Coronary angiography with 5 French diagnostic catheters may miss an ostial left main stenosis.

Critical ostial left main disease may lead rapidly to sudden death and is, therefore, of paramount importance to diagnose. While the number of cardiac catheterizations is increasing, government and third party reimbursement sources are imposing pressure to perform more studies in an outpatient setting, as the economic resources for medical procedures are shrinking. Outpatient cardiac catheterization requires the patient to ambulate within several hours after the procedure. In order to allow patients to safely ambulate early after their procedures, 5 French catheters are often used (whether the femoral or brachial approach is used) rather than the standard 7 French catheters. We describe a patient with an ostial left main stenosis that was not visualized when coronary arteriography was performed using a diagnostic 5 French catheter. Selective intubation of the left main coronary artery was easily achieved without damping of the pressure tracing. Selective coronary angiography did not demonstrate the ostial stenosis, and there appeared to be a normal amount of contrast refluxing into the aortic root. When the patient returned for an angioplasty and a guiding angiogram was performed with an 8 French catheter, an ostial stenosis was evident with coronary angiography.