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Biomedical subjects

U Thadani

Publications and source records attributed to U Thadani.

At least 109 records · Page 6Linked to original sources

Comparison of antihypertensive activity of beta-blocking drugs during chronic treatment.

The hypotensive activity of five beta-adrenoceptor antagonists with different ancillary pharmacological properties was compared in a randomised double-blind factorial trial in 25 untreated patients with stable, uncomplicated essential hypertension. In doses that produced similar reductions in exercise tachycardia all drugs had similar blood-pressure lowering activity, greater on systolic than diastolic pressure and greatest during exercise. With the exception of vasodilator activity the possession of any particular combinaton of ancillary pharmacological properties did not significantly influence the specific antihypertensive activity of these compounds.

Adrenergic beta-Antagonists↗

Comparative anti-hypertensive effectiveness of beta-adrenoreceptor antagonists with different pharmacological properties: dose-response studies during acute and chronic administration.

1. Immediate and long-term blood pressure-lowering activity of five beta-adrenoreceptor antagonists with different ancillary pharmacological properties were compared in a randomized double-blind placebo controlled factorial trial in twenty-five previously untreated patients with stable uncomplicated essential hypertension. 2. In doses which produced similar reductions in exercise tachycardia, all drugs exerted similar anti-hypertensive activity, which was greater on systolic than diastolic pressure and greatest during exercise. 3. These effects were maximum within an hour and lasted for over 8 h after a single oral dose. 4. Blood pressure-lowering activity, particularly the reduction in exercise systolic pressure, was significantly related to the logarithm of the dose of each drug. 5. Anti-hypertensive activity was maximally enhanced after 4 weeks of sustained treatment at any given dose. There was no short-term habituation to treatment and substitution with placebo resulted in a return of the blood pressure to pretreatment values within 4 weeks without subsequent overshoot. 6. The blood pressure-lowering activity of these drugs was predominantly related to their common property of competitive antagonism of cardiac beta-adrenoreceptors; their ancillary pharmacological properties, with the exception of intrinsic vasodilator activity, played little part in this response.

Adrenergic beta-Antagonists↗

Cardiac tamponade, constrictive pericarditis and pericardial resection in rheumatoid arthritis.

Four patients with rheumatoid constrictive pericarditis and two patients with rheumatoid cardiac tamponade are presented, and 60 previously reported cases with these two complications are reviewed. Rheumatoid arthritis was moderate to severe in 84% of the patients with cardiac tamponade and in 74% of the patients with constrictive pericarditis. However, both these complications were also seen in patients who had only mild arthritis and in two previously reported cases constrictive pericarditis actually preceded the onset of rheumatoid arthritis. The duration of rheumatoid arthritis had no bearing on the development of these complications. In 75% of patients with cardiac tamponade, and in 66% of cases with constrictive pericarditis, subcutaneous nodules were present. In those cases where the rheumatoid factor was measured it was positive in 92% with cardiac tamponade and in 84% with constrictive pericarditis. In 63% of patients with cardiac tamponade and in 70% of cases with constrictive pericarditis a history of pericardial type of pain was obtained and/or a pericardial rub heard. The diagnosis of cardiac tamponade and constrictive pericarditis was made clinically and in doubtful cases confirmed by cardiac screening and intracardiac pressure recordings. The low sugar content in the pericardial fluid in the absence of infection or malignancy was an important clue to the rheumatoid etiology of the effusion. In the majority of the cases histological appearances of the pericardial tissue showed non-specific fibrous reaction and infiltration with plasma cells and lymphocytes. Only in five of the cases, including one from the present series, were typical rheumatoid granulomatous lesions demonstrated. Treatment with corticosteroids neither prevented the occurrence nor led to amelioration of either cardiac constriction or tamponade. Pericardial resection was life saving, producing both symptomatic and objective involvement of the cardiac function. In the present series of six cases two patients developed aortic incompetence. In one of these it was due to rheumatoid granulomatous valve disease and in the other due to non-specific aortic valvulitis. The combination of constrictive pericarditis and granulomatous aortic valve disease has not been previously recorded.

Adult↗

Aortic valve incompetence and replacement in rheumatoid arthritis.

