Real‐Time, Intracardiac, Two‐Dimensional Echocardiography

Abstract

Advances in catheter-based ultrasound imaging technology allow for a unique opportunity to develop two-dimensional intracardiac echocardiography, an imaging method that could have significant clinical applications. In this study, we evaluated the potential of a new, percutaneous, 9-Fr prototype intracardiac echocardiographic catheter with a 12.5-MHz rotating crystal in 13 dogs. In all dogs, we were able to easily advance the intracardiac echocardiographic catheter into the right and left hearts percutaneously and obtain dynamic images of cardiac structures in various imaging planes. With the intracardiac echocardiographic catheter in the right atrium, the whole chamber could be visualized. Minor manipulation allowed visualization of the right atrium, right ventricle, and tricuspid valve in a two-chamber view; further maneuvering yielded four-chamber views. With advancement of the catheter into the right ventricle and pulmonary artery, the right ventricular cavity, right ventricular outflow tract, and pulmonary artery could be imaged. The intracardiac echocardiographic catheter in the aortic root allowed visualization of the pulmonary artery and its bifurcation, superior portions of the atria, interatrial septum, aortic valve, and the proximal left coronary artery. With the intracardiac echocardiographic catheter in the left ventricle, short-axis images of the whole left ventricle were obtained. Manipulating the catheter tip within the left ventricle, we could visualize the left ventricle, left atrium (LA), and the mitral valve in the long axis. We were also able to visualize and identify experimentally-induced ischemic regional left ventricular dyskinesis (four of of five dogs), aortic valvular tear (five out of five dogs), and pericardial effusion with right atrial collapse (two out of two dogs). Intracardiac echocardiography was not associated with any complications. We conclude that percutaneous, low-frequency intracardiac echocardiography with a 12.5-MHz, 9-Fr catheter yields cardiac images in many imaging planes with a good depth of field, allows identification of valvular, myocardial, and pericardial abnormalities, and has excellent clinical potential in the assessment of many cardiovascular disorders.

Intracardiac echocardiography: current developments

“…To explore the potential of ICE using relatively lower frequency ultrasound catheters, we employed a mechanically rotating 12.5 MHz ultrasound catheter in animals and humans [48][49][50]. The ultrasound catheter we used is a prototype device (Son- icath, Boston Scientific Corp., Watertown, Massachusetts) that consists of an outer 9F or 6F disposable catheter enclosing a mechanically rotatable driveshaft with the ultrasound crystal at its tip.…”

Cardiac computed tomography angiography for assessment of endothelial insufficiency of left atrial appendage disc‐like occluder

“…In TEE, the blood flow from the periphery of the occluder to the residual cavity of the LAA can be observed. 4 In patients with EIS, blood flow can be observed only in the residual cavity of the LAA; it cannot be observed at the periphery of the occluder. However, some patients cannot tolerate the TEE examination because it takes a long time to perform and is associated with a risk of esophageal damage.…”

“…The traditional method for differentiating between EIS and PDL is transesophageal echocardiography (TEE). In TEE, the blood flow from the periphery of the occluder to the residual cavity of the LAA can be observed 4 . In patients with EIS, blood flow can be observed only in the residual cavity of the LAA; it cannot be observed at the periphery of the occluder.…”