Neurohumoral arrhythmogenic mechanisms and the treatment of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in humans. For AF to occur a trigger and substrate are necessary to start and perpetuate the arrhythmia. AF is induced by a complex interplay of clinical and biological risk factors. Despite of state-of-the-art therapeutic interventions AF remains a progressive, symptomatic disease. The first part of the thesis focusses on predicting patients who are at risk to develop AF. We found that body composition, especially a greater abdominal fat distribution, was association with new-onset AF. In the PREDICT-AF study we will investigate blood and atrial tissue markers of pathophysiological changes in new-onset AF in 150 patients, aiming to predict post-operative and new-onset AF and identify new targets of therapies. In the second part, we found that mineralocorticoid receptor antagonists significantly lowered the risk of new-onset or recurrent AF risk compared to control. This effect was more pronounced in patients with heart failure, but neutral in heart failure with a preserved ejection fraction. In the last part, we found that freedom of AF after thoracoscopic AF ablation plus ganglion plexus ablation was similar to control, but was associated with more major complications. Sinus node dysfunction (SND) occurred in 7.1% of patients after thoracoscopic AF ablation, but the majority of SND was of temporary nature and resolved within days postoperatively. In patients with an extremely enlarged left atrium the efficacy of standalone thoracoscopic AF ablation was considerable. The thromboembolic risk per risk factor of the CHA2DS2-VASc score was the highest in age group 65-74 years, while comorbid cardiovascular conditions were associated with lower, but still considerably increased risks. After a standardised evaluation visit with a dedicated AF nurse practitioner, a quarter of the patient remained under nurse-led care and almost half of patients could be referred back to a general practitioner.