ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The effect of 0.3 mg sublingual nitroglycerin (NTG) was evaluated by hemodynamic measurements and precordial S-T-segment mapping in 17 patients following acute myocardial infarction.In all cases NTG produced a prompt reduction in mean pulmonary capillary wedge pressure (PCW) from an average of 19 ± 2 to 14 ± 1 mm Hg associated with a small fall in mean arterial pressure from a mean of 85 ± 4 to 82 ± 4 mm Hg. No significant change in heart rate occurred.In patients without left ventricular failure (PCW 3-12 mm Hg) cardiac output (CO) fell 9%. By contrast, in patients with moderate left ventricular failure (PCW 13-22 mm Hg) CO rose 18%. In three patients with refractory left ventricular failure (PCW 25-31 mm Hg) CO rose 25%. Two of these patients were treated with repetitive NTG doses in addition to previously ineffective diuretic therapy with resolution of resistant pulmonary edema. No significant changes in the magnitude of S-T-segment elevations were noted.NTG may have a special role in the management of acutely ill patients with myocardial infarction in whom pulmonary edema does not respond to conventional therapy.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

By the use of a precise and sensitive double-isotope derivative technic, plasma catecholamine concentration was measured at 2-hour intervals in 10 patients during the first 48 hours of myocardial infarction.Plasma catecholamine concentration was elevated in most patients, but to an extremely variable degree. In each patient, however, the values were rather stable during the study period. High levels of plasma catecholamines were correlated to the clinical state of the patients. Patients who received antiarrhythmic treatment on admission to the hospital had higher values than untreated patients. There was no temporal correlation between plasma catecholamine concentration and ventricular arrhythmias. In contrast to the plasma catecholamine level, the heterotopic ventricular activity declined spontaneously in the untreated patients within the study period.It is emphasized that the plasma catecholamine concentration in patients with acute myocardial infarction is considerably lower than the level necessary to produce arrhythmias in experimental myocardial infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The relationship between shortened electromechanical systole (QS2I) and 24-hour urinary catecholamine excretion (E+NE) was studied in 51 patients admitted to the coronary care unit with suspected acute myocardial infarction. Among these patients, 24 had a documented acute myocardial infarction while 27 had chest pain without evidence of recent myocardial infarction. Patients receiving cardioactive drugs or with impaired renal function were excluded. Initial elevation of catecholamine excretion was found in 22 of 24 subjects with myocardial infarction and 14 patients without documented myocardial infarction. A close linear correlation (r = -0.82,P< 0.001) was noted between shortening of the QS2I and catecholamine excretion among all patients irrespective of the presence of documented infarction. Patients with serious arrhythmias had significantly higher levels of catecholamine excretion. In 13 patients with a short QS2I, 2.5 mg of propranolol given intravenously produced a significant lengthening of the QS2I while no change in the QS2I occurred in normal controls. This test provided useful corroborative evidence that the short QS2I was related to excessive adrenergic stimulation. In view of the current availability of effective beta-adrenergic blocking agents, these results may improve the selection of patients for antiarrhythmic therapy with these drugs.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The anginal syndrome (AP) typically includes sensations of chest tightness or difficulty in breathing. Left ventricular (LV) dysfunction during myocardial ischemia incident with AP is now well documented. Since secondary alterations in lung mechanics could relate to these symptoms, we examined airway resistance (Raw), lung volume (TGV), lung compliance (CL), and LV pressure-volume relations during pacing-induced AP.LV end-diastolic pressure (EDP) increased suddenly with AP, (mean + 41%,p< 0.01), without change in end-diastolic volume (EDV). LV distensibility (EDV/EDP) decreased abruptly, (−37%,P< 0.01), with reduction in airway conductance (1/Raw/TGV), (−40%,P< 0.05), and CL(−27%,P< 0.05). When AP was relieved, these changes returned toward preangina levels.Ischemia-induced LV dysfunction abruptly increases LVEDP. The resulting increased pulmonary capillary pressure effects an alteration of lung mechanics consisting of increasing Raw and reduced CL. The changes in ventilatory effort which ensue may be interpreted as chest tightness, heaviness, or constriction by the AP patient.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Aortocoronary vein grafts were placed in seven patients to bypass severe proximal stenosis in nine coronary arteries. Routine postoperative angiography showed patent grafts in all patients and substantial increase of proximal occlusive disease, diffusely or at the points of narrowing, in six of nine arteries (four patients), with complete obstruction of four of the six vessels. Two of the four patients experienced improvement in angina which was sustained despite the advanced proximal disease. The third patient suffered a late postoperative myocardial infarction and the fourth had recurrence of angina, both probably as a result of the increased proximal disease. The possibility is considered that a successful vein graft, by diverting flow from the poststenotic segment, may accelerate its occlusion and that consequences of advancing occlusive disease may not be prevented by vein-grafting surgery.