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Biomedical subjects

A S Mitha

Publications and source records attributed to A S Mitha.

At least 19 recordsLinked to original sources
PubMed2000

Follow-up of patients with arrhythmogenic right ventricular cardiomyopathy dysplasia.

OBJECTIVE: The enlargement of data on the natural course and management of patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). DESIGN: Retrospective and partly prospective observational study. SETTING: Cardiac Unit, Wentworth Hospital, Durban--the only unit in KwaZulu-Natal providing an arrhythmia and electrophysiology service. STUDY POPULATION: Those included were: (i) patients referred for palpitations, unexplained syncope, or ventricular tachycardia and in whom ARVC/D was diagnosed according to multiple criteria; and (ii) family members of patients with ARVC/D in whom the disease was documented using the same criteria. MAIN OUTCOME AND MEASUREMENTS: Diagnosis, management, morbidity and mortality were analysed. RESULTS: Twelve patients were diagnosed with ARVC/D over a period or 6 years. At the end of follow-up for 3.4 +/- 3.2 years, 7 of them were well and alive on anti-arrhythmic medication, 2 were asymptomatic, and 3 had died. One death was sudden, 1 patient died due to left ventricular failure, and 1 patient died due to a low cardiac output syndrome 3 months after right ventricular isolation, i.e. the mortality rate was 25%. ARVC/D was found in all racial groups and was familial in 5 patients (42%). In all but one patient the correct diagnosis was not suspected by the referring institution, physician or cardiologist. CONCLUSIONS: ARVC/D needs to be included into a differential diagnosis of unexplained syncope, palpitations, or ventricular tachycardia by all health service providers. Its management remains a complex challenge with varying results.

Adult↗
PubMed1998

Evaluation of ibopamine plus prazosin in congestive heart failure.

STUDY OBJECTIVE: To determine the acute haemodynamic response of a single dose co-administration of ibopamine plus prazosin in patients with congestive heart failure. DESIGN: A double-blind, placebo-controlled randomised crossover study followed by a 2-week, open safety evaluation. SETTING: Wentworth Hospital, Durban. PATIENTS: 12 patients with congestive heart failure who were in functional class (NYHA) II-III. INTERVENTIONS: All patients underwent right heart catheterisation. On days 1 and 2 they received study drug or placebo plus prazosin and underwent haemodynamic recordings for 4 hours. RESULTS: Single-dose (200 mg) ibopamine plus prazosin augmented cardiac output (and index) and an early (0-60 minute) phasic response in the pulmonary capillary wedge pressure (PCWP) that did not appear to be influenced by the presence of prazosin. The increase in cardiac output was accompanied by a moderate decline in systemic vascular resistance (P = NS) without a change in heart rate. In the open evaluation, 8/14 patients reported adverse events. Six events were considered to be related to study medication of which one (dizziness) occurred in the haemodynamic phase. CONCLUSION: This study shows that ibopamine has beneficial haemodynamic effects in patients with moderate to severe heart failure. The increase in cardiac output was mild and sustained but with little change in systemic vascular resistance. The early rise in PCWP is not mediated by the alpha-agonistic vasoconstrictor effects of ibopamine.

Adrenergic alpha-Antagonists↗
PubMed1995

Beta adrenergic blockade does not improve effort tolerance in patients with mitral stenosis in sinus rhythm.

