Transesophageal echocardiographic evaluation of aortic valve integrity with antegrade crystalloid cardioplegic solution used as an imaging agent

Forceful intravascular injection of crystalloid causes microbubble (cavitation) formation. The resulting ultrasound-opaque medium is widely used in echocardiography as a source of contrast The following study was performed to determine the feasibility of using antegrade crystalloid cardioplegic solution as a transesophageal two-dimensional echocardiographic imaging agent to evaluate aortic valve integrity. In patients with preexisting aortic regurgitation (n = 12), cardioplegic solution administration (driving pressure 150 to 200 mm Hg) was associated with the appearance of intracardiac cavitations in 12 of 12 patients. Among patients without preexisting valve dysfunction (n = 22), intracardiac cavitations were manifested in 20 of 22, with extension of the cavitations to the left atrium in 17. Associated cardiac dimensions (left ventricular outflow tract area and left ventricular diameter) did not exceed preceding cardiopulmonary bypass values in these patients (2.0 ± 1.6 cm2 versus 2.6 ± 1.2 cm2 and 1.4 ± 0.7 cm versus 1.5 ± 0.8 cm, respectively). It was concluded that antegrade crystalloid cardioplegic solution can be used as an echocardiographic contrast agent in this context The inability to establish a relationship between the extent of cardioplegic intracardiac penetration and left ventricular dimensional changes limits the technique, as presently employed, to qualitative analysis of valve dysfunction. (J Thorac Cardiovasc Surg 1992;104:637-41)