Occasional occurrence of 42 beats/min sudden death is unlikely, but repeated occurrences will increase the chance of sudden death and should be taken seriously. Normal people’s heart rate is between 60 and 100 beats per minute. Occasionally, a heart rate of 42 beats per minute is not accompanied by other uncomfortable symptoms, which is usually not serious and does not cause sudden death. If the heart rate of 42 beats/minute occurs several times within a short period of time and is accompanied by symptoms such as blackout, dizziness and fainting, then we should be alert to the fact that it is caused by heart disease, medication and other factors, which may increase the chance of sudden death. Those who have a heart rate of 42 beats/minute once in a while should pay attention to adjusting their heart, and then measure it again at intervals. If the heart rate is still below the normal range, you can get an ambulatory electrocardiogram (ECG) and record your heart rate for 24 hours to determine whether there is any arrhythmia or other cardiac abnormality. For those who have a heart rate of 42 beats per minute accompanied by uncomfortable symptoms, it is necessary to consult a doctor immediately to prevent accidents from occurring.