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Radiofrequency catheter ablation has recently been successfully applied to patients suffering from atrial flutter. We report our experience in the ablation of typical atrial flutter in 17 consecutive patients refractory to drug treatment. The procedure was initially successful restoring sinus rhythm in 16 patients (94%). During a mean follow-up of 9 months atrial flutter recurred in 4 patients (23%). A second procedure was successfully performed in 2 patients; the other two patients are presently in sinus rhythm under amiodarone which was formerly ineffective. Finally, 59% of the patients were able to discontinue antiarrhythmic medication. In 4 out of 7 patients with dilated cardiomyopathy, the left ventricular ejection fraction normalized a few weeks after ablation. This successful technique should be considered early in the therapeutic approach to patients suffering from typical atrial flutter, to avoid numerous drug treatments, multiple hospitalizations and possible evolution toward non reversible dilated cardiomyopathy.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most frequent paroxysmal supraventricular tachycardia and results from reentry in the atrioventricular nodal region via slow and fast pathways. The curative treatment of choice consists of selective radio-frequency catheter ablation of the slow pathway. In this retrospective study we report our experience of 73 consecutive patients suffering from AVNRT treated by selective slow pathway ablation and also review some features of AVNRT. AVNRT appeared for the first time at the age of 29 +/- 15 years and lasted for 17 +/- 13 years. In 37% of the patients AVNRT recurred at least weekly, 10% presented with syncope and 15% were admitted to hospital more than 5 times. On average, 2.5+/-1.6 drugs were prescribed to 66 of the 73 patients and 83% of them were drug-refractory. Selective slow pathway ablation was successfully performed in 65 patients (89%). The procedure, although effective, was complicated by atrioventricular block in 2 patients (2.7%) and failed in 6 patients. In 5 of them, fast pathway ablation was attempted and was successful in 2 cases, resulted in atrioventricular block in one case and failed in 2 cases. The complications, apart from atrioventricular block necessitating a pacemaker in all cases, were one pulmonary embolism and 2 pneumothorax. The mean follow-up for the 70 patients for whom ablation was effective (with or without atrioventricular block) is 12.7+/-7.3 months. AVNRT relapsed in 5 patients (7%); all of them underwent a second ablation with 4 successes (slow pathway) and one atrioventricular block (fast pathway after failed slow pathway ablation). 11 patients (16%) developed palpitations: in one case they were due to atrial fibrillation and in 10 cases they remained of unknown origin. The palpitations were of short duration and well tolerated, and these patients nevertheless felt an improvement after the ablation. Therefore, at medium term, 62 patients (85%) remained free from symptoms or only slightly symptomatic and without a pacemaker, and 51 of them (70%) remained completely asymptomatic and without a pacemaker. AVNRT can result in considerable morbidity and antiarrhythmic drugs are frequently ineffective. Slow pathway ablation is a safe and effective treatment for AVNRT. In our opinion, if AVNRT or medical treatment diminish the quality of life, ablation is indicated. When AVNRT presents with hemodynamic collapse, ablation is mandatory. Fast pathway ablation after failed slow pathway ablation is associated with a high incidence of atrioventricular block and is targeted only at very symptomatic patients who accept the possibility of definitive pacemaker implantation.

We report our experience of 5 patients with the permanent form of junctional reciprocating tachycardia (PJRT), a rare form of supraventricular arrhythmia. PJRT was discovered at a mean age of 31 years (8-60 years) and the mean duration of tachycardia was 13 years (1-40 years). 4 patients had nearly incessant tachycardia and one had paroxysmal attacks. Heart rate varied between 100 and 190 beats/minute and the minimal heart rate was on average 114 beats/minute. Four patients had palpitations, 2 developed tachycardia-induced cardiomyopathy, reversible after control of the arrhythmia, and 4 had asymptomatic episodes of PJRT. ECG showed in all cases a narrow-complex tachycardia with inverted P waves in inferior leads and RP interval greater than PR. All patients presented a posteroseptal accessory pathway. 4 patients received different antiarrhythmic drugs with only partially effective results. Radiofrequency catheter ablation of the accessory pathway was performed in all patients and was successful in 4, who remained free of recurrence after a mean follow-up of 26.5 months (4-37 months). The procedure was partially successful in the 5th patient, who is now asymptomatic under sotalol. Radiofrequency catheter ablation is therefore the treatment of choice of PJRT, a rare arrhythmia which should nevertheless be known in order to treat the patient correctly and avoid progression to cardiac failure, which is not always completely reversible.

The indication and result of catheter ablation for supraventricular and ventricular arrhythmias are reviewed, with special emphasis on the need to inform the patient undergoing this type of procedure, the possible complications and our center's results.

The purpose of this study was to evaluate longterm mortality in 44 patients undergoing electrophysiologically guided therapy for sustained monomorphic ventricular tachycardia. We applied the following modified response criteria: non-inducibility or slowing of induced ventricular tachycardia to < or = 150 bpm. On this basis, 25/44 (57%) patients were classified as responders, and 19/44 (43%) as non-responders. Responders had palpitations significantly more often as the leading clinical sign (68% vs. 21%, p < 0.05). Non-responders showed a lower mean ejection fraction (36 +/- 15% vs. 46 +/- 17%, p < 0.05) and a trend to higher incidence of syncopal ventricular tachycardia (58% vs. 12%, p = 0.15). All responders and 3/19 non-responders continued on drug therapy. 11 non-responders received an implantable cardioverter-defibrillator (ICD), 3 underwent surgery and 2 catheter ablation. 14/44 patients (32%) died during a mean follow-up of 3.2 years. Sudden arrhythmic death occurred in 3/28 patients on drug therapy (1/25 responders, 2/3 non-responders), and in 2/16 non-responders with invasive therapy (one with an ICD and one after catheter ablation). The cumulative all-cause mortality at 3 years was similar in both groups (26% vs 22%, n.s.), but the mortality from sudden arrhythmic death showed a trend to be lower in the responder-group (0% vs 17%, p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

The efficacy of adenosine triphosphate (ATP) was tested in 23 patients suffering from supraventricular tachycardia; 10 patients had orthodromic circus movement tachycardia and 13 typical av nodal reentrant tachycardia. At a mean dose of 0.18 mg/kg all tachycardias were halted in less than 1 minute due to transient acute av nodal block followed by return to normal av conduction within 8 seconds. All patients had transient minor side effects. One elderly subject had a short episode of atrial fibrillation after the acute av block. In conclusion, ATP is useful and safe for rapid termination of supraventricular tachycardias incorporating the av node in their circuit.

Interventional arrhythmology deals with the nonpharmacological management of patients with symptomatic arrhythmias. Percutaneous catheter ablation is used to cure patients with arrhythmias due to accessory pathways or AV-node reentrant tachycardia. In patients with drug-refractory sustained, hemodynamically significant ventricular tachyarrhythmias, implantable third generation defibrillators provide an effective therapeutic modality. Our article provides a brief overview of these new therapeutic modalities and summarizes our local experience.

The electrocardiographic diagnosis of left ventricular hypertrophy is often difficult because it is based on a large number of criteria which, even if taken on their own or as "scoring systems", have a poor sensitivity ranging from 10 to 60%. Some authors have shown that the diagnosis is easier--though at first sight this seems paradoxical--in the presence of altered ventricular depolarization. To verify this statement in the case of left anterior fascicular block, we tested the value of six different indices for the detection of left ventricular hypertrophy. We analyzed 100 patients with left anterior fascicular block and compared the six electrocardiographic indices with the echocardiographic reference method, using the formula of the Penn convention, to establish the left ventricular mass. The best index of the six was that of Gertsch: [S3+ (R+S) maximal precordial] greater than or equal to 30 mm. Its sensitivity was 74%, its specificity 69%, its positive predictive value 79% and its negative predictive value 63%. The other tested indices had a sensitivity of less than 45% with a specificity of more than 80%. Furthermore, Gertsch's index was of equal value in confirming the increased left ventricular mass due either to concentric hypertrophy or to dilated cardiomyopathy. This study therefore confirms that electrocardiographic diagnosis of left ventricular hypertrophy is even easier in the presence of left anterior fascicular block than in absence of altered ventricular depolarization. This result is of practical interest, the incidence of left anterior fascicular block being 1 to 5% in the general population and as high as 30% after the age of 80.

Nowadays patients suffering from supraventricular tachycardia are first treated with antiarrhythmic drugs. In refractory cases alternative treatment is antitachycardia pacemaker implantation or surgery. Recently new percutaneous catheter techniques have been developed to ablate directly the anatomical substrate responsible for the arrhythmia by delivering energy (high or low energy shock or radiofrequency) at the tip of a catheter. This article summarizes the results of clinical application of these different techniques and briefly presents our experience. The very recent studies with RF in patients with drug-refractory av nodal reentry or accessory pathway related tachycardia (WPW syndrome) report a success rate of 92-99% with a very low complication rate. If the long term success of radiofrequency is confirmed this technique will emerge in the near future as the treatment of choice in patients suffering from symptomatic supraventricular tachycardia, since it avoids expensive, longlasting drug treatment with the permanent risk of side effects.