A sudden increase in heart rate may be related to poor rest, sudden mood swings, or stress at work or school. If these are ruled out, then it may be related to an isolated arrhythmia, a sudden onset of sinus tachycardia, or other arrhythmias. For example, paroxysmal supraventricular tachycardia, or fibrillation of the atria. Some arrhythmias cause, if they only appear occasionally, in principle, observation is the main concern, after all, they are not frequent occurrences. If frequent panic and fast heartbeat occur, you must go to the cardiology department within the first time. Do an electrocardiogram, preferably a 24-hour ambulatory electrocardiogram, to see what the cause is. To clarify what causes it, you can take a most appropriate treatment plan.