The findings indicate that prolongation of duration of in vivo lidocaine nerve blockade by clonidine is not mediated by an alpha-adrenergic mechanism but likely involves the Ih current.

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Objectives Right ventricular (RV) failure is common after left ventricular assist device (LVAD) surgery and is associated with higher mortality. Measurement of longitudinal RV strain using speckle-tracking technology is a novel approach to quantify RV function. We hypothesized that depressed peak longitudinal RV strain measured by intraoperative transesophageal echocardiography (TEE) examinations would be associated with adverse outcomes after LVAD surgery. Design Retrospective Cohort Study. Setting Tertiary academic medical center. Participants Following IRB approval, we retrospectively identified adult patients that underwent implantation of non-pulsatile LVAD. Exclusion criteria included: inadequate TEE images and device explantation within six months for heart transplantation. Interventions None. Measurements and Main Results The postoperative adverse event outcome was defined as a composite of one or more of death within six months, ≥14 days of inotropes, mechanical RV support, or device thrombosis. Intraoperative TEE images were analyzed for peak RV free wall longitudinal strain by two blinded investigators. Simple logistic regression was used to assess the relationship between adverse outcome and the mean of the strain measurements of the two raters. Agreement between the raters was assessed by intra-class correlation (0.62) and Pearson correlation coefficient (0.63). Of the 57 subjects, 21 (37%) had an adverse outcome. The logistic regression indicated no significant association between RV peak longitudinal strain and adverse events. Conclusions In this retrospective study of patients undergoing non-pulsatile LVAD implantation, peak longitudinal strain of the RV free wall was not associated with adverse outcomes within six months after surgery. Additional quantitative echocardiographic measures for intraoperative RV assessment should be explored.

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