Hemodynamic Significance of Coronary Cameral Fistula Assessed by Fractional Flow Reserve
A 73-year-old woman was admitted to the hospital with dyspnea on exertion for one month. She underwent a total gastrectomy, due to advanced gastric cancer, 13 years ago. She had a history of diabetes mellitus and was on antianginal medication. Her resting ECG demonstrated a sinus rhythm with anterolateral and inferior T-wave inversions. The chest X-ray exhibited cardiomegaly. Transthoracic echocardiography showed a hypertrophied LV wall with an average thickness of 12 mm. The LV systolic function was normal with impaired relaxation patterns. Selective coronary angiography revealed normal right coronary artery and multiple coronary-left ventricular fistulas, arising from the left coronary artery system. A severe myocardial bridge, with total obstruction at the systolic phase, was observed in the mid segment of the LAD (). The FFR measurement was performed to evaluate the hemodynamic consequences, resulting from the myocardial bridge and the fistulas. The FFR value of the LAD was obtained by an intravenous adenosine infusion (140 µg/kg/min). During hyperemia, the FFR value was 0.92 in the LAD, beyond the bridging segment. The pressure pull back tracing showed that the FFR value increased from 0.92 to 0.94 in the segment that was proximal to the bridge (). Notably, the intracoronary systolic pressure overshooting was followed by the abrupt early diastolic pressure gradient in the distal segment beyond the bridge (). Those findings disappeared immediately after the sensor proceeded through the bridging segment into the proximal segment of the LAD with a pull-back maneuver. The multiplicity of the fistulas and the lack of evidence of ischemia, we concurred to manage the patient medically.