Citations

Background: Each year, nearly 700,000 Americans suffer from strokes, resulting in 150,000 deaths and significant disability among survivors. Despite advances in therapeutic options for acute stroke within a critical time window, patient delay in seeking medical attention remains a significant barrier to improving outcomes. In a recent study of the effect of marital status on the timing of presentation for medical care in patients with chest pain, married men presented earlier than married women. In this study, we hypothesize that marital status is a predictor of earlier health-seeking behavior following the onset of stroke symptoms. Methods: We conducted a retrospective review of 100 patients with acute stroke symptoms in our stroke alert quality initiative database who were brought by Emergency Medical Services (EMS) to the Mayo Clinic Hospital, Arizona between December 1, 2010 and June 30, 2011. Nine patients were excluded due to lack of data. The database contains the following information for each patient: age, gender, marital status, the time of symptom awareness, and the time of EMS dispatch. Using both an independent samples t-Test and ANOVA, we compared the time from symptom awareness to EMS dispatch both between married and single patients, and between men and women, (married and single). Results: The mean age of the 91 patients studied was 76 years (SD = 12.5 years) and 52% were women. Forty-five patients (49.5%) were married, and 46 (50.5%) were single. The mean time from symptom awareness to EMS activation was 52 minutes (median 21.0, SD 87.3, range 2-519 minutes.) Categorized by marital status, married patients activated EMS earlier that single patients, but this difference was not significant (43 versus 60 minutes, p=0.35.). Analyzing the data separately for gender, we found that married men activated EMS significantly earlier than married women (26 versus 72 minutes, p=0.04.). Single men activated EMS earlier than single women, but this difference was not significant (50 versus 66 minutes, p=0.60.) Conclusions: Among persons with acute stroke symptoms, earlier medical-seeking behavior was seen in married compared to single persons, and particularly in married men. We plan to analyze a larger sample of patients, and if these preliminary findings are confirmed, we will conduct a prospective study evaluating reasons why married men with stroke symptoms seek medical attention earlier.

Background: Multifocal ectopic Purkinje-related premature contractions (MEPPC), the most recent addition to the spectrum of SCN5A -mediated cardiac channelopathies, is characterized by frequent premature ventricular complexes (PVCs) originating from the Purkinje system, atrial arrhythmias, and a predilection for PVC-mediated dilated cardiomyopathy. MEPPC-causative variants tend to cluster within the voltage sensing domain (VSD) of Na v 1.5. Objective: To describe the clinical and cellular electrophysiological phenotype associated with a novel, putative MEPPC-causative SCN5A variant (p.Gln419Pro-SCN5A) that resides outside the VSD of Na v 1.5. Methods: p.Gln419Pro-SCN5A was identified in a 21-year-old male with a history of frequent, multifocal PVCs and atrial tachycardia. Subsequently, three p.Gln419Pro-SCN5A-positive relatives, each with early onset atrial arrhythmias and/or frequent, multifocal PVCs, were identified. All individuals had structurally normal hearts by echocardiography and/or cardiac magnetic resonance imaging. p.Gln419Pro-SCN5A was engineered by site directed mutagenesis and heterologously expressed in TSA201 cells. The standard whole-cell patch clamp technique was used to measure SCN5A wild-type (WT) and p.Gln419Pro-SCN5A sodium currents. Results: Analysis of the current-voltage relationship revealed that neither peak sodium current densities nor late inward sodium current were impacted by p.Gln419Pro-SCN5A. However, p.Gln419Pro-SCN5A significantly shifted V 1/2 in inactivation by -4.6 mV from -84.5±0.7 mV (WT, n=10) to -89.1±0.4 mV (Gln419Pro, n=12, p<0.05 vs. WT) and V 1/2 in activation by -11.6 mV from -30.9±1.3 mV (WT, n=10) to -42.5±1.0 mV (Gln419Pro, n=12, p<0.05 vs. WT) leading to a larger hyperpolarized window current. Flecainide dramatically reduced PVC burden in p.Gln419Pro-SCN5A-positive patients. Conclusions: p.Gln419Pro-SCN5A represents only the fifth MEPPC-causative variant described to date and the first associated with a classic MEPPC phenotype localizing outside Na v 1.5’s VSD. As class I antiarrhythmic drugs are highly efficacious in MEPPC, this clinical entity merits consideration in all young patients found to have a high burden of Purkinje-related PVCs.

