Ablation of residual potentials along the circumferential line reduces acute reconnection in patients undergoing pulmonary vein isolation

Introduction

Acute pulmonary vein (PV) reconnection is frequently encountered in patients with atrial fibrillation (AF) subjected to PV isolation (PVI).

Purpose

In this prospective, multicenter, randomized study, we investigated whether the identification and ablation of sites along the circumferential line with specific electrogram criteria indicative of nontrasmurality, after initial achievement of PVI, reduces acute PV reconnection rate.

Methods

Patients referred for AF ablation at five European centers were enrolled. PVI with antral circumferential isolation of ipsilateral PVs was performed using a contact force sensing ablation catheter delivering 35–40W at the anterior/superior and 30W at the posterior wall with target ablation index of 550 at the anterior wall/roof and 400 at the posterior/inferior segments. Following PVI, mapping with the ablation catheter was performed to identify residual potentials (RP) along the ablation line, defined as bipolar amplitude ≥0.2 mV or 0.1–0.19 mV combined with negative component of the unipolar electrogram as recorded by the 3D mapping system. Ipsilateral PV sets with RPs were randomized to either no further ablation (Group B) or to additional ablation of RPs (Group C). The primary study endpoint was defined as spontaneous or adenosine-mediated recovery of conduction after 30-minute waiting period which was also evaluated in ipsilateral PV sets without residual potentials (Group A).

Results

In total, 109 patients (59.3±10.6 years, 47% hypertension, 9.3% diabetes, left atrial diameter 39.1±4.6mm) were enrolled in the study. After initial isolation of 194 PV pairs, 98 PV pairs had no RPs (Group A) while the remaining 96 with RPs were randomized to either Group B or C (48 PV pairs each). The number of sites with RPs did not differ between groups B and C (4.1±2.5 vs 4.7±3.2, p=0.27). The occurrence of the primary endpoint in Group A was 7.1%. Ablation of residual potentials resulted in significant reduction of spontaneous or adenosine mediated reconnection (14.6% vs 47.9%, p<0.001).

Conclusion

Following initial PVI achievement, ablation of RPs along the antral circumferential line reduces spontaneous or adenosine-mediated acute PV reconnection rate in patients undergoing first-time AF ablation. Therefore, scanning of the PVI line in search of weak links with specific electrogram criteria indicative of nontrasmurality, and subsequent deployment of bonus lesions, could represent a convenient and practical way to reduce acute PV reconnection. Further studies are required to assess long term effects on AF recurrence rates.

Funding Acknowledgement

Type of funding sources: None.

Applying the Molecular Adsorbent Recirculating System (MARS) in the Treatment of Acute Liver Failure (ALF) Case Report

Acute liver failure (ALF) is a rare but life-threatening illness with multiple organ failure. The short-term mortality rate exceeded 80 % despite modern approaches in treatment. Drugs, infections by hepatic viruses and toxins are the most common causes of ALF. Progressive jaundice, coagulation disorder and hepatic encephalopathy are dominated as a clinical signs of the illness. We present a case of a 36-year-old Caucasian woman hospitalized in ICU due to yellow discoloration of the skin and sclera, severe disseminated coagulopathy and hemodynamic instability. ALF is developed due to Hepatitis B Virus infection, resulting in hepatic toxicity as well as coma. General condition rapidly improved after applying of Molecular Adsorbent Recirculating System (MARS), an extracorporeal liver support system based on albumin dialysis. It is relatively expensive treatment that is used for the patient with hepatic encephalopathy grade 3 or 4 in our institution. In conclusion, an early administration of MARS significantly reveals subjective and objective clinical improvement in the case we presented.

Is there a Need for Own Median Calculation in the Second Trimester Biochemical Markers Screening?

Screening of fetal aneuploidies in early pregnancy is a well-established method in the materno-fetal medicine. The aim of our study was to analyze if the medians recommended by the manufacturers are adequate to perform an accurate screening or if there is a need for own laboratory medians calculation in second trimester biochemical marker screening.Sera were collected between 14 wp and 22 wp from 3374 singleton pregnancies. We analyzed three second trimester biochemical markers (AFP, hCG and free Estriol) concentration in all pregnant women and in a subgroup of pregnant women in which gestational age was determined based on crown-rump length. Our results showed that for all biochemical markers the difference between the manufacturer and the own calculated median was lower than 10% excepting the hCG value in the group of pregnant women in which the gestational age was determined on basis of crown-rump-length. Our results show it is recommended to replace the values of the median for hCG measurement with the own laboratory calculated medians. This does not seem to be necessary in the case of AFP and free Estriol measurement.

Oxidative stress indicators are elevated in de novo Parkinson's disease patients

In order to determine the baseline state of oxidative stress indices in drug-free patients with Parkinson's disease (PD), we analyzed cerebrospinal fluid (CSF) and peripheral blood samples of 34 subjects in disease stages I-III, according to the Hoehn & Yahr scale, compared with controls. The results showed a highly significant increase in malondialdehyde content in CSF (p < 0.001) in the patients with PD. We also found significant differences in peripheral blood parameters between the two groups: malondialdehyde content was increased in patients with PD (p < 0.05), as was the activity of antioxidative defense enzymes, glutathione reductase, Cu, and Zn-superoxide-dismutase (p < 0.05). The production of a highly reactive oxygen species--superoxide radical (p < 0.05) was also increased. These findings indicated an important role of oxidative stress in PD evolution and progress. The increased levels of reactive oxidative species (malondialdehyde content and superoxide radical production) in peripheral blood, and excessive activity of protective enzymatic systems (glutathione reductase Cu, and Zn-superoxide-dismutase) could indicate an additional systemic reaction related to a chronic oxidative stress state in the brain.