My Husband Has Had 3 Episodes In A Few Month

My husband has had 3 episodes in a few month period of coughing just a few times and blacking out. 2 of the 3 times he was driving and had a wreck. We went to a pulmonologist last week because we thought cough syncope. His chest X-Ray was good and his breathing test was good. The dr said he didn't have cough syncope. His employer is wanting further testing since he drives a truck. We've made an appt with a cardiologist but after further research I'm not so sure it's not laryngospasm. He did smoke, he has quit and he takes omerprazole daily. My question is what kind of dr would he need to see to find out if that's what it is? Thanks