India: is it plague?
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Disease Outbreaks↗
Biomedical subjects
R Thakur
Publications and source records attributed to R Thakur.
Shortening of fast pathway refractoriness after slow pathway ablation. Effects of autonomic blockade.
BACKGROUND: Shortening of the anterograde effective refractory period (ERP) of the fast pathway has been reported after radiofrequency ablation of the slow pathway. We hypothesized that ERP shortening may be related to autonomic changes, possibly catecholamine release, as a result of ablation. METHODS AND RESULTS: To test this, 10 consecutive patients with atrioventricular node reentry undergoing slow pathway ablation were given autonomic blockade before the ablation procedure. This was achieved by atropine 0.03 mg/kg and propranolol 0.15 mg/kg IV supplemented by half the initial dose after ablation and before the final study. A control group of 10 patients underwent the protocol without autonomic blockade. Before ablation, autonomic blockade did not alter the ERP of either the fast pathway (295 +/- 22 versus 298 +/- 26 milliseconds) or the slow pathway (264 +/- 36 versus 269 +/- 38 milliseconds). Autonomic blockade obscured dual pathway physiology in 2 patients and brought it out in another 2 without dual pathway physiology initially. Slow pathway ablation shortened the ERP of the fast pathway for the group as a whole (331.5 +/- 54 versus 305.5 +/- 60 milliseconds, mean +/- SD, n = 20, P < .04). There was no difference in degree of ERP shortening in control patients (23.5 +/- 58 milliseconds) or autonomic blockade patients (25.5 +/- 52 milliseconds). CONCLUSIONS: These data suggest that shortening of the ERP of the fast pathway after slow pathway ablation is not mediated by autonomic changes.
Adult↗
Intravenous streptokinase in the management of a subset of patients with unstable angina: a randomized controlled trial.
We report the results of a randomized controlled trial of intravenous streptokinase in a subset of patients with unstable angina. Seventy-six patients were admitted with prolonged (more than 20 minutes) angina at rest of less than 3 weeks onset. Fifty-two patients continued to have more than 3 episodes of prolonged angina in 48 hours on medical therapy with metoprolol, isosorbide dinitrate, nifedipine and intravenous nitroglycerin. Forty-eight patients consented to enter the study and were randomized into two groups. The first group, of 24 patients, received 1.5 million units of streptokinase infusion and the second group, also of 24 patients, received a placebo. Pain relief within 48 hours was achieved in 19/24 (79.1%) patients after streptokinase infusion as compared to 9/24 (37.5%) of the controls (P less than 0.05). Approximately 90% (17/19) of patients responding to streptokinase therapy were relieved of chest pain within the first six hours as against none in the controls. The incidence of acute myocardial infarction within six months was 12.5% (3/24) in those receiving streptokinase and 25% (6/24) in the controls. Mortality at six months stood at 8.33% (2/24) in the treated patients and 16.6% (4/24) in the controls. Intravenous streptokinase thus appears to be of benefit in patients with angina at rest of recent onset which does not respond to conventional medical therapy.
Angina Pectoris↗
Unusual "high take off" of the right coronary artery from the ascending aorta.
An exceedingly rare anomaly is described in which the right coronary artery originated two centimetres above the left posterior sinus of Valsalva in association with an aortic valve having two leaflets.
Aorta↗
Failure of oral atenolol and verapamil to increase the capacity and duration of exercise in patients in sinus rhythm with mitral stenosis.
The efficacy of oral atenolol in increasing the capacity and duration of exercise in 43 patients in sinus rhythm with mitral stenosis was evaluated and compared with that of oral verapamil in an open-label cross-over design. It was observed that although oral atenolol (100 mg per day) caused significant reductions in heart rate while resting and during exercise (P less than 0.001), the increases in capacity and duration of exercise were not significant. Oral verapamil (80 mg three times per day) also caused significant reductions in the heart rates at rest and during exercise (P less than 0.05) but the increases observed, although greater than that with atenolol, failed to reach the level of statistical significance. Occasional side effects occurred with both the drugs. Subjective symptoms of dyspnoea at rest and on exertion were relieved with both the drugs. We conclude that, although both drugs reduce the symptoms of dyspnoea, they cause only minor increases in the objective parameters. They do not, therefore, provide an alternative to surgery and have only a temporary place in the management of patients in sinus rhythm with mitral stenosis who are awaiting surgery.