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Relief of angina by nitroglycerine has been attributed to two possible mechanisms: (1) Increase in myocardial blood supply by direct action of the drug on the coronary arteries. (2) Reduction in myocardial oxygen demand by action of the drug on the systemic circulation. Sublingual application of nitroglycerin in previous studies did not allow the ruling out of the operation of either or both mechanisms. This study was, therefore, designed in such a way that the effect of the direct action of nitroglycerin on the coronary bed on angina could be studied in the absence of changes in the systemic circulation. In 25 patients undergoing cardiac catheterization and coronary arteriography as possible candidates for revascularization surgery, nitroglycerin, 0.075 mg in 1 ml of 5% dextrose, was injected into the left coronary artery through the angiographic catheter during angina pectoris induced by pacing. Coronary sinus blood flow by the continuous thermodilution method, femoral artery blood pressure, and lead V5were recorded continuously. In 20 patients the procedure was repeated with injection into the right coronary artery. In none of the 25 patients did the intracoronary injection of nitroglycerin alleviate the angina during the 1-min observation period, whether injected into the obstructed artery or into the artery supplying collaterals to the obstructed artery. The intracoronary injection was ineffective despite a significant increase in coronary sinus blood flow in 14, lasting 26 sec on the average. This suggests that the increase in blood flow did not occur in the ischemic areas where it was needed, but in other areas where the arterioles were not maximally dilated by ischemia. This explanation is further supported by the fact that in five patients with very severe restriction of the left coronary artery system the coronary sinus blood flow failed to increase in response to intracoronary nitroglycerin during angina, but increased significantly in response to nitroglycerin after discontinuation of pacing and disappearance of angina. In six patients, 0.2 mg nitroglycerin injected intravenously 1 min following the intracoronary injection relieved the angina unaffected by the preceding intracoronary injection. The relief was associated with a fall in arterial blood pressure and coronary sinus blood flow. The study indicates that the direct action of nitroglycerin on the coronary bed plays little, if any, role in the antianginal effect of the drug, which appears to be due entirely to the action of the drug on the systemic circulation.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Coexistent idiopathic hypertrophic subaortic stenosis (IHSS) and coronary arterial disease (CAD) was found in 10 patients studied because of disabling angina. Only one had experienced consistent relief of angina with nitroglycerin. All had systolic murmurs which had been ascribed to valvular stenosis or papillary muscle dysfunction. Mean patient age was 57 years. Nine were males. All patients were shown to have the characteristic hemodynamic and angiographic findings of classical IHSS. Coronary cineangiography revealed severe CAD in each patient. Precatheterization diagnosis of combined IHSS and CAD was difficult to make unless a very well-documented history of prior myocardial infarction was available, and clinical evaluation revealed the typical auscultatory and pulse contour changes of IHSS. In six of the patients clinical evidence alone was not sufficient to diagnose combined disease with any certainty. There is a significant incidence of IHSS in the coronary disease-prone age group. The possible coexistence of the two diseases has not been appreciated previously. Patients with IHSS and angina should be evaluated for CAD as they may benefit if therapy is directed at both disorders. Patients with CAD, angina, and systolic murmurs should be evaluated for possible IHSS, especially if coronary artery surgery is contemplated, since such therapy may be inappropriate or incomplete.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The echocardiographic findings of eight patients with hypertrophic cardiomyopathy without outflow obstruction (HMC) and of 15 normal (Norm) individuals are presented.The characteristic features in HMC were: (1) interventricular septal width much greater than normal (HMC = 2.5 ± 0.3 cm, Norm = 1.0 ± 0.2 cm,P< 0.005); (2) normal or only slightly increased posterior left ventricular wall thickness; (3) the ratio of interventricular septal to posterior wall thickness ≧2.0; (4) ejection fraction greater than normal (HMC = 0.76 ± 0.08, Norm = 0.68 ± 0.06,P< 0.025); (5) reduced velocity of the early diastolic closing motion of the anterior mitral leaflet (HMC = 60 ± 23 mm/sec, Norm = 124 ± 29 mm/sec,P< 0.005); (6) absence of abnormal systolic movement of the anterior mitral valve, as seen in hypertrophic obstructive cardiomyopathy. The diagnosis of hypertrophic cardiomyopathy can be made with echocardiography, even when outflow tract obstruction of the left ventricle is absent.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Echocardiographic waves from the posterior left ventricular endocardium were recorded in 30 normal subjects and in nine patients during 13 anginal episodes. At rest the normal maximal systolic endocardial velocity (SEVM) was 6.2 ± 1.4 cm/sec, the mean systolic endocardial velocity (SEV) was 4.1 ± 0.7 cm/sec, and the systolic endocardial excursion (SEE) was 1.4 ± 0.3 cm. The maximal diastolic endocardial velocity (DEVM) was 18 ± 3 cm/sec, and the mean early diastolic endocardial velocity (DEV) was 9.4 ± 1.7 cm/sec. Exercise in 20 normals caused a significant increase in SEVM, SEV, DEVM, and DEV, but not SEE. In no instance did any of these values fall below the resting levels. The angina patients differed significantly from the normals having at rest a slower DEVM (15 ± 4 cm/sec) (P< 0.025) and DEV (8.4 ± 0.8 cm/sec) (P< 0.025). During exercise, but before angina, there was a significant increase in SEVM and SEV but not SEE, DEVM, or DEV. In no instance did any of these values fall below the resting levels. During angina SEVM and SEV reacted variably and together with SEE were not significantly different from the resting values. In contrast, there was a remarkable slowing of DEVM (8.2 ± 3.2 cm/sec) (P< 0.001) and DEV (5.7 ± 2.2 cm/sec) (P< 0.001). Five minutes after the pain and S-T-segment depression disappeared, the endocardium moved as it did before exercise.

ISSN:0009-7322    

出版商:OVID    

年代:1972

数据来源: OVID