Is cardiac arrhythmias a life-threatening condition?

Hi doctor,

I am a 42 years old mother of two boys with 1.80 m height and 145 pounds of weight. Following considerable stress at work, the last few days, I have experienced some rare palpitations. Although they are not frequent, I am distraught because they give me a different feeling than those I had a few years ago. In particular, 3.5 years ago, I used to have frequent extra beats for 1.5 years. I had done all tests (ECG, triplex, MRI, stress test, etc.), which did not show anything. My doctor said it is idiopathetic extra beats ventricular arrhythmia of the font bundle. He gave me Bisoprolol. After a few weeks, extra beats stopped entirely for two years. They have returned in the last few days but feel a bit different. They do not feel like I am losing a beat but like my heart flutters. Last week I had an incident of this feeling lasting for a few seconds (about 10”), although the last time (two years ago), the sense of extra beats lasted only 1”. The fact that it lasted for a few seconds panicked me. I went to the emergency room in a small medical center as I was on holiday, but at that time, it had stopped, and my ECG was very good. Shall I worry? Is this arrhythmia life-threatening? Many thanks for considering my request. Currently away from the city, I live with no access to doctors. Please help.