Artificial Intelligence-Enabled ECG to Identify Silent Atrial Fibrillation in Embolic Stroke of Unknown Source.

OBJECTIVES: Embolic strokes of unknown source (ESUS) are common and often suspected to be caused by unrecognized paroxysmal atrial fibrillation (AF). An AI-enabled ECG (AI-ECG) during sinus rhythm has been shown to identify patients with unrecognized AF. We pursued this study to determine if the AI-ECG model differentiates between patients with ESUS and those with known causes of stroke, and to evaluate whether the AF prediction by AI-ECG among patients with ESUS was associated with the results of prolonged ambulatory cardiac rhythm monitoring. MATERIALS AND METHODS: We reviewed consecutive patients admitted with acute ischemic stroke to a comprehensive stroke center between January 2018 and August 2019 and employed the TOAST classification to categorize the mechanisms of ischemia. Use and results of ambulatory cardiac rhythm monitoring after discharge were gathered. We ran the AI-ECG model to obtain AF probabilities from all ECGs acquired during the hospitalization and compared those probabilities in patients with ESUS versus those with known stroke causes (apart from AF), and between patients with and without AF detected by ambulatory cardiac rhythm monitoring. RESULTS: The study cohort had 930 patients, including 263 patients (28.3%) with known AF or AF diagnosed during the index hospitalization and 265 cases (28.5%) categorized as ESUS. Ambulatory cardiac rhythm monitoring was performed in 226 (85.3%) patients with ESUS. AF probability by AI-ECG was not associated with ESUS. However, among patients with ESUS, the probability of AF by AI-ECG was associated with a higher likelihood of AF detection by ambulatory monitoring (P = 0.004). A probability of AF by AI-ECG greater than 0.20 was associated with AF detection by ambulatory cardiac rhythm monitoring with an OR of 5.47 (95% CI 1.51-22.51). CONCLUSIONS: AI-ECG may help guide the use of prolonged ambulatory cardiac rhythm monitoring in patients with ESUS to identify those who might benefit from anticoagulation.

Spontaneous Spinal Subarachnoid Hemorrhage: Presentation and Outcome.

BACKGROUND: Spontaneous spinal subarachnoid hemorrhage (SSAH) is a rare but serious condition that can lead to a variety of medical complications. METHODS: Using the Mayo Clinic Rochester database, consecutive patients admitted to the Mayo Clinic Rochester, Minnesota hospital with spontaneous SSAH (not iatrogenic or traumatic) between January 2000 and December 2015 were retrospectively reviewed. Demographic and clinical data and functional outcomes as categorized by the modified Rankin Scale (mRS) score at the time of discharge and at postadmission follow-up were assessed. RESULTS: Eight patients (median age 70 years, range 51-87) were identified. Seven patients presented with acute back pain or headache. Seven patients had poorly controlled chronic hypertension. Two patients had vasculitis and 1 had an arteriovenous malformation. Complications included cord compression (n = 4), hyponatremia (n = 5), sulcal subarachnoid hemorrhage (n = 2), chronic arachnoiditis (n = 1), vasospasm (n = 1), ischemic infarct (n = 1), and late cord ischemia (n = 1). All patients were managed medically including blood pressure control and repeat imaging. One patient had an aneurysm, which was embolized, and 2 received steroids for vasculitis. One patient died during hospitalization and 1 died within a week of discharge. Five patients had improved and 1 had unchanged mRS score at posthospitalization follow-up. CONCLUSIONS: SSAH should be considered in patients with sudden onset of severe back pain and headache, especially if as associated with lower extremity weakness or urinary retention. Our findings suggest that older patients with poorly controlled hypertension are at particular risk for spontaneous SSAH. In our study vascular anomalies were found in 25% of patients, vasculitis in 25%, hyponatremia in 63%, and cord compression in 50%. Cord compression may be managed conservatively. Mortality was 25% in the 3 months following the initial event, primarily due to other medical comorbidities.

Ascending Spinal Cord Infarction Secondary to Recurrent Spinal Cord Cavernous Malformation Hemorrhage.

We report a case of a 58-year-old Hispanic man who developed ascending paraparesis over several weeks secondary to recurrent hemorrhages and resulting in spinal cord ischemia from a low thoracic spinal cord cavernous malformation. The patient's deterioration was attributed to recurrent hemorrhage of a thoracic intramedullary cavernous malformation at T11 resulting in vascular congestion and spinal cord ischemia. The patient was found to have a heterozygous mutation on exon 13 of gene KRIT1, which was consistent with autosomal dominant familial cerebral cavernous malformations. Expedited surgical intervention potentially could have prevented this patient's progressive paraplegia.