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Biomedical subjects

Amit Vora

Publications and source records attributed to Amit Vora.

8 recordsLinked to original sources

Management of atrial fibrillation in rheumatic valvular heart disease.

PURPOSE OF REVIEW: Atrial fibrillation in patients with rheumatic valvular heart disease results in significant morbidity and possibly mortality. RECENT DEVELOPMENTS: The recent advances in treatment options for non-rheumatic atrial fibrillation have widened its scope of management. These treatment modalities have not been extensively validated in rheumatic valvular heart disease. SUMMARY: A review and comparison of the available data in atrial fibrillation and rheumatic valvular heart disease vis-à-vis non-rheumatic atrial fibrillation is presented.

Anti-Arrhythmia Agents↗

Control of heart rate versus rhythm in rheumatic atrial fibrillation: a randomized study.

BACKGROUND: Patients with rheumatic heart disease with atrial fibrillation incur significant morbidity and mortality. Which approach, ventricular rate control or maintenance of sinus rhythm, in this setting might be superior is not known. The role of amiodarone in this patient population for maintaining sinus rhythm has not been evaluated. METHODS AND RESULTS: We prospectively studied 144 patients with chronic rheumatic atrial fibrillation in a double-blind protocol in which rhythm control (group I), comprising 48 patients each with amiodarone (group Ia) and placebo (group Ib), were compared with each other and with patients in a ventricular rate control group (group II) in which the effects by diltiazem were determined (n = 48, open-label). Direct current cardioversion was attempted in group I. The mean age of the study population was 38.6 +/- 10.3 years, left atrial size, 4.7 +/- 0.6 cm; atrial fibrillation duration, 6.1 +/- 5.4 years; and 72.9% had valvular interventions performed. At 1 year, 45 patients with sinus rhythm in group I compared with 48 in group II demonstrated an increase in exercise time (2.6 +/- 1.9 vs. 0.6 +/- 2.5 min, P =.001), improvement in New York Heart Association class of 1 or more (P =.002), and improvement in the quality-of-life score of one or greater (P = 0.01) with no difference in hospitalizations, systemic bleeds, or thromboembolism. Five patients died in group II; none died in group I (P =.02). In group I, 73 of 87 (83.9%) patients converted to sinus rhythm and 45 of 86 (52.3%) patients maintained the rhythm at 1 year. Conversion rates were 38 of 43 (88.4%) with amiodarone versus 34 of 44 (77.3%) with placebo (P =.49); the corresponding rate for maintaining sinus rhythm was 29 of 42 (69.1%) versus 16 of 44 (36.4%) (P =.008). A larger number of electrical cardioversions were required in the placebo group (2.1 vs. 1.4, P =.011). CONCLUSIONS: Maintenance of sinus rhythm is superior to ventricular rate control in patients with rheumatic atrial fibrillation with respect to effects on exercise capacity, quality of life, morbidity, and possibly mortality. Sinus rhythm could be restored in most patients, and amiodarone was superior to placebo in the restoration and maintenance of sinus rhythm.

Adult↗

Importance of reciprocal leads in acute myocardial infarction.

OBJECTIVES: To study the relevance of the ECG changes in the reciprocal leads in patients with acute anterior and inferior wall myocardial infarction, with regard to culprit artery localization and left ventricular (LV) function. METHODS: Three hundred patients of acute myocardial infarction (AMI) (180 anterior, 120 inferior) aged between 30-90 years (mean age - 60 yrs; M:F - 220:80) were studied with regard to the reciprocal lead changes which were correlated with the culprit coronary artery and LV function. 285/300 (95%) patients underwent echocardiography and 62/300 (20.67%) underwent coronary angiography (CAG). RESULTS: In patients with acute anterior wall MI (AWMI), Q wave in inferior leads was found in 38.8% (70/180) patients. Nineteen patients underwent (CAG) and all 70 patients underwent 2D echocardiography. CAG revealed 10/19 and 9/19 patients to have single vessel disease (SVD) and multivessel disease (MVD), respectively. In presence of SVD, 80% (8/10) patients were found to have a distal/mid LAD occlusion. The echocardiogrpahy of these 19 patients showed that 15/19 (78.94%) of these had LV ejection fraction (EF) > 40% as against only 4/19 (21.05%) patients with LVEF < 40%. The echocardiographic study of patients with and without reciprocal ST depression in inferior leads more than or equal to the ST elevation in anterior leads, showed higher incidence of LV dysfunction i.e. LVEF < 40% in patients with reciprocal changes (72.05%) as compared to patients without the reciprocal changes (27.94%). In patients with acute inferior wall MI (IWMI), anterior and lateral ST depression more than or equal to ST elevation in inferior leads was found in 80% (96/120) patients. 27/96 patients underwent coronary angiography and all 96 underwent echocardiography. Patients with ST depression in I, a VL, V4-V6 (apicolateral leads) > or = ST elevation in inferior leads were found to have more occurrence of multivessel disease (21/27) with LVEF < 40% (50/64 i.e. 78.12%, P < 0.001). 12.5% (4/32) patients with reciprocal changes in anterior i.e. VI-V3 leads and 15% (3/20) patients without significant reciprocal changes in anterior and lateral leads had LVEF < 40%. Also, patients with ST depression in I, aVL showed higher incidence of right coronary artery (RCA) lesion (23/27) (P < 0.001). CONCLUSIONS: Patients of acute AWMI with Q waves in inferior leads indicate a smaller infarct with higher incidence of mid/distal LAD occlusion and a relatively preserved LV function. AWMI patients without reciprocal changes in inferior leads have a better LVEF. Patients of acute IWMI with ST depression in apicolateral leads have more occurrence of multivessel disease with significant LV dysfunction. Reciprocal ST depression in I, aVL suggests a possibility of RCA lesion.

