LV noncompaction is a rare primary cardiomyopa- thy possibly caused by an arrest of normal embryo- genesis of the endocardium and mesocardium that leads to the formation of prominent trabeculations and deep intertrabecular recesses within the LV wall communicating with the cavity. The inferior and lat- eral walls of the LV from the midcavity to the apex are most commonly involved by this process.547 Among cohorts of patients with cardiac disease, the esti- mated prevalence of LV noncompaction varies from 0.9% by echocardiographic criteria to 9.8% with car- diac magnetic resonance criteria.548 LV noncompac- tion has a broad spectrum of clinical manifestations, ranging from asymptomatic state to severe heart failure, ventricular arrhythmias, and thromboembolic The risk of thromboembolism in LV noncompaction cardiomyopathy has been evaluated in several case series, which have reported an up to 24% risk of cerebral embolism at follow-up.534,549 This increased risk has been theorized to result from blood stasis within the prominent LV trabecula- tions and intertrabecular recesses.533 535 Given the shared pathophysiological basis with LV endocavi- tary thrombus, we make this recommendation. 4. 