in unstable phase]. 387 10

Diltiazem is an orally and intravenously active calcium channel blocking agent shown to be an effective and well-tolerated treatment for stable angina and angina due to coronary artery spasm. Its efficacy in these diseases has generally been similar to that of nifedipine or verapamil - alternative calcium channel blockers with which diltiazem has many electrophysiological, haemodynamic, and antiarrhythmic similarities. The antianginal mechanism of diltiazem cannot be precisely described; however, it appears to increase myocardial oxygen supply and decrease myocardial oxygen demand, mainly by coronary artery dilatation and/or via both direct and indirect haemodynamic alterations. Diltiazem has also shown substantial efficacy in the treatment of unstable angina, hypertension, and supraventricular tachyarrhythmias, but further study is necessary before its place in the treatment of these diseases may be clearly established. Although headache due to peripheral vasodilatation and depression of atrioventricular nodal conduction may be troublesome, side effects occur in only 2 to 10% of patients receiving diltiazem and are generally minor in nature. Thus, diltiazem offers a worthwhile alternative to other agents currently available for the treatment of angina pectoris. Although the infrequency of serious side effects may offer an advantage, its relative place in therapy compared with that of other calcium channel blockers remains to be clarified.
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PMID:Diltiazem. A review of its pharmacological properties and therapeutic efficacy. 389 2

High doses of verapamil, diltiazem or nifedipin were administered to three groups of eight patients each, with severely abnormal left-ventricular (LV) function (mean ejection fraction 0.29). Various haemodynamic measurements were made immediately before and 30 minutes after drug administration: LV ejection fraction, ratio of peak systolic pressure to endsystolic volume index, stroke index, pulmonary capillary closing pressure, and maximal diastolic filling rate. None of these were reduced. In fact, ejection fraction rose by a mean of 0.05, stroke index by a mean of 5 ml/m2, while p.c. closing pressure and contractility did not alter significantly. Verapamil and diltiazem reduced the pressure X rate product (an important determinant of oxygen consumption); nifedipine reduced total systemic resistance. It is concluded that verapamil and diltiazem can be used with advantage in cases of unstable angina, if there are severe abnormalities of LV function; they are to be preferred to beta-blockers in this situation. Nifedipin is the calcium antagonist of choice in hypertension and abnormal LV function.
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PMID:[Verapamil, diltiazem or nifedipine in severe left ventricular functional disorder? A comparative study of the immediate hemodynamic effects]. 394 Aug 29

The purpose of this study was to delineate the clinical, ECG, and angiographic features of a large series of consecutive patients with angina at rest. Transient ST segment elevation during pain was observed in 219 patients (group I), while 220 patients showed ST segment depression during pain (group II). Group II patients were found to have higher incidence of hypertension (p less than 0.001), prior myocardial infarction (p less than 0.0005), history of exertional angina (p less than 0.0005), and a progressive aggravation of symptoms before hospitalization (p less than 0.0005), while group I patients had a prevalence of recent onset angina (p less than 0.05) and more frequently developed severe ventricular arrhythmias during pain (p less than 0.0005). Furthermore, a larger number of patients showing ST segment depression during chest pain had multivessel disease (p less than 0.0005), left main involvement (p less than 0.005), and lower values of left ventricular ejection fraction (p less than 0.001) than patients with ST segment elevation during pain. Survival curves of medically treated patients showed a significantly better long-term prognosis in patients of group I (p less than 0.01). The direction of the ST segment shift during anginal attacks at rest may therefore allow a classification of patients included into the broad spectrum of unstable angina. This distinction should be taken into consideration in studies aimed at evaluating long-term prognosis or the results of medical and surgical therapy.
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PMID:Clinical and angiographic findings in angina at rest. 394 60

