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Background: The 3-dimensional (3D) nature of sinoatrial node (SAN) function has not been characterized in the intact human heart., Objective: The purpose of this study was to characterize the 3D nature of SAN function in patients with structural heart disease (SHD) using simultaneous endocardial-epicardial (endo-epi) phase mapping., Methods: Simultaneous intraoperative endo-epi SAN mapping was performed during sinus rhythm at baseline (SR baseline ) and postoverdrive suppression at 600 ms (SR post-pace600 ) and 400 ms (SR post-pace400 ) using 2 Abbott Advisor HD Grid Mapping Catheters. Unipolar and bipolar electrograms (EGMs) were exported for phase analysis to determine (1) activation exits; (2) wavefront propagation sequence; (3) endo-epi dissociation; and (4) fractionation. Comparison of these variables was made among the 3 rhythms from an endo-epi perspective., Results: Sixteen patients with SHD were included. SR baseline activations were unicentric and predominantly exited cranially (87.5%) with endo-epi synchrony. However, with overdrive suppression, a tendency for caudal exit shift and endo-epi asynchrony was observed: SR post-pace600 vs SR baseline : cranial endo 75% vs 87.5% (P = .046); cranial epi 68.8% vs 87.5% (P = 0.002); caudal endo 12.5% vs 6.2% (P = 0.215); caudal epi 25% vs 6.2% (P = .0003); and SR post-pace400 vs SR baseline : cranial endo 81.3% vs 87.5% (P = 0.335); cranial epi 68.7% vs 87.5% (P = 0.0034; caudal endo 12.5% vs 6.2% (P = .148); caudal epi 31.2% vs 6.2% (P = 0.0017), consistent with multicentricity. EGM fractionation was more prevalent with overdrive suppression., Conclusion: During mapping of the intact human heart, SAN demonstrated redundancy of sinoatrial exits with postoverdrive shift in sites of earliest activation and epi-endo dissociation of sinoatrial exits., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Objectives: This study evaluated if modifying electrocardiographic (ECG) precordial leads to a higher intercostal position improved the accuracy of outflow tract ventricular arrhythmia (OTVA) localization., Background: Precordial ECG prediction algorithms that use a standard lead configuration localize OTVA with variable accuracy., Methods: Patients who underwent OTVA ablation were prospectively enrolled to have a standard and modified (high) precordial ECG. R- and S-wave amplitudes and intervals were measured to develop an algorithm that differentiated the right ventricular outflow tract (RVOT) and the left ventricular outflow tract (LVOT) with high accuracy-the modified lead R-wave deflection interval (RWDI). This interval was defined from the earliest QRS onset (using all modified leads) to the lead with longest R-wave deflection. The RWDI was compared with all other ECG algorithms., Results: A total of 50 patients (38 women; mean age 51 ± 17 years) had successful catheter ablation for OTVA (RVOT 60%, LVOT 40%). The modified lead RWDI was significantly shorter in the RVOT group (18.5 ms, interquartile range 25th to 75th percentile [IQR 25-75 ]: 0 to 29.5 ms) compared with the LVOT group (67.5 ms, IQR 25-75 : 56.5 to 77 ms; p < 0.05). Using a RWDI ≤40 ms to predict an RVOT focus, the sensitivity and specificity of the modified lead RWDI were 100% and 95%, respectively; the area under the receiver-operating characteristic curve was 0.96. This was superior to all previously developed algorithms. In a computed tomography analysis (n = 50), the modified leads were significantly closer to the outflow tracts compared with the standard precordial leads., Conclusions: The modified lead RWDI is a simple, easily interpretable algorithm that can potentially differentiate a right- or left-sided origin of OTVA with high accuracy., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Endocardial-epicardial dissociation and focal breakthroughs in humans with atrial fibrillation (AF) have been recently demonstrated using activation mapping of short 10-second AF segments. In the current study, we used simultaneous endo-epi phase mapping to characterize endo-epi activation patterns on long segments of human persistent AF., Methods: Simultaneous intraoperative mapping of endo- and epicardial lateral right atrium wall was performed in patients with persistent AF using 2 high-density grid catheters (16 electrodes, 3 mm spacing). Filtered unipolar and bipolar electrograms of continuous 2-minute AF recordings and electrodes locations were exported for phase analyses. We defined endocardial-epicardial dissociation as phase difference of ≥20 ms between paired endo-epi electrodes. Wavefronts were classified as rotations, single wavefronts, focal waves, or disorganized activity as per standard criteria. Endo-Epi wavefront patterns were simultaneously compared on dynamic phase maps. Complex fractionated electrograms were defined as bipolar electrograms with ≥5 directional changes occupying at least 70% of sample duration., Results: Fourteen patients with persistent AF undergoing cardiac surgery were included. Endocardial-epicardial dissociation was seen in 50.3% of phase maps with significant temporal heterogeneity. Disorganized activity (Endo: 41.3% versus Epi: 46.8%, P =0.0194) and single wavefronts (Endo: 31.3% versus Epi: 28.1%, P =0.129) were the dominant patterns. Transient rotations (Endo: 22% versus Epi: 19.2%, P =0.169; mean duration: 590±140 ms) and nonsustained focal waves (Endo: 1.2% versus Epi: 1.6%, P =0.669) were also observed. Apparent transmural migration of rotational activations (n=6) from the epi- to the endocardium was seen in 2 patients. Electrogram fractionation was significantly higher in the epicardium than endocardium (61.2% versus 51.6%, P <0.0001)., Conclusions: Simultaneous endo-epi phase mapping of prolonged human persistent AF recordings shows significant Endocardial-epicardial dissociation marked temporal heterogeneity, discordant and transitioning wavefronts patterns and complex fractionations. No sustained focal activity was observed. Such complex 3-dimensional interactions provide insight into why endocardial mapping alone may not fully characterize the AF mechanism and why endocardial ablation may not be sufficient. Graphic Abstract: A graphic abstract is available for this article.