Five cases of aortic incompetence and nodular seropositive rheumatoid arthritis are presented. Four cases underwent aortic valve replacement. Two of these had granulomatous involvement of the aortic cusps similar to subcutaneous rheumatoid nodules, and another showed a nonspecific fibrosis. One case had definite coincidental rheumatic aortic and mitral heart disease. Two patients had undergone pericardectomy previously for constrictive pericarditis. Good results were obtained in all four operated cases and cardiac surgery enabled continuation of rehabilitation for the rheumatoid arthritis, including major orthopaedic procedures. A review of 22 cases from the literature with rheumatoid granulomata within the aortic valve shows that they are associated with mitral valve granulomata in 63-6%. Congestive cardiac failure was found in 75%. Macroscopical evidence of aortic incompetence was seen in 36-8% and of aortic stenosis in 15-8%. Associated pericarditis occurred in 59-1%, which was severe or complicated in 13.6%. The associated arthritis was severe in 77-8% with subcutaneous nodules (71-5%), rheumatoid factor (83-6%), and episcleritis (66-6%). From these cases and a review of the literature the following points are emphasized. (1) Both the granulomatous and nonspecific aortic valvulitis of rheumatoid arthritis may result in significant haemodynamic abnormality. (2) The valve lesions found are often clinically and macroscopically indistinguishable from rheumatic valve lesions. (3) Granulomata, when present, are usually found in the valve cusp or ring and only occasionally in the aortic wall. (4) Associated joint disease, although usually severe, may be mild. (5) The valve lesion may be accompanied by a severe pericardial involvement--either tamponade or constriction. (6) Aortic valve replacement for aortic incompetence in rheumatoid arthritis is both feasible and worthwile, despite severe joint disease.

Adult↗

Congenital intrapericardial aneurysms of the left atrium.

A patient with congenital intrapericardial aneurysm/diverticulum of the left atrium diagnosed preoperatively is described. A review of the 16 previously reported cases revealed that the majority of the patients present with palpitation and are found to have an abnormal cardiac shadow on chest radiography, as did this patient. The aneurysm appears to cause systemic emboli and paroxysmal or persistent atrial tachyarrhythmias which are often resistant to medical therapy. The presence of the aneurysm is suggested by an abnormal contour of the left cardiac border in the postero-anterior chest radiograph and this can be confirmed by angiocardiography. Surgical excision of the aneurysm is indicated in all patients to prevent the occurrence or recurrence of systemic emboli and atrial arrhythmias. Our patient has remained free of symptoms since her operation 14 months ago.

Adult↗

Massive splenomegaly, pancytopenia and haemolytic anaemia in sarcoidosis.

A 53-year-old dock labourer, presented with massive splenomegaly and subsequently developed pancytopenia. Complete haematoglogical remission was observed following splenectomy. Histological examination of the liver and spleen revealed sarcoid granulomata. A year after splenectomy, he died in an acute haemolytic crisis, a very rare complication of sarcoidosis. Evidence of generalized sarcoidosis was found at autopsy. The literature on haematological complications in sarcoidosis is reviewed.

Anemia, Aplastic↗

Pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease has recently been recognized as a distinct pathological entity and a cause of pulmonary arterial hypertension. Twenty previously reported cases and a new patient are here reviewed. The majority presented with breathlessness and in the early stages of the disease, when the abnormal signs were not striking, some patients were wrongly diagnosed as suffering from an anxiety state. The condition usually has an insidious onset but is remorselessly progressive and since no effective treatment is available at present, invariably fatal and the majority of patients have died within two years. The fully developed clinical picture is dominated by symptoms and signs of pulmonary arterial hypertension, similar to those found with other diseases causing a raised pulmonary arterial blood pressure. However, some patients with pulmonary veno-occlusive disease show, in addition, signs of pulmonary venous and capillary hypertension, which can lead to its clinical recognition when associated with a normal left atrial blood pressure. In this condition the pulmonary wedge pressure would appear to be unreliable as a record of the left atrial blood pressure. Pulmonary angiography and lung scanning will differentiate pulmonary veno-occlusive disease from massive thromboembolic pulmonary arterial hypertension but not from primary pulmonary arterial hypertension or micro thromboembolism. Although in some patients it should now be possible to recognise pulmonary veno-occlusive disease in life, there will be others where, even after full investigation, it will still be impossible to differentiate the condition from primary pulmonary arterial hypertension or micro thromboembolism and in these the diagnosis will only be made when the distinctive histological pattern of the disease is demonstrated. In pulmonary veno-occlusive disease there is a widespread occlusion of the pulmonary veins and venules by a loose intimal fibrosis which is often basophilic. Recanalization of the occluded veins is common and in some cases may be very striking. These occlusive lesions in the pulmonary veins lead to an elevation of pulmonary arterial pressure with associated disease of these vessels, and are also responsible for chronic oedema of the elveolar walls with subsequent development of interstitial pulmonary fibrosis. In the present case organised thrombi were present in the pulmonary arteries in addition to the pulmonary venous lesions.