The importance of a positive family history as a primary risk factor for coronary heart disease was examined in a case history study. Of 792 consecutive male patients aged under 60 years who survived a first episode of unstable angina or myocardial infarction, 326 had a negative family history, 298 had a positive history, and in 168 a family history could not be established with certainty. There was no significant difference in the distribution of the three primary coronary risk factors--cigarette smoking, hypertension, and hypercholesterolaemia--between those with and those without a positive family history. The 133 subjects with a positive family history of premature coronary heart disease (occurrence in near relatives under 60 years) were significantly younger than those with a negative family history. It is concluded that there is little evidence to confirm a positive family history as an important independent risk factor for coronary heart disease, although there may be familial aggregation of subjects with a high susceptibility to the effects of the three primary risk factors, cigarette smoking, hypertension, and hyperlipidaemia.
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PMID:Is a family history of coronary heart disease an independent coronary risk factor? 398 54

Nifedipine, a calcium channel blocking agent, has been shown safe and effective in the treatment of various cardiac disorders. In Prinzmetal's variant angina, nifedipine relieves the acute spasm of a large coronary artery, and thereby reverses the sudden decrease in myocardial oxygen supply. In chronic stable angina, the efficacy of nifedipine stems from an interplay of direct and reflex effects. A decrease in systemic vascular resistance, and thus, myocardial oxygen demand, is considered the most important effect. Although this is partially offset by baroreceptor-mediated reflex increases in blood pressure and heart rate, the net effect is a decrease in myocardial oxygen consumption. The importance of nifedipine-induced increases in coronary blood flow in relieving stable angina remains controversial. Numerous clinical trials in patients with chronic angina have demonstrated that nifedipine increases exercise tolerance by lowering the heart rate-blood pressure product (an approximation of myocardial oxygen consumption). The maximal double product during exercise, however, does not increase, suggesting that the drug does not importantly improve myocardial oxygen supply. Nifedipine may also be of value in the therapy of unstable angina, acute myocardial infarction, and hypertension, as well as in the protection of the myocardium at risk during open heart surgery. However, definite recommendations on the use of the drug for these indications must await results of ongoing randomized studies. The effects of nifedipine are dose-related. Larger doses have been shown more effective than smaller doses, as long as an appropriate blood pressure is maintained. The side effects of nifedipine are mild and related to its vasodilating action.
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PMID:Nifedipine in the treatment of cardiovascular disease. 610 Aug 18

Unstable angina can be defined by the development of chest pain at rest, usually with reversible S-T segment changes. It has been found in patients in whom angina developed at rest in the cardiac catheterization laboratory that a decrease in coronary sinus oxygen saturation preceded changes in left ventricular relaxation and contractility that preceded the development of chest pain and/or electrocardiographic changes. Increases in heart rate and/or blood pressure followed, rather than preceded, these ischemic episodes. These findings suggest that a decrease in oxygen supply, rather than an increase in oxygen demand, is the cause of episodes of angina at rest. Although principles of treatment of effort angina have emphasized the reduction of myocardial oxygen demand, treatment of rest angina should logically emphasize therapies that improve oxygen supply. A stepwise approach to the treatment of patients admitted to the Coronary Care Unit with unstable angina is proposed. The initial step consists of replacing oral and/or transcutaneous nitrates with an intravenous infusion of nitroglycerin while maintaining beta-blockers and calcium blockers at their previous doses. Nitroglycerin dilates coronary arteries and intercoronary collateral channels in addition to reducing preload and afterload. Intravenous administration allows faster titration to an effective dose and also more rapid reversal of hemodynamic effects, if the patient's status changes. The second step would consist of maintaining the nitroglycerin infusion and beta-blockers and adding or increasing the dose of calcium channel blockers. Slow channel calcium blockers dilate coronary arteries and prevent or reverse coronary spasm in addition to reducing afterload. The third step consists of adding or increasing the dose of beta-blockers in subgroups of patients with resting tachycardia and/or arterial hypertension. The fourth and final step would be to employ intra-aortic balloon counterpulsation therapy and/or to perform urgent coronary angiography. In patients with suitable coronary anatomy, angiography could be followed by percutaneous transluminal angioplasty or coronary artery bypass surgery.
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PMID:Unstable angina. Rational approach to management. 614 57

