Echocardiography guided creation of balloon pericardial window.
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Biomedical subjects
Publications and source records attributed to A M Vora.
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Left-sided accessory pathways are a common substrate for supraventricular tachycardias in children. A transseptal approach to catheter ablation has been primarily advocated in this population because of concerns regarding vascular injury, aortic, and mitral valvular damage using the transaortic approach via retrograde femoral arterial cannulation. However, the transaortic approach is simpler and may be less time consuming. We, therefore, compared the efficacy and safety of the transseptal vs the transaortic approach in 49 consecutive pediatric patients. In both groups, the atrial insertion site of the accessory pathways was targeted. Postprocedure two-dimensional and Doppler echocardiograms were obtained in all patients. The transseptal and transaortic groups were similar in age (15.8 +/- 1.6 vs 13.5 +/- 3.6 p NS), manifest vs concealed (9/5 vs 20/15), and number of radiofrequency lesions (4 vs 6). Fluoroscopy time was significantly shorter in the transaortic group (33 vs 58 min, p < 0.05). The only evident complications were mild mitral regurgitation seen in two patients (one in each group). Two patients in the transseptal group had recurrence of tachycardia on follow-up and were successfully ablated by the transaortic method. In this series from a single center, a transaortic approach to ablation of left-sided accessory pathways in children older than 4 years was as effective as a transseptal approach.
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Radiofrequency ablation produces a focal area of myocardial necrosis. Creatine kinase (total & MB fraction) and troponin-T were analysed in 54 patients who underwent electrophysiological study and radiofrequency ablation for atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia and idiopathic ventricular tachycardia. The age of the patients was 36 +/- 12 years; 17 patients underwent slow pathway modification for atrioventricular nodal reentrant tachycardia, 26 patients underwent accessory pathway ablation and 11 patients underwent ablation for idiopathic ventricular tachycardia. There was no significant rise in creatine kinase, creatine kinase total & MB fraction and troponin-T in the patients who underwent slow pathway ablation for atrioventricular nodal reentrant tachycardia. In patients with atrioventricular reentrant tachycardia, there was no significant rise in creatine kinase and creatine kinase total & MB fraction levels, while troponin-T levels rose from 0.13 +/- 0.06 to 0.29 +/- 0.16 eta g/ml (p < 0.05). There was an increase in creatine kinase, creatine kinase total & MB fraction and troponin-T levels after idiopathic ventricular tachycardia ablation from 68.4 +/- 44.9 to 138.0 +/- 81.7 IU (p < 0.05), 2.77 +/- 3.34 to 25.2 +/- 19.8 IU (p < 0.05) and 0.09 +/- 0.04 to 0.34 +/- 0.08 eta g/ml (p < 0.001) respectively. Radiofrequency ablation of atrioventricular nodal reentrant tachycardia does not cause any significant myocardial damage to raise any cardiac enzymes. Ablation of atrioventricular reentrant tachycardia results in only minor injury causing rise in only troponin-T levels. However, ventricular tachycardia ablation results in significant myocardial injury raising all the cardiac enzymes.
The presence of atrioventricular block and ST segment elevation in lead V4R accurately predicts right coronary artery occlusion in patients with inferior wall myocardial infarction. However, these electrocardiographic signs are absent in the majority of patients with inferior myocardial infarction. We studied ST segment elevation in leads II and III, ST segment in lead I and T wave polarity in lead V4R in order to differentiate between right coronary artery and left circumflex coronary artery occlusions in 104 patients with inferior myocardial infarction who subsequently underwent coronary angiography. The ST segment elevation was greater in lead III than in lead II when the right coronary artery was the culprit vessel and vice versa when the left circumflex was the culprit vessel (p < 0.001). An upright T wave in lead V4R and ST segment depression in lead I was common when the right coronary artery was the culprit vessel and not seen with left circumflex occlusion (p < 0.001). ST segment elevation in lead III was higher than in lead II with a sensitivity of 99 percent and a specificity of 100 percent for diagnosing right coronary artery as the culprit vessel. ST segment elevation in lead II was higher than in lead III with a sensitivity of 93 percent and a specificity of 100 percent in identifying the left circumflex as the culprit vessel. Thus, these signs are very useful in identifying the culprit vessel in inferior myocardial infarction.
