Atrial fibrillation progression and the importance of early treatment for improving clinical outcomes.

Over time, atrial fibrillation (AF) naturally progresses from initially paroxysmal to persistent/permanent AF caused by structural and electrical remodelling with a complex underlying pathogenesis. It has been demonstrated that this progression of AF itself is linked to negative cardiovascular outcomes (stroke, systemic embolism, and hospitalization due to heart failure). Consequently, there is a profound rationale for early treatment of AF as a cornerstone of AF management. Recent randomized trials produced evidence that early rhythm control is effective in maintaining sinus rhythm, lower the risk of cardiovascular outcomes, and that catheter ablation of AF is effective to delay AF progression. This review will illuminate current evidence regarding the hypothesis of early AF treatment to prevent AF progression and improve clinical outcomes.

WNT signaling in atrial fibrillation.

The Wnt signaling pathway regulates physiological processes such as cell proliferation and differentiation, cell fate decisions, and stem cell maintenance and, thus, plays essential roles in embryonic development, but also in adult tissue homeostasis and repair. The Wnt signaling pathway has been associated with heart development and repair and has been shown to be crucially involved in proliferation and differentiation of progenitor cells into cardiomyocytes. The investigation of the role of the Wnt signaling pathway and the regulation of its expression/activity in atrial fibrillation has only just begun. The present minireview (I) provides original data regarding the expression of Wnt signaling components in atrial tissue of patients with atrial fibrillation or sinus rhythm and (II) summarizes the current state of knowledge of the regulation of Wnt signaling components' expression/activity and the contribution of the various levels of the Wnt signal transduction pathway to the processes of the development, maintenance, and progression of atrial fibrillation.

Lower preoperative fluctuation of heart rate variability is an independent risk factor for postoperative atrial fibrillation in patients undergoing major pulmonary resection.

OBJECTIVES: The following study presents a special independent atrial fibrillation (AF) risk factor-preoperative fluctuation of heart rate variability (HRV), as well as other perioperative AF risk factors in patients qualified for pneumonectomy and undergoing pneumonectomy or lobectomy for lung cancer. METHODS: The prospective study was performed in patients who had undergone anatomical resection for non-small-cell lung cancer. A total of 117 patients (92 men and 25 women) qualified for statistical research. In order to determine the risk factors, all patients were divided into two groups: Group A-98 patients without AF and Group B-19 patients with AF during the perioperative time. A number of different risk factors of AF have been analysed and further divided into preoperative, operative and postoperative. RESULTS: Postoperative AF occurred in 19 patients (16%), all of them were male. The patients with higher short-term HRV parameters (SD1, RMSSD), slower mean heart rate and those with a lower fluctuation of HRV-related parameters (HRV Afternoon, Night, Day (A/N/D)) before the operation, were more prone to AF. Postoperative risk of AF was higher in patients with a higher number of ventricular ectopic beats before the operation, a higher number of supraventricular and ventricular ectopic beats and a higher maximal heart rate after the operation. Statistical analysis revealed that male gender and the extent of pulmonary resection, particularly left pneumonectomy, constituted significant risk factors. AF was more often observed in patients who had ASA physical status score of III, in comparison with ASAI and ASAII patients. CONCLUSIONS: Along with other concomitant AF risk factors presented in this work, the evaluation of the fluctuation tendencies of HRV parameters should be taken into consideration before any major lung resection. The balance disturbance between the sympathetic and parasympathetic nervous systems is responsible for AF.