MUlticenter STudy of tissue plasminogen activator (alteplase) use in COVID-19 severe respiratory failure (MUST COVID): A retrospective cohort study.

Background: Few therapies exist to treat severe COVID-19 respiratory failure once it develops. Given known diffuse pulmonary microthrombi on autopsy studies of COVID-19 patients, we hypothesized that tissue plasminogen activator (tPA) may improve pulmonary function in COVID-19 respiratory failure. Methods: A multicenter, retrospective, observational study of patients with confirmed COVID-19 and severe respiratory failure who received systemic tPA (alteplase) was performed. Seventy-nine adults from seven medical centers were included in the final analysis after institutional review boards' approval; 23 were excluded from analysis because tPA was administered for pulmonary macroembolism or deep venous thrombosis. The primary outcome was improvement in the PaO2/FiO2 ratio from baseline to 48 h after tPA. Linear mixed modeling was used for analysis. Results: tPA was associated with significant PaO2/FiO2 improvement at 48 h (estimated paired difference = 23.1 ± 6.7), which was sustained at 72 h (interaction term p < 0.00). tPA administration was also associated with improved National Early Warning Score 2 scores at 24, 48, and 72 h after receiving tPA (interaction term p = 0.00). D-dimer was significantly elevated immediately after tPA, consistent with lysis of formed clot. Patients with declining respiratory status preceding tPA administration had more marked improvement in PaO2/FiO2 ratios than those who had poor but stable (not declining) respiratory status. There was one intracranial hemorrhage, which occurred within 24 h following tPA administration. Conclusions: These data suggest tPA is associated with significant improvement in pulmonary function in severe COVID-19 respiratory failure, especially in patients whose pulmonary function is in decline, and has an acceptable safety profile in this patient population.

Reversible Mechanical Atrioventricular Block Caused By A Steerable Introducer Sheath During Transseptal Catheterization.

A 62-year-old woman presents for pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation. During transseptal catheterization (TSC) the patient sustained mechanical injury to the atrioventricular node (AVN) with consequent complete heart block (CHB). Injury to the AVN and CHB recovered after approximately forty minutes. The patient subsequently underwent a successful PVI with the remainder of the hospital stay uneventful. We present a case of reversible injury to the AVN caused by a steerable introducer sheath during TSC and discuss the mechanisms of injury as well as potential measures to avoid such a complication in the future.

A dilemma of hemorrhage vs thrombosis: a case of watchman device thrombus in a patient with intracranial hemorrhage history.

Recently updated guidelines for Atrial Fibrillation (AF) outline that percutaneous left atrial appendage (LAA) occlusion with the Watchman device may be a reasonable alternative for those who have contraindications to long-term oral anticoagulation. However, optimal periprocedural antithrombotic therapy remains disputable, particularly in patients who are ineligible for oral anticoagulation or those with history of intracranial hemorrhage (ICH). We present the case of a 67-year-old male with a history of ischemic stroke with hemorrhagic conversion and permanent AF, who was treated with the Watchman device and subsequently developed device related thrombus and recurrent ischemic stroke. We discuss the dilemma and review the literature regarding anticoagulation for device related thrombus in this patient with increased bleeding risk, given his history of ICH. His course and antithrombotic strategy are described and despite the use of anticoagulation with warfarin in the setting of recurrent ischemic stroke, he did not develop hemorrhagic transformation. He also did, ultimately, achieve device related thrombus resolution on repeat Transesophageal Echocardiogram (TEE). This case supported the use of warfarin for device related thrombus in the setting of ischemic stroke and history of ICH. However, evidence-based guidelines for periprocedural antithrombotic regimens in patients with high bleeding risk have yet to be released and further research is needed.

Obstructive Sleep Apnea as a Risk Factor for Atrial Fibrillation: A Meta-Analysis.

OBJECTIVES: To conducted a meta-analysis assessing the relationship between Obstructive Sleep Apnea (OSA) and the risk of Atrial Fibrillation (AF). METHODS: We searched PUBMED, Medline, and Cochrane Library using the keywords "atrial fibrillation", "obstructive sleep apnea" and "sleep disordered breathing (SDB)". All subjects included had established diagnosis of OSA/SDB. We then compared the occurrence of AF versus no AF. Analysis done with Comprehensive Meta-Analysis package V3 (Biostat, USA). RESULTS: A total of 579 results were generated. Duplicates were removed and 372 records were excluded based on irrelevant abstracts, titles, study design not consistent with the stated outcome, or full-text unavailable. Twelve studies meeting the inclusion criteria were reviewed in full-text; 2 of these articles were eventually removed due to unconfirmed OSA diagnostic modality, and one was also removed based on a control group inconsistent with the other studies. Therefore, a total of 9 studies were included (n=19,837). Sample sizes ranged from n=160 patients to n=6841 patients. The risk of AF was found to be higher among OSA/SDB versus control group (OR; 2.120, C.I: 1.845-2.436, Z; 10.598 p: <0.001). The heterogeneity observed for the pooled analysis was Q-value; 22.487 df (Q); 8 P-value; 0.004, I-squared; 64.424 Tau2; 0.098, suggesting appropriate study selection and moderate heterogeneity. CONCLUSION: OSA/SDB is strongly associated with AFib confirming the notion that OSA/SDB populations are high risk for development of AF. Prospective studies are needed to ascertain the effect of the treatment of OSA/SDB for the prevention of AF, a growing health burden with serious consequences.

Inappropriate implantable cardioverter-defibrillator shocks attributed to alternating-current leak in a swimming pool.

Implantable cardioverter-defibrillators (ICDs) are the standard of care for preventing sudden cardiac death in patients who are predisposed to malignant ventricular arrhythmias. Causes of inappropriate ICD shock include equipment malfunction, improper arrhythmia evaluation, misinterpretation of myopotentials, and electromagnetic interference. As the number of implanted ICDs has increased, other contributors to inappropriate therapy have become known, such as minimal electrical current leaks that mimic ventricular fibrillation. We present the case of a 63-year-old man with a biventricular ICD who received 2 inappropriate shocks, probably attributable to alternating-current leaks in a swimming pool. In addition, we discuss ICD sensitivity and offer recommendations to avoid similar occurrences.