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Aims: In patients with post-myocardial infarction (post-MI) ventricular tachycardia (VT), the presence of myocardial calcification (MC) may prevent heating of a subepicardial VT substrate contributing to endocardial ablation failure. The aims of this study were to assess the prevalence of MC in patients with post-MI VT and evaluate the impact of MC on outcome after endocardial ablation.Methods and Results: In 158 patients, the presence of MC was retrospectively assessed on fluoroscopy recordings in seven standard projections obtained during pre-procedural coronary angiograms. Myocardial calcification, defined as a distinct radiopaque area that moved synchronously with the cardiac contraction, was detected in 30 patients (19%). After endocardial ablation, only 6 patients (20%) with MC were rendered non-inducible compared with 56 (44%) without MC (P = 0.033) and of importance, 8 (27%) remained inducible for the clinical VT [compared with 9 (6%) patients without MC; P = 0.003] requiring therapy escalation. After a median follow-up of 31 months, 61 patients (39%) had VT recurrence and 47 (30%) died. Patients with MC had a lower survival free from the composite endpoint of VT recurrence or therapy escalation at 24-month follow-up (26% vs. 59%; P = 0.003). Presence of MC (HR 1.69; P = 0.046), a lower LV ejection fraction (HR 1.03 per 1% decrease; P = 0.017), and non-complete procedural success (HR 2.42; P = 0.002) were independently associated with a higher incidence of VT recurrence or therapy escalation.Conclusion: Myocardial calcification was present in 19% of post-MI patients referred for VT ablation and was associated with a high incidence of endocardial ablation failure. [ABSTRACT FROM AUTHOR]

To compare clinical outcomes of clamping devices and linear nonclamping devices for isolation of the posterior left atrium (box) in thoracoscopic ablation of long-standing persistent atrial fibrillation. Eighty patients who underwent thoracoscopic pulmonary vein and box isolation using a bipolar clamping device (42 patients) or bipolar nonclamping device (38 patients) to create the roof/inferior lesions for box isolation were included from 2 centers. Follow-up consisted of 24-hour Holter at regular intervals. Freedom from AF during 1-year follow-up and catheter repeat interventions were compared between groups. Acute intraoperative electrical isolation of the box compartment was significantly higher in the clamping group than in the nonclamping group (100% and 79%, respectively, P <.01). At 1-year follow-up, 91% of the clamping group and 79% of the nonclamping group were in sinus rhythm. During 1-year follow-up, recurrence rates did not significantly differ between the 2 groups (P =.08). Repeat catheter interventions were required in 10% of the clamping group and 21% of the nonclamping group (P =.15). Conduction gaps in the roof or inferior lesions were found in 1 patient (2%) in the clamping group versus 4 patients (11%) in the nonclamping group (P =.13). Thoracoscopic pulmonary vein and box isolation are highly effective in restoring sinus rhythm in long-standing persistent atrial fibrillation on short-term follow-up. Comparison of clamping and nonclamping devices revealed lower rates of intraoperative exit block of the box in the nonclamping group. However, this did not translate into a significant difference in atrial fibrillation freedom at short-term (1-year) follow-up. Main outcomes when comparing clamping versus nonclamping ablation devices for box ablation in the treatment of long-standing persistent AF. AF , Atrial fibrillation. [ABSTRACT FROM AUTHOR]

Aims: Pulmonary vein isolation (PVI), the standard for atrial fibrillation (AF) ablation, is most commonly applied with radiofrequency (RF) energy, although cryoballoon technology (CRYO) has gained widespread use. The aim was to compare the second-generation cryoballoon and the irrigated RF energy regarding outcomes and safety.Methods and Results: Of 4657 patients undergoing their first AF ablation, 982 with CRYO and 3675 with RF energy were included from the Swedish catheter ablation registry and the Atrial Fibrillation Ablation Long-Term registry of the European Heart Rhythm Association of the European Society of Cardiology. The primary endpoint was repeat AF ablation. The major secondary endpoints included procedural duration, tachyarrhythmia recurrence, and complication rate. The re-ablation rate after 12 months was significantly lower in the CRYO vs. the RF group, 7.8% vs. 11%, P = 0.005, while freedom from arrhythmia recurrence (30 s duration) did not differ between the groups, 70.2 % vs. 68.2%, P = 0.44. The result was not influenced by AF type and lesion sets applied. In the Cox regression analysis, paroxysmal AF had significantly lower risk for re-ablation with CRYO, hazard ratio 0.56 (P = 0.041). Procedural duration was significantly shorter with CRYO than RF, (mean ± SD) 133.6 ± 45.2 min vs. 174.6 ± 58.2 min, P < 0.001. Complication rates were similar; 53/982 (5.4%) vs. 191/3675 (5.2%), CRYO vs. RF, P = 0.806.Conclusion: The lower re-ablation rates and shorter procedure times observed with the cryoballoon as compared to RF ablation may have important clinical implications when choosing AF ablation technique despite recognized limitations with registries. [ABSTRACT FROM AUTHOR]

