Ventricular tachycardia in structurally normal hearts: recognition and management.

Idiopathic ventricular tachycardia is a defined set of tachycardias when structural or pathological cause has been ruled out for the same. This paper tries to define and classify these arrhythmias to organize a logical therapeutic approach to deal with them. 60-80% of the idiopathic tachycardias originate from the right ventricular outflow tract (RVOT) and in 10% from the left ventricular outflow tract (LVOT). Outflow tract tachycardias have either LBBB or RBBB morphology with early R wave transition in chest leads. Adenosine, beta blockers and calcium channel blockers is the common medical treatment. Radiofrequency ablation is however the treatment of choice. Verapamil sensitive left ventricular tachycardia (ILVT) and propranolol sensitive left ventricular tachycardia (IPVT) are the other two forms recognized. RF ablation seems ideal for long-term management of ILVT and implantable cardioverter defibrillator (ICD) for IPVT. Inherited channelopathies include catecholaminergic polymorphic ventricular tachycardia (CPVT), Brugada syndrome and long QT syndrome where there is an inherited disorder in the ion-exchange channels of the cell-membrane leading to tachycardia. Prognosis in these is variable; CPVT, in particular, has a malignant course when untreated. RF ablation and placement of an ICD are important in the overall management of specific arrhythmia.

All that glitters is not gold ... all that faints is not slow.

An 82 year old man presented with multiple syncopal episodes. Since his ECG showed LBBB (left bundle branch block) with first degree AV block, he was advised permanent pacemaker implantation. However, a wide QRS tachycardia on the Holter raised the possibility of tachycardia-mediated syncope. EP (electrophysiological) studies revealed easily and repeatedly inducible short lasting slow-fast AVNRT (atrioventricular nodal reentry tachycardia) with severe hypotension. After RF ablation of the slow pathway, he is asymptomatic at six month follow-up.

Radiofrequency ablation for accessory pathways: success and variants.

INTRODUCTION: Radiofrequency ablation (RFA) is currently being advocated as the first line of therapy for symptomatic and drug refractory arrhythmias mediated by accessory pathways (APs). However, a large database on RFA for APs from India is still lacking. METHODS: Four hundred thirty-four patients (298 males, (69%)), with APs who underwent RF ablation between January, 1998 and May, 2001 were included. The success and variants were evaluated retrospectively from the data. RESULTS: The mean age was 36 +/- 11 years. There were 314 (73%) patients with WPW syndrome while the other 120 (27%) had concealed APs. Documented tachycardia was noted in 406 (91%) patients. Forty-six (11%) patients had associated structural heart disease (Ebstein's anomaly in 18). The procedure was successful in 414 (97%) of 425 patients in whom it was attempted. Of those unsuccessful, five had epicardial APs, four had multiple APs and two had immediate recurrence of APs. RFA was not attempted in nine parahissian pathways. Additional mechanisms were seen in 48 (11%) patients with WPW syndrome (14 (4.4%) AV nodal reentrant tachycardias, 16 (5%) additional concealed APs and 18 (5.7%) multiple APs). Coronary sinus diverticulum were detected in 23 (7.3%) patients, and Mahaim-like APs were diagnosed in 24 (6\8%) patients. The procedural and fluoroscopy time was 96 +/- 41 and 19 +/- 13 minutes, respectively. There were no deaths; three patients developed pericardial tamponade, which was promptly treated by pericardiocentesis. CONCLUSION: Radiofrequency ablation is a safe and effective treatment for AP mediated tachycardia, especially for younger patients and children in whom life-long drug therapy may not be best option.

Pre-excitation with syncope: a false lead?

An 18-year-old girl with pre-excitation presented with a history of recurrent syncope preceded by palpitation. The accessory pathway, which had a relatively long antegrade effective refractory period of 340 ms, was mapped and successfully ablated in the left lateral region. However, after ablation, she had reproducible sustained polymorphic ventricular tachycardia, which was found to be the cause of her syncope. Thus, alternate mechanisms of tachycardia need to be considered in patients with pre-excitation when the presentation is atypical.

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.

Adenosine-induced ventricular fibrillation.

The use of adenosine has been suggested as a diagnostic tool in the evaluation of wide ORS complex tachycardia. However, adenosine shortens the antegrade refractoriness of accessory atrioventricular connections and may cause acceleration of the ventricular rate during atrial fibrillation. We observed ventricular fibrillation in 2 patients who presented to the emergency department with pre-excited atrial fibrillation and were given 12 mg of adenosine.

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.

L-carnitine moderately improves the exercise tolerance in chronic stable angina.

OBJECTIVES: To study the safety and efficacy (with reference to exercise ECG testing) of oral L-carnitine in chronic stable angina. METHODS: Forty-seven patients, 30 men and 17 women, aged 56 +/- 8 years, were randomized to receive L-carnitine (n = 28) or placebo (n = 19) in the dose of 2 g/day for 3 months. The adjuvant treatment was not changed during the study. Patients were evaluated by computerized stress test (CST) done at the beginning and end of the trial. The parameters assessed were exercise duration, time to onset of ST changes, total ST score at peak exercise, rate-pressure product at peak exercise, and time needed for the ST changes to recover to baseline. RESULTS: The two groups were comparable at the beginning of the study. There was no change in the CST parameters in the placebo group at the end of 3 months. In the L-carnitine group there was a statistically significant improvement in the exercise duration from 7.8 +/- 2.2 min to 8.6 +/- 1.8 min (p = 0.006) and in the time needed for the ST changes to revert to baseline from 7.2 +/- 3.9 min to 5.7 +/- 3.8 min (p = 0.019). No change was noted in the time to onset for ST depression, ST score and double product. There were no systemic adverse effects or coronary events in either group. CONCLUSION: Oral L-carnitine is safe and moderately improves the duration of exercise and time to recovery of ST changes in patients with chronic stable angina.

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.

Is dietary fiber beneficial in chronic ischemic heart disease?

OBJECTIVES: To evaluate the benefit of a dietary fiber preparation (Fibernat) in patients with chronic ischemic heart disease (IHD). METHODS: From January 1997 to March 1998, 114 consecutive patients with chronic IHD were enrolled in this prospective double blind randomized placebo controlled trial. The fiber (F) and placebo (P) groups were comparable at baseline. All patients were given advice regarding dietary and lifestyle modifications. Concomitant drug therapy was not altered. The drug (consisting of soluble and insoluble fibers obtained from fenugreek, guar gum and wheat bran) and placebo were administered for six months (10 grams twice daily). RESULTS: The following parameters improved in both groups: HDL cholesterol (32 to 39 mg/dl, p < 0.0009 in F and 33 to 38, p < 0.007 in P), total: HDL cholesterol ratio (6.7 to 5.6, p < 0.0007 in F and from 7.0 to 6.0, p < 0.01 in P) and weight (64.0 to 63.0 kg, p < 0.002 in F and 60.3 to 59.5, p < 0.002 in P). The Apolipoprotein B increased (101 to 129 mg/dl, p < 0.00001 in F and 98 to 127, p < 0.0008 in P). The following parameters improved only in group F: LDL cholesterol (146 to 134, p < 0.027), Apolipoprotein A-1 (105 to 139, p < 0.001), body mass index (24.9 to 24.5, p < 0.03) and waist circumference (37.2 to 36.7, p < 0.03). Total cholesterol, VLDL cholesterol, triglycerides, hip circumference, W:H ratio, exercise time and blood sugar were unchanged in both groups. CONCLUSIONS: Fibernat is well tolerated, safe and had favorable effects on LDL cholesterol, Apolipoprotein A-1, body mass index and waist circumference.

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.