Predicting Cardiotoxic Effects of Carbon Monoxide Poisoning Using Speckle Tracking Echocardiography.

Carbon monoxide (CO) poisoning could cause significant cardiac injury. This study aimed to evaluate patients with CO poisoning by using speckle tracking echocardiography (STE), a potentially more sensitive technique, to identify left systolic ventricular dysfunction for the first time in the literature. Seventy-two patients who were exposed to CO poisoning were studied. Blood collection and echocardiography were performed at admission and after patients' discharge on days 10-15 (mean 12 days). Global longitudinal strain (GLS) and global circumferential strain (GCS) were calculated using STE. In order to find the normal strain levels and to compare it to the patient with CO poisoning, 35 healthy subjects were included in the study. Left ventricular ejection fraction was analyzed according to Simpson's method. Patients were divided into two groups based on their LVEF values. LVEF < 55%, Group 1 (n = 24); LVEF ≥ 55%, Group 2 (n = 48). The reduction in Group 1 strain levels decreased in correlation with LVEF (p < 0.001) while in Group 2, there were no significant changes in LVEF but strain levels were significantly reduced (p = 0.091; p < 0.001). Compared with the control group patients, admission GLS and GLC values of CO-poisoned patients were significantly low both in Group 1 and 2. On the contrary, no significant difference was observed when compared with follow-up GLS value. For prediction of CO cardiotoxicity, the cutoff value of GLS was ≥ - 19.1 with a sensitivity of 70.3% and a specificity of 100% [(AUC) 0.840, 95% (CI) 0.735-0.916; p < 0.001] in the ROC curve analyses. GLS was found as independent predictors of cardiotoxicity. Our study demonstrates the potential of using systolic strain values obtained using 2D-STE in determining cardiotoxicity due to CO poisoning. Speckle tracking echocardiography has the potential of demonstrating subtle LV systolic dysfunction even in CO poisoning patients with preserved EF.

Predictors of false negative diffusion-weighted MRI in clinically suspected central cause of vertigo.

INTRODUCTION: Vertigo is classified as peripheral and central. Differentiation of stroke mimics is the most important diagnostic challenge. There is no clinical guidance for the indications of neuroimaging in isolated vertigo patients. The primary aim of this study is to test the diagnostic value of a DWI-MRI protocol to rule-out a central cause in patients with acute isolated vertigo in the ED. METHODS: We prospectively enrolled 144 patients who were presented with isolated vertigo to the ED. A detailed neurological examination and maneuvers were performed for differential diagnosis. All patients underwent CT and/or DW-MRI either during ED visit or at the follow-up, if necessary. Out-patient follow-up exams and evaluations were repeated until all patients had a definitive diagnosis. RESULTS: In the study, 137 of the 144 patients completed the follow-up period, and 34 of 137 patients were diagnosed with central vertigo. Six of 34 central vertigo patients had normal DW-MRI findings. One was diagnosed with migraine headache and five with vertebra-basilar insufficiency during the out-patient follow-up. One of the 28 patients with a pathological MRI was diagnosed with mass and the rest was stroke. The utility of DW-MRI in vertigo patients was moderately high (sensitivity: 82%, specificity: 100%). We found that age, history of HT, history of CAD and vertigo unresponsive to ED treatment were significantly associated with a central cause of vertigo. CONCLUSION: We suggest that unresponsiveness to ED treatment, especially in patients with a history of HT and CAD, should alert physicians for central causes and warrant DW-MRI imaging.