Biomedical subjects
Publications and source records attributed to K Bhagat.
This case report describes a patient presenting with atrial tachyarrhythmia and severe left ventricular failure in which rate control was associated with restoration of normal contractile function.
A 27 year old woman presented with a two year history of cardiac symptoms. Echocardiographic examination revealed a ruptured aneurysm of the sinus of Valsava. Of note the patient was known to be HIV positive.
Beta blockade may be beneficial for most patients with congestive cardiac failure (CCF) whether due to ischaemic or idiopathic dilated cardiomyopathy (DCM), although they are more effective if the CCF is idiopathic. Beta blockers are additive to angiotensin converting enzyme (ACE) inhibitors in their effects on CCF. Beta blockers have been shown in most studies to increase ejection fraction, cardiac output, and exercise capacity and are sometimes capable of resolving almost all the symptoms of heart failure. Treatment should begin with the smallest possible dose and this should be gradually increased to the maximum tolerated level.
The impact of ischaemic heart disease on the burden of cardiovascular disease continues to escalate worldwide, although international statistics suggest a levelling off in Western world, in the less industrialised parts of the world the effects of this disease are only beginning to be documented, nonetheless, rapid advances have been made in the diagnosis and management of the acute coronary syndromes (the term which encompasses the protean clinical manifestations of the ischaemic process). The therapeutic strategies discussed in this article cover two broad subjects that have been found to be critical in the evolution of the disease:- i. interfering with the haemostatic balance by retarding the thrombotic process; ii. modifying local and systemic vasoconstricting stimuli.
Nitric oxide (NO) is a unique, endogenous regulatory molecule that is involved in a wide variety of physiological processes in multiple organ systems. This simple gas functions as a cellular messenger in a broad range of biological activities that include blood pressure regulation, immunomodulation and neurotransmission. It has also been implicated in a number of homeostatic functions in the cardiovascular system: it is a significant determinant of basal vascular tone and, in addition is thought to regulate myocardial contractility and platelet aggregation. Dysregulation of NO mediated effects have been implicated in the pathogenesis of essential hypertension, atherosclerosis, and the hypotension associated with septic shock. This review will focus on these multiple effects of NO in the cardiovascular system.
We report a case of a 47 year old woman who presented with a history of motor convulsions and a three month history of an increasingly painful and progressively enlarging mass on the right side of her back. Neurological examination revealed generalised wasting and a right sided hemiplegia. A biopsy of the mass was taken for microbiology which reported growing branching gram positive rods after three days of incubation. A mycological diagnosis of Nocardia asteroides was made. An MRI scan revealed extensive infiltration of the fungal mass into extending from the base of the skull to fifth cervical vertebra.
Many people could define with ease the job of a cardiologist, a paediatrician or an obstetrician. However, only a few would have any clear idea of how a clinical pharmacologist might fill a day. Indeed, within the medical profession, and often within the scientific community, there has been a sneaking suspicion that clinical pharmacologists are themselves unsure of their remit. This article describes the possible role for clinical pharmacologists and different areas where they can make significant contributions to medical services.
There have been important advances in the management of migraine headache. Revised diagnostic criteria, which were introduced in 1988 1 have led to more reliable assessment of the prevalence of migraine and the way it affects attendance and efficiency at work. In addition, the use of the 5HTI agonists has become established. The correct diagnosis of migraine and other headaches is of greatest importance as unless the right diagnosis is made, the right treatment cannot be given. In this article, we discuss how these changes have altered the management of migraine in adults.
