ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Twelve patients with angina pectoris were evaluated in a single blind crossover study with respect to objective changes in exercise performance on the treadmill and subjective, clinical improvement on oral administration of propranolol, isosorbide dinitrate (ISD), and a combination of propranolol and ISD. Combined objective and subjective evaluations showed that nine of 12 patients improved on propranolol, seven of 10 on ISD, and all 10 on the combination of drugs. The differences in objective improvement between the various drug regimens were not significant. However, subjectively all patients on the combination of drugs improved markedly. The patients on propranolol or the combination had a decrease in pressure-rate index of about 30% both at rest and during exercise, while these values did not change on ISD. A significant reduction in exercise-induced S-T depression was observed with propranolol alone and in combination with ISD at grade 3+ pain. Adrenergic activity, estimated from plasma and urinary catecholamines, appeared to be increased in these patients before drug treatment and was not altered during treatment. It is concluded that propranolol, ISD, and the combination of these drugs all improve exercise performance in patients with angina. Although the combination of drugs could not be shown to produce a greater increase in exercise performance than either drug alone, the combination effected a greater overall clinical improvement.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Glucose utilization and secretion of insulin and growth hormone after intravenous administration of glucose were measured during the evolution of myocardial infarctions. Two patterns of responses were found. Patients who developed myocardial infarction with either no prior cardiovascular disease or stable coronary artery disease had depressed glucose utilization for the first 48 hours and exhibited a hyperinsulinemic response to glucose during the sixth to fourteenth day; and, about 50% of them, had an increase in the secretion of growth hormone during the initial 4 days of the infarction. Patients who had had progressively increasing angina in the 7 to 14 days preceding infarction showed a different pattern. No initial depression of glucose utilization was found. Their hyperinsulinemic response occurred within the first 96 hours of the occlusion. Growth hormone secretion was increased in 83% of the patients during the first 96 hours. The data suggest the possibility that the exaggerated insulin secretion may be associated with myocardial repair processes while the changes in growth hormone secretion may be related to the acute stress or necrosis of the infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

A 36-year-old housewife with type II hyperlipoproteinemia became pregnant with twins. Although the pregnancy was uneventful, the serum triglycerides were elevated during the third trimester, the delivery, and early puerperium. The mother had no complications directly related to the pregnancy despite hypercholesterolemia, coronary atherosclerosis, and hypertension. Cord blood cholesterol and beta lipoprotein in both twins were greater than twice normal. Despite this genetic defect in lipid transport the twins have developed normally during their first year of life. Since lipids and lipoproteins do not cross the placental barrier, it is concluded that type II hyperlipoproteinemia may have been present at birth.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Permanent pacemakers are useful in the management of certain patients with arrhythmias in the absence of heart block. Five patients are presented, four of whom obtained a satisfactory response to pacing. Continuous electrocardiographic monitoring by means of a magnetic tape system is useful in diagnosis as well as in the evaluation of the effects of therapy.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Mitral valve function was assessed by roentgen videodensitometry. Mitral reflux was rare when single ventricular ectopic systoles were produced by electronic stimulation of the right or left ventricle at various times in the cardiac cycle. It was also rare during the compensatory pause after the ectopic systole or with the following postectopic systole. Recurrent ventricular ectopic systoles interposed once per cycle were associated with minor reflux when introduced in mid-cycle. Such extrasystoles occurred late enough in the cardiac cycle for the ventricle to relax after the primary systole and for the mitral valve to open before the extrasystole. The extrasystolic contractions were, however, weak and incapable of opening the aortic valve. When interposed early in the cardiac cycle, extrasystolic potentiation of the primary ventricular contraction occurred, and no or minimal mitral reflux was observed.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

