Assessment of the Helical Ventricular Myocardial Band Using Standard Echocardiography

Background The purpose of this study was to assess the feasibility of morphological and functional evaluation of the helical ventricular myocardial band using standard echocardiographic images. Methods Echocardiographic data were obtained from 132 normal children. We attempted to identify the echogenic bright line serving as the boundary between the ascending and descending segments in the ventricular septum, and between the left and ascending segments in the left ventricular inferior wall in the helical myocardial band model proposed by Torrent-Guasp. Myocardial deformations on both sides of the bright line were compared using speckle tracking echocardiography. Results The bright line separating the ascending from descending segment was visible in the mid-ventricular septum in the four-chamber view in all subjects. This echogenic boundary was observed obliquely in the parasternal short-axis view in 116 subjects (87.9%). There was no significant difference in peak longitudinal or circumferential strain between the ascending and descending segments. However, the time from the QRS onset to peak circumferential strain was significantly lower in the descending than ascending segment (394.5 ± 37.0 vs. 432.7 ± 33.1 ms, P < 0.0001), whereas there was no significant difference in the time to peak longitudinal strain (394.4 ± 26.4 vs. 393.2 ± 24.1 ms). The bright line between the left and ascending segment was detected in the short-axis view from the subcostal region in 86 subjects (65.2%). The time to peak circumferential strain was significantly lower in the left than ascending segment (380.1 ± 32.0 vs. 435.7 ± 37.9 ms, P < 0.0001). Conclusion There is a helical ventricular myocardial band that can be observed in standard echocardiographic images.