Editors' note: Atrial cardiopathy in patients with embolic strokes of unknown source and other stroke etiologies

In the article “Atrial cardiopathy in patients with embolic strokes of unknown source and other stroke etiologies,” Jalini et al. reported atrial cardiopathy in 26.6% of patients meeting the criteria for embolic stroke of unknown source (ESUS) vs 12.1% of patients with large artery atherosclerosis and 16.9% of those with small vessel disease in a cross-sectional study of 846 consecutive patients with ischemic stroke. They also found that patients with ESUS were younger, less hypertensive, and had higher cholesterol and low-density protein levels but fewer left ventricular or atrial abnormalities compared with yet another group with cardioembolism. In response, Drs. Lattanzi and Silvestrini note that they recently found an inverse association between abnormally increased P-wave terminal force in lead V1 (a marker of atrial cardiopathy) and paradoxical or artery-to-artery embolic sources in patients with ESUS. Patients with anterior circulation ESUS more often had ipsilateral (vs contralateral) internal carotid artery plaques with more concerning atherosclerotic findings, whereas younger patients with ESUS had higher incidence of patent foramen ovale (PFO) and lower rates of other vascular risk factors or markers of cardiopathy or atherosclerosis. Stating that ESUS is thus a heterogeneous entity, they encourage the identification of such distinct phenotypes to help guide secondary prevention and potentially targeted interventions. In their reply, the authors agree that the ESUS definition seems too broad and that factors such as PFO, aortic arch, and nonstenotic carotid plaques that were not addressed in their study are important embolic sources in subgroups of patients with ESUS. They note that ongoing trials in subgroups of patients with ESUS will further inform secondary prevention in this population.