Electrical cardioversion in patients with left ventricular thrombus: A systematic review of safety and thromboembolic risk

Background The thromboembolic risk of electrical cardioversion in patients with left-ventricular (LV) thrombus is poorly defined, producing variable clinical practice. We performed a systematic review to synthesize reported thromboembolic outcomes after cardioversion in patients with imaging-documented LV thrombus. Methods We searched PubMed and Scopus through 25 July 2025 for studies reporting outcomes after external direct-current cardioversion or internal/intra-procedural electrical shocks in patients with known LV thrombus. Case reports and pharmacological cardioversion studies were excluded. The primary outcome was clinically apparent thromboembolic complications. Data were extracted and synthesized narratively. Results Three retrospective studies met criteria, comprising 68 patients with known, imaging-proven LV thrombus. Thrombus morphology was predominantly laminated/fixed, but about 8% of patients had mobile thrombi in one series. Anticoagulation practices varied; a subset (21%) had no anticoagulation prior to electrical cardioversion. In total, 60 patients underwent direct-current cardioversion while eight patients underwent multiple internal intra-procedural cardioversions in the setting of known LV thrombus. Overall, no thromboembolic events directly attributable to cardioversion were observed over a follow-up period of 3 months to 1 year. Conclusion Available evidence, although limited, did not identify clinically overt thromboembolic events after electrical cardioversion in patients with known LV thrombus. Decisions should, however, be individualized, imaging-guided, accompanied by optimized anticoagulation whenever possible and multidisciplinary discussions.