Adult↗

Identification of novel genes preferentially expressed in the retina using a custom human retina cDNA microarray.

PURPOSE: To construct a custom cDNA microarray for comprehensive human retinal gene expression profiling and apply it to the identification of genes that are preferentially expressed in the retina. METHODS: A cDNA microarray was constructed based on the predicted human retina gene expression profile according to expressed sequence tag (EST) databases. Gene expression profiles were obtained from five human retinas, two livers, and the cerebral cortical regions of two brains. Each sample was studied in duplicate, using a reference sample experimental design. Retina-enriched genes were identified by using the significance analysis for microarray (SAM) algorithm. Quantitative real time PCR was used to confirm microarray results. Bioinformatic analysis was performed to compare the array results with expression data available from public databases. RESULTS: The cDNA microarray contains 10,034 sequences: 67% represent known genes and 33% represent ESTs. Differential hybridization with the array identified, in addition to known retinal genes, 186 retina-enriched genes that do not have known retinal function. Of these, 96 represent novel genes. Quantitative real-time PCR of 11 of the identified genes and ESTs confirmed their retina-enriched expression pattern. Bioinformatic analysis of EST databases suggests that of the 186 genes, approximately 40% are predominantly expressed in the retina, whereas the remainder show significant expression in other tissues. Comparison of this study's microarray-based retina-enriched gene set with three published similar sets identified using complementary high-throughput approaches demonstrated only limited overlap of the identified genes. CONCLUSIONS: Because previous studies have demonstrated that many retina-enriched genes are crucial for maintaining normal retinal function, the genes identified here are likely to include ones that have important roles in the retina and ones that when mutated can cause or modulate retinal disease. In addition, the retina custom array should provide a useful resource for comparing expression profiles between normal and diseased human retinas.

Adult↗

Tachyarrhythmias: the era of cure.

Radiofrequency ablation for tachyarrhythmias is a treatment modality, in the recent times, which has permanently cured the patients. The subject is discussed here in some details.

Catheter Ablation↗

Control of rate versus rhythm in rheumatic atrial fibrillation: a randomized study.

BACKGROUND: Patients with rheumatic heart disease and atrial fibrillation incur significant morbidity and mortality. It is not known which approach, rate control or maintenance of sinus rhythm might be most appropriate. The present study was undertaken to compare the strategy of ventricular rate control versus maintenance of sinus rhythm in rheumatic atrial fibrillation, and to evaluate the role of amiodarone in this patient population. METHODS AND RESULTS: We prospectively studied 144 patients with chronic rheumatic atrial fibrillation in a double-blind protocol-rhythm control (group I: 48 patients each with amiodarone -group Ia; and placebo -group Ib) and compared the effects with the ventricular rate control (group II) by diltiazem (n=48, open-label). Direct current cardioversion was attempted in group I. The mean age of the study population was 38.6+/-10.3 years, left atrial size was 4.7+/-0.6 cm, atrial fibrillation duration was 6.1+/-5.4 years, and 72.9% patients had undergone valvular interventions. At 1 year, 45 patients with sinus rhythm in group I compared to 48 patients in group II demonstrated significant increase in exercise to sinus rhythm time, had improvement in functional class and quality of life score. There was no difference in hospitalization rates, systemic bleeds or incidence of thromboembolism. Five patients died in group II but none in group I (p=0.02). In group I, 73/87 (83.9%) patients converted, and 45/86 (52.3%) patients maintained sinus rhythm at 1 year. Conversion rates were 38/43 (88.4%) with amiodarone versus 34/44 (77.3%) with placebo (p=0.49): corresponding rate for maintaining sinus rhythm was 29/42 (69.1%) versus 16/44 (36.4%), p=0.008 respectively. CONCLUSIONS: Maintenance of sinus rhythm appeared to be superior to ventricular rate control in patients with rheumatic atrial fibrillation in terms of an effect on mortality and morbidity. Sinus rhythm could be restored in the majority and amiodarone was superior to placebo in this regard.

Adult↗