Administration, Oral↗
Randomized study of epinephrine versus methoxamine in prehospital ventricular fibrillation.
Experimental data suggest that a pure alpha-agonist, such as methoxamine, may improve the outcome of patients in ventricular fibrillation. A double-blind, randomized, prospective study was conducted in a paramedic system comparing the use of methoxamine with epinephrine in enhancing conversion of ventricular fibrillation while otherwise following American Heart Association protocols. One hundred two patients in ventricular fibrillation not responding to initial defibrillations with a pulsatile rhythm were randomized into one of two groups, each containing 51 patients. Equipressor doses of epinephrine (0.5 mg) and methoxamine (5 mg) were given intravenously and repeated according to American Heart Association guidelines. The mean age, sex ratio, and mean paramedic response times were comparable for the two groups. The mean time at scene until conversion was 22 +/- 10 minutes for methoxamine and 17 +/- 7 minutes for epinephrine (P = NS). The methoxamine group received 3.1 +/- 1.4 doses as compared with 2.8 +/- 1.3 doses for the epinephrine group (P = NS). Conversion rate, defined as the percentage of patients who developed a pulse during resuscitation, was 27.5% for the methoxamine group and 49.0% for the epinephrine group (P less than or equal to .03). Successful resuscitation, defined as the conveyance of a patient to an emergency department with a pulse and rhythm, was 17.7% for the methoxamine group and 39.2% for the epinephrine group (P less than or equal to .02). Save rate, defined as the percentage of patients discharged alive after hospitalization, was 7.8% for the methoxamine group and 19.6% for the epinephrine group (P less than or equal to .07).(ABSTRACT TRUNCATED AT 250 WORDS)
Clinical Trials as Topic↗
Comparison of outcome of resuscitation of out-of-hospital cardiac arrest in persons younger and older than 70 years of age.
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Adult↗
Jaccoud's arthropathy--diagnostic and therapeutic implications.
A case of isolated chronic severe aortic regurgitation with Jaccoud's arthropathy involving the foot is presented. The interesting feature of the case is the absence of history of acute rheumatic arthritis at any stage of the illness. The diagnostic and possible therapeutic significance of this otherwise uncommon and benign condition are discussed.
Adult↗
Sinus arrest caused by atenolol-verapamil combination.
A case on concomitant atenolol-verapamil therapy for hypertension and angina pectoris, developing sinus arrest and life-threatening bradycardia is described. The complication occurred with low doses of both the agents and normal electrophysiologic status of the heart. The example suggests that pharmacodynamic synergism contributes more than pharmacokinetic interaction causing adverse reactions during beta blocker-verapamil therapy.
Adult↗
Value of the treadmill exercise test in asymptomatic and minimally symptomatic patients with chronic severe aortic regurgitation.
The value of the graded treadmill exercise test was assessed in 19 asymptomatic and minimally symptomatic (13 NYHA class I and 6 NYHA class II) male patients with chronic severe aortic regurgitation. It was observed that, in 2 patients who showed significant ST segment depression at peak exercise, the total exercise duration was significantly shorter (P less than 0.001) than in the patients not showing such changes. During left ventricular and aortic root angiography (in both patients) and selective left coronary angiography (in one of them), ST segment changes similar to those seen during exercise testing were observed. The mean rise in left ventricular end-diastolic pressure after injection of contrast material was significantly more (P less than 0.001) in these 2 patients compared to the other 17 patients. Both patients had normal resting M-mode echocardiographic parameters. It is concluded that ST segment depression on exercise testing and reduced exercise capacity are indicants of exercise-induced left ventricular dysfunction in asymptomatic and minimally symptomatic patients with chronic severe aortic regurgitation. Furthermore, it is suggested that this simple and cheap test can be used for serial evaluation of such patients in the absence of the facility of radionuclide cineangiography.
Adolescent↗
Development of subaortic stenosis and regurgitation several years after successful operation on a common atrium.
A patient who had had successful operation for a common atrium subsequently developed subaortic stenosis and regurgitation several years later. The diagnosis of subaortic lesion was confirmed by echocardiography. This case shows that the left ventricular outflow tract gradient should be measured before operation for common atrium and that after operation such cases should be examined by cross sectional echocardiography at follow up visits.
