Electrocardiographic changes with the onset of diabetes and the impact of aerobic exercise training in the Zucker Diabetic Fatty (ZDF) rat.

BACKGROUND: Early markers of diabetic autonomic neuropathy (DAN) in an electrocardiogram (ECG) include elevated R wave amplitudes, widening of QTc intervals and decreased heart rate variability (HRV). The severity of DAN has a direct relationship with mortality risk. Aerobic exercise training is a common recommendation for the delay and possible reversal of cardiac dysfunction. Limited research exists on ECG measures for the evaluation of aerobic exercise training in Zucker Diabetic Fatty (ZDF) rat, a model of type 2 diabetes. The objective of this study was to assess whether aerobic exercise training may attenuate diabetes induced ECG changes. METHODS: Male ZDF (obese fa/fa) and control Zucker (lean fa/+) rats were assigned to 4 groups: sedentary control (SC), sedentary diabetic (SD), exercised control (EC) and exercised diabetic (ED). The exercised groups began 7 weeks of treadmill training after the development of diabetes in the ED group. Baseline (prior to the training) and termination measurements included body weight, heart weight, blood glucose and glycated hemoglobin levels and ECG parameters. One way repeated measures ANOVA (group) analyzed within and between subject differences and interactions. Pearson coefficients and descriptive statistics described variable relationships and animal characteristics. RESULTS: Diabetes caused crucial changes in R wave amplitudes (p < 0.001), heart rate variability (p < 0.01), QT intervals (p < 0.001) and QTc intervals (p < 0.001). R wave amplitude augmentation in SD rats from baseline to termination was ameliorated by exercise, resulting in R wave amplitude changes in ED animals similar to control rats. Aerobic exercise training neither attenuated QT or QTc interval prolongation nor restored decreases in HRV in diabetic rats. CONCLUSION: This study revealed alterations in R wave amplitudes, HRV, QT and QTc intervals in ZDF rats. Of these changes, aerobic exercise training was able to correct R wave amplitude changes. In addition, exercise has beneficial effect in this diabetic rat model in regards to ECG correlates of left ventricular mass.

Evolution of Paroxysmal Atrial Fibrillation to Persistent or Permanent Atrial Fibrillation: Predictors of Progression.

Introduction: Paroxysmal atrial fibrillation (PAF) eventually progresses to persistent and permanent AF. The predictors of progression from PAF to persistent and permanent AF are poorly understood. Methods: Electronic medical records of 437 patients with PAF were reviewed in a retrospective cohort study. Patients were followed in time and progression to persistent/permanent AF was recorded. Demographic, clinical and echocardiographic information was collected. A logistic regression analysis was performed to identify predictors of progression to persistent/permanent AF. Results: Over a mean duration of 57.3±55.9 months, 32.4% of patients progressed to persistent/permanent AF. Mean age of the population was 67.9±13.4 years with 57% males and 92% Caucasian. Univariate analysis identified higher body higher mass index (BMI), cardiomyopathy, diabetes, valvular heart disease (VHD), larger left atrial size (LA) and higher pulmonary artery pressure as predictors of progression. Multivariate logistic regression analysis larger left atrial size (OR 1.46, CI 1.05-2.04, P 0.002), cardiomyopathy (OR 2, CI 1.1- 3.3, P 0.003), and moderate to severe valvular heart disease (OR 3.3, CI 1.4-5, P 0.008) as significant predictors of progression to persistent/permanent AF. Conclusions: Our study shows that PAF patients with larger LA, valvular heart disease and cardiomyopathy predict progression of PAF to persistent/permanent AF. Higher BMI and cardiomyopathy predicted progression to persistent AF while larger LA size and VHD predicted progression to permanent AF.

Integrity of prostatic tissue for molecular analysis after robotic-assisted laparoscopic and open prostatectomy.

OBJECTIVES: The warm ischemia time of tissue before fixation for pathologic analysis has been linked to changes in cell morphology and nucleic acid and protein integrity. Robotic-assisted laparoscopic prostatectomy (RALP) results in longer warm ischemia times than open radical retropubic prostatectomy. To assess the effect of longer ischemia times on biomolecular integrity, we analyzed DNA, RNA and protein collected from robotic and open prostatectomy specimens. METHODS: We examined 22 consecutive RALP (n = 11) and open radical retropubic prostatectomy (n = 11) specimens after hematoxylin-eosin staining by light microscopy. To assess protein integrity, immunohistochemical staining for p63, E-cadherin, and AE1/AE3 was performed. DNA was assessed by gel analysis. An RNA integrity score was determined by microfluidic capillary electrophoresis and calculated according to the electropherogram findings and simulated gel view. Finally, epithelial cells were cultured on collagen-coated plates. RESULTS: No differences in clinicopathologic characteristics were found between the two groups, with the exception of a significantly longer warm ischemia time during RALP (82 +/- 23 minutes) compared with open radical retropubic prostatectomy (23 +/- 2 minutes; P <0.001). Tissue integrity was suitable for the assessment of pathologic grade and stage for all samples. Protein and DNA analyses demonstrated no evidence of degradation in any samples. No significant differences in the RNA integrity scores were demonstrated between the surgical approaches. Prostate epithelial cells were cultured successfully in 66% of the RALP specimens. CONCLUSIONS: RALP, although it involves additional exposure to warm ischemia, does not significantly affect the histopathologic characteristics or biomolecular integrity of the specimen. Provided a rapid response occurs for tissue banking after specimen removal, molecular research studies using prostatic tissue harvested by way of RALP appear feasible.