Introduction: Catheter ablation of the arrhythmogenic substrate reduces the recurrence of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy and implantable cardioverter-defibrillator (ICD). However, the all-cause mortality benefit in this population is unclear. Hypothesis: Prophylactic ablation of the arrhythmogenic substrate decreases all-cause mortality and prevents the recurrence of VT/ventricular fibrillation (VF) in patients with ischemic cardiomyopathy. Methods: We searched the MEDLINE and EMBASE databases from inception through May 2021. We included randomized controlled trials that compared all-cause mortality and ventricular arrhythmia recurrence in patients with ischemic cardiomyopathy who underwent ICD implantation with and without prophylactic ablation. The data from each study was combined using a fixed effects model to calculate the hazard ratio and 95% confidence interval (CI). Results: Four randomized controlled trials during 2007-2020 involving 505 patients (249 patients with and 256 patients without prophylactic VT ablation) were included in our meta-analysis. Compared with control, prophylactic VT ablation did not decrease the all-cause mortality (pooled hazard ratio = 0.94, 95% CI 0.54-1.63, p = 0.818, I2 = 5.8%). However, prophylactic VT ablation significantly decreased appropriate ICD therapy (pooled hazard ratio = 0.58, 95% CI 0.41-0.82, p = 0.002, I 2 = 26.1%) and VT/VF recurrence (pooled hazard ratio = 0.70, 95% CI 0.52-0.93, p = 0.015, I 2 = 0.0%). Conclusions: Prophylactic VT ablation in patients with ischemic cardiomyopathy did not decrease all-cause mortality; however, it did lead to decreased appropriate ICD therapy and VT/VF recurrence.

Background: Mutations in the CACNA1C-encoded L-type calcium channel have been associated with Timothy Syndrome (TS) with severe QT prolongation, cardiac hypertrophy, syndactyly, facial dysmorphisms, developmental delay, and sudden death by impaired channel inactivation and increase peak current. Recently, a small number of patients with CACNA1C mutations with only long QT syndrome (LQTS) have been described. Objective: To explore whether CACNA1C mutations associated with TS were mechanistically and clinically distinct from CACNA1C-mediated LQTS. Methods/Results: Illumina HiSeq 2000 platform-based whole exome sequencing with variant alignment using HGSC Mercury analysis and Atlas2 revealed a novel variant CACNA1C-L762F that co-segregated with affected patients of a large, multi-generational family with LQTS and sudden death. The proband presented at 3 years of age with out-of-hospital cardiac arrest and demonstrated QTc of 530. The mutation localized to the DII/DIII intracellular linker domain of the channel in a highly conserved region in close proximity to the 6th DI transmembrane domain. Whole cell patch clamp of heterologously expressed CACNA1C-L762F in TSA201 cells demonstrated slower inactivation tau and increased late current indicating its gain-of-function cellular electrophysiological phenotype. Comprehensive review and topological mapping of all described CACNA1C mutations associated with TS or LQTS revealed disease-specific hotspots. TS-associated mutations localized to cytoplasmic aspects of transmembrane domains while LQTS-associated mutations localized to cytoplasmic N- and C-terminal domains and linker regions. Probands hosting TS mutations demonstrated markedly prolonged QTc values compared to LQTS (618 vs 486 ms, p<0.001) and were younger at presentation (2.7 vs 20.1 years, p<0.002). Supporting these associations, the L762F mutation localized closer to the CACNA1C transmembrane domain than any other LQTS mutation and are associated with a QTc and age of diagnosis reflective of TS-associated mutations. Conclusions: The CACNA1C-L762F mutation is associated with biochemical and clinical features which highlight a molecular and clinical distinction between TS- and LQTS-associated CACNA1C mutations.

