How is vasovagal syncope managed after surgery?

Hi doctor,

I was in the recovery room after undergoing total knee replacement (TKR) when my heart rate dropped to 38 beats per minute. I felt weak and tired, so the nurse added something to my IV, and I began to feel better; all my vital signs returned to normal. Afterward, they took me to my room, where I ate and rested. However, my heart rate dropped to 32 beats per minute, and I experienced nausea, cold sweats, and a very pale complexion. The emergency team was called, and after 20 minutes, they stabilized all my vital signs. They then connected me to a portable heart monitor to monitor my condition.

The next day, while doing knee exercises with the nurse, I walked down the hall and returned to my room. I was put in a chair to finish my exercises when I suddenly passed out. According to my heart monitor, my heart stopped for 30 seconds, and I had no recollection of what happened. After about 30 minutes, the emergency team managed to stabilize my vital signs again, and I was taken to the ICU. My heart chambers, valves, and arteries were found to be normal.

I am 61 years old and have a history of stage III colon cancer, for which I underwent six months of chemotherapy. I have no history of blackouts, heart issues, or any family history of such conditions. The next day, they implanted a pacemaker as a precautionary measure, but they could not explain how or why this episode occurred. Now, three weeks later, I am not experiencing any problems.

Do you think the TKR could have caused this to happen?