If your system is adjusted to a low systemic blood pressure, would that present a problem on CPM? May depend on the cause. Some experts define low blood pressure as readings lower than 90 systolic or 60 diastolic — you need to have only one number in the low range for your blood pressure to be considered lower than normal. In other words, if your systolic pressure is a perfect 115, but your diastolic pressure is 50, you're considered to have lower than normal pressure. A 102/52 baseline as you state may or may not be considered abnormally low!?
A sudden fall in blood pressure can also be dangerous. A change of just 20 mm Hg — a drop from 130 systolic to 110 systolic, for example — can cause dizziness and fainting when the brain fails to receive an adequate supply of blood. And big plunges, especially those caused by uncontrolled bleeding (a surgical risk...a low going into surgery does not leave much slack) and that is a surgeon's call to assume the risk, and it can be life threatening.
Cardiopulmonary bypass (CPM) is commonly used in heart surgery because of the difficulty of operating on the beating heart. Operations requiring the opening of the chambers of the heart require the use of CPB to support the circulation during that period. If your valve can be repaired, CPM may not be necessary.
No doctor has ever told me that my blood pressure is a problem or a cause for concern. I was concerned only when a doctor suggested lowering it further. (My previous cardiologist - who I hated to leave when I moved cross country - once joked that we wouldn't want my BP any lower. The assumption being that if it was an issue he wouldn't have made the joke.)
I'm not sure what you mean about my system on a pump.
Whether your bp is too low is question the surgeon may ponder, and may depend on the underlying cause. Your a correct it could cause a problem. And what are the implications if your system is on a pump?