That's similar to what happens to me, and yes, I think he had a panic attack. When a person experiences a panic attack, the "fight or flight" instinct is triggered (for whatever reason) and that results in measurable physiological responses: hyperventillation, adrenaline is released, chest pain, feeling faint, etc. Although there is no "thing" there to fight, the body reacts as though there is something trying to harm it. I experienced panic attacks while going through a divorce, and also when driving over very tall bridges. Go figure! Now that I know the bridges are a problem, I can at least control my breathing enough to get over them without totally wigging out and causing a wreck. My psychologist tells me that the first thing to do is focus on breathing. The "fight or flight" response makes us hyperventillate, which makes us feel faint, which adds to the panic, and there you go into the vicious circle until you pass out.
If your husband can recognize the panic attack when it first comes on, or can recognize anything that triggers it, he needs to start reminding himself that it's just that: a panic attack. He is NOT going to die. Next, concentrate on deep breathing instead of hyperventillating. Slow, deep breaths focusing on the "out" more than the "in". If he can stop the hyperventillation, he won't pass out. Some people even keep paper bags handy to breathe in just in case they get into a triggering situation and can't control their breathing.
Is this something new for your husband, or a recurring problem? If it's happened for a while, a psychologist can help him learn some techniques to deal with the attacks when he feels them coming on. And NO, that doesn't mean he is "crazy." It is nothing to be ashamed of, but something that can be dealt with so it doesn't take over his life.
Living in the Republic of Texas minus a gallbladder, a couple of cervical discs, appendix, uterus, and 18" of colon; but living with my wonderful husband, 2 dogs, 1 cockatiel, and 2 gold fish.