Prenatal diagnosis of congenital left ventricular aneurysm by four-dimensional ultrasonography with spatio-temporal image correlation (STIC) [1]
Journal
Ultrasound in Obstetrics and Gynecology
Journal Volume
28
Journal Issue
3
Pages
345-347
Date Issued
2006
Author(s)
Abstract
Four-dimensional (4D) ultrasonography with spatio-temporal image correlation (STIC) provides a novel method of examining the fetal heart in a dynamic and multidirectional way. We present a case of congenital ventricular aneurysm diagnosed using this technology. A 30-year-old woman, gravida 2, para 0, with an uneventful pregnancy until 34 weeks' gestation, was referred to our institute following sonographic detection of fetal cardiomegaly. Fetal echocardiography with a segmental approach revealed cardiomegaly with enlargement of the left ventricle and focal thinning of the myocardium over the apex (Figure 1). The other cardiac structures appeared normal. To investigate the left ventricular dimensions throughout the cardiac cycle, volume data sets were acquired by STIC with a Voluson 730 Expert ultrasound system (General Electric Medical Systems, Milwaukee, WI, USA). The center of the scanning volume was placed at the conventional apical four-chamber view. The acquisition time and angle were set at 15 s and 30°, respectively. The multislice mode revealed a left ventricular aneurysm behind the right ventricle. The inversion mode was applied to render the cardiac chambers. In the anteroposterior projection, only ventricular asymmetry was seen (Figure 2a). However, a large aneurysm arising from the left ventricular apex with a wide-based communication was evident and was particularly noticeable when the data set was rotated ± 45° from the anteroposterior projection (Figure 2, b–d). The geometric shape of the left ventricular appendage altered during the systolic and diastolic phases, and the wall of the cystic lesion was hypokinetic compared to the rest of the ventricle. Following spontaneous onset of labor at 39 weeks, a term male weighing 3520 g and with good Apgar scores was delivered. Postnatal echocardiography showed a dilated left ventricle with an aneurysm of the ventricular apex and good left ventricle contractility. The boy was treated conservatively and, at the time of writing, had been healthy for a year. The four-chamber view at 34 weeks' gestation shows cardiomegaly with enlargement of the left ventricle. *The normal myocardium of the left ventricle. Arrows, focal thinning of the myocardium over the apex of the left ventricle. Inversion-mode rendered STIC images. (a) Ventricular asymmetry in the anteroposterior projection. (b) A large aneurysm arising from the apex of the left ventricle in the right lateral view. (c, d) The change in size of the aneurysm during various cardiac phases in left oblique view rotating 45° from anteroposterior projection. Arrows indicate the location of the left ventricular apical aneurysm. *The location of moderator bands of the right ventricle. RL, right lateral view; LO, left oblique view; S, the end of the systolic phase; D, the end of the diastolic phase; RA, right atrium; RV, right ventricle; LA, left atrium; LV, left ventricle. Congenital ventricular aneurysm is a rare condition characterized by protrusion or out-pouching of the ventricular wall, especially of the left ventricle1. It has a prevalence of about 1 in 200 000 births with equal distribution between the sexes2, 3. The etiology is unknown, but several theories have been proposed2-5. Surgical correction has been confined to symptomatic cases, while conservative treatment is used for asymptomatic cases3, 5, 6. The prognosis varies, ranging from no symptoms to heart failure. In previous reports1-7 (Table 1), the diagnosis depended mainly on the demonstration of a protruding cystic lesion from the ventricle. In our case the aneurysm was caudal to the four-chamber view and could not be clearly revealed using a conventional approach. The most important advantage of STIC is its ability to examine carefully the anatomy of the fetal heart in almost any plane8, 9. The wide-based cystic protrusion that was obscured by the right ventricle in the conventional view could be identified from the apex of the left ventricle using STIC technology. Though it has the advantage of being highly sensitive to low-flow rates, 3D power Doppler has the inherent problem of overwhelming noise during cardiac scanning. Since the flow in the aneurismal left ventricle in our case was almost parallel to the probe, it was not demonstrable by 4D STIC color acquisition. The inversion mode appeared to render the geometric contour of the cardiac chambers precisely10, and demonstrated the characteristic hypokinetic motion of the protruding lesion. To our knowledge this is the first case of ventricular aneurysm diagnosed with STIC technology to date. The author sincerely appreciates the great technical assistances of Mr Guenther Hinterleitner from GE Healthcare of Asia, and Miss Tracy Lu from Medsun Company of Taiwan. Y.-C. Chiang* , C.-K. Yang , J.-C. Shih* , C.-N. Lee* , * Department of Obstetrics and Gynecology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan, National Taiwan University College of Medicine, Taipei Buddhist Tzu Chi General Hospital, Taipei, Taiwan, Department of Obstetrics and Gynecology, Taipei Buddhist Tzu Chi General Hospital, Taipei, Taiwan
SDGs
Type
letter