<qa>  What is the only way to enter the study if they are considered to be in aPatients who suffer from serious cardiac arrhythmia requiring medication can enter the study only if they are considered to be in a stable condition regarding both the arrhythmia and their medication. Patients with pacemakers are allowed to enter the study only if they are considered as being in a stable condition. In case of doubt, the investigator should obtain a consultation with a local cardiologist. 