This is the ECG of an 81-year-old man with hypertension. Currently, he has no complaints: no palpitations, no shortness of breath, no syncope, no chest pain. The rhythm is irregular, but all P-waves have the same shape. There is a non-respiratory sinus arrhythmia present, which is essentially the minimal variant of a sick sinus syndrome. There are no consequences for the patient resulting from this diagnosis.