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A 72-year-old woman was referred to us with typical symptoms of paroxysmal supraventricular tachycardia for electrophysiological diagnostics and catheter ablation. During the first session of catheter ablation, a probing of the right ventricle was not successful. Therefore, an angiography of the central veins was performed. A rare anatomical variation with atresia of the inferior vena cava below the hepatic veins with azygos persistence was detected. The blood of the lower half of the body was drained via the dilated azygos into the superior vena cava; the blood of the liver veins enters into the right atrium directly. By atypical catheter placement over the azygos vein in the right ventricle and coronary sinus, an AV nodal reentry tachycardia (AVNRT) could be confirmed as the mechanism of tachycardia. However, a stable position of the ablation catheter could not be achieved by the femoral approach, so the successful AV node modulation with ablation of the slow pathway was performed via jugular access.

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Left atrial appendage (LAA) may be the source for initiation and maintenance of atrial fibrillation (AF). This report shows restoration of sinus rhythm in the atria during radiofrequency wide-area LAA electrical isolation, whereas AF persists in the LAA.

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Catheter ablation of para-Hisian premature ventricular contractions (PVCs) still represents a challenge and is a compromise between success and inadvertent AV block. We describe a possible strategy to address PVCs from this location with high-amplitude His-bundle potentials at the site of earliest activation.

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INTRODUCTION: Radiofrequency (RF) ablation of atrial tachycardia (AT) with earliest activation at the His-bundle may be associated with the risk of AV block, and detection of this AT origin using the electrocardiogram (ECG) would be helpful in planning ablation. Aim of this study was to characterize the P-wave morphology and intracardiac electrograms at the successful ablation site for this group of ATs. METHODS: All consecutive patients undergoing ablation for AT with earliest activation at the His-bundle were included. Twelve-lead ECG and intracardiac electrograms were analyzed. RESULTS: A total of 33 patients underwent successful ablation. The P-wave and the PR interval during AT (cycle length 460 ± 88, range 360-670 milliseconds) were significantly shorter compared to sinus rhythm 87 ± 18 vs. 117 ± 23 and 131 ± 37 vs. 170 ± 47 milliseconds, respectively, P < 0.01. In 28 patients (85%), the P-wave was biphasic (-/+) or triphasic (+/-/+) in the precordial leads, especially V4 -V6 , and in 25 patients (76%) it was biphasic (-/+) or triphasic (+/-/+) in the inferior leads. RF was delivered at the following locations: noncoronary aortic cusp (NCC) in 24 patients, antero-septal left atrium in 4, supero-septal right atrium in 3, left coronary cusp in 1, and between the right coronary cusp and the NCC in 1. Atrial bipolar electrograms at the successful ablation site preceded the P-wave by 38 ± 11 (range 10-60) milliseconds, and AT termination was obtained after a mean RF energy time of 10 ± 8 (range 2-31) seconds. CONCLUSION: A characteristic narrow and biphasic (-/+) or triphasic (+/-/+) P-wave in the inferior and precordial leads reliably identifies the group of AT arising from the para-Hisian region.

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INTRODUCTION: Recurrences after pulmonary vein isolation (PVI) in patients (pts) with paroxysmal atrial fibrillation (AF) are mostly due to PV reconnection. The effect of adenosine, orciprenalin and their combination on left atrial PV conduction after PVI with a phased radiofrequency (RF) circular multielectrode ablation catheter (Pulmonary Vein Ablation Catheter, PVAC) was prospectively evaluated during a prolonged waiting time. In addition, it was assessed whether pharmacological reconnection characterizes veins requiring use of an irrigated catheter. METHODS AND RESULTS: In 116 consecutive pts [age 62 (IQR:52,68) years, 46% female], PVI was achieved with the PVAC alone in 114/116 (98%) pts and 461/464 (99%) veins after a median of 26 (IQR:22,32) applications delivering 1782 s (IQR:1518,2197) of RF. Mostly transient PV reconnections were observed in 40/116 (34%) pts and 57/464 (12%) PVs, a median of 44 (IQR:30,58) min after initial isolation. Adenosine, alone (43/57, 75%) or during orciprenalin infusion (7/57, 12%), unmasked residual conduction in the majority of veins (50/57, 88%). Additional PVAC applications less frequently achieved permanent isolation in veins showing reconnection compared to those that didn't (52/57, 91% vs. 404/407, 99%; P < .001). All PVs that could not be isolated with the PVAC were successfully treated with a standard irrigated catheter. CONCLUSIONS: After apparent PVI with the PVAC, drug-challenge after prolonged observation unmasked residual PV conduction in a significant number of pts, and adenosine was the most effective strategy. Drug-induced PV reconnection was difficult to treat with the PVAC. Whether this strategy improves clinical outcome of PVI with phased RF needs to be investigated.

