Phospholipids containing trans-unsaturated fatty acid residues are the major products of the thiyl radical attack on L-alpha-phosphatidylcholine from soybean lecithin in homogeneous solution or in liposomes (LUVET). Thiyl radicals act as the catalyst for the cis-trans isomerization, and the number of catalytic cycles depends on the reaction conditions. The presence of approximately 0.2 mM oxygen does not influence the reaction outcome but accelerates the efficiency of cis-trans isomerization in homogeneous solution. Under these conditions, the PUFA peroxidation is found to be unimportant. A detailed study of the isomerization of methyl linoleate including product studies indicates the formation of a small amount of conjugated dienes that act as inhibitors. Indeed, all-trans-retinol substantially retarded the isomerization process.

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Background Radiofrequency high‐power ablation appears to be a novel concept for atrial fibrillation (AF). The ablation index (AI) value has been associated with durability of pulmonary vein isolation (PVI). Objectives This study aimed to report the procedural data and initial results of a combined ablation technique using AI‐guided high‐power (AI‐HP; 50 W) ablation for PVI. Methods Symptomatic AF patients were consecutively enrolled and underwent wide‐area contiguous circumferential PVI. Contact‐force catheters were used, ablation power was set to 50 W targeting AI values (550 anterior and 400 posterior). Esophageal temperature was monitored during procedure, all patients underwent postablation esophageal endoscopy. Results PVI was achieved in all (n = 50, mean age: 68 ± 9 years, female: 60%) patients, rate of first‐round PVI was 92%. A total of N = 2105 AI‐guided ablation lesions were analyzed. Comparing left anterior wall vs left posterior wall and right anterior wall vs right posterior wall, mean ablation time (s) per lesion was 20.5 ± 8 vs 8.6 ± 3 and 12.2 ± 4 vs 9.3 ± 3; mean contact force (g): 17.1 ± 12 vs 25.4 ± 14 and 33.7 ± 13 vs 21.0 ± 11; mean AI: 547 ± 48 vs 445 ± 55 and 555 ± 56 vs 440 ± 47 (all P < .0001). Procedure and fluoroscopy time (minute) were 55.6 ± 6.6 and 6 ± 1.7, respectively. Only one (2%) patient had a minimal esophageal lesion. During In‐hospital and 1‐month follow‐up no major complications such as death, stroke, tamponade, or atriaesophageal fistula (AE) occurred. Preliminary 6‐month follow‐up showed 48 of 50 (96%) patients were free from clinical AF/atrial tachycardia recurrence. Conclusion AI‐HP (50 W) ablation appears to be a feasible, safe, fast, and effective ablation technique for PVI.

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