A 64-year-old woman of good past health presented to the emergency department with syncope. She had upper respiratory symptoms and dizziness followed by worsening exertional dyspnea and palpitation for 2days. She then developed sudden lightheadedness and transient loss of consciousness. She denied any chest pain. Physical examination found normal blood pressure and pulse, oxygen saturation 94% in ambient air, elevated jugular venous pressure and bilateral ankle edema. A parasternal heave and a grade 2/6 pansystolic murmur at lower left sternal border were noted.