The study focuses on people who have Atrial Fibrillation, a common heart rhythm problem where the upper chambers of the heart beat irregularly and often too fast. The treatment being tested is a nasal spray that contains the drug etripamil, which is designed to slow down the heart’s beating speed quickly when given through the nose. The main goal of the trial is to see whether this spray works better than a harmless powder (placebo) in lowering the rapid heart rate caused by the condition.
Participants will receive either the active nasal spray or the harmless powder in a single dose and will be observed for a short period, usually about half an hour, during which their heart’s speed is measured using a simple test that records the heart’s electrical activity (an ECG). They will also answer brief electronic questions (ePRO) about how they feel. Throughout the visit, safety checks such as checking blood pressure and looking for any side effects will be performed. The study follows a straightforward schedule: screening, a single treatment visit, and a short follow‑up period to collect the needed information.
The Netherlands 
