Does having a 43 as a heart rate mean there is something wrong with your heart?

My husband had gotten fluid while he was off at Annual Training for the military....he said it wasn't bothering him so he didn't want to go to the doctor. I made him go, I guess because I'm paranoid, and we have insurance, so why not.....rather be safe than sorry! Well, we went. and his blood pressure was low. And the doctor said it could be a heart problem (I didn't understand why, but trusted him) so they hooked him up to a EKG and found out that his heart rate is at 43. He said that's extremely low. He is a 23 year old male. He said his heart rate has always been that low his whole life. His dad had a heart problem (don't know exactly what it is though). He enlisted in the military two years ago, but they never looked into why his heart rate was so low. The docotr made him an appointment for a cardiologist for 6 days from now, and he said they would probably do a Echo (ultrasound of the heart) to see if anything is wrong with his heart. I was just wondering if having a 43 heart rate could mean a heart problem. He is suppose to deploy to Afghanistan in a year...so i he does have a heart problem, I'm concerned about them deploying him with a heart problem. Does anyone have any advice as to what it could be?