Adolescent↗

A comparative study of the activity of beta-adrenoceptor antagonists in man.

1. In healthy subjects the plasma concentration of unchanged drug, heart rate response to excerise and attenuation of isoprenaline tachycardia were maximal at one hour after ingestion of a range of doses of propranolol, oxprenolol, practolol, tolamolol, atenolol and metoprolol. 2. There was a within-drug relationship between plasma concentration of unchanged drug and the attenuation of exercise and iosprenaline tachycardia. There was no similar between-drug relationship. 3. There was a similar exponential relationship between oral dose and reduction of exercise tachycardia for all six drugs. 4. The linear relationship between oral dose and antagonism of infused isoprenaline was significantly greater for oxprenolol and propranolol than for the other four drugs. 5. "Cardioselective" activity was the only ancillary pharmacological property which differentiated the activity of these drugs in normal subjects.

Adrenergic beta-Antagonists↗

Comparison of adrenergic beta-receptor antagonists in angina pectoris.

The symptomatic, electrocardiographic, and circulatory effects of intravenous and oral preparations of propranolol, oxprenolol, and practolol were compared in 16 patients with uncomplicated angina pectoris precipitated by exertion. The method of study included treadmill exercise, double-blind assessment, single-blind analysis, with placebo control and randomized serial comparison of each drug in each patient. The doses used were selected to give the same near-maximum suppression of the heart rate response to exercise. The symptomatic, electrocardiographic, and circulatory response of each patient to both preparations of each of the three drugs was similar. Exercise tolerance was increased in two-thirds, unchanged in one-sixth, and significantly worsened in one-sixth of the studies. Electrocardiographic evidence of myocardial ischaemia was conspicuously reduced by all three drugs in most studies irrespective of their symptomatic effects. Though the exclusive choice of patients, the single dose design of the trial, and the treadmill method of assessment limit the general application of these results, they do clearly indicate that in doses that induce equal suppression of the exercise heart rate these three drugs have similar distinct anti-anginal activity. Their ancillary pharmacological properties are probably of little importance in this respect. Equally, the similarity in the symptomatic, circulatory, and electrocardiographic response to the intravenous and oral preparations suggests that metabolic breakdown products are probably of therapeutic importance only in so far as they antagonize beta-receptor activity.

Acetanilides↗

Lignocaine therapy for ventricular ectopic activity after acute myocardial infarction: a double-blind trial.

The effectiveness of intravenous lignocaine in suppressing ventricular ectopic activity after acute myocardial infarction was examined in a double-blind trial in 82 patients. Whereas suppression of unifocal ventricular ectopics was achieved by lignocaine in 90% of patients, other forms of potentially more dangerous ectopic activity (multifocal or R-on-T ectopics) seemed more resistant to therapy. Cessation of ectopic activity was also observed in about one-third of the patients in the control group. The incidence of ventricular tachycardia and fibrillation and the mortality during and after the trial period were similar in the lignocaine-treated and control groups, whether or not the initial ventricular ectopics had been suppressed.This study provides no evidence to support the routine use of intravenous lignocaine in the management of ventricular ectopic activity after acute myocardial infarction.

Acute Disease↗

Pericarditis after acute myocardial infarction.

Fifty-two (6.8%) of 779 patients admitted to a coronary monitoring unit with acute myocardial infarction developed a pericardial friction rub. A diagnosis of postmyocardial infarction syndrome was made in three of these.The course of the 52 patients with pericarditis was compared with that of a consecutive series of 100 patients without pericarditis. As a group those with pericarditis manifested a longer period of pyrexia, a greater rise in serum enzymes, and a higher incidence of major arrhythmias and of radiological pulmonary oedema. The Peel prognostic index, however, did not differ significantly in the two groups. The hospital mortality of the pericarditis group was not significantly different from that of the 727 non-pericarditis patients. No specially adverse features were found in a follow-up of the pericarditis group.Though the presence of a pericardial rub in the first few days after a myocardial infarction may be a sign of extensive myocardial damage and is associated with a relatively high incidence of ventricular fibrillation, it does not appear to influence the hospital mortality of patients treated in a monitoring unit.

Acute Disease↗