A 33-year-old woman had undergone aortic and mitral valve replacement with Björk-Shiley prostheses in 1973 because of rheumatic valvular disease. She has been receiving digoxin and warfarin sodium since then. In November 1978, she noted the gradual onset of exertional dyspnea and orthopnea, which prompted her admission to the hospital. Physical examination disclosed a regular heart rate of 96 beats per minute, blood pressure of 120/70 mm Hg, and a grade 3/6 midsystolic murmur at the apex. A third sound of variable timing was noted. The ECG indicated left ventricular hypertrophy and left atrial enlargement only. A chest roentgenogram was compatible with congestive heart failure. Figure 1 is a simultaneous recording of the ECG, apical phonocardiogram (PCG), and mitral prosthetic valve echogram (PVE).
What is your diagnosis?
—Malfunction of Björk-Shiley Mitral Prosthesis.Figure 2 is a higher paper-speed recording of the same graphics as in Fig 1. Note