OBJECTIVES: This study was designed to assess the effects of beta-blockade on cardiopulmonary exercise performance in symptomatic patients with tight mitral stenosis in sinus rhythm. BACKGROUND: The role of beta-blockers in these patients has been controversial and assessment of effort tolerance using treadmill exercise time has produced conflicting results. METHODS: Nineteen patients with isolated symptomatic (New York Heart Association class II or III) mitral stenosis received a beta-blocker (acebutalol or atenolol) or matching placebo for one week each in a randomized double-blind crossover fashion. Exercise on a treadmill with real time gas exchange analysis was performed six times over 4 weeks in each patient. The test was further repeated once within a week of percutaneous mitral valvotomy. RESULTS: Heart rate at rest and during peak exercise was significantly lower with beta-blockade compared to control state or placebo treatment. Mean peak oxygen consumption did not differ significantly between treatment groups. When patients were arbitrarily classified into those with (group I, heart rate < or = 130.min-1) and those without (group II, heart rate > or = 131.min-1) adequate beta-blockade, there was a significant difference in peak VO2. The peak VO2 for group I: 14.0 +/- 3.2 vs 17.5 +/- 4.0 ml.min-1.kg-1; peak VO2 for group II: 17.2 +/- 2.4 vs 18.0 +/- 2.4 ml.min-1.kg-1 (beta-blockade vs control state respectively). Treadmill exercise time did not differ between treatment groups. The slope of minute ventilation (MV) and carbon dioxide (CO2) excretion, and instantaneous carbon dioxide ventilatory equivalent (MV/VCO2) was unchanged with beta-blocker therapy indicating no improvement in ventilatory performance. CONCLUSIONS: Beta-blocker therapy in tight mitral stenosis appears to have no beneficial effect on aerobic capacity, nor does it improve ventilatory performance. Adequate beta-blockade may adversely effect peak oxygen consumption.

Acebutolol↗
PubMed1995

Percutaneous balloon dilatation of the mitral valve in critically ill young patients with intractable heart failure.

OBJECTIVE: To assess the outcome of percutaneous balloon dilatation of the mitral valve in critically ill young patients with intractable heart failure. DESIGN: Retrospective analysis of all such patients presenting over a period of 4 years. PATIENTS: Of 432 consecutive patients undergoing percutaneous balloon dilatation of the mitral valve, 12 (mean age 29 years) with intractable heart failure were identified. Nine had severe pulmonary oedema and three had pulmonary oedema with severe right heart failure and hypotension. Three patients were pregnant and three required mechanical; ventilatory support. PROCEDURE: Percutaneous balloon dilatation of the mitral valve was performed using the Inoue balloon technique. The procedure was shortened by excluding full right study, cardiac output measurement, and left ventriculography. The mitral valve morphology and mitral valve area were determined before and after percutaneous balloon dilatation using cross sectional Doppler echocardiography. RESULTS: The procedure was technically successful in all patients. The mean (SD) echocardiographic value of the mitral valve area increased from 0.7 (0.1) to 1.4 (0.2) cm2 with a concomitant reduction in pulmonary artery systolic pressure (Doppler) from 81 (17) to 50 (7) mm Hg. There was a significant clinical improvement in all patients. The mean (range) fluoroscopy time for the procedure was 6.9 (1.7-14.1) min. During follow up (mean 10 months) nine patients were in New York Heart Association (NYHA) functional class I, one was in class II, one under NYHA elective mitral valve replacement, and one, who refused elective surgery, died suddenly at home. CONCLUSION: Percutaneous balloon dilatation of the mitral valve can be performed as a life saving procedure in critically ill patients with mitral stenosis, as even a modest increase in valve area in these patients produces gratifying clinical improvement.

Adult↗
PubMed1994

Iliac compression: a rare hindrance to percutaneous mitral valvuloplasty.

Percutaneous mitral valvuloplasty using the Inoue technique was complicated by the failure to pass the dilator or balloon catheter above the vertebral level of L5 due to compression of the right common iliac vein by the right common iliac artery. The procedure was accomplished when a long sheath was used to pass the Inoue balloon catheter beyond the obstruction.

Adult↗
PubMed1993

Intravenous fenoldopam infusion in severe heart failure.

