Natural Vs. Cesarean with a Heart Condition?

Hi everyone! I'm 27 weeks pregnant with my first child. My baby girl is measuring already 2 weeks ahead and has some cute chubby cheeks and my long legs. There is a history of big babies on both mine and my husband's sides of the family. My husband was born at 39 weeks weighing 9 pounds, 9 ounces! I was born at 35 weeks and was already 7 pounds, 6 ounces even with being 5 weeks premature. 😁 My doctors say she will probably be big and is already showing signs of being a chunk at birth. However, I am NOT a big person by any means. I'm tall but very lean and lanky, and my doctor's do not think my body can handle a 9+ pound baby. On top of this, I have a heart condition called SVT. It's where I have uncontrollable irregular heartbeats. I also had a hole in my heart at birth, hence why I was born early. Since having a strenuous natural birth wouldn't be good for my heart, They're leaning toward a c-section for me. I'm just curious of two things: