Supraventricular Tachycardia (SVT) and Stroke: Should We Pump the Brakes on Cardioversion?

In the list of top 10 causes of death worldwide in 2019, stroke ranks number two, with a recent uptick in incidence involving younger adults. While common risk factors like tobacco use, hypertension, diabetes, and atrial fibrillation have been well studied, recent reports have also linked paroxysmal supraventricular tachycardia (PSVT) with strokes. This case highlights a rare presentation of a 25-year-old female who suffered an ischemic stroke shortly after undergoing chemical cardioversion for sustained SVT. To date, there are only three documented cases reporting an ischemic event following shortly after cardioversion of SVT, all confined to the pediatric population. Currently, there is limited evidence to guide the management of these complex patients. This case presents a valuable discussion regarding the futility or efficacy of imaging prior to cardioversion of SVT as well as furthers the conversation behind the theorized mechanisms linking PSVT and strokes.

Exploring Reperfusion Following Endovascular Thrombectomy

Background and Purpose- Cerebral perfusion in acute ischemic stroke patients is often assessed before endovascular thrombectomy (EVT), but rarely after. Perfusion data obtained following EVT may provide additional prognostic information. We developed a tool to quantitatively derive perfusion measurements from digital subtraction angiography (DSA) data and examined perfusion in patients following EVT. Methods- Source DSA images from acute anterior circulation stroke patients undergoing EVT were retrospectively assessed. Following deconvolution, maps of mean transit time (MTT) were generated from post-EVT DSA source data. Thrombolysis in Cerebral Infarction grades and MTT in patients with and without hemorrhagic transformation (HT) at 24 hours were compared. Receiver operating characteristic modeling was used to classify the presence/absence of HT at 24 hours by MTT. Results- Perfusion maps were generated in 50 patients using DSA acquisitions that were a median (interquartile range) of 9 (8-10) seconds in duration. The median post-EVT MTT within the affected territory was 2.6 (2.2-3.3) seconds. HT was observed on follow-up computed tomography in 16 (32%) patients. Thrombolysis in Cerebral Infarction grades did not differ in patients with HT from those without (P=0.575). Post-EVT MTT maps demonstrated focal areas of hyperperfusion (n=8) or persisting hypoperfusion (n=3) corresponding to the regions where HT later developed. The relationship between MTT and HT was U-shaped; HT occurred in patients at both the lowest and highest extremes of MTT. An MTT threshold <2 or >4 seconds was 81% sensitive and 94% specific for classifying the presence of HT at follow-up. Conclusions- Perfusion measurements can be obtained using DSA perfusion with minimal changes to current stroke protocols. Perfusion imaging post-recanalization may have additional clinical utility beyond visual assessment of source angiographic images alone.