Fenoldopam, a selective DA1-receptor agonist, infused intravenously for 24 hours (0.6 +/- 0.3 microgram/kg/min, range 0.1-1.5) in 25 patients with NYHA functional class III or IV heart failure, produced a prompt and sustained hemodynamic response. Cardiac index rose from an average preinfusion baseline value of 1.8 to 2.6/l min. Stroke volume index increased from 19 to 26 ml/m2 and stroke work index increased from 18 to 25 g M/m2. These changes were accompanied by a reduction in systemic vascular resistance from an average of 2400 to 1500 dynes sec/cm5. There was no change in the heart rate or right atrial pressure. There was a transient reduction in the left ventricular filling pressure from 25 to 20 mmHg. Urinary sodium excretion did not change significantly. Transient asymptomatic thrombocytopenia developed in four patients. The drug was well tolerated by all patients. These results suggest that continuous intravenous infusion of fenoldopam is safe and produces favorable hemodynamic responses in severe heart failure. However, unlike its effects in patients with hypertension, it failed to produce sustained natriuresis in these patients.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1993

Percutaneous balloon mitral valvotomy in pregnant patients with tight pliable mitral stenosis.

Percutaneous balloon mitral valvotomy was attempted in severely symptomatic (New York Heart Association class III or IV) pregnant patients (mean age 30 years) with tight mitral stenosis. Nineteen patients were pregnant (mean gestation 30 weeks, range 26 to 34) and one patient was in the immediate postpartum period. All patients had undergone a trial of diuretic therapy and 16 were also taking atenolol. Percutaneous valvotomy was performed with the Inoue catheter (18 patients) or the Schneider-Medintag bifoil (2 x 19 mm) balloon catheter (2 patients). The fluoroscopy time was 9.2 +/- 3.4 minutes. After percutaneous valvotomy the mean mitral gradient decreased from 17.9 +/- 6.2 to 5.9 +/- 2.4 mm Hg (p < 0.001). The mitral valve area (pressure half time) increased from 0.8 +/- 0.2 to 1.7 +/- 0.2 cm2 (p < 0.001). These hemodynamic changes were accompanied by immediate symptomatic improvement by at least one New York Heart Association functional grade in all patients. Moderate (3+) mitral regurgitation developed in one patient. Eighteen patients had normal infants delivered vaginally at term without assistance, and one patient had a normal infant delivered by cesarean section at 35 weeks' gestation. We conclude that percutaneous balloon mitral valvotomy for pliable mitral stenosis in pregnancy is safe for both the mother and fetus. We recommend that it be performed in symptomatic patients with tight mitral stenosis so as to avoid hemodynamic complications in the latter stages of pregnancy.

Adult↗
PubMed1993

Balloon mitral valvotomy with a single catheter: a comparison between bifoil/trefoil and the Inoue balloon.

Results of percutaneous mitral valvotomy were compared in two groups undergoing the procedure at our institution. Group I: 100 patients having had percutaneous valvotomy with the Schneider-Medintag bifoil (2 x 19 mm) or trefoil (3 x 15 mm or 3 x 12 mm) catheters, and group II; 150 patients in whom the procedure was performed with the Inoue balloon (24-30 mm). Baseline clinical (age, gender, NYHA class and echo score) and haemodynamic variables were similar in both groups. Haemodynamic improvement occurred in both groups. Although the reduction in left atrial pressure did not differ significantly between the two groups, the increase in mitral valve area was significantly (P < 0.001) higher for group I (0.8 +/- 0.2 to 1.9 +/- 0.7 and 0.8 +/- 0.3 to 1.6 +/- 0.3 cm2 respectively for mitral area, and 22 +/- 6 to 13 +/- 5 and 21 +/- 6 to 13 +/- 5 mmHg respectively for mean left atrial pressure). The increase in cardiac output was statistically significant in group I (3.2 +/- 0.7 to 4.0 +/- 0.9 l.min-1, P < 0.05) but not in group II (3.5 +/- 2.0 to 3.7 +/- 0.9 l.min-1, ns). Inter-atrial shunting immediately after valvotomy was recorded in 19% of group I patients compared with 6% in group II (P < 0.001). The overall incidence of significant mitral regurgitation (3+ or 4+) was similar in both groups (5% and 4% respectively). However, when the stepwise dilatation technique was employed in group II, the incidence had dropped to 2.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Balloon valvuloplasty versus closed commissurotomy for pliable mitral stenosis: a prospective hemodynamic study.

