Echocardiography of primitive ventricle

Double-inlet single left ventricle: echocardiographic anatomy with emphasis on the morphology of the atrioventricular valves and ventricular septal defect

The echocardiographic anatomy of double-inlet single left ventricle was studied