A 42-year-old woman comes with 10 years of intermittent palpitations. Symptoms last a few minutes and have no chest pain, shortness of breath, or dizziness. Worse with stress and caffeine. No problems with exercise. Cardiovascular exam is largely normal. There is a midsystolic click heard best at the apex. Most likely diagnosis?
A) Atrial fibrillation
B) Ventricular tachycardia
C) Mitral valve prolapse
D) Supraventricular tachycardia