Closed surgical mitral valvotomy is the procedure of choice in most patients with symptomatic pliable mitral stenosis in developing countries. The procedure is efficacious and safe. Mitral valvotomy performed with a balloon has shown similar good results, with infrequent complications in selected subjects. Because there is a paucity of studies comparing the two techniques, this study was undertaken to compare the results of percutaneous balloon mitral valvuloplasty with those of closed commissurotomy as determined by catheterization studies. Forty-five patients with tight pliable mitral stenosis were randomly assigned to one of two groups: 23 patients had balloon valvuloplasty by the single catheter technique (group I) and 22 underwent closed surgical valvotomy (group II). The two groups were similar with regard to clinical and hemodynamic findings before intervention. Mitral valve area increased from 0.8 +/- 0.3 to 2.1 +/- 0.7 cm2 in group I (p less than 0.001) and from 0.7 +/- 0.2 to 1.3 +/- 0.3 cm2 in group II (p less than 0.001). Pulmonary artery pressure and pulmonary vascular resistance decreased in both groups, but these changes did not reach statistical significance in group II. Treadmill exercise time increased from 3.8 +/- 2.3 to 7.3 +/- 2.6 min in group I (p less than 0.001) and from 4 +/- 2.6 to 5.6 +/- 2.6 min in group II (p less than 0.001). There were no deaths. One patient in each group developed moderate (3+) mitral regurgitation. A small interatrial shunt (less than 1.5:1) was detected in three patients in group I immediately after the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Continuous electrocardiographic monitoring in hypertensive crises in pregnancy.

Twenty-four patients first seen with hypertensive crises during pregnancy were studied by continuous electrocardiographic monitoring for a period of 24 hours to detect the presence of serious ventricular arrhythmias. Three patients were excluded from analysis because of low serum potassium levels. Thirteen of the remaining 21 patients had ventricular tachycardia on subsequent analysis of the electrocardiogram. These arrhythmias subsided after induction of anesthesia when blood pressure control was optimal. This finding may be implicated in the pathogenesis of pulmonary edema and sudden death in these patients.

Adult↗
PubMed1991

Pulmonary hypertension in aortic regurgitation: early surgical outcome.

A review of the haemodynamic data of 139 patients with isolated, severe, chronic aortic regurgitation revealed severe pulmonary hypertension (pulmonary artery systolic pressure of greater than or equal to 60 mmHg) in 34 (24 per cent). The left ventricular end-diastolic pressure was high in all patients, suggesting that pulmonary hypertension was a consequence of severe long-standing regurgitation with ventricular dysfunction. Aortic valve replacement was performed in 69 patients, 33 of whom had normal or mildly elevated pulmonary artery systolic pressure (less than 39 mmHg; group I) and 36 of whom had moderate or markedly elevated pulmonary artery systolic pressures (less than 40 mmHg; group II). There was no difference in mortality or prevalence of post-operative complications between these two groups of patients. Furthermore, New York Heart Association (NYHA) functional class and cardiothoracic ratio were similar in both groups at the six-month assessment. The pulmonary vascular resistance fell from 4.7 +/- 3.5 to 1.5 +/- 0.8 units x m2 in 13 of 17 patients who had repeat catheterization after surgery. Pulmonary artery systolic pressure reverted to normal in 10 of these 13 patients. It is concluded that pulmonary hypertension consequent upon raised left ventricular end-diastolic pressure is common in severe aortic regurgitation, is largely reversible, and does not influence the early outcome after aortic valve replacement.

Adult↗
PubMed1990

Isolated tricuspid valve infective endocarditis. A report of 6 cases.

