Introduction: Cryptogenic stroke comprises about 25% of all ischemic strokes. Depending on modality and duration of ECG monitoring, subclinical atrial fibrillation (AF) is detectable in 2.7-30% of cryptogenic stroke patients. Hypothesis: Extended ECG monitoring after cryptogenic stroke has not been studied in the African American (AA) population. This retrospective study aims to study the incidence and risk factors of subclinical AF in African Americans. Methods: We retrospectively reviewed 96 patients who received implantable loop recorders (ILR) for detecting subclinical atrial fibrillation after cryptogenic stroke. In the vast majority of patients, the ILR was implanted during index hospitalization. Binary univariate and multivariate analyses were performed to determine predictors for AF detection. Results: AF was detected in 29% of patients (28/96) at 1000 days. All AF that was detected was exquisitely paroxysmal and ranged in duration between 0.05-103 minutes (mean 8.4 minutes with SD= 22.1 minutes). Binary univariate analysis revealed the use of non-dihydropyridine calcium-channel blockers to be associated with decreased odds of AF detection. Multivariate analysis found coronary artery disease diagnosis to be associated with increased odds of AF detection. Fifty percent of the events in the AF group were detected within the first 36 days of loop recorder implantation. Conclusions: AF detection in our population occurs very early after index stroke and at significantly higher rates that reported before. Baseline characteristics have a poor predictive ability for the detection of AF. These findings emphasize the need for pre-discharge ILR implantation to improve AF detection in all patients with cryptogenic stroke.

Introduction Atrioventricular node (AVN) radiofrequency ablation is a highly effective treatment of atrial tachycardias resistant to other management modalities. There are limited studies that compare different radiofrequency ablation catheters. Our study aimed to compare the effectiveness of several types of ablation catheters in AVN ablation. Methods We identified patients who underwent AVN ablation for different indications at our institution. Data related to patients and procedures were collected through retrospective chart review. The radiofrequency catheters used were: plain non irrigated, externally irrigated (EI), and contact force sensing with 10-20 gm of force in two different settings: low power long duration (LPLD) (30W, 45°C, and 60 sec) and high-power short duration (HPSD) (50W, 43°C, and 12 sec). We compared the different catheters in terms of success rate using logistic regression and lesion time using linear regression. Results We identified 66 patients who underwent AVN ablation, out of which 31 were female (47%). The patients were elderly, with a mean age of 73.27 years. The indications were resistant atrial fibrillation in 74%, atrial flutter in 18%, and other atrial tachycardias in 8% of patients. Types of catheters used were plain non irrigated in 48%, EI in 2%, LPLD in 16%, and HPSD in 34% of patients. All ablation procedures were successful with no immediate post-procedure complications. Regarding lesion time, HPSD was significantly shorter compared to plain catheters by 403.42s[-631.67, -175.17]. Conclusions Radiofrequency ablation of AVN is a highly effective treatment modality for atrial tachyarrhythmias that failed other management methods. While plain catheter, LPLD, and HPSD were equally safe and effective, HPSD catheter had significantly shorter lesion time and thus procedure time.

Abstract: Background: This meta-analysis assessed the relationship between Obstructive Sleep Apnea (OSA) and echocardiographic parameters of diastolic dysfunction (DD), which are used in the assessment of Heart Failure with Preserved Ejection Fraction (HFpEF). Methods: We searched the databases including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 26th, 2020. The search was not restricted to time, publication status or language. Comparisons were made between patients with OSA, diagnosed in-laboratory polysomnography (PSG) or home sleep apnea testing (HSAT), and patients without OSA in relation to established markers of diastolic dysfunction. Results: Primary search identified 2512 studies. A total of 18 studies including 2509 participants were included. The two groups were free of conventional cardiovascular risk factors. Significant structural changes were observed between the two groups. Patients with OSA exhibited greater LAVI (3.94 CI [0.8, 7.07]; p=0.000) and left ventricular mass index (11.10 CI [2.56,19.65]; p=0.000) as compared to control group. The presence of OSA was also associated with more prolonged DT (10.44 ms CI [0.71,20.16]; p=0.04), IVRT (7.85 ms CI[4.48, 11.22]; p=0.000), and lower E/A ratio (-0.62 CI [-1,-0.24]; p=0.001) suggestive of early DD. The E/e’ ratio (0.94 CI[0.44, 1.45]; p=0.000) was increased. Conclusion: An association between OSA and echocardiographic parameters of DD was detected that was independent of conventional cardiovascular risk factors. OSA may be independently associated with DD perhaps due to higher LV mass. Investigating the role of CPAP therapy in reversing or ameliorating diastolic dysfunction is recommended.