Search

The long-term effects of radiofrequency catheter ablation on quality of life in patients with typical atrial flutter are still unknown. This study included 100 consecutive patients with clinically documented typical atrial flutter. Subjective perception of quality of life was assessed by a semiquantitative questionnaire before, and 1 and 6 months after ablation. Ablation of typical atrial flutter was associated with a significant improvement in the general quality of life, frequency of significant symptoms, and symptoms during attacks. The frequency of hospital admission and emergency room visits, and number of antiarrhythmic drugs significantly decreased after ablation. Activity capacity significantly improved after ablation in patients with depressed left ventricular function. All improvements after ablation were maintained over 6-month follow-up. However, patients with atrial fibrillation compared with those without atrial fibrillation before ablation had less improvement in the general quality of life, frequency of significant symptoms, and symptoms during attacks (including palpitation, asthenia, effort, dyspnea, rest dyspnea, and dizziness). Furthermore, patients with atrial fibrillation before ablation needed more antiarrhythmic drugs, and had a higher frequency of hospital admission and emergent room visits at 6-month follow-up (all variables p0.01). Multivariate analysis demonstrated that only the presence of atrial fibrillation before ablation could independently predict improvement in general quality of life (p = 0.03), frequency of significant symptoms (p = 0.03), symptoms during attacks (p = 0.04), and decrease in the consumption of health care resources including antiarrhythmic drugs (p = 0.01), hospital admission (p = 0.02), and emergency room visits (p = 0.02). Ablation of typical atrial flutter could significantly improve quality of life, but patients who had atrial flutter associated with atrial fibrillation before ablation had less improvement than those without atrial fibrillation.

Information on the long-term results of radiofrequency catheter ablation in a large group of patients with multiple accessory pathways (APs) was not available. This study included 858 patients with Wolff-Parkinson-White syndrome who underwent electrophysiologic study and radiofrequency catheter ablation: 73 patients (8.5%) had multiple APs. Sixty-six patients had 2 APs, 5 had 3 APs, 1 had 4 APs, and 1 had 5 APs. The most common combination pattern of these pathways were concealed APs (38 patients, 52%). Localization of accessory pathways showed a higher incidence of right free wall (22% vs 11%, p0.05), anteroseptal, and midseptal APs (9% vs 5%, p0.05) in patients with multiple APs than in patients with 1 AP. The most common anatomic sites for multiple APs were 2 APs in the left wall (21 patients, 28%). Although the success rate was similar (98% vs 99%, p0.05), procedure time (3.1 +/- 1.2 vs 2.0 +/- 1.1 hours, p0.05) and radiation exposure time (48 +/- 26 vs 29 +/- 19 minutes, p0.05) were longer in patients with multiple APs. The recurrence rate was higher in patients with multiple APs (9.5% vs 2.5%, p0.05), and the most common site of recurrent APs was in the left free wall (7.2%); in contrast, it was in the right free wall in patients with 1 AP. These findings demonstrated that a high success rate of radiofrequency catheter ablation was found in patients with multiple APs; however, the higher recurrence rate in patients with multiple APs should be considered.

