P6572Sinus arrest post-cardioversion

Introduction

Sinus arrest remains a recognized but likely underreported complication of cardioversion, with incidence ranging widely in the literature, from virtually 0% to 1.5%. After a case of elective cardioversion resulting in the need for ECMO support, we investigated possible risk factors that could help predict adverse outcomes after cardioversion.

Hypothesis

Cardioversion, while generally benign, is not without risks, and further study may help elucidate predictors of morbidity and mortality.

Methods

We retrospectively reviewed data of all patients who underwent cardioversion at three hospitals within the Lifespan health system, Rhode Island Hospital, Newport Hospital, and the Miriam Hospital, between 2000 and 2015. 23 patients who experienced sinus arrest after cardioversion, and characteristics of these patients were compared with those of 3:1 age-and-gender matched controls using binomial logistic regression analysis on Stata.

Results

Of 12,156 patients who underwent cardioversion, 23 patients (57% male, mean age 78±14), or 0.18%, experienced immediate post-cardioversion sinus arrest, defined as absence of sinus activity for greater than five seconds. Compared with 3:1 age-and-gender-matched controls who underwent cardioversion without incident, binomial logistic regression revealed that paroxysmal atrial fibrillation (OR 11.8; 95% CI 1.85–75.72; p=0.009), beta-blocker use (OR 58.0; 95% CI 2.4–1404.48; p=0.013), Amiodarone use (OR 19.9; 95% CI 2.0–198.32; p=0.011), and elevated ventricular rate (CV 0.028; 95% CI 0.0031–0.053; p=0.027) were statistically significant predictors of sinus arrest after cardioversion. Calcium-channel blocker use, Digoxin use, age, gender, PR interval, QRS duration, and corrected QT interval were not significant associations.

Conclusions

Sparse data exists regarding characteristics predisposing patients to adverse outcomes following cardioversion, and further risk stratification is warranted, given the potential for significant morbidity and mortality. Our findings raise questions that demand elucidation, such as whether beta-blockers or Amiodarone should be held prior to cardioversion.

Response of green roof performance to multiple hydrologic and design variables: a laboratory investigation

Multiple factors affect green roof performance and their effects might vary at different stages of operation. This paper aimed to link green roof performance to hydrologic variables (antecedent moisture condition (AMC) and rainfall intensity) and design variables (growing medium (GM) type and depth) under multiple dimensions at the early stage of operation using laboratory experiment data. The results showed that the AMC is the most influential factor of hydrologic performance, whereas the GM type appeared to primarily affect the nutrient levels of the outflow. The significant main effects of other variables and interaction effects between two variables point to challenges in green roof design.

Characterization of proximal femoral anatomy in the skeletally-immature patient

PURPOSE

The morphology of the proximal femur has been extensively studied in the adult population. However, no literature providing a comprehensive evaluation of the anatomy in paediatric patients exists. The current study aims to characterize such anatomy in skeletally-immature patients, examine potential differences between genders, and analyze how these anatomical parameters change with age.

METHODS

Cadaveric femurs from the Hamann-Todd Osteological Collection were examined. Specimens with open physes and no skeletal disease or deformity were included for analysis. Age and gender were recorded for each specimen. Each femur was photographed in standardized modified axial and anteroposterior views. In all, 14 proximal femoral anatomical parameters were measured from these photographs. Comparisons between genders and age were calculated.

RESULTS

A total of 43 femurs from ages four to 17 years met inclusion criteria. The majority were female (56%); no difference existed in age between genders (p = 0.62). The specimens had a neutral mean neck-shaft angle (130.7º) and anteversion (12.8º), and the sphericity of the ossified femoral heads was symmetrical. Male specimens had significantly higher alpha angles (p = 0.01), posterior offset (p = 0.02), neck width (p = 0.04) and head-neck length ratio (p = 0.02) values than female specimens. Strong positive correlations exist between length/size parameters and age, while negligible correlations were noted for angular measurements.

CONCLUSIONS

This study establishes reference values for a comprehensive list of anatomical parameters for the skeletally-immature ossified proximal femur. It highlights gender differences in morphology and demonstrates that angular characteristics remain relatively stable while length parameters generally increase with age.

LEVEL OF EVIDENCE

Level III Diagnostic.

A Simple Automated Method for Detecting Recurrence in High-Grade Glioma

Our aim was to develop an automated multiparametric MR imaging analysis of routinely acquired imaging sequences to identify areas of focally recurrent high-grade glioma. Data from 141 patients treated with radiation therapy with a diagnosis of high-grade glioma were reviewed. Strict inclusion/exclusion criteria identified a homogeneous cohort of 12 patients with a nodular recurrence of high-grade glioma that was amenable to focal re-irradiation (cohort 1). T1WI, FLAIR, and DWI data were used to create subtraction maps across time points. Linear regression was performed to identify the pattern of change in these 3 imaging sequences that best correlated with recurrence. The ability of these parameters to guide treatment decisions in individual patients was assessed in a separate cohort of 4 patients who were treated with radiosurgery for recurrent high-grade glioma (cohort 2). A leave-one-out analysis of cohort 1 revealed that automated subtraction maps consistently predicted the radiologist-identified area of recurrence (median area under the receiver operating characteristic curve = 0.91). The regression model was tested in preradiosurgery MRI in cohort 2 and identified 8 recurrent lesions. Six lesions were treated with radiosurgery and were controlled on follow-up imaging, but the remaining 2 lesions were not treated and progressed, consistent with the predictions of the model. Multiparametric subtraction maps can predict areas of nodular progression in patients with previously treated high-grade gliomas. This automated method based on routine imaging sequences is a valuable tool to be prospectively validated in subsequent studies of treatment planning and posttreatment surveillance.