In this case report, we describe the recovery of abnormal coronary pressure waveform using a PressureWire Certus during percutaneous coronary intervention in a patient with severe stenosis in the proximal segment of the left anterior descending coronary artery. Since the diastolic pressure in the distal left anterior descending coronary artery was lower than that in the aorta, the pressure waveform before percutaneous coronary intervention represented the left ventricular pressure through a fistula due to a "wedge effect" in the stenosis as if the pulmonary artery wedge pressure determined by a Swan-Ganz catheter reflected the pressure in the distal portion (left atrium). We diagnosed this case coronary artery-left ventricular fistula based on the above findings. PressureWire Certus may be a valuable tool with which to estimate the hemodynamics in a patient with a coronary anomaly.