Greater distance between ablation lines reduces the arrhythmia recurrence rate after pulmonary vein isolation

INTRODUCTION

Pulmonary vein isolation (PVI) is a recommended strategy for rhythm control in atrial fibrillation (AF), but its success rate remains unsatisfactory. Continuous research is being conducted to explore new technologies and modifications to the existing ablation workflow in order to reduce the arrhythmia recurrence rate.

OBJECTIVES

This study aimed to determine the influence of the distance between ablation lines (DBL) on AF recurrence rate in patients undergoing their first PVI; and thus to optimize the procedure outcomes.

PATIENTS AND METHODS

This is a retrospective cohort study conducted at a tertiary care center in Poland. A total of 146 patients (median age, 62 years; women, 34.3%) referred for a first PVI for either paroxysmal (n = 103) or persistent (n = 43) AF were evaluated. The procedures were performed with the use of a very‑high‑power, short‑duration catheter (QDot MicroTM, Biosense Webster, Inc., Irvine, California, United States) or a conventional, ablation index-guided ThermoCool Smarttouch SF catheter (Biosense Webster, Inc.). Freedom from AF recurrence was used as a primary end point. The impact of DBL on the outcome of PVI, accounting for conventional risk factors, was evaluated.

RESULTS

Greater distance between opposite circumferential PVI lines and its ratio to the transverse diameter of the left atrium (DLB/TD) were associated with a lower risk of AF recurrence (hazard ratio [HR], 0.966; 95% CI, 0.935-0.998 [per 1 mm]; P = 0.04 and HR, 0.968; 95% CI, 0.944-0.993 [per 1%]; P = 0.01, respectively). There was no correlation between DBL or DBL/TD ratio and the impedance level.

CONCLUSIONS

Close distance between PVI lines contributes to AF recurrence; thus, increasing the DBL and ensuring a higher DBL/TD ratio may be an advantageous ablation strategy.

Intravascular Imaging versus Physiological Assessment versus Biomechanics-Which Is a Better Guide for Coronary Revascularization

Today, coronary artery disease (CAD) continues to be a prominent cause of death worldwide. A reliable assessment of coronary stenosis represents a prerequisite for the appropriate management of CAD. Nevertheless, there are still major challenges pertaining to some limitations of current imaging and functional diagnostic modalities. The present review summarizes the current data on invasive functional and intracoronary imaging assessment using optical coherence tomography (OCT), and intravascular ultrasound (IVUS). Amongst the functional parameters-on top of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR)-we point to novel angiography-based measures such as quantitative flow ratio (QFR), vessel fractional flow reserve (vFFR), angiography-derived fractional flow reserve (FFRangio), and computed tomography-derived flow fractional reserve (FFR-CT), as well as hybrid approaches focusing on optical flow ratio (OFR), computational fluid dynamics and attempts to quantify the forces exaggerated by blood on the coronary plaque and vessel wall.

Evaluation of the prognostic value of the admission ECG in COVID-19 patients: a meta-analysis

The assessment of the prognostic value of the admission electrocardiography (ECG) (specifically of the duration of the PR and QTc intervals, the QRS complex and the heart rate [HR]) in COVID-19 patients on the basis of nine observational studies (n=1,424) indicates that relatively long duration of the QTc interval and QRS complex, as well as higher HR, are linked to a severe course of COVID-19, which may be of use in risk stratification. Since there are important differences in suggested indicators of adverse prognosis between observational studies, further research is necessary to clarify high-risk criteria.

[Study on behavior of thyroid gland hormones in Bydgoszcz province children and teenagers with simplex struma]

Struma caused by iodine deficit is an endemic disorder in specified regions. The purpose of the study was a biochemical characteristic of struma simplex in children from Bydgoszcz province and evalued correlation between laboratory exponents of thyroid gland function, size of the gland and kind of the struma. It was confirmed that neutral struma of children generally takes a course with euthyroidism. In children with struma were confirmed significant lower values of T4 and no significant higher values of T3. Value of TSH was no different in comparison with the control group. Proved was that hormonal thyroid activity is lower when struma is getting bigger.