An animal model of cardiogenic shock has been developed in the intact unanesthetized dog. Selective embolization of the circumflex coronary artery with 0.2 ml of mercury produces infarction of the posterolateral wall of the left ventricle and a shocklike state in the dog which results in death of the animal in 5 to 48 hr. The syndrome of cardiogenic shock in the animal model simulates closely that observed in man. Systemic blood pressure falls sharply (25 to 30% of control) immediately after embolization, remains low for several hours, then slowly increases toward normal, but never reaches preinfarct levels. The left ventricular end-diastolic pressure (LVEDP) remains within normal limits (5 to 10 mm Hg) during the initial hypotensive state, but increases to values above 10 mm Hg during the period of rising systemic pressures. As left ventricular failure begins to develop as evidenced by the rise in LVEDP, the mean pulmonary artery pressure also rises above control values. The cardiac output falls to 40% of control levels following embolization and never recovers. Peripheral resistance rises to compensate for the reduction of cardiac output and remains above control levels. Electrocardiograms indicate an essentially normal sinus rhythm with short runs (5 to 15 beats) of ventricular tachycardia with A-V dissociation. The hypotensive state does not seem to be related to this arrhythmia. Death of the animal appears to be due to progressive failure of the left ventricular pump to maintain cardiac output and systemic pressures.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Catapres is a new imidazoline compound with potent antihypertensive properties. Significant reduction in blood pressure occurs between 1 and 4 hours after oral administration, with the peak effect occurring at 2 to 4 hours and the antihypertensive effect extending for 6 to 10 hours. Blood pressure is reduced in both the supine and erect positions, although the orthostatic response is the more prominent.Cardiac output is reduced moderately in both the supine and erect positions. Peripheral vascular resistance is also reduced, particularly in the erect posture. Accordingly, the cardiac hemodynamic findings suggest that the antihypertensive effect of Catapres is related to the combination of reduction in cardiac output plus decrease in peripheral resistance. Renal blood flow and glomerular filtration rate are preserved in both the supine and erect positions following Catapres administration. Contrasting with the preservation of renal blood flow and glomerular filtration rate, however, is the marked reduction in sodium chloride excretion which follows acute administration of the drug.The clinical utility of the drug was demonstrated in the chronic outpatient study. Although Catapres administered alone exerted only modest antihypertensive effects, a markedly enhanced antihypertensive response was achieved when the drug was combined with a potent oral diuretic, with 80% of patients so treated achieving significant blood pressure reduction in both the supine and erect positions.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

New quantitative norms for clinical evaluation of the atrial vectorcardiogram are presented. Real-time computer processing digitizes atrial electrocardiograms, reduces random noise content, rectifies base-line configuration, and corrects preamplifier distortion. Axial-system leads of 106 normal persons were so treated. The basic information derived includes spatial distribution and magnitudes of P, TP, and polar P vectors; length, width, and planarity of P loops; spatial P-TPangles; and the Eulerian angles of P-loop normalization. Normal P vectors show predominant leftward, inferior, and anterior orientation, with opposing TPdirection. Polar P vectors show predominant superior, anterior, and leftward clustering. The scatter of parameters in the orthogonallead frontal plane is about the same as for the tetrahedral system. Similarly, the atrial deflections of normals show equally rich notching in both systems. Resolution of the P-wave population into uncorrelated components, followed by resynthesis from these principal factor wave forms, revealed a fairly continuous “spectrum” of signal configurations. This technique, and extensive attempts by alternate means, failed to support the view that normal P waves can be separated into distinctive right and left atrial components.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Correlations were computed for 320 electrocardiographic measurements and variables of ventricular conduction defects in 452 unselected patients. The variables consisted of right and left ventricular conduction defects with and without myocardial infarction. Quantitative criteria were established which led to the identification of infarction in the presence of a ventricular conduction defect. The data were analyzed by two methods: (1) using four independent measurements, and (2) discriminant function analysis in conjunction with a likelihood ratio test using 9 or 10 measurements. Both techniques yielded similar results. In the presence of left ventricular conduction defects 52% of the cases of infarction were identified with a 14% false positive diagnosis of infarction. In the cases of right ventricular conduction defects the results were 54% and 11%, respectively. In both, the sensitivity could be increased at the expense of an increase in the false positive frequency. This study confirms the difficulties in the electrocardiographic diagnosis of infarction in the presence of left ventricular conduction defects. In addition, it emphasizes that a simlar problem exists with right ventricular conduction defects, a finding which has not been adequately appreciated to date.

ISSN:0009-7322    

出版商:OVID    

年代:1969

数据来源: OVID