Adenosine induced PR jump on surface ECG to differentiate atrioventricular nodal re-entrant tachycardia from concealed accessory pathway mediated tachycardia: a bedside test.

OBJECTIVE: To evaluate the efficacy of single dose intravenous adenosine in differentiating atrioventricular nodal re-entrant tachycardia (AVNRT) from concealed pathway mediated atrioventricular re-entrant tachycardia (AVRT) using surface ECG at the bedside. METHOD: 12 mg of adenosine was administered to 97 consecutive patients who had documented narrow QRS tachycardia without manifest pre-excitation. The test was labelled positive for AVNRT if surface ECG recordings showed signs of dual atrioventricular (AV) node physiology-namely, PR jump or AV nodal echo. The diagnostic value of this test was evaluated by electrophysiological study as the yardstick. RESULTS: The adenosine test was positive for AVNRT in 48 patients (adenosine induced PR jump in 48, AV nodal echo in 3) and negative in 49 patients. On electrophysiological study, 62 patients had AVNRT and 35 had concealed pathway mediated AVRT. Thus, the test had a sensitivity of 74% and specificity of 94%. The positive predictive value was 96% and the negative predictive value was 67%. CONCLUSION: Single dose (12 mg) intravenous adenosine administered during sinus rhythm can identify dual AV node physiology on surface ECG recording at the bedside. A positive adenosine test identified by a PR jump can differentiate AVNRT from AVRT with a high specificity and positive predictive accuracy.

Coronary sinus diverticulum with a concealed posteroseptal accessory pathway: a red herring?

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.

Restenosis after coronary stenting--incidence and predictors.

OBJECTIVE: To determine the intermediate term outcome after coronary artery stenting. METHODS: The six month angiographic and clinical follow-up of 92 consecutive patients (94 lesions) undergoing successful coronary stenting was performed. Multiple variables were analyzed for predicting restenosis. RESULT: The mean age was 49.7 +/- 8.5 years. There were 73 males and 19 females. Coronary artery involvement was left anterior descending artery (LAD) in 67%, left circumflex artery (LCx) in 16.5% and right coronary artery (RCA) in 16.5%. The pre-procedure mean reference diameter was 3.1 +/- 0.38 mm, minimal luminal diameter (MLD) was 0.47 +/- 0.28 mm and percentage diameter stenosis (DS) was 85 +/- 9%. Post procedure MLD improved to 3.1 +/- 0.4 mm with an acute gain of 2.6 +/- 0.4 mm and residual DS of only 3 +/- 3%. Clinical and angiographic variables were correlated with restenosis assessed as both binary and continuous variables. Angiographic follow-up could be obtained in 55 out of 92 patients (60%) and 86 patients (88%) had a clinical follow-up. Angiographic restenosis (> 50% diameter stenosis) was present in 12 (22%) patients, seven of whom required a repeat angioplasty procedure. There was no death. At follow-up, the MLD was 2.1 +/- 0.93 and the DS was 32 +/- 29% with a lumen loss of 0.92 +/- 0.84 mm. Only 14 (16%) of patients had angina and stress test was positive in 21 (23%). Hypercholesterolemia (p < 0.001) and female gender (p < 0.05) were independently associated with high lumen loss. CONCLUSION: Intracoronary stenting in an unselected patient group is associated with a 22% restenosis rate. Hypercholesterolemia and female gender are associated with higher restenosis.

Atrial fibrillation: how effectively can sinus rhythm be restored and maintained after balloon mitral valvotomy?

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.

Radiofrequency ablation: a cure for tachyarrhythmias.

Radiofrequency (RF) ablation is a new modality of pennanently curing patients with various tachycardias using radiofrequency energy, a technique evolved in the past decade. RF ablation was performed on 913 patients with different tachyarrhythmias from April, 1994 to July, 1999. There were 491 men and 422 females aged 42 +/- 34 years (range 1 to 76 years). Supraventricular tachycardia (SVT) was present in 462 patients, accessory pathway mediated atrioventricular re-entrant tachycardia (AVRT) in 355 patients (377 accessory pathways) and idiopathic ventricular tachycardia (VT) in 96 patients. Amongst the patients with SVT, 402 had atrioventricular nodal re-entrant tachycardia (AVNRT), 22 had atrial flutter, 20 had ectopic atrial tachycardia and 18 had atrial fibrillation. RF successfully abolished the tachycardia in 400/402 patients (99.5%) with AVNRT, 330/377 (87.5%) accessory pathways in patients with AVRT, 14/22 patients (63.6%) of atrial flutter, 18/20 patients (90%) of atrial tachycardia and 79/96 patients (82.3%) with idiopathicVT. Successful AV nodal ablation with pacemaker implantation was done in 10/18 patients with chronic atrial fibrillation with fast ventricular rate and tachycardia induced cardiomyopathy. AV nodal modulation for atrial fibrillation was tried in the remaining 8 patients and was successful in 4 (4/8). The overall success rate for all arrhythmias was 93.6%, and there was no mortality. At a follow-up of 6.8 +/- 5.4 months, there was a recurrence in 34/420 patients (8%), in whom successful re-ablation was performed. One patient with AVNRT and another with a parahisian pathway developed complete heart block and were given pacemakers. One patient developed inferior wall infarction on the next day post RF. There were 4 patients who had pericardial tamponade necessitating pericardiocentesis and 2 patients developed deep vein thrombosis, which was treated conservatively. Thus RF ablation is an effective, safe and curative therapy for various arrhythmias.

Does radiofrequency ablation increase creatine kinase and troponin-T?

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.

Dual morphology of idiopathic ventricular tachycardia.

