Tina Lin

Description:The adult QT interval has sex-specific reference ranges, reflecting a decrease in the QT interval by 20 ms after male puberty.1 The QT interval appears to be modulated by serum testosterone concentrations; it is prolonged in men treated with androgen deprivation therapy for prostate cancer2 and shortened in women with hyperandrogenism.3 A 2022 cohort study4 showed an increased risk of arrhythmia in transgender women compared with cisgender women, but the mechanisms are unclear. We examined the effect of feminizing hormone therapy on the QT interval in transgender women and nonbinary or transfeminine individuals and hypothesized that this would be prolonged due to suppression of serum testosterone levels.

Description:Aim The primary aim was to ascertain long-term rates of atrial fibrillation (AF) recurrence in this all-comer patient population undergoing elective electrical cardioversion (DCR). Secondary aims included procedural DCR success, clinical predictors of long-term maintenance of sinus rhythm (SR) and AF related hospitalizations.Material and Methods A retrospective cohort study was conducted. Consecutive patients (n=316) undergoing elective DCR were included.Results Successful immediate reversion to SR was attained in 266 (84 %) of patients. 224 (84 %) patients were followed up for a median period of 3.5 years (IQR 2.7-4.3). Most patients (150 [67 %]) had recurrence of AF / flutter at a median time of 240 days. Clinical predictors of AF recurrence included a history of AF (HR 0.63, p=0.038) and a dilated left atrium (HR 4.13, p=0.048). Maintenance of SR was associated with fewer unplanned hospitalizations for AF (HR 3.25, p<0.01).Conclusion There was high procedural success post DCR. However, long-term rates of AF recurrence were high, and AF recurrences were associated with increased hospitalizations. These findings underscore the importance of clinical vigilance and multi-modal management as part of a comprehensive and effective rhythm control strategy.

Description:Objective For risk stratification of sudden cardiac death in patients with structural heart disease, more precise predictors in addition to left ventricular ejection fraction (LVEF) are clinically needed. The present study assessed the utility of galectin-3 as an independent indicator for the prognosis of heart failure patients with implantable cardioverter-defibrillators (ICD). Methods The study population consisted of 91 consecutive patients who underwent a routine ICD checkup in our ICD outpatient clinic. Circulating galectin-3 was assessed using a commercially available enzyme-linked immunosorbent assay kit. The enrolled patients were prospectively followed. The primary endpoint was defined as the occurrence of appropriate ICD therapy (AIT), and the secondary endpoint was defined as the occurrence of unplanned overnight hospitalization due to decompensated heart failure (dHF). Results During a mean follow-up of 472±107 days, AIT occurred in 18 patients (20%). Unplanned hospitalizations due to dHF were noted in 12 patients (13%). A receiver-operative characteristics analysis demonstrated a sensitivity of 83% and specificity of 68% for AIT occurrences with a galectin-3 cut-off value of 13.1 ng/mL (area under the curve =0.82). A Kaplan-Meier analysis demonstrated that patients with galectin-3 >13.1 ng/mL had significantly higher incidences of AIT as compared to those with lower galectin-3 (log-rank, p<0.001). This significance was also observed in both subgroup analyses with ischemic and non-ischemic etiology. Cox regression demonstrated that higher galectin-3 was an independent predictor of AIT and dHF, even after adjusting for previous arrhythmic events. Conclusion The circulating galectin-3 level can be used as a clinical indicator of subsequent occurrence of ventricular arrhythmic events and decompensated heart failure, regardless of a history of ventricular arrhythmias.

Description:Background and purpose: Research into the temporal relationship between atrial tachyarrhythmias (atrial tachycardia [AT] and atrial fibrillation [AF]) and stroke has produced conflicting findings. Systematic categorization of stroke subtypes may help clarify the discussion. Objectives: The objective of the study was to examine the presence and timing of AT/AF in relation to ischemic stroke subtypes, categorized as either cardioembolic (CE) or non-CE. Methods: Consecutive patients presenting to the Austin Hospital with acute stroke from 2012 to 2019 and a cardiac implantable electronic device (CIED) were identified. Using a case-control design, the temporal proximity of AT/AF episodes in the 90 days prior to stroke was compared in the CE and non-CE stroke groups. Results: 5,591 patients presented to the Austin Hospital with acute stroke from 2012 to 2019, of whom 31 patients with an ischemic stroke and a CIED with ≥90 days of monitoring were identified. Twelve strokes were adjudicated as CE and 19 as non-CE by a stroke neurologist. Six of the 12 CE stroke patients (50%) experienced AT/AF within 30 days preceding their stroke, while none of the 19 non-CE stroke patients recorded any AT/AF in the same period (p = 0.001). Four CE stroke patients (33%) had no AT/AF preceding their strokes at any time. The odds ratio for CE stroke was highest (39; 95% confidence interval [CI]: 1.92-791.5) when AT/AF occurred in the 30 days prior, declining to 20.65 (95% CI: 1.00-427.66) and 6.07 (95% CI: 0.94-39.04) in the subsequent 31-60- and 61-90-day windows, respectively. Conclusions: CE strokes were associated with a significantly higher proportion of preceding AT/AF compared with non-CE strokes. These findings support a potential temporal relationship between AT/AF and CE stroke and demonstrate that stroke subtyping can better characterize the relationship between AF and ischemic stroke. However, this study's findings are limited by its sample size and small number of informative cases.

Description:Objective: Recently, a novel cardiac imaging system based on a wide-band dielectric technology (KODEX-EPD) was introduced to guide catheter ablation. The aim of the study was to evaluate this 3D wide-band dielectric imaging system (WDIS) during cryoballoon (CB)-based atrial fibrillation (AF) ablation focusing on accuracy of pulmonary vein (PV)-anatomy. Methods: In consecutive patients with symptomatic AF, CB-based ablation was performed in conjunction with the 3D WDIS. Selective PV-angiographies were performed, and 3D anatomy of the left atrium (LA) and PVs using the 3D WDIS was created. The ostial diameters of the ipsilateral right-sided and left-sided PVs and ostial diameters of the right-/left-sided upper/lower PVs demonstrated by selective angiographies were analyzed and compared to 3D WDIS-based PV visualization. Results: In 65 patients (42/65 (65%) male, age 65 ± 9 years, 29/65 (45%) paroxysmal AF) a total of 260 PVs were identified. Median ostial PV-diameters for the ipsilateral left- and right-sided PVs were 38 [34; 43] and 37 [34; 40.3] mm when assessed fluoroscopically and 40 [35.7; 43] and 39 [35.0; 43] mm as demonstrated by 3D WDIS. There was no statistically significant difference between both methods regarding PV-diameter measurements. KODEX-EPD overestimated fluoroscopy measurements by 1.08 mm (95% limits of agreement of -1.93 mm and 4.1 mm). Conclusions: The novel wide-band dielectric 3D-imaging system is feasible to create high-resolution images of cardiac structures during CB ablation procedures and accurately visualizes PV-anatomy.