Background and objectives Documentation is important for quality improvement, education, and research. There is currently a lack of recommendations regarding key aspects of documentation in regional anesthesia. The aim of this study was to establish recommendations for documentation in regional anesthesia. Methods Following the formation of the executive committee and a directed literature review, a long list of potential documentation components was created. A modified Delphi process was then employed to achieve consensus amongst a group of international experts in regional anesthesia. This consisted of 2 rounds of anonymous electronic voting and a final virtual round table discussion with live polling on items not yet excluded or accepted from previous rounds. Progression or exclusion of potential components through the rounds was based on the achievement of strong consensus. Strong consensus was defined as ≥75% agreement and weak consensus as 50%–74% agreement. Results Seventy-seven collaborators participated in both rounds 1 and 2, while 50 collaborators took part in round 3. In total, experts voted on 83 items and achieved a strong consensus on 51 items, weak consensus on 3 and rejected 29. Conclusion By means of a modified Delphi process, we have established expert consensus on documentation in regional anesthesia.

Objective: To analyze insulin delivery and glycemic metrics throughout the menstrual cycle for women with type 1 diabetes using closed loop control (CLC) insulin delivery. Methods: Menstruating women using a CLC system in a clinical trial were invited to record their menstrual cycles through a cycle-tracking application. Sixteen participants provided data for this secondary analysis over three or more complete cycles. Insulin delivery and continuous glucose monitoring (CGM) data were analyzed in relation to reported cycle phases. Results: Insulin delivery and CGM metrics remained consistent during cycle phases. Intraparticipant variability of CGM metrics and weight-based insulin delivery did not change through cycle phases. Conclusions: For this sample of menstruating women with type 1 diabetes using a CLC system, insulin delivery and glycemic metrics remained stable throughout menstrual cycle phases. Additional studies in this population are needed, particularly among women who report variable glycemic control during their cycles. Trial Registration: NCT03591354.

AbstractMagnetic resonance imaging (MRI) is a valuable imaging modality for the assessment of both cardiac and non‐cardiac structures. With a growing population of patients with cardiovascular implantable electronic devices (CIEDs), 50%–75% of these patients will need an MRI. MRI‐conditional CIEDs have demonstrated safety of MRI scanning with such devices, yet non‐conditional devices such as hybrid CIEDs which have generator and lead brand mismatch may pose a safety risk. In this retrospective study, we examined the outcomes of patients with hybrid CIEDs undergoing MRI compared to those patients with non‐hybrid CIEDs. A total of 349 patients were included, of which 24 patients (7%) had hybrid CIEDs. The primary endpoint was the safety of MRI for patients with hybrid CIEDs as compared to those with non‐hybrid devices, measured by the rate of adverse events, including death, lead or generator failure needing immediate replacement, loss of capture, new onset arrhythmia, or power‐on reset. Secondary endpoints consisted of pre‐ and post‐MRI changes of decreased P‐wave or R‐wave sensing by ≥50%, changes in pacing lead impedance by ≥50 ohms, increase in pacing thresholds by ≥ 0.5 V at 0.4 ms, and decreasing battery voltage of ≥ 0.04 V. The primary endpoint of any adverse reaction was present in 1 (4.2%) patient with a hybrid device, and consistent of atrial tachyarrhythmia, and in 10 (3.1%) patients with a non‐hybrid device, and consisted of self‐limited atrial and non‐sustained ventricular arrhythmias; this was not statistically significant. No significant differences were found in the secondary endpoints. This study demonstrates that MRI in patients with hybrid CIEDs does not result in increased patient risk or significant device changes when compared to those patients who underwent MRI with non‐hybrid CIEDs.