THE RELATIONSHIP BETWEEN EPICARDIAL FAT TISSUE THICKNESS AND RISK OF FREQUENT PREMATURE VENTRICULAR CONTRACTIONS

Objectives: This study aimed to evaluate the relation between epicardial fat tissue (EFT) thickness and frequent premature ventricular contractions. Methodology: In this cross-sectional study, patients with no structural heart diseases diagnosed with PVCs on a 24 holter rhythm monitoring were included. EFT thickness was measured by 2-dimensional transthoracic echocardiography. PVCs of more than 10 per hour were considered as frequent PVCs. To investigate the effect of independent variables, univariate logistic regression was performed. Results: Of total 50 studied patients, 64% were females. The mean age of subjects was 46.8 ± 13.1 years. Twenty-five patients were experiencing frequent PVCs of >10 per hour. In univariate analysis, age (OR= 1.05, 95 % CI; 1.01-1.10, p=0.050), left ventricular end diastolic diameter (LVEDD) (OR= 1.14, 95 % CI; 1.01-1.28, p=0.036) and left atrial (LA) diameter (OR= 1.35, 95 % CI; 1.11-1.62, p=0.002) were significantly associated with developing frequent PVC. EFT thickness was positively correlated with age (r= 0.389, p= 0.005) and inter-ventricular septum thickness in diastole (IVSD) (r= 0.384, p= 0.006). No significant correlation between EFT and PVCs was found (p=0.669). Conclusion: Patients with frequent PVCs had significantly higher LVEDD and LA diameter. Although patients with higher EFT thickness were more likely to experience frequent PVCs, there was no statistically significant correlation between EFT thickness and frequent PVCs.

Biophysical evaluation of clinical bipolar radiofrequency ablation approaches in a porcine ex-vivo model

Funding Acknowledgements Type of funding sources: None. Background Bipolar radiofrequency catheter ablation (BA) is an important therapeutic option for therapy refractory ventricular arrhythmias. BA approaches may frequently include titration of energy from lower to higher levels and target epicardial sites with overlying fat tissue. However, the actual effect on lesion formation has not been evaluated. Purpose Investigating lesion modalities during BA (a) using low-to-high energy titration, (b) conducting prior sequential unipolar ablation additional to BA and (c) in epicardial fat tissue. Methods An ex-vivo model consisting of freshly explanted swine hearts positioned in a circulating temperature-controlled saline bath was established. An irrigated active and ground ablation catheter with a 3.5mm tip connected to a novel single generator capable of performing BA were positioned on both sides of the left ventricular/ventricular septal myocardium orthogonal to respective swine tissue. Radiofrequency energy was applied with a fixed force of 10 g for 60 s using different approaches: (1) Titration group, BA of 30 W following BA of 50W; (2) sequential group, ablating unipolar from both catheters using 30 W; (3) epicardial fat group (fat thickness >1 cm) with BA of 50W; (4) sequential + BA group, applying unipolar energy of 30 W first on both catheters with consecutive BA of 50W; (5) control group, with BA of 30, 40 or 50 W only. Dimensions of set lesion as well as bipolar generator impedance during ablation were assessed. Results A total of 65 ablation lesions were analyzed. The mean tissue thickness was 18 ± 3 mm (range 11-23 mm), with a mean fat thickness of 3.5 ± 1.1 mm in the epicardial fat group. Overall, transmurality was observed in 17 lesions (26%) with the highest rates in the titration and sequential + BA group (75 / 100%), while no difference to the control group applying 50 W was detected (Kruskal-Wallis test, p = 0.30/0.19) and no lesion displaying transmurality in the epicardial fat group (p < 0.001). The maximum impedance drop during ablation was highest in the control group applying 50 W and lowest in the epicardial fat group (51 ± 24 vs 23 ± 12 Ω, p = 0.02). The lesion volume did not differ between titration and control group applying 50 W (455 ± 230 vs 426 ± 268 mm3, p > 0.99), whereas being significantly larger than in the epicardial fat group [median 59 (interquartile range 41-92 mm3), p = 0.02/0.01]. The sequential + BA group showed significantly increased lesion volume compared with both titration and control group [1401 (1093-1728) mm3, p = 0.004, Figure]. Eleven steam pops (17%) were registered with similar distribution between groups (p = 0.24). Conclusion Lesion dimensions were similar between the BA titration approach and BA solely applying 50 W. Prior sequential unipolar ablation may significantly increase ablation lesion volumes during BA. The effect of BA at sites of significant epicardial fat tissue >1 cm may be severely limited, which should be considered during procedure planning. Abstract Figure. Lesion dimensions in BA approaches

Evaluation of epicardial fat tissue thickness and aortic stiffness in patients with gestational diabetes mellitus

Objective We aimed to assess the relationship between gestational diabetes mellitus and coronary artery disease by measuring epicardial fat tissue thickness and aortic stiffness in pregnant women diagnosed with gestational diabetes mellitus. Methods 28 pregnant women diagnosed with gestational diabetes mellitus and 25 pregnant women without gestational diabetes mellitus were included in the research. Body mass index, laboratory values, blood pressure measurements and obstetric history findings of the study population were recorded. All participants of the study population were evaluated with transthoracic echocardiography between 24 and 28 weeks of gestational period. The measurement of epicardial fat tissue thickness was taken and aortic stiffness index was also calculated. Results The age, gravidity, parity and obstetric history of the two groups were similar. Epicardial fat tissue thickness was found significantly higher in gestational diabetes mellitus group than control group (0.416 cm and 0.336 cm, respectively; p<0.001). However, no significant difference was found in aortic stiffness measurements of the two groups (p=0.079). Conclusion According to the results of our study, epicardial fat tissue thickness was found to be statistically significantly higher in pregnant women with gestational diabetes mellitus compared to the control group. The fact that no difference was detected in other cardiovascular parameters suggests that measurement of epicardial fat tissue thickness in gestational period may be a beneficial adjunctive tool in early detection of gestational diabetes mellitus.