Coronary heart diseases (CHD) have high indices of mortality and morbidity. A number of CHD and myocardial ischaemic syndromes such as unstable angina pectoris, sudden death ischaemic heart disease, acute myocardial infarction and ventricular arrhythmias have been associated with losses of myocardial magnesium and potassium. Mg++ ions are essential for regulation of Na+ and K+ transport across cell membranes, including those found in cardiac and vascular smooth muscle cells. Mg++ activates an Na+-K+-ATPase pump which in turn plays a major role in regulating Na+-K+ transport. Loss of cellular Mg++ results in loss of critically important phosphagens: MgATP and creatine phosphate. Thus, under conditions where cellular Mg++ is depleted (e.g. hypoxia, ischaemia, anoxia), the Na+-K+ pump and phosphagen stores will be compromised, leading to alterations in resting membrane potentials. Cellular Mg++ depletion has been found to result in concomitant depletion of K+ in a number of cells, including cardiac and vascular muscles. The consequences of these events are often production of cardiac arrhythmias. Myocardial and vascular injury lead to disturbances in electrolyte transport across cell membranes, whereby Na+ and Ca++ uptakes are enhanced and, just prior or concomitantly, Mg++ and K+ are lost. Such electrolyte disturbances often lead to necrotic foci. Considerable evidence has accumulated to indicate that the extracellular concentration of Mg++ is important in control of arterial tone and blood pressure via pressure via regulation of vascular membrane Mg++-Ca++ exchange sites. A reduction in the extracellular Mg++ concentration can produce hypertension, coronary vasospasm and potentiation of vasoconstrictor agents by allowing excess entry of Ca++; concomitantly, the potency of vasodilator agents is reduced. Alterations in vascular membrane Mg++ results in arterial and arteriolar membranes which are 'leaky', thus contributing to the cellular reduction in K+ and gain of Na+ and Ca+. Alterations in extracellular K+ or Na+ concentrations over physiological ranges, in the face of a Mg++ deficit, can exacerbate the coronary vasospasm noted with reduction in only extracellular Mg++. Since free Mg++ ions are necessary for maintaining Ca+ ions (both plasma membrane-bound and sarcoplasmic reticulum membrane-bound via Ca++ ATPases), intracellular free Mg++ would rise in conditions which result in cellular loss of Mg++, thereby exacerbating and contributing to elevation of blood pressure and coronary vasospasm.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Magnesium, electrolyte transport and coronary vascular tone. 614 22

The aim of this study was to compare the medium-term results of medical therapy and aortocoronary bypass surgery in 87 patients selected on the following criteria: Clinical: unstable angina, defined as effort and/or resting angina appearing for the first time or increasing in severity within the previous 3 months, the last attack of chest pain occurring less than 8 days before admission to the Coronary Care Unit, with no signs of myocardial infarction before hospital admission and at coronary angiography. Coronary angiography: proximal isolated left anterior descending artery stenosis (greater than 70%). Thirty five patients were treated medically and 52 underwent coronary bypass surgery on the LAD artery: the results were compared at 18 and 24 months. Six patients were lost to follow-up, 2 from the medical group; the other 33 patients comprised group A. Four surgical patients were lost to follow-up, the other 48 patients comprised group B. The two groups had comparable clinical and epidemiological features. They differed in the incidence of hypertension which was more common in group A (p less than 0.01), in the better quality of the distal LAD artery in group B (p less than 0.01), and in the coexistence of less than 50% stenosis on the right coronary and left circumflex arteries which was commoner in group A (p less than 0.05). The mean follow-up period was comparable in the two groups (group A: 20.5 +/- 4.6 months; group B: 19.8 +/- 5.5 months).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Unstable angina caused by monotruncular stenosis of the anterior interventricular artery (87 cases). Results of medical and surgical treatment]. 615 Jun 92


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