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Ventricular fibrillation can be the presenting arrhythmia in children with asymptomatic Wolff-Parkinson-White syndrome. In asymptomatic, high-risk children with the Wolff-Parkinson-White syndrome, prophylactic catheter ablation performed by an experienced operator reduces the risk of life-threatening arrhythmias.

To investigate if Brain Natriuretic Peptide (BNP) and highsensitivity troponin I predict significant arrhythmia, symptomatic significant arrhythmia and 90-day death and/or Major Adverse Cardiac Event in Emergency Department (ED) unexplained syncope patients investigated with a 14-day ambulatory electrocardiogram (ECG) recorder. Single-centre, prospective, cohort study. Patients 16 years or over presenting within 6 hours of an episode of unexplained syncope were fitted with an ambulatory ECG recorder (Zio® XT monitor) and had high-sensitivity troponin I and BNP measured on ED admission and 3 hours later. Between 17/11/2015 and 13/06/2017, 86 patients were recruited. 24 had significant arrhythmia, 9 symptomatic significant arrhythmia and 26 patients had death and/or Major adverse cardiac events by 90 days. BNP at admission, three hours and change in BNP and high-sensitivity troponin I at three hours were associated with significant arrhythmia and serious outcome. BNP >20pg/mL and/or high-sensitivity troponin I above the 99% sex specific centile (M>34ng/L, F>16ng/L) at 3 hours had a sensitivity of 100% (21/21; 95% CI 81%-100%) and specificity of 43% (16/37; 28%-60%) for significant arrhythmia and a sensitivity of 100% (22/22; 95% CI 82%-100%) and specificity of 44% (16/36; 28%-62%) for serious outcome both at 90 days. The combination of BNP and high-sensitivity troponin I at 3 hours shows promise as a potential predictive marker for serious arrhythmia and serious outcome at 90 days and deserves further exploration as a rule out test to enable safe discharge of patients from the ED who are at low risk of having cardiac syncope and subsequent adverse events. [ABSTRACT FROM AUTHOR]

An 81-year-old female Jehovah's Witness (JW) patient with severe aortic stenosis required aortic valve replacement (AVR). However, the patient's religious beliefs precluded the use of primary blood components. Since the definitive treatment of AVR required bloodless open heart surgery, careful peri-operative plans were set forth by a multi-disciplinary team involving the cardiothoracic surgeon, haematologist and anaesthetist. The patient went on to successfully recover postoperatively. This case highlights: 1) The importance of carefully navigating through the most recent clinical and ethical protocol involved in the surgical management of JW's. 2) The importance of preparing individually tailored pre, intra and postoperative plans that are delivered through a multi-disciplinary clinical team to ensure the best and safest possible outcomes. [ABSTRACT FROM AUTHOR]

Background: Ventricular fibrillation can be the presenting arrhythmia in children with asymptomatic Wolff–Parkinson–White syndrome. Deaths due to this arrhythmia are potentially preventable. Methods: We performed a randomized study in which prophylactic radiofrequency catheter ablation of accessory pathways was compared with no ablation in asymptomatic children (age range, 5 to 12 years) with the Wolff–Parkinson–White syndrome who were at high risk for arrhythmias. The primary end point was the occurrence of arrhythmic events during follow-up. Results: Of the 165 eligible children, 60 were determined to be at high risk for arrhythmias. After randomization, but before any ablation had been performed, the parents withdrew 13 children from the study. Of the remaining children, 20 underwent prophylactic ablation and 27 had no treatment. The characteristics of the two groups were similar. There were three ablation-related complications, one of which led to hospitalization. During follow-up, 1 child in the ablation group (5 percent) and 12 in the control group (44 percent) had arrhythmic events. Two children in the control group had ventricular fibrillation, and one died suddenly. The cumulative rate of arrhythmic events was lower among children at high risk who underwent ablation than among those at high risk who did not. The reduction in risk associated with ablation remained significant after adjustment in a Cox regression analysis. In both the ablation and the control groups, the independent predictors of arrhythmic events were the absence of prophylactic ablation and the presence of multiple accessory pathways. Conclusions: In asymptomatic, high-risk children with the Wolff–Parkinson–White syndrome, prophylactic catheter ablation performed by an experienced operator reduces the risk of life-threatening arrhythmias. N Engl J Med 2004;351:1197-205. [ABSTRACT FROM AUTHOR]