INTRODUCTION: Idiopathic ventricular tachycardia (VT) typically has a single morphology originating either in the right ventricular outflow tract (RVOT) or near the posterior fascicle of the left ventricle (LV) in most instances. We present our observations in six patients with idiopathic VT in whom two morphologies were present. METHODS AND RESULTS: Of 55 patients with idiopathic VT who underwent radiofrequency (RF) ablation, 44 had LV "fascicular" tachycardia, whereas 11 had RVOT tachycardia. During RF energy delivery, there was a change in VT morphology in two patients with idiopathic LV tachycardia. This second morphology was not ablated initially, recurred at follow-up, and was reablated successfully. In two additional patients with idiopathic LV tachycardia, a second VT was inducible after ablation of the "clinical" VT. This second morphology recurred at follow-up and was ablated successfully in one patient. The site where the second VT was ablated in all the three patients was remote from that of the first VT. In two patients with RVOT tachycardia, a second VT, originating from a different area of the RVOT, was induced after RF ablation of the "clinical" VT. This second VT recurred at follow-up and was reablated successfully in one patient. CONCLUSION: Idiopathic VT is a more heterogenous entity than hitherto believed. A second VT was seen in 11% of patients during or after RF ablation of the "clinical" VT. The appearance of a second VT suggests either a different exit site of the same circuit or another site of origin.

Electrocardiographic differentiation between right coronary and left circumflex coronary arterial occlusion in isolated inferior wall myocardial infarction.

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.

Age at onset, gender distribution and intraarterial blood pressure changes in atrioventricular node-dependant tachycardias.

OBJECTIVE: Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) utilising accessory pathways constitute the vast majority of paroxysmal supraventricular tachycardia (SVT). We studied the age at onset, the gender distribution and the intraarterial hemodynamics of these tachycardias. METHODS: The data of 224 patients who underwent electrophysiology study (EPS) and radiofrequency ablation was analysed. The age at onset of tachycardia was assessed by a careful history. The intraarterial BP was noted during sinus rhythm (SR), immediately after tachycardia onset (T0) and 15 seconds after the onset of tachycardia (T15). RESULTS: The age at onset of tachycardia was a decade later for AVNRT (48 +/- 10 years) than for AVRT (37 +/- 11 years). There was no gender preponderance in the AVNRT group (60 males, 56 females) while a male preponderance was seen in the AVRT group (71 males, 37 females, p < 0.01). There was a marked fall in the intraarterial systolic BP in both groups at the onset of tachycardia, from 143 +/- 24 mm Hg to 108 +/- 16 mm Hg (p < 0.05) for AVNRT and from 139 +/- 25 mm Hg to 107 +/- 18 mm Hg (p < 0.05) for AVRT. There was no correlation between the rate of tachycardia and the extent of fall of BP. CONCLUSION: Hospital-based data in an Indian setting found a similar pattern of age of onset of AV node-dependant tachycardia as in Western literature. However, unlike in Western studies, no female preponderance was seen in the AVNRT group. The fall in systolic BP at the onset of tachycardia is significant, similar in the two groups and independent of the rate of tachycardia.

Arrhythmogenic right ventricular dysplasia: electrophysiologic and morphologic features in nine patients.

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.

Emergent balloon mitral valvotomy in patients presenting with cardiac arrest, cardiogenic shock or refractory pulmonary edema.

OBJECTIVES: The present study was performed to determine the outcome of emergent balloon mitral valvotomy (BMV) in patients with cardiac arrest, pulmonary edema or cardiogenic shock. BACKGROUND: In India, many patients with mitral stenosis present in critical condition. They have high mortality despite surgical relief. The role of BMV in such patients is ill-defined. METHODS: Of 558 patients undergoing BMV between January 1993 and December 1994, 40 presented with cardiogenic shock, cardiac arrest or pulmonary edema refractory to medical treatment and underwent emergent BMV (group I). Elective BMV was performed in the remaining 518 patients (group II). RESULTS: Age ([mean +/- SD] 40 +/- 13 vs. 31 +/- 9 years, p < 0.05), incidence of atrial fibrillation (35% vs. 11%, p < 0.05), pulmonary artery systolic pressure (PAsP) (64 +/- 14 vs. 51 +/- 12 mm Hg, p < 0.001) and mitral valve (MV) score (7.4 +/- 1.2 vs. 6.4 +/- 1, p < 0.001) were higher and MV area lower (0.74 +/- 0.17 vs. 0.86 +/- 0.14 cm2, p < 0.001) in group I patients. After emergent BMV in group I, mitral regurgitation occurred in 15%, and the mortality rate was 35%. Stepwise logistic regression analysis identified MV score > or =8 (p = 0.008), PAsP > or =65 mm Hg (p = 0.023) and cardiac output < or =3.151 liters/min (p = 0.001) as significant predictors of a fatal outcome. Follow-up of 1 to 16 months (median 8) was available in 20 of 26 survivors in group I, of whom 15 were asymptomatic. The gain in MV area and the decrease in transmitral gradient and PAsP obtained immediately after BMV persisted during the follow-up period. CONCLUSIONS: Emergent BMV is feasible in critically ill patients. In-hospital survivors have excellent clinical and hemodynamic status at intermediate follow-up.

Scope and efficacy of complex radiofrequency ablation.

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.

Safety and feasibility of same day discharge in patients undergoing radiofrequency catheter ablation.

We retrospectively analyzed outcomes of radiofrequency catheter ablation in patients who were discharged the same day and compared them with patients staying overnight. For most tachyarrhythmias, it is safe and feasible to discharge patients undergoing radiofrequency ablation on the same day.

Ablation of atrial insertion sites of left-sided accessory pathways in children: efficacy and safety of transseptal versus transaortic approach.

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.