Presence of sinus rhythm at time of ablation in patients with persistent atrial fibrillation undergoing pulmonary vein isolation is associated with improved long-term arrhythmia outcomes.

BACKGROUND: Adverse structural and electrical remodeling underlie persistent atrial fibrillation (PersAF). Restoration of sinus rhythm (SR) prior to ablation in PersAF may improve the underlying substrate, thus improving arrhythmia outcomes. The aim of this study was to evaluate if the presence of SR at time of ablation is associated with improved long-term arrhythmia outcomes of a limited catheter ablation (CA) strategy in PersAF. METHODS: Patients with PersAF undergoing pulmonary vein isolation at our institution from 2014-2018 were included. We compared patients who presented for ablation in SR (by cardioversion and/or antiarrhythmic drugs [AADs]) to those who presented in AF. Primary outcome of interest was freedom from atrial arrhythmias (AAs) on or off AADs at 1 year after single ablation. Secondary outcomes included freedom from AAs on or off AADs overall, freedom from AAs off AADs at 1 year, and time to recurrent AF. RESULTS: Five hundred seventeen patients were included (322 presented in AF, 195 SR). The primary outcome was higher in those who presented for CA in SR as compared to AF (85.6% vs. 77.0%, p = 0.017). Freedom from AAs off AAD at 12 months was also higher in those presenting in SR (59.0% vs. 44.4%; p = 0.001) and time to recurrent AF was longer (p = 0.008). Presence of SR at CA was independently associated with the primary outcome at 12 months (OR 1.77; 95% CI 1.08-2.90) and overall (OR 1.89; 95% CI 1.26-2.82). CONCLUSIONS: Presence of SR at time of ablation is associated with improved long-term arrhythmia outcomes of limited CA in PersAF.

Impact of Left Ventricular Papillary Muscle Ventricular Arrhythmia Ablation on Mitral Valve Function.

BACKGROUND: Although efficacious, catheter ablation (CA) of ventricular arrhythmias (VAs) originating from left ventricular (LV) papillary muscles (PAPs) has the potential to affect mitral valve (MV) function. OBJECTIVES: The aim of this study was to determine whether lesions delivered during CA of VAs from LV PAPs affected MV function. METHODS: Consecutive patients undergoing CA of LV PAP VAs from January 2015 to December 2020 in whom both preprocedural and postprocedural transthoracic echocardiography was performed were included. Radiofrequency ablation was performed with an irrigated-tip catheter with or without contact force sensing and intracardiac echocardiographic guidance. The PAPs were delineated into segments: tip, body, and base. Pre- and post-CA transthoracic echocardiograms were reviewed to assess MV regurgitation, which was graded 0 (none), 1 (mild), 2 (moderate), or 3 (severe). A change of ≥2 grades from baseline was considered significant. RESULTS: A total of 103 patients (mean age 63 ± 15 years, 78% men) were included. VAs were ablated from the anterolateral PAP in 35% (n = 36), posteromedial PAP in 55% (n = 57), and both PAPs in 10% (n = 10). Lesion distribution was as follows: PAP tip in 52 (50%), PAP base in 34 (33%), PAP body in 13 (13%), and entire PAP in 4 (4%). The mean number of lesions delivered was 16 ± 13 (median 14). Of 103 patients, 102 (99%) showed no change in MV function. CONCLUSIONS: Using intracardiac echocardiographic guidance, lesions can be safely delivered on various aspects of this structure without adverse impact on MV function.

Identification and Endocardial Ablation of the Ligament of Marshall for Pulmonary Vein Isolation.

OBJECTIVES: The aims of this study were to establish criteria for identifying ligament of Marshall (LOM) connections that are responsible for pulmonary vein isolation (PVI) failure, assess their incidence, and determine if they can be targeted by focal endocardial ablation at the anterior carina of the left superior pulmonary vein (LSPV). BACKGROUND: Wide antral ablation of the left pulmonary veins (PVs) may not achieve PVI, sometimes requiring empirical ablation of the PV carina. The mechanism could be due to epicardial conduction along the LOM, which courses adjacent to the anterior carina. METHODS: In patients undergoing radiofrequency ablation for atrial fibrillation, if wide ablation of the left PV did not achieve isolation, bidirectional mapping was performed. A presumptive LOM connection was diagnosed if the earliest entrance was mapped to the anterior LSPV, while the earliest exit was mapped inferior to the left inferior PV. Focal ablation at the LSPV anterior carina was performed, even if not at the site of earliest entrance activation. The primary endpoint was successful PVI immediately after ablation. RESULTS: The study included 455 consecutive patients who underwent 570 procedures, of which 364 were first-time ablations. Presumptive LOM connections were identified in 48 procedures (8.4%) and in 41 patients (11.2%) undergoing first-time ablation and were successfully ablated at the anterior carina of the LSPV in 47 of 48 procedures (98%). CONCLUSIONS: LOM connections may be a common cause of PVI failure and can be easily identified and reliably ablated with focal endocardial ablation at the anterior LSPV carina.

