Medical term for a resting heart rate over 100 beats per minute. Used in clinical contexts.
頻脈の原因を調べるために心電図をとります。
We'll take an electrocardiogram to investigate the cause of the tachycardia.
From 頻 (hin, 'frequent') + 脈 (myaku, 'pulse'). A straightforward Sino-Japanese medical compound.