A 40-year-old woman is in the office complaining of palpitations and some light headedness for the past 6 months. These are random episodes. The nurse practitioner notices a mid-systolic click with a late systolic murmur that is best heard in the apical area during auscultation of the chest. The NP would suspect:
1) Atrial fibrillation
2) Sinus arrhythmia
3) Mitral stenosis
4) Mitral valve prolapse