Aortic Valve Insufficiency↗
Failure of acetylmethadol in treatment of narcotic addicts due to nonpharmacologic factors.
Acetylmethadol, a new narcotic substitute, has a longer duration of action than methadone. Seventeen subjects, former heroin users currently under methadone treatment, entered a study of the toxicity and efficacy of this drug. Only nine subjects completed the assessment phase of the study and began the acetylmethadol phase, and only one completed the 8-week study phase. Hence, no conclusions can be drawn about acetylmethadol's efficacy. The high attrition rate was unrelated to pharmacologic factors; the subjects were concerned that if this drug was effective there would be no methadone to take home and hence no opportunity to trade, sell or "play with" (that is, combine with other drugs) the latter. This study emphasizes the difficulty in determining the efficacy of specific drug treatments for opiate-dependent patients.
Adult↗
Partial agonist properties and toxicity of oral oxilorphan.
Alternative pharmacologic adjuncts are needed for the management of opiate abuse. Oxilorphan, a narcotic antagonist, was studied at 5 different dose levels (1, 2, 4, 6, and 8 mg) in 30 normal subjects to determine the relation of single oral doses and toxicity. The drug causes pupillary constriction and mild central nervous system side effects (nausea, dizziness) at all doses. Mean urine volume increased (P less than 0.05) during the 12 hours after 1 and 2 mg. Oxilorphan has partial agonist properties similar to dl-cyclazocine.
Adult↗
New technique for superior hypogastric plexus block.
BACKGROUND AND OBJECTIVES: : The classical technique for blocking the superior hypogastric plexus (SHP) described by Plancarte sometimes renders the desired needle placement difficult. This article describes an alternative approach for blocking the SHP. METHODS: Three patients with pelvic pain from endometriosis underwent an anterior approach to block the SHP with fluoroscopic guidance. The ages of the patients ranged from 21 to 34 years, pain duration ranged from 2 to 4 years, and pain score on a visual analog scale of 0-10 ranged from 7 to 8. RESULTS: All patients had significant pain relief immediately after the block. The pain scores postblock ranged from 0 to 4/10. The duration of pain relief varied from 1 to 14 days. The contrast material localized at the L5 vertebral body in the posteroanterior and lateral views. CONCLUSION: We present a new approach to block the SHP with fluoroscopic guidance in patients with chronic benign pelvic pain.
Adult↗
Expression of cell surface glycoprotein CD44 and integrins in breast cancers among Indian women.
Parsis, the sole surviving group of followers of Zoroaster who are settled in Bombay, have a fourfold higher incidence of breast cancer than the general population of Greater Bombay. CD44 expression was studied by immunohistochemistry in breast cancers of 50 non-Parsi and 35 Parsi women, 10 normal breast tissues, 10 proliferative lesions and 49 tissues adjoining a tumor mass. Alpha2 and beta1 integrins could be studied in only 42 malignant cases and five normal tissues. The immunohistochemistry results were correlated with other parameters including tumor grade and size, estrogen and progesterone receptor status, lymph node involvement and mitotic index. CD44 was not expressed in normal areas. Benign areas and tissues adjacent to tumor masses showed increased staining. Both Parsi and non-Parsi women showed significantly high CD44 expression. All Parsi ILCs were strongly positive for CD44. In both groups ER negativity was associated with strong CD44 positivity, while mitotic counts correlated with decreased CD44 expression in Parsis but not in non-Parsis. Alpha2 and beta1 integrins were strongly expressed on the basolateral surface of normal epithelium. However, they were downregulated in tumors. In general breast tumor tissues from Parsi and non-Parsi patients did not differ significantly with respect to most parameters. However, among Parsis lymph node involvement and CD44 correlated weakly whereas the mitotic index was inversely correlated with CD44. The reverse was true for non-Parsis. The deviation from the general pattern needs further study based on a large number of samples and appropriate use of splice variants.
Breast↗
Comparative evaluation of acute effects of sublingual nifedipine and oral diltiazem by echocardiographic right ventricular systolic time intervals in primary pulmonary hypertension.
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Administration, Oral↗