Usually benign, but always frightening--that's mitral valve prolapse.
D000328:Adult; D001007:Anxiety; D004452:Echocardiography; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006326:Heart Auscultation; D006801:Humans; D008297:Male; D008945:Mitral Valve Prolapse / Q000175:diagnosis* / Q000523:psychology