Background: Circumferential pulmonary vein ablation (CPVA) is an effective treatment for atrial fibrillation (AF). Accurate left atrial (LA) mapping is essential for creating lesions at the LA-pulmonary vein (PV) junction, avoiding PV stenosis., Objectives: The purpose of this study was to establish whether endocardial impedance varies within the LA and PVs and whether it is a useful tool for mapping and ablation., Methods: Pilot Phase: Three-dimensional LA maps were created using CARTO. Impedance (Z) was measured using a radiofrequency generator at multiple points in the LA, PV ostia (PVO), and deep PVs in 79 patients undergoing their first AF ablation (group 1) and 29 patients undergoing repeat CPVA (group 2). Prospective Phase: In an additional 20 patients, using pilot phase data, one operator defined catheter tip location as either LA or PVO based on CARTO and fluoroscopy. A second operator blinded to CARTO simultaneously did the same based on impedance at 15 +/- 4 points per patient., Results: Group 1: Z(LA) was 99.4 +/- 9.0 omega. Z(PVO) was higher (109.2 +/- 8.5 omega), rising further as the catheter advanced into deep PV (137 omega +/- 18). Z(PVO) differed from Z(LA) by 9 +/- 4 omega. Group 2 had a lower Z(LA) and Z(PVO) compared with group 1 (P <.05). Impedance monitoring differentiated between LA and PVO, with 91% specificity and sensitivity, 96% positive predictive value, and 81% negative predictive value. At 3-month follow-up, no patients had evidence of PV stenosis on magnetic resonance imaging., Conclusion: Impedance mapping reliably identifies the LA-PV transitional zone, facilitating AF ablation, and its use is associated with a low incidence of PV stenosis.

Prolonged temporary pacing is associated with frequent complications. We describe a patient with aortic endocarditis and acquired tri-fascicular block in whom back-up pacing was indicated. Using a Seldinger technique via a subclavian approach, a permanent active-fixation lead was positioned in the right ventricle. The lead was tunnelled subcutaneously for 6 cm, and the proximal end was connected to a standard single chamber pulse generator. The procedure was well tolerated and over a period of four months there were no complications or infection. The PR interval subsequently reduced in duration to 200 ms and as no episodes of AV block had occurred, the lead was easily removed with retraction of the helix and gentle traction.

Objectives: The purpose of this study was to evaluate the electroanatomic characteristics of left atrial tachycardia (AT) in a series of patients who underwent circumferential pulmonary vein ablation (CPVA) and to describe the ablation strategy and clinical outcome., Background: Circumferential pulmonary vein ablation is an effective treatment for atrial fibrillation. A potential midterm complication is the development of left AT. There are only isolated reports describing mapping and ablation of such arrhythmias., Methods: Thirteen patients (age 57.4 +/- 8.9 years, five female) underwent mapping and ablation of 14 left ATs via an electroanatomic mapping system a mean of 2.6 +/- 1.6 months after CPVA., Results: Three patients were characterized as having focal AT (cycle length: 266 +/- 35.9 ms). Of 11 macro-re-entrant tachycardias studied in the remaining 10 patients (cycle length: 275 +/- 75 ms), 5 showed single-loop and 6 dual-loop circuits. Re-entrant circuits used the mitral isthmus, the posterior wall, or gaps on previous encircling lines. Such gaps and all three foci occurred anterior to the left superior pulmonary vein or at the septal aspect of the right pulmonary veins. Thirteen of 14 tachycardias (93%) were successfully ablated., Conclusions: Left AT after CPVA can be due to a macro-re-entrant or focal mechanism. Re-entry occurs most commonly across the mitral isthmus, the posterior wall, or gaps on previous ablation lines. Such gaps and foci occur most commonly at the anterior aspect of the left superior pulmonary vein and at the septal aspect of the right pulmonary veins. These arrhythmias can be successfully mapped and ablated with an electroanatomic mapping system.