 It's still June, but the 4th of July getaway is on. More than 3 million passengers expected to go through airport security checkpoints today, setting a new record. This is ABC News. I'm Kareem Abdul-Jabbar. I learned about atrial fibrillation the hard way. My symptoms would come and go. Shortness of breath, fatigue. I kept going. Then I got so lightheaded, I couldn't. My doctor said I have AFib, so I'm about five times more likely to have a stroke.