Six cases of isolated tricuspid valve endocarditis in young women are described. Preceding genital sepsis was a predisposing factor in 4 patients. Cardiac signs are unusual at presentation, rendering the diagnosis difficult. Pleuropulmonary manifestations are the predominant findings, while overt signs of tricuspid insufficiency and right heart failure occur late in the disease. Staphylococcus aureus is the pathogen most commonly found and requires energetic treatment for a minimum of 4 weeks. The value of echocardiography in establishing an early diagnosis is stressed. Persistent sepsis constitutes a major indication for surgery.

Adult↗
PubMed1990

Arrhythmias in idiopathic dilated cardiomyopathy. A preliminary study.

Idiopathic dilated cardiomyopathy is second to valvular heart disease as a cause of congestive heart failure in blacks in southern Africa. The disease has a deteriorating clinical course with high mortality. More than half these deaths are sudden and have been related to arrhythmias. In a preliminary study of 20 black patients in congestive heart failure caused by dilated cardiomyopathy, 24-hour ambulatory ECG monitoring was used to assess the prevalence, type and clinical significance of arrhythmias. Eighteen of the 20 patients (90%) had arrhythmias. Supraventricular arrhythmias were detected in 17 (85% of the total), and 18 (90%) had complex ventricular arrhythmias. Eleven (55%) had non-sustained ventricular tachycardia (VT). There was no correlation between complex ventricular arrhythmia and clinical features, resting ECG, chest radiograph or echocardiographic data. Over a 3-year period 13 patients died (65%), half these deaths being unexpected. All 13 had complex ventricular arrhythmias, and those who died suddenly had non-sustained VT. This small prospective study shows that ventricular arrhythmias are common in dilated cardiomyopathy in blacks and are frequently complex and dangerous. Sudden death is common and is more than likely to be related to VT in the presence of an already poorly functioning left ventricle.

Adolescent↗
PubMed1990

Balloon dilatation of the mitral valve by a single bifoil (2 x 19 mm) or trefoil (3 x 15 mm) catheter.

The efficacy of balloon dilatation of the mitral valve by a bifoil (2 x 19 mm) or trefoil (3 x 15 mm) catheter (single catheter technique) was assessed in 53 patients (mean age 28) with mitral stenosis, most of whom were women. The procedure was unsuccessful in three patients. After balloon dilatation the left atrial pressure decreased from 22 mm Hg to 13 mm Hg and the mitral valve gradient from 12 mm Hg to 4 mm Hg. The mitral valve area increased from 0.7 cm2 to 2.1 cm2. Exercise time on the standard Bruce protocol increased from 3.9 minutes to 7.2 minutes. In 22 (44%) patients mitral regurgitation developed or the grade of regurgitation increased. Left to right shunts with pulmonary to systemic flow ratios greater than 1:5 were detected in four patients. Transient cerebrovascular episodes developed in two patients. One patient died after emergency valve replacement for severe mitral regurgitation. Balloon dilatation of the mitral valve by the single catheter technique with the bifoil or trefoil catheters is an effective treatment for patients with mitral stenosis. Mild mitral regurgitation is a frequent complication of the procedure.

Adolescent↗
PubMed1988

High-dose oral amoxycillin in the treatment of infective endocarditis.

Oral antibiotic therapy for infective endocarditis is not yet widely accepted. A study was undertaken to assess the efficacy of oral amoxycillin in this condition. Fifteen patients were treated with high-dose oral amoxycillin for 6 weeks. Twelve responded to treatment and remain well at 3 years. There were 3 deaths--1 at day 7 due to sudden aortic cusp rupture, and 2 late deaths due to pulmonary and cerebral embolism respectively. There was 1 relapse of streptococcal prosthetic valve endocarditis 8 weeks after oral treatment, but this responded to conventional intravenous therapy. Oral amoxycillin is effective in uncomplicated streptococcal endocarditis, and should not be used with prosthetic valve infections.

Administration, Oral↗