Localization of Ventricular Septal Defects Using a Simultaneous Color Doppler and Cross-Sectional Echocardiographic Display

Abstract

Precise noninvasive ultrasonic localization of the site of a small ventricular septal defect can often be difficult, particularly within the trabecular septum [1–3]. There remains a sizeable number of patients in whom the diagnosis of ventricular septal defect is based solely on clinical findings, such as the character and location of the systolic murmur. This study aimed to determine if a diagnosis could be improved by the detection of transseptal blood flow in patients with small ventricular septal defects by using a new color-coded Doppler system (Aloka SSD-880). This scanner encodes the direction of blood flow in terms of color, and it instantaneously superimposes this information in real time across a standard cross-sectional echocardiographic display. This system has already been proven useful in assessing acquired valvular diseases, particularly regurgitation [4, 5]. The emitting frequency used was 2.5 or 3.5 MHz as appropriate. Real time signals were stored by using a Sony SLO-420 Betamax videotape recorder; later, they were transferred to a Sony U-matic format. Color Doppler images were studied in detail by replay either at normal speed or in slow motion, as required.