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Background: Traditional vascular risk factors appear to exert varying magnitudes of risk for different major vascular events. For example, hypercholesterolemia is a much stronger risk factor for myocardial infarction than ischemic stroke. Limited evidence also suggests that vascular risk factors may exert differing magnitudes of risk for ischemic stroke within different cerebral arterial territories. We sought to determine the association between traditional vascular risk factors and the location of ischemic stroke (posterior versus anterior). Methods: Consecutive patients with acute ischemic stroke who were admitted to 11 regional stroke centers within the Registry of the Canadian Stroke Network were included in the study sample. The Oxfordshire Community Stroke Project classification was used to distinguish posterior from anterior circulation ischemic stroke. Multivariable logistic regression was applied to determine the association between risk factors (age, gender, diabetes mellitus, hypercholesterolemia, hypertension, atrial fibrillation and smoking history) and posterior (compared to anterior) circulation ischemic stroke. Results: In total, 8,489 patients with acute ischemic stroke were included. On multivariable analysis, diabetes mellitus (OR = 1.14; 95% CI = 1.02–1.27) was associated with an increased odds of posterior circulation ischemic stroke, whereas age (OR = 0.86; 95% CI = 0.83–0.90), female sex (OR = 0.84; 95% CI = 0.76–0.93), atrial fibrillation (OR = 0.83; 95% CI = 0.74–0.94) and pulmonary edema (OR = 0.74; 95% CI = 0.62–0.88) were related to a reduced odds of posterior compared with anterior circulation ischemic stroke. Conclusions: Some traditional vascular risk factors for ischemic stroke appear to exert different magnitudes of risk for posterior compared to anterior circulation ischemic stroke.

Background: We investigated the impact of regionally imposed social and healthcare restrictions due to coronavirus disease 2019 (COVID-19) to the time metrics in the management of acute ischemic stroke patients admitted at the regional stroke referral site for Central South Ontario, Canada. Methods: We compared relevant time metrics between patients with acute ischemic stroke receiving intravenous tissue plasminogen activator (tPA) and/or endovascular thrombectomy (EVT) before and after the declared restrictions and state of emergency imposed in our region (March 17, 2020). Results: We identified a significant increase in the median door-to-CT times for patients receiving intravenous tPA (19 min, interquartile range (IQR): 14–27 min vs. 13 min, IQR: 9–17 min, p = 0.008) and/or EVT (20 min, IQR: 15–33 min vs. 11 min, IQR: 5–20 min, p = 0.035) after the start of social and healthcare restrictions in our region compared to the previous 12 months. For patients receiving intravenous tPA treatment, we also found a significant increase (p = 0.005) in the median door-to-needle time (61 min, IQR: 46–72 min vs. 37 min, IQR: 30–50 min). No delays in the time from symptom onset to hospital presentation were uncovered for patients receiving tPA and/or endovascular reperfusion treatments in the first 1.5 months after the establishment of regional and institutional restrictions due to the COVID-19 pandemic. Conclusion: We detected an increase in our institutional time to treatment metrics for acute ischemic stroke patients receiving tPA and/or endovascular reperfusion therapies, related to delays from hospital presentation to the acquisition of cranial CT imaging for both tPA- and EVT-treated patients, and an added delay to treatment with tPA.

Myocardial infarction is an important medical complication after acute ischaemic stroke.

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Phentolamine was administered orally to 21 These studies indicate that phentolamine warrants further study as an antiarrhythmic agent.

Ahlquist (1948) proposed two distinct adrenergic receptor sites, the alpha-and beta-adrenergic receptors. Stimulation of the alpha-adrenergic receptors produces arteriolar constriction unaccompanied by any primary cardiac action, presumably due to the absence of alpha receptors in the heart. Selective blockade of the alpha receptors produces arteriolar dilatation, and this also is unaccompanied by any primary cardiac effect. This blockade can be accomplished by using the drug phentolamine.Despite intensive studies on the adrenergic blocking activity of phentolamine there have been few reports analysing its haemodynamic effects and its mode of action. Taylor and his co-workers (1965a b, c) have investigated the haemodynamic effects in man of the acute intravenous injection of 5 mg. phentolamine and of intravenous infusion of the drug at a rate of 2 mg. per minute for 10 minutes. Both methods of administration produced an increase in the heart rate and cardiac output and a decrease in the systemic arterial pressure. They concluded that the hypotensive effect limited the clinical applicability of the drug.We now report an investigation of the action of phentolamine in the dog, in which a marked increase in the force of myocardial contraction' was shown. Based on this finding, the study was extended to investigate more fully the haemodynamic actions of this drug in man. METHODSAnimals. Four normal mongrel dogs weighing 11-3 kg. to 22-7 kg. (25-50 lb.) were studied. They were lightly pre-anaesthetized with acetyl-promazine (1 mg./ 11-3 kg.) and succinyl-choline (1 mg./2-7 kg.). Pentothal was given intravenously until endotracheal intubation was established. They were maintained on a nitrous oxide and oxygen gas mixture, with intermittent Received September 9, 1968. 154 administration of methoxyflurane. Respiration was kept constant by a Bird respirator through a cuffed endotracheal tube.After making an intercostal incision and spreading the ribs, the pericardium was opened and a strain gauge arch was attached on the right ventricle. Arterial blood pressure was measured through a Cournand needle in the femoral artery by means of a Statham pressure transducer. Continuous recordings of myocardial contractile force and blood pressure were made simultaneously with a multichannel oscillograph before and after the rapid intravenous injection of 5 mg. of phentolamine.Human Subjects. Our observations were made in 5 patients (Group 1) with relatively normal left ventricles, who had never been in left ventricular failure, and 13 patients (Group 2) with abnormal left ventricles, who had previously been in left ventricular failure, and who underwent right and left heart catheterizations primarily as an aid to their clinical management. The diagnoses of the patients are listed in Table II. Patients 4 and 16 were in atrial fibrillation; the rest were in sinus rhythm. Patients 3, 4, 6, 8, 9, 13, 14, 15, 16, and 17 were taking digoxin; the rest were not receiving any therapy.Catheterization of the left ventricle was performed ei...