accurancy heart rate

hello all, i am using apple watch series 8. I noticed that I had some isolated recorded heat rates around 150/160 bpm - even when i am not doing anything e.g. the heat rate recorded at time x is 80 bpm, the heat rate recorded at time x + 1 is 150 bpm and then the following recorded heat rate is 80 bpm. As i didn't perceive the heat rate going up so much neither there are good reasons for (e.g., gym), i am trying to understand if there are circumstances that can influence the way in which apple watch measures the heart rate and bring to overestimated data point. I add that i am using apple watch since November and i noticed this for the last month and half. thanks for your help.