Every catheter laboratory is equipped with an X-ray system designed to provide fluoroscopic imaging of the heart. Although cardiac catheters are well visualized in all X-ray imaging, the soft tissue of myocardium is not. Therefore the imaging of the cardiac chambers is indirect through relation to the cardiac silhouette. However, fluoroscopy can be used to detect complications from the invasive procedures in the cardiac catheterization laboratory, such as cardiac tamponade where the excursion of the cardiac silhouette decreases, and visceral and parietal pericardium are seen separated by the blood of accumulation in the pericardial cavity. Even if a transthoracic or intracardiac echocardiography guidance is immediately available, early fluoroscopic detection of tamponade should be remembered during the invasive procedures in the cardiac catheterization laboratory.