OBJECTIVES: To assess the prescribing patterns for the use of antithrombotics in the management of atrial fibrillation. DESIGN: A descriptive cross sectional study. SETTING: Parirenyatwa Hospital, Harare, Zimbabwe. SUBJECTS: The outpatient records of 200 outpatients attending the cardiac clinic (with a documented history of an irregular pulse) between January and August 1999 at Parirenyatwa Hospital, Harare, Zimbabwe were reviewed. MAIN OUTCOME MEASURES: In addition to antithrombotic therapy prescribed at the time of review, patient information (rural or urban), relative contra-indications to antithrombotic therapy, and risk factors for stroke were identified. RESULTS: Patients were similar in terms of age, sex, and risk factors for stroke. At least one stroke risk factor was noted in 79% of urban and 83% of rural patients. Two risk factors were noted in 26% of patients. It was noted that urban patients were more likely to have a relative contra-indication to antithrombotic therapy compared with rural patients (24% vs 10%, p = 0.028) but received antithrombotic therapy more often (38% vs 19%, p = 0.025). CONCLUSIONS: Patients with atrial fibrillation are being inappropriately managed in terms of their major prognostic risk factor. Rural patients with atrial fibrillation receive antithrombotic therapy less frequently than urban patients despite having a similar high risk profile and fewer relative contra-indications.
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Patients with re-entrant supraventricular tachycardias frequently attend casualty departments for termination of their rhythm. With the advent of adenosine in the physician's pharmaceutical armoury, the ease and effectiveness of vagal stimulation is being forgotten.
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BACKGROUND: Endothelial dysfunction occurs in many diseases associated with increased cardiovascular risk. We examined the effects of pro-inflammatory cytokines on endothelial function. METHODS AND RESULTS: Subjects lay with one hand placed on an angled support. The diameter of a vein was recorded by measuring the linear displacement of a probe placed on the skin overlying the vein when the pressure in a congesting cuff placed around the upper arm was deflated from 40 to 0 mm Hg. A length of the vein was isolated by two wedges. TNF-alpha (1 ng), IL-1beta (1 ng), or IL-6 (100 pg) were instilled for 1 hour, either individually or together. At the end of the hour, the wedges were removed and the vein reconnected with the circulation. Dose-response curves (bradykinin: 2, 4, and 8 pmol/min; arachidonic acid: 0.2, 2, and 20 nmol/min; and glyceryl trinitrate 1, 2, and 4 pmol/min) were constructed before and 1, 6, 24, and 48 hours after instillation. In another study, hydrocortisone (100 mg) was given 2 hours before the study. In a different study, subjects were given oral aspirin (75 mg or 1 g) 2 hours before the study. TNF-alpha and IL-1beta alone but not IL-6 attenuated the dilatation to bradykinin and arachidonic acid; the response was greatest at 1 hour with recovery occurring by 6 hours. Combination of IL-1beta and TNF-alpha prolonged the endothelial dysfunction, resulting in recovery at 24 hours. Hydrocortisone and high-dose aspirin prevented endothelial dysfunction. CONCLUSIONS: The results demonstrate that pro-inflammatory cytokines induce transient and reversible endothelial dysfunction and indicate that cyclooxygenase activity may contribute to the genesis of the effect. If other vessels behave similarly, this may provide further insight into the mechanisms precipitating acute cardiovascular events after inflammatory disorders.
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AIMS: Endothelin-1 is a potent endogenous vasoconstrictor that acts on the endothelin A (ET[A]) receptor. The dose-response and time-course of the dilator effect of the ET(A) receptor antagonist, BQ-123, was investigated in the forearm of healthy volunteers. METHODS: Forearm blood flow was measured using mercury-in rubber strain gauge venous occlusion plethysmography. RESULTS: Following intra-arterial infusion of BQ-123 (50 nmol min-1) for 5 min, forearm blood flow increased by approximately 60% over the next 60 minutes; lower doses were without significant effect. The degree of dilatation was similar to that observed in previous studies using 20-fold larger doses. CONCLUSIONS: This study confirms that basal endothelin-1 has a role in the physiological regulation of vascular tone. It is possible that at low doses, BQ-123 might be a more sensitive pharmacological tool for the detection of abnormal endothelin-1 mediated constriction.