Sudden rise in heartbeat. Other tests?

Hello Doctor, I wanted to ask about some episodes I’ve been experiencing. During the day, while I was completely at rest, my heart rate suddenly increased to around 160–170 bpm and stayed high for about 5 minutes. I got an ECG done immediately, which showed normal rhythm with sinus tachycardia. Then at night after dinner, while resting, my heart rate was around 72 bpm and suddenly increased to about 135 bpm, and within 2 minutes it came down to around 100 bpm on its own. This has happened more than once. I did not have significant chest pain or severe symptoms, just the sudden increase in heart rate. Could this be something like episodic sinus tachycardia or SVT? Do I need further evaluation like a Holter monitor or any other tests?