Decision between rate control and rhythm control can be a challenge in clinical practice. While there is some guiding evidence, we still lack a comprehensive insight into different subgroups of patients that will benefit from a rhythm control treatment.

EMPATHY is a prospective clinical study in patients presenting with heart failure and a tachyarrhythmic rhythm disturbance. Biomarkers, routinely obtained results from clinical examinations, and results from endomyocardial biopsies shall be evaluated to identify patients which have better outcome from a rhythm control strategy by ablation therapy or, if contraindicated by pharmacological rhythm control.

This study is designed to identifying risk factors and subgroups profiting from rhythm restoration and therefore improve current therapeutic approaches and the rate of recurrence-free survival.

Inclusion Criteria:

• newly diagnosed left ventricular ejection fraction ≤ 50%
• endomyocardial biopsy available
• tachycardic rhythm disturbance with a rhythm control strategy planned for tachycardic atrial fibrillation or flutter (≥100/min) or more than 10000 ventricular premature beats in 24 hours

Exclusion Criteria:

• age <18 years
• patient unable or unwilling to give informed consent
• coronary artery stenosis >50%
• relevant valvular disease
• simultaneous contraindications against amiodarone treatment and pulmonary vein isolation/ablation therapy
• present or suspected alcohol/drug dependency will result in exclusion from the study

Patients presenting at the University Hospital Tübingen with decreased left ventricular ejection fraction.