Combined aquaretic and diuretic therapy in acute heart failure.

INTRODUCTION: Acute heart failure (AHF) is a leading cause of hospitalization and readmission in the US. The present study evaluated maximum diuresis while minimizing electrolyte imbalances, hemodynamic instability, and kidney dysfunction, to achieve a euvolemic state safely in a shorter period of time. METHODS AND RESULTS: A protocol of combined therapy with furosemide, metolazone, and spironolactone, with or without tolvaptan and acetazolamide, was used in 17 hospitalized patients with AHF. The mean number of days on combination diuretic protocol was 3.8 days. The mean daily fluid balance was 3.0±2.1 L negative. The mean daily urine output (UOP) was 4.1±2.0 L (range 1.8-10.5 L). There were minimal fluctuations in serum electrolyte levels and serum creatinine over the duration of diuretic therapy. There was no statistically significant change in patients' creatinine from immediately prior to therapy to the last day of therapy, with a mean increase in creatinine of 0.14 mg/dL (95% CI -0.03, +0.30, p=0.10). CONCLUSION: Our strategy of treating AHF by achieving high UOP, while maintaining stable electrolytes and creatinine in a short period to euvolemic state, is safe.

Mineralocorticoid Receptor Antagonism in Acute Heart Failure.

OPINION STATEMENT: Heart failure (HF) remains a tremendous burden to health care systems and patients worldwide. The cornerstone neurohormonal disruption that leads to the debilitating sequelae in HF patients revolves primarily around aldosterone and the renin-angiotensin-aldosterone system (RAAS). Aldosterone plays a detrimental role in tissue remodeling by inducing inflammation and fibrosis within the cardiovascular and renal systems, leaving mineralocorticoid receptor antagonists (MRAs) as key pharmacological tools to slow pathogenesis and improve patient outcomes. The role of MRA in improving morbidity and mortality in outpatients with chronic HF and low ejection fraction is well established and supported by large randomized controlled trials. However, evidence-based data relating to the use of MRA in acute HF (AHF) remain somewhat limited, and therefore, the use of MRA is not ubiquitously considered in the acute setting. Current studies for the use of MRA in AHF are limited by small sample size as well as safety concerns relating to the dose-dependent effects on electrolyte homeostasis and renal function. Here, we discuss the imperative need for additional trials elucidating the potential benefits of MRA in AHF as an adjunct diuretic therapy. We not only discuss the role of MRA in neurohormonal regulation of aldosterone but also highlight a potential dose-dependent role for MRA in natriuresis. Furthermore, we showcase existing and recent evidence-based data demonstrating the effectiveness of MRA in AHF and on long-term outcomes. Finally, we look at several treatment strategies and safety concerns as they relate to MRA use so as to aid in avoidance of MRA-related complications while facilitating achievement of treatment goals.

Clinical simulation using deliberate practice in nursing education: a Wilsonian concept analysis.

Effective use of simulation is dependent on a complete understanding of simulation's central conceptual elements. Deliberate practice, a constituent of Ericsson's theory of expertise, has been identified as a central concept in effective simulation learning. Deliberate practice is compatible with simulation frameworks already being suggested for use in nursing education. This paper uses Wilson's Method of concept analysis for the purpose of exploring the concept of deliberate practice in the context of clinical simulation in nursing education. Nursing education should move forward in a manner that reflects best practice in nursing education.

Synthesis and Chemistry of Bicyclo[4.1.0]hept-1,6-ene.

Bicyclo[4.1.0]hept-1,6-ene has been generated by elimination of 1-chloro-2-(trimethysilyl)bicyclo[4.1.0]heptane in the gas phase over solid fluoride at 25 degrees C. The cyclopropene dimerizes by a rapid ene reaction forming two diastereomeric cyclopropenes. In tetrahydrofuran or chloroform the ene dimers couple to form a single crystalline triene tetramer, whereas a mixture of tricyclohexane tetramers is formed when the neat dimers are allowed to warm to room temperature. Oxidation by dimethyldioxirane or dioxygen gives carbonyl products. Quantum mechanical calculations yielded an increase in strain of approximately 17 kcal/mol over that for 1,2-dimethylcyclopropene. The potential enegy barrier to flexing (folding) along the fused double bond of bicyclo[4.1.0]hept-1,6-ene is only approximately 1 kcal/mol at the highest level of theory investigated.