[Right atrial ablation of ectopic atrial tachycardia using a 20-pole mapping catheter]. / Ablation ektoper rechtsatrialer Tachykardien unter Verwendung eines 20-poligen Mapping-Katheters.

INTRODUCTION: Ectopic atrial tachycardia (EAT) are frequently unresponsive to pharmacological antiarrhythmic therapy. Radiofrequency ablation seems to be a safe approach to treat those arrhythmias. In the present study we report our results of radiofrequency ablation of EAT with a new mapping system (Stablemapr, Medtronic). METHODS: Thirty consecutive patients with right atrial tachycardia were included in the study. In 15 patients (G1) the 20-polar Stablemapr was used for localization of the arrhythmia foci. Data were compared with a control group (G2, n=15), in which mapping was performed conventionally. The demographic characteristics and the distribution of the different cardiac diseases were comparable in both groups. In group 1 the identification of the EAT was facilitated by the placement of the 20-pole mapping catheter in the right atrium. In group 2 point by point measurements were performed to find the earliest local atrial activation compared to a reference electrode in the high right atrium (activation mapping), or foci were identified by analysis of the P-wave morphology during stimulation (pacemapping). RESULTS: It was possible to successfully ablate all atrial tachycardias. The distribution of the foci was similar in both groups (G1/G2): near to the superior (3/5) and inferior (1/0) caval vene ostium, on the free wall (3/3), at the coronary sinus ostium (3/3) and on the interatrial septum (5/4). The mean procedure (G1: 88+/-33 vs G2: 151+/-61 min; p= or <0.05) and fluoroscopic times (G1: 19+/-9 vs G2: 38+/-28 min; p= or <0.05) were significantly shorter in group 1. Moreover, the mean number of radiofrequency applications was reduced significantly by using the new mapping system (G1: 10+/-10 vs G2: 16+/-13; p= or <0.05). CONCLUSION: Radiofrequency ablation of EAT with right atrial focus can be performed safely and successfully using a 20-pole mapping catheter. The greatest advantages compared to conventional mapping and ablation strategies lies in the shortened investigation and fluoroscopic time.

[Determinants of paroxysmal atrial fibrillation in patients with arterial hypertension]. / Determinanten des paroxysmalen Vorhofflimmerns bei Patienten mit arterieller Hypertonie.

INTRODUCTION: Atrial fibrillation represents an important arrhythmia, in particular in patients with arterial hypertension. Hitherto, the connection between paroxysmal atrial fibrillation, left atrial size and left ventricular muscle mass has not been investigated sufficiently. In the present study, determinants of paroxysmal atrial fibrillation in patients with arterial hypertension were evaluated. METHODS: 104 consecutive patients were enrolled into this study. All of them suffered from arterial hypertension for more than one year. Persistent or permanent atrial fibrillation was not documented. In all of these patients, clinical, echocardiographic and rhythmologic variables were evaluated. RESULTS: In 10.3% of the patients, paroxysmal atrial fibrillation was found. These patients showed a significantly larger left atrium (43.3 +/- 6.7 vs 37.5 +/- 4.9 mm, p < 0.001), a significantly higher muscle mass of the left ventricle (152.38 +/- 43.57 vs 134.41 +/- 27.19 g/m2, p < 0.01) and significantly more frequent a mild mitral regurgitation (38.1 vs 28.6%, p < 0.01). The multivariate regression analysis revealed as independent factors for paroxysmal atrial fibrillation the size of the left atrium and the presence of mild mitral regurgitation. Independent factors for an enlarged left atrium were mitral insufficiency and left ventricular muscle mass. CONCLUSION: This study shows that paroxysmal atrial fibrillation in aterial hypertension is based on the left atrial size, and left atrial size on left ventricular muscle mass. Therefore, these results should lead to a causal therapy for treatment of paroxysmal atrial fibrillation in these patients.

[Long-term follow-up of right atrial multilinear high-frequency ablation in the treatment of recurrent paroxysmal atrial fibrillation]. / Langzeitverlauf nach rechtsatrialer, multilinearer Hochfrequenzablation zur Behandlung von rezidivierendem paroxysmalem Vorhofflimmern.

BACKGROUND AND OBJECTIVE: To investigate the long-term follow-up after right atrial compartmentalization using radiofrequency catheter ablation to treat recurrent paroxysmal atrial fibrillation. PATIENTS AND METHODS: 33 patients (eight women / 25 men, mean age 56.1+/-9.9 years) with highly symptomatic recurrent paroxysmal atrial fibrillation and mostly unresponsive to antiarrhythmic drugs were enrolled in this prospective study. All patients underwent radiofrequency catheter ablation, including right atrial compartmentalization and ablation of the right atrial isthmus region. The primary goal during follow-up was documentation of arrhythmia-related symptoms using a SF-36 quality-of-life questionnaire. RESULTS: During a mean follow-up of 2.1 years 21 % of patients were free of a relapse under continued antiarrhythmic medication, 79 % suffered at least from one period of atrial fibrillation. According to the underlying heart disease patients classified as "lone atrial fibrillation" (40 % without a relapse) showed improvement particularly compared to patients with coronary heart disease (10 % without a relapse). In the group of patients with a relapse of atrial fibrillation the mean of duration of an arrhythmic episode decreased significantly from 10.6 to 2.3 hours under continued administration of antiarrhythmic drugs (p = 0.01), as did the number of episodes, from 2.2 to 1.9/week. CONCLUSION: Despite of the high rate of clinical relapse, patients can profit due to an improved responsiveness to antiarrhythmic drugs after ablation. Right atrial compartmentalization should not be understood as a causal therapy but as an approach to a symptomatic form of hybrid therapy.

Adenosine in the noninvasive diagnosis of dual AV nodal conduction: use as a follow-up parameter after slow pathway ablation in AVNRT.

OBJECTIVE: The aim of this study was to evaluate if administration of adenosine during sinus rhythm to patients with PSVT of unknown mechanism is capable to detect dual AV nodal conduction and furthermore to evaluate this diagnostic parameter as a controlling test after slow pathway ablation in AVNRT. METHODS AND RESULTS: Before electrophysiological study 35 consecutive patients with PSVT were given adenosine during sinus rhythm. After radiofrequency ablation the adenosine test was repeated in a subset of 19 patients. The electrophysiological study revealed 19 patients (54%) with typical AVNRT (study group), 10 (29%) with atrioventricular reentry tachycardia (AVRT), 4 (11%) with ectopic atrial tachycardia (EAT) and 2 patients (6%) with inducible atrial flutter (AF) (control group). We observed a sudden increment of the PQ interval of more than 50 msec between two consecutive beats in 15 of 19 patients (79%) in the study group (75+/-35 msec) and in 2 patients (1 with EAT, AF) of the control group (19+/-12 msec) (p<0.001). After slow pathway radiofrequency ablation the sudden increment of PQ interval persisted in 4 of 12 patients (33%) of the study group. Three of these 4 patients had a relapse of AVNRT during a follow-up of 3 months. CONCLUSION: The administration of adenosine during sinus rhythm is an excellent noninvasive diagnostic test for identifying dual AV nodal conduction and additionally for verifying radiofrequency ablation results in patients with AVNRT.