Stroke: Highlights of Selected Articles
Paroxysmal Supraventricular Tachycardia and the Risk of Ischemic Stroke
Atrial fibrillation and atrial flutter are currently the only cardiac arrhythmias known to be risk factors for ischemic stroke. Patients with cardioembolic-appearing stroke have supraventricular arrhythmias more often than patients with other types of stroke. Multiple studies have also shown a link between frequent supraventricular ectopy and stroke in the absence of atrial fibrillation. Paroxysmal supraventricular tachycardia (PSVT) affects mostly older patients who have a high burden of cardiovascular disease. Atrial fibrillation is associated with PSVT. The current retrospective study by Kamel et al sought to demonstrate a possible association between PSVT and stroke. They reviewed ≈4.8 million patients from emergency room visits and hospitalizations at California’s nonfederal acute care hospitals in 2009. Of these patients, >14 000 (0.29%) were diagnosed with PSVT, and >14 000 (0.30%) had a diagnosis of ischemic stroke. Patients with PSVT were older and had significantly more cardiovascular risk factors than patients without PSVT. The cumulative stroke rate after the diagnosis of PSVT (0.94%) significantly exceeded the rate among patients without PSVT (0.21%; P<0.001). Stroke occurred a median of 70 days after index visit. PSVT was independently associated with a higher risk of subsequent stroke (hazard ratio, 2.10). An age cutoff existed such that PSVT was associated with a higher risk of stroke in patients ≥65 years old. This is an important work, for PSVT may be an independent risk factor for ischemic stroke and thus accounts for a proportion of stroke currently classified as cryptogenic. Further prospective studies are needed. See p 1550.
Incidence and Predictors of Late Seizures in Intracerebral Hemorrhages
The Prognosis of InTra-Cerebral Hemorrhage cohort is an observational cohort at the Lille University Hospital in France. Early seizures were classified as ≤7 days and late seizures (LSs) as >7 days after stroke onset. The authors previously reported an early seizure incidence of 14%. Early seizures in this cohort were associated with cortical intracerebral hemorrhage and did not influence in-hospital mortality or 6-month outcome. The current study population consisted of 324 patients. During 778 person-years of follow-up, 31 patients developed ≥1 LS, resulting in an incidence rate of 4 new cases/100 person-years. Nine months were the median delay between intracerebral hemorrhage and LS. Cortical involvement of the intracerebral hemorrhage was the only factor independently associated with LS. Lobar microbleeds were predictors of LS as well. Early seizures were not predictive of LSs. Interestingly, LSs were associated with a worse functional outcome after 3 years of follow-up. Further prospective studies are needed to confirm these findings. It would be interesting to know as well whether location of the cortical hemorrhage and microbleed differed significantly with the risk of LS. See p 1723.
- © 2013 American Heart Association, Inc.