Aims Coronary atherosclerosis has been associated with the development of atrial fibrillation (AF). However, little is known about the impact of coronary atherosclerosis on the outcome treatment of AF. The aim of this study was to investigate the impact of coronary atherosclerosis on the efficacy of radiofrequency catheter ablation (RFCA) for AF using multi-detector row computed tomography (MDCT). Methods In 125 consecutive patients undergoing RFCA for AF, a pre-procedural MDCT examination (coronary angiography and/or coronary calcium score) was performed to evaluate the presence and severity of coronary atherosclerosis. Furthermore, all patients underwent a comprehensive echocardiographic evaluation to measure the left atrial size and to rule out structural heart disease. After RFCA all patients were regularly evaluated at the outpatient clinic. Results After a mean follow-up of 12 ± 3 months, 78 patients (62%) had maintained stable sinus rhythm and 47 patients (38%) had recurrence of AF. Left atrial volume index was a significant predictor of AF recurrence after RFCA. The presence of coronary atherosclerosis on MDCT did not influence the efficacy of RFCA for AF. Conclusions The presence of coronary atherosclerosis on MDCT is not associated with a higher risk for AF recurrence after RFCA. [ABSTRACT FROM AUTHOR]

Aims: Total atrial activation time has been identified as an independent predictor of new-onset atrial fibrillation (AF). Echocardiographic assessment of PA-TDI duration provides an estimation of total atrial conduction time. The aim of this study was to investigate the prognostic value of total atrial conduction time to predict AF recurrence after radiofrequency catheter ablation (RFCA). Methods and Results: In 213 patients undergoing RFCA for symptomatic drug-refractory paroxysmal AF, the total atrial conduction time was estimated by measuring the time delay between the onset of the P-wave in lead II of the surface electrocardiogram and the peak A'-wave on the tissue Doppler tracing of the left atrial (LA) lateral wall (PA-TDI duration). After RFCA, all patients were evaluated on a systematic basis at the outpatient clinic. After a mean follow-up of 13 ± 3 months, 74 patients (35%) had recurrent AF whereas 139 patients (65%) maintained sinus rhythm. Left atrial maximum volume index and PA-TDI duration were identified as independent predictors of AF recurrence after RFCA. However, receiver operator characteristics curve analyses demonstrated that PA-TDI duration had a superior accuracy to predict AF recurrence compared with LA maximum volume index (area under the curve 0.765 vs. 0.561, respectively). Conclusion: Assessment of total atrial conduction time using tissue Doppler imaging can be used to predict AF recurrence after RFCA. [ABSTRACT FROM AUTHOR]

Background: A novel non-fluoroscopic catheter tracking system (Mediguide) can be used in combination with a 3D mapping system for atrial fibrillation (AF) ablation. However, the benefit on radiation exposure of the Mediguide system compared to other ablation systems is unknown. Methods: We retrospectively enrolled consecutive 73 patients (51 men; 59±11 years; 60 paroxysmal AF) undergoing pulmonary vein isolation by the same operator. Radiation time, radiation effective dose, procedure time, AF recurrence after ablation, and procedure-related complications were compared among 4 different ablation systems. Results: Mediguide was used in 16 patients (group A), CARTO? in 17 (group B), Cryoballoon in 30 (group C), and Multi-electrode Pulmonary Vein Ablation Catheter (PVAC) in 10 (group D). Although procedure time was shorter in patients with Cryoballoon (median 110 [interquartile range 99-120] min) and PVAC (123 [112-146] min) compared to those with Mediguide (181 [168-214] min) and CARTO (179 [160-195] min) (P<0.001), radiation exposure time and effective dose were decreased in patients with Mediguide compared to the other ablation systems (A: 5 [3-6] min; B: 14 [11-16] min; C: 14 [11-18] min; D: 20 [16-24] min, P<0.001 and A: 1.1 [0.8-2.0] mSv; B: 2.5 [1.3-3.8] mSv; C: 2.0 [1.4-2.5] mSv; D: 1.7 [1.4-3.6] mSv, P=0.015, respectively). AF recurrence rates and procedure-related complications were comparable among the 4 groups. Conclusion: The Mediguide system reduces radiation exposure compared to other ablation systems without increasing AF recurrence or procedure-related complications. [ABSTRACT FROM AUTHOR]