Related Experiment Video
Updated: Feb 5, 2026

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Registry of left atrial appendage closure and initial experience with intracardiac echocardiography
Liliana Reis1, Luís Paiva2, Marco Costa1
1Serviço de Cardiologia, Centro Hospitalar e Universitário de Coimbra - Hospital Geral, Coimbra, Portugal.
Introduction:
Percutaneous closure of the left atrial appendage (LAA) is a promising therapy in patients with atrial fibrillation with high risk for stroke and contraindication for oral anticoagulation (OAC). Intracardiac echocardiography (ICE) may make this percutaneous procedure feasible in patients in whom transesophageal echocardiography (TEE) is inadvisable. Our aim was to assess the efficacy and safety of LAA closure and the feasibility of ICE compared to TEE to guide the procedure.
Methods:
In this cohort study of patients who underwent LAA closure between May 2010 and January 2017, clinical and imaging assessment was performed before and after the procedure.
Results:
In 82 patients (mean age 74±8 years, 64.4% male) the contraindications for OAC were severe bleeding or anemia (65%), high bleeding risk (14%), labile INR (16%), or recurrent embolic events (5%). The procedural success rate was 96.3%. The procedure was guided by TEE or ICE, and no statistically significant differences were observed between the two techniques. During follow-up, one patient had an ischemic stroke at 12 months, two had bleeding complications at six months, and there were four non-cardiovascular deaths. Embolic and bleeding events were less frequent than expected from the observed CHA2DS2VASc (0.6% vs. 6.3%; p<0.001) and HAS-BLED (1.2% vs. 4.1%; p<0.001) risk scores.
Conclusions:
In this population percutaneous LAA closure was shown to be safe and effective given the lower frequency of events than estimated by the CHA2DS2VASc and HAS-BLED scores. The clinical and imaging results of procedures guided by ICE in the left atrium were not inferior to those guided by TEE.
Related Concept Videos
Initiation of Translation
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Initiation of Translation
Surface Appendages of Archaea
Transcription Initiation
The promoters and enhancers and their accessory proteins allow tight regulation of...
Angle Closure Glaucoma: Treatment
What is an Experiment?

