Risks of erging at max heart rate?

I am a 40-something female. Erg/row 2-3 days a week. (I am overweight and getting back into shape.)

I am very strong for my age (decades of rowing) and fitness level, and I get a bit enthusiastic at practices and forget to follow the coach's guidance for pressure.

I feel no ill effects. I can talk but breathing hard, as one would expect during a workout.

I have a heart rate monitor (polar) and a garmin.

My garmin says my resting heart rate is 50-55. When walking around, I can be between 70-95.

Today, my total high-intensity workout time was 35 minutes, not including warm-up, rest, and cool down.

I was mostly in the high 170s/low 180s for the full time, according to the Polar monitor.

My heart rate goes down as soon as the exercise ends. By the time I leave the gym, I'm at 90.

I talked to a PCP today, and she said that's awfully high to be doing for an extended time and my high shouldn't be that high.

From what you know, does this do damage to the heart? Does anyone else have this issue?