Intracardiac echocardiography: Observations in normal and diseased heart

In order to test the feasibility of a newly developed 8 F 10 MHz ultrasound catheter and usefulness of intracardiac echocardiography (ICE) in clinical practice, we conducted this study. From August 1991, 90 patients (pts) (M:38; F:2) received ICE examination. Their ages ranged from 18 to 76 years old (Mean:47). Five pts who had chest pain with normal coronary angiograms were as a control group. 30 pts were severe mitral stenosis. 2 pts had aortic stenosis. 24 pts had congenital heart disease including Ebstein's anomaly 1, pulmonary stenosis 1, atrial septal defect 7, ventricular septal defect 6, patent ductus arteriosus 4, unroofing coronary sinus 1, coronary artery-vein fistula 1, and coarctation of aorta 1.15 pts had coronary artery disease, 2 pts had aortic dissection, 4 pts had pericardial disease, 2 pts had cardiac tumor and 2 pts had cardiomyopathy. Others had pulmonary embolism, Budd-Chiari syndrome and one had aortic valve replacement. The transducer catheter used was 8 F 10 MHz non-over-the wire catheter. The imaging system used was Cardiovascular Imaging System. From our primitive study, we have the following conclusions: 10 MHz transducer catheter is feasible and useful in defining the cardiac structure especially in some rare or special conditions. As a diagnostic modalities, ICE has limited clinical applications in usual diseases. In rare cases such as connection between SVC and right upper vein or unroofing coronary sinus, ICE plays an important and unexpected role in diagnosis. The most useful indications of ICE is in guiding or monitoring invasive interventional procedures. The limited condition is the frequency of the available transducer being too high for whole heart imaging. Development of lower frequency transducer catheter is desirable for better depth penetration.