Atrial fibrillation, commonly associated with rheumatic mitral stenosis, worsens the prognosis. We studied the efficacy of achieving and maintaining sinus rhythm in patients with chronic atrial fibrillation who underwent a successful balloon mitral valvotomy. Fifty-four patients (26 men, 28 women; age 36+/-8 years) received amiodarone 200 mg thrice daily in the first week, and thereafter a maintenance dose of 200 mg once daily. Electrical cardioversion was attempted at 1 and 3 months and patients were followed up at 6, 12 and 18 months. At the end of 1, 3, 6, 12 and 18 months 81 percent, 72 percent, 60 percent, 54 percent and 49 percent of patients, respectively, were in sinus rhythm. Only one patient had a severe adverse effect (hypothyroidism). Univariate analysis revealed that lower age, shorter duration of atrial fibrillation and smaller left atrial size was associated with successful restoration to sinus rhythm. On multivariate analysis, the duration of atrial fibrillation was the only significant predictor of long-term maintenance of sinus rhythm. Amiodarone seems safe and reasonably effective in restoration and maintenance of sinus rhythm in patients of atrial fibrillation with rheumatic heart disease.
A 21-year-old male presented with episodes of paroxysmal tachycardia mediated via a concealed posteroseptal accessory pathway. He was also found to have a diverticulum of the coronary sinus. However, successful radiofrequency ablation was achieved only endocardially under the mitral annulus and not within the diverticulum.
Radiofrequency ablation is an effective treatment for various tachycardias. In some patients undergoing radiofrequency ablation, there are additional complexities. Of 254 consecutive patients (161 males, 93 females, aged 38 +/- 15 years) who underwent radiofrequency ablation, two groups were identified. Patients with structural heart disease, multiple accessory pathways, multifocal idiopathic ventricular tachycardia, parahisian accessory pathways, and multiple mechanisms of tachycardia were considered as complex radiofrequency ablation (Group I) and the remaining as non-complex radiofrequency ablation (Group II). There were 23 patients in Group I. The overall success rate was not different in the two groups: 20/23 (87%) vs 208/231 (90%) in groups I and II, respectively. The procedure and fluoroscopy time (212 +/- 91 min vs 136 +/- 45 min; p = 0.0001; and 55 +/- 31 min vs 31 +/- 21 min; p = 0.001, respectively) were significantly longer in Group I. There was a higher recurrence rate in Group I (6/20, 30% vs 20/208, 9.6%; p = 0.02); repeat radiofrequency ablation was successfully performed in four patients with recurrence in Group I. Complications were rare in both the groups. There was no mortality. Thus radiofrequency ablation in complex situations was effective, though more demanding than non-complex radiofrequency ablation and associated with higher recurrence.
Arrhythmogenic right ventricular dysplasia is a potentially life-threatening disorder, not previously well described in India. We analysed the electrocardiographic, electrophysiologic, angiographic, signal-averaged electrocardiogram and magnetic resonance imaging features of nine patients having arrhythmogenic right ventricular dysplasia at our centre. There were seven males and two females, aged 25 to 55 years. Eight patients presented with sustained monomorphic ventricular tachycardia. The electrocardiogram showed prolonged QRS duration in four, T inversion in leads V2-V3 in four, and epsilon wave in two patients. Abnormal late potentials were present in eight patients. During electrophysiologic study in seven patients, 13 different VTs were induced. Seven patients had right ventricular dilatation and dysfunction and left ventricular involvement was seen in three patients. Eight patients were treated with amiodarone, including one who received an implantable cardioverter-defibrillator. At a follow-up of 8.6 +/- 5.3 months, there was no death, while one patient had recurrence of ventricular tachycardia. Arrhythmogenic right ventricular dysplasia seems to predominantly affect middle-aged men, the presentation most often being sustained monomorphic ventricular tachycardia. Depolarisation and/or repolarisation abnormalities in the electrocardiogram are commonly present. Multiple ventricular tachycardia morphologies during electrophysiologic study and abnormal right ventricular angiograms are usually observed.