It absolutely can manifest that way. The mind and body are super powerful & anxiety will attack the things we fear & worry about most. My heart is one of my biggest HA worries , I've had numerous EKG's, blood tests , x-rays , CT scans , & an echocardiogram and all have checked out fine answer was.... ANXIETY. Try and do something to take your mind off thinking about it ( easier said than done) , sometimes i find going for a walk & getting fresh air helps. Hope you get some relief soon!