Matching Ablation Endpoints to Long-Term Outcome: The Prospective Multicenter Italian Ventricular Tachycardia Ablation Registry.

BACKGROUND: Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies. OBJECTIVES: This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center. METHODS: This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT. RESULTS: A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035). CONCLUSIONS: A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022).

Predictors of Zero X-Ray Ablation for Supraventricular Tachycardias in a Nationwide Multicenter Experience.

BACKGROUND: This multicenter, prospective study evaluated the determinants of zero-fluoroscopy (ZFL) ablation of supraventricular tachycardias. METHODS AND RESULTS: Four hundred thirty patients (215 male, 55.4±22.1 years) with indication to electrophysiological study or ablation of supraventricular tachycardias were enrolled. All participating physicians agreed to follow the as low as reasonably achievable policy. A procedure was defined as ZFL when no fluoroscopy was used. The total fluoroscopy time inversely correlated to the number of procedures previously performed by each operator since study start (r=-0.112; P=0.02). Two hundred eighty-nine procedures (67.2%) were ZFL; multivariable analysis identified as predictors of ZFL: procedure after the 30th for each operator, compared with procedures up to the ninth (P=0.011; hazard ratio, 3.49; 95% confidence interval [CI], 1.79-6.80); the type of arrhythmia (P=0.031; electrophysiological study and atrioventricular nodal reentry tachycardia ablation having the highest probability of ZFL; hazard ratio, 6.87; 95% CI, 2.08-22.7 and hazard ratio, 2.02; 95% CI, 1.04-3.91, respectively); the operator's (P=0.002) and patient's age (P=0.009). Among operators, achievement of ZFL varied from 0% to 100%; 8 (22.8%) operators achieved ZFL in <25% of their procedures; 17 (48.6%) operators achieved ZFL in >75% of their procedures. The probability of ZFL increased by 2.8% (hazard ratio, 0.98; 95% CI, 0.97-0.99) as patient's age decreased by 1 year. Acute procedural success was obtained in all cases. CONCLUSIONS: The use of 3-dimensional mapping system completely avoided the use of fluoroscopy in most cases, with very low fluoroscopy time in the remaining and high safety and effectiveness profiles. Achievement of ZFL was predicted by the type of arrhythmia, operator's experience, and patient's age.

Biliopancreatic diversion reduces QT interval and dispersion in severely obese patients.

OBJECTIVES: The objectives were to evaluate QT interval (QTc) and QT-interval dispersion (QTd) in severely obese individuals and to determine the effects of biliopancreatic diversion (BPD) and weight loss after BPD on ventricular repolarization parameters. BACKGROUND: People with severe obesity (SO) have a 50% to 100% increased risk of death associated with a 1.6-fold increased risk of sudden death. BPD surgery induces rapid and considerable weight loss through severe lipid malabsorption, thus achieving long-term weight control. RESEARCH METHODS AND PROCEDURES: A total of 85 subjects with SO (age, 42 +/- 12 years; 66 females; mean body weight, 120 +/- 29 kg; BMI, 45 +/- 11 kg/m(2)) of 330 who had a bariatric surgical consultation between January 2001 and July 2002 were enrolled. Inclusion criteria were sinus rhythm, unremarkable 12 leads surface electrocardiogram, no atrioventricular blocks and/or bundle branch blocks, normal serum electrolyte profile, and no medical therapies exerting known effects on QTc. Exclusion criteria were previous diagnosis of coronary artery disease, known cardiovascular disease, atrial fibrillation or any other known cardiac arrhythmias, cancer, or renal dysfunction. RESULTS: A total of 86% of patients had QTc >440 ms and/or QTd >60 ms. Subjects with SO showed a mean maximum QTc of 446 +/- 28 ms and a mean QTd of 52 +/- 20 ms. A close correlation was found between QTc and QTd (p < 0.0001; R(2) = 0.33). One month after BPD, mean QTc was 420 ms and remained stable at follow-up; QTd was 32 ms at 1 and 6 months and became 35 ms at 1 year. CONCLUSIONS: Ventricular repolarization abnormalities are significantly increased in subjects with SO. Reduction of QT abnormalities after BPD is independent of weight loss and is caused by the 100% reduction of glucose plasma shortly after surgery. This effect may be related to surgical interruption of the entero-insular axis.

Improved assessment of left ventricular volumes and ejection fraction by contrast enhanced harmonic color Doppler echocardiography.

AIMS: Test the accuracy of contrast enhanced harmonic color Doppler technique (CHCD) to determine left ventricular volumes and ejection fraction (LVEF) compared to equilibrium radionuclide ventriculography (MUGA). METHODS AND RESULTS: A total of 35 patients were enrolled (male 74.3%) with the mean age of 64.5 +/- 10 years and 6.8 +/- 4.9 days between echo and MUGA scans. The correlation of LVEF by CHCD with MUGA was better (R2 = 0.89) than that of harmonic 2D (H2D) and of contrast enhanced harmonic 2D (CH2D) (R2 = 0.74, R2 = 0.82, respectively). The RMS residual of CHCD (0.056) was smaller than that of H2D and CH2D (0.079, 0.067, respectively). The LVED and LVES volumes by H2D, CH2D and CHCD correlate well with MUGA but there was a significant over estimation of LVED and LVES volumes by H2D and CH2D as compared to MUGA. Also, the RMS residuals were the lowest for the CHCD method. The CHCD had the highest mean inter-observer agreement (90.9%) for LVEF compared with H2D and CH2D (78.9% and 88.1%, respectively). CONCLUSIONS: CHCD has been feasible in all patients in the present study and it has shown a good concordance with ejection fraction and volumes provided by MUGA.