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AIMS: Anatomic variability of the pulmonary vein (PV) ostium may adversely affect isolation rates with the circular fixed-size pulmonary vein ablation catheter (PVAC). We wanted to assess the influence on PV isolation rates of anatomic characteristics of the ostium, increasing experience of four different operators, and additional use of a steerable sheath. METHODS AND RESULTS: In the first 190 patients (pts) undergoing PVAC ablation, minimum/maximum diameter, area and shape of the PV ostia, and the length of a common ostium were analysed from computed tomography 3D reconstructions of the left atrium and related to isolation rates. In addition, a comparison was drawn between pts at the beginning and after completion (isolation of all PVs in ≥ 85% of pts) of the learning curve, and the effect of a steerable sheath was assessed. Pulmonary vein isolation was achieved with the PVAC alone in 85% of pts and in 94% of veins after a median procedure and ablation time of 154 [interquartile ranges (IQR): 120, 200] and 51 (IQR: 38, 70) min. An increase in isolation rates was observed after the first 60 pts (73 vs. 90% of pts; P< 0.01; 88 vs. 96% of PVs; P< 0.001), coincident with routine use of a steerable sheath. Anatomic characteristics (larger minimum diameter and area) identified unsuccessful isolation only of the left inferior PV at the beginning of the learning curve. CONCLUSIONS: Pulmonary vein isolation rates using this catheter are high. Anatomic variability of PV ostia modestly affects PV isolation rates. Standard use of a steerable sheath plays a major role in increasing isolation rates and overcoming 'difficult' anatomies.

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AIMS: The aim of the study was to determine the level of pulmonary vein (PV) isolation achieved with the use of a novel radiofrequency circular multielectrode ablation catheter [pulmonary vein ablation catheter (PVAC)] in patients with paroxysmal atrial fibrillation. Although some efficacy data have been presented, the level of PV isolation, which is crucial both for efficacy and safety of the ablation, has not been defined with this new ablation catheter. METHODS AND RESULTS: Detailed sinus rhythm voltage maps using an electroanatomic mapping system and projected on 3D computed tomography-derived reconstructions of the left atrium (LA) were obtained before and after PV isolation with the PVAC. Left atrium-PV entry and exit block was assessed for each vein. The population consisted of 12 patients, mean age 57+/-6 years, seven male. After ablation, an extensive zone of potential reduction that included the ostium of each PV was observed in all patients. Bipolar voltages were significantly reduced in all PVs and in the LA close to the vein ostia, the mean voltage reduction was >80%. CONCLUSION: Using the PVAC, (i) PVs are isolated at the level of the PV ostium and, importantly, outside the tubular portion and (ii) significant voltage reduction is also recorded at various extent proximal to the PV ostium at the level of the antral region.

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The use of adenosine in unmasking potential 'trigger' activity in a patient with paroxysmal atrial fibrillation (AF) and persistent left superior vena cava (LSVC) has never been reported. In a 75-year-old woman with paroxysmal AF and LSVC anomaly, pulmonary vein isolation (PVI) procedure was performed. After successful PVI, repeated bolus adenosine infusions were given. Adenosine response originating from the LSVC was observed: it was reproducible, brief, and exhibited decremental atrial-to-LSVC conduction properties until cessation. Pacing from the LSVC resulted in atrial capture (confirming vein-to-atrium conduction). Disconnection of the LSVC from the coronary sinus (CS) was obtained by successfully ablating within the distal CS. Adenosine challenge may be important to identify AF triggers in non-PVI foci.

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UNLABELLED: AF Burden After CRT Implantation. AIMS: Cardiac resynchronization therapy (CRT) is increasingly used in congestive heart failure (CHF) patients (with cardiac dyssynchrony). In addition to delivering therapy, CRT devices offer a variety of diagnostic tools for continuous long-term monitoring of clinically relevant information (i.e., occurrence and duration of arrhythmia episodes). METHODS AND RESULTS: Eighty-four patients with drug-refractory CHF in NYHA-class II-IV received a CRT device. The response to CRT was assessed by determining NYHA class at baseline and at 3 months follow-up. Atrial fibrillation (AF) burden (defined as time of AF per day) was continuously measured by the device. A significant gradual reduction of AF burden (from 9.88 +/- 12.61 to 4.20 +/- 9.24 [hours/day]) and number of patients experiencing AF episodes (from 26 to 13) were observed during CRT. CONCLUSIONS: (1) Diagnostic features for long-term monitoring of physiological variables provide useful information on the state and course of AF and may improve disease management. (2) AF burden reduces over time during the first 3 months after CRT implantation.

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