Background: Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF)., Objective: The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men., Methods: We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these., Results: A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm 2 ; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01)., Conclusion: Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Patent foramen ovale (PFO) is a potential mechanism for paradoxical embolism in cryptogenic ischaemic stroke or transient ischaemic attack (TIA). PFO is typically demonstrated with agitated saline ("bubble study", BS) during echocardiography. We hypothesised that the BS is frequently requested in patients that have a readily identifiable cause of stroke, that any PFO detected is likely incidental, and its detection often does not alter management., Methods: This was a retrospective observational study of patients with recent ischaemic stroke/TIA referred for a BS. Patient demographics, stroke risk factors, vascular/cerebral imaging results and transoesophageal echocardiogram (TOE) reports were recorded. A "modified" Risk of Paradoxical Embolism (RoPE) score was calculated. Change in management was defined as antiplatelet/anticoagulant therapy alteration or referral for PFO closure. Bubble Study complications were recorded., Results: Among 715 patients with ischaemic stroke/TIA referred for a BS, 8.7% had atrial fibrillation and 9.2% had carotid stenosis ≥70%. At least three stroke risk factors were present in 39.3% and only 47.1% of patients screened had a "modified" RoPE score of >5. A PFO was detected in 248 patients of whom only 31% (77/248) had a subsequent change in management. Of BS performed, 1/924 patients (0.1%) suffered a TIA as a complication., Conclusions: The echocardiographic BS is frequently performed in patients that have a readily identifiable cause of stroke and whose PFO unlikely relates to the stroke/TIA. Bubble Study findings resulted in a change in management in the minority. The procedure is safe but the complication rate warrants informed consent., (Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.)

Defibrillator technology for sudden cardiac death (SCD) prevention now includes the transvenous implantable cardiac defibrillator (ICD), subcutaneous ICD (S-ICD) and wearable cardioverter defibrillator (WCD). ICD use improves survival in patients who survived previous sudden cardiac arrest (SCA) due to ventricular tachycardia (VT)/ventricular fibrillation (VF), as well as in patients who experienced haemodynamically significant VT. It is also currently indicated for primary prevention in ischaemic/non-ischaemic cardiomyopathies, certain congenital heart disease conditions and inherited channelopathies. In this review article, we hope to present an updated review on ICD use for SCD prevention, with a focus on contemporary issues affecting ICD selection. These include: the role of primary prevention ICD in patients with non-ischaemic cardiomyopathy (NICM) in light of the 2016 DANISH (Danish Study to Assess the Efficacy of ICDs in Patients with Non-Ischemic Systolic Heart Failure on Mortality) trial; the role of defibrillator component (CRT-D) in patients receiving cardiac resynchronisation therapy (CRT-P); and the emerging role of cardiac magnetic resonance imaging (cMRI) in particular, the presence of late gadolinium enhancement (LGE), as an important SCD risk predictor. The current use of S-ICD and WCD, including clinical indications, evidence for efficacy and limitations, will also be discussed., (Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Background: Elevated lipoprotein(a) (Lp[a]) and low-density lipoprotein (LDL) cholesterol are important inheritable risk factors for premature coronary artery disease (CAD). Lp(a) mediates cardiovascular risk through prothrombotic, proinflammatory, and proatherogenic properties. The association of Lp(a) and LDL cholesterol with angiographic disease severity and complexity in patients with premature CAD has yet to be established., Objective: To investigate the relationship of Lp(a) and LDL cholesterol with the severity and complexity of coronary artery lesions using the SYNergy between percutaneous coronary intervention with TAXUS and Cardiac Surgery (SYNTAX) and Gensini scores, in patients with premature CAD., Methods: Plasma Lp(a) levels were consecutively measured by an automated latex-enhanced immunoassay in 147 patients with premature coronary events (aged <60 years). Elevated Lp(a) was defined as >0.5 g/L, and elevated LDL cholesterol as an untreated LDL cholesterol of >5.0 mmol/L (>193 mg/dL). Demographical, biochemical, and clinical data were retrospectively collected from medical records. SYNTAX and Gensini scores were independently assessed by 2 investigators., Results: Patients were subdivided into tertiles using SYNTAX scores. The proportion of patients with elevated Lp(a) and elevated LDL cholesterol were significantly higher in patients with higher SYNTAX and Gensini scores (P < .05). In multivariate analysis (adjusting for age, diabetes, hypertension, and previous coronary event), elevated Lp(a) and elevated LDL cholesterol remained significant, independent predictors of higher SYNTAX and Gensini scores (P < .05). Patients with both elevated Lp(a) and elevated LDL cholesterol constituted most of the patients in the highest SYNTAX tertile, while patients with nonelevated Lp(a) and nonelevated LDL cholesterol were predominantly in the lowest SYNTAX tertile (P < .05)., Conclusion: In patients with premature CAD, elevated Lp(a) and LDL cholesterol (in a range consistent with familial hypercholesterolemia) were significant, independent predictors of the severity of CAD. Both lipid disorders should be routinely screened for in younger patients presenting to the coronary care unit., (Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.)