Prediction of accessory pathway location before radio-frequency ablation has become increasingly important for patients with Wolff-Parkinson-White syndrome. However, existing electrocardiographic (ECG) criteria for localization of accessory pathways have several limitations, and the polarity of delta waves has not been well defined. In the present study, 369 patients with a single anterogradely conducting accessory pathway who underwent successful radiofrequency ablation were included. The polarity of delta waves was defined and categorized in detail, and various ECG characteristics of the most preexcited QRS complexes were examined and compared with QRS complexes after successful ablation in the initial 182 patients, which included morphology and polarity of delta waves, initial 20, 40, and 60 ms segments of the preexcited QRS complex, R/S ratio in the precordial leads, R/S ratio in the frontal leads, delta wave axis in the frontal plane, polarity of delta waves in the frontal leads, and polarity of delta waves in the precordial leads. The polarity of the initial 40 ms segment of the most preexcited QRS complexes in each of the frontal leads, and the polarity of the initial 60 ms segment of the most preexcited QRS complex in each of the precordial leads proved to be the best representatives of delta wave polarity in the respective leads.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine, which binds to cell surface receptors and couples with guanosine triphosphate-binding inhibitory proteins (G i ), is potent in terminating supraventricular tachycardia (SVT). However, whether the differences in autonomic tone will influence this effect remains unknown. This study was designed to investigate the role of β -adrenergic and vagal activity on the action of adenosine. Forty patients with clinically documented SVT (22 with atrioventricular node reentrant tachycardia and 18 with atrioventricular reciprocating tachycardia) were divided into 4 groups with 10 patients in each group. In groups 1 and 2, adenosine was intravenously injected during the baseline state and during infusion of isoproterenol (2 and 4 μ g/min, respectively). Group 2 patients received atropine (0.04 mg/kg) injection before isoproterenol infusion. In groups 3 and 4, intravenous injection of adenosine was given during the baseline state and after injection of atropine (0.02 and 0.04 mg/kg, respectively). Group 4 patients received propranolol (0.2 mg/kg) before atropine injection. The minimal dose of adenosine to terminate tachycardia during isoproterenol infusion of 2 μ g/min was greater than that during the baseline state in both groups 1 and 2. The minimal dose of adenosine during isoproterenol infusion with 4 μ g/min was higher than that with 2 μ g/min in group 2, but not in group 1 patients. In both groups 3 and 4, the minimal dose of adenosine required to terminate tachycardia during atropine injection with 0.02 mg/kg was greater than that during the baseline state. The minimal effective dose of adenosine during atropine injection with 0.04 mg/kg was higher than that with 0.02 mg/kg in group 4, but not in group 3 patients. In conclusion, either limb of the autonomic nervous system may modulate the adenosine dosage required for termination of SVT. Patients taking drugs such as β blockers or vagolytic agents may need alterations in the dose of adenosine for therapy. Infusion of isoproterenol or atropine increased the minimal effective dose of intravenous adenosine required for termination of supraventricular tachycardia. This suggested that differences in autonomic tone may influence the effects of adenosine.

The main goal of this study is to evaluate the safety and efficacy of propafenone versus sotalol as an initial choice of treatment in patients with symptomatic paroxysmal atrial fibrillation (AF), according to a double-blind randomized system. In the oral propafenone group (n = 41), 2 patients (5%) discontinued therapy because of gastrointestinal discomfort in 1 and dizziness in the other. Thirty-one (79%) of the 39 patients who continued the treatment had effective response to oral propafenone (>75% reduction of symptomatic arrhythmic attacks) on a mean dose of 663 ± 99 mg/day with a decrease in attack frequency from 10 ± 3 to 2 ± 1 times per week. In the oral sotalol group (n = 38), 4 patients (11%) discontinued treatment because of dizziness in 2 and symptomatic bradycardia in 2. Twenty-six of the 34 patients (76%) who continued the treatment had effective response to oral sotalol on a mean dose of 200 ± 57 mg/day with a decrease in attack frequency from 11 ± 3 to 2 ± 1 times per week. Comparisons of the results between propafenone and sotalol groups showed a similar incidence of intolerable (2 of 41 vs 4 of 38, p = 0.42) and tolerable side effects (10 of 39 vs 8 of 34, p = 1.0). The attack frequency at baseline (11 ± 3 vs 10 ± 4 times per week, p = 0.23) and after treatment (3 ± 1 vs 3 ± 2 times per week, p = 0.85) did not differ significantly between the 2 groups. The incidence of effective response to drugs was also similar (31 of 39 vs 26 of 34, p = 0.78). Furthermore, the decrease of symptom scores (−32 ± 8% vs −29 ± 7%, p = 0.18) and percentage decrease of ventricular rate (−15 ± 4% vs −18 ± 4%, p = 0.10) during AF were also similar between the 2 groups. In conclusion, oral propafenone and sotalol are equally effective and safe in preventing attacks and alleviating symptoms of paroxysmal AF. A double-blind randomized study protocol was designed to evaluate the safety and efficacy of propafenone versus sotalol as an initial choice of treatment in 79 patients with frequent attacks of symptomatic paroxysmal atrial fibrillation. The study result demonstrated that oral propafenone and sotalol were equally effective and safe in preventing attacks and alleviating symptoms of paroxysmal atrial fibrillation.

Among 1,281 patients with symptomatic supraventricular tachycardia, 34 patients (2.7%) with presumed diagnosis of atrioventricular node reentrant tachycardia and orthodromic atrioventricular reciprocating tachycardia did not have inducible tachycardia in the electrophysiologic laboratory. Application of radiofrequency energy to the presumed arrhythmogenic sites could achieve a high success rate, with a low recurrence rate in these patients.

This study demonstrates that the fast-slow form of atrioventricular nodal reentrant tachycardia is usually catecholamine-sensitive and its electrophysiologic characteristics are significantly different from those of the slow-fast form. However, radiofrequency catheter ablation is a safe and effective treatment for patients with the fast-slow form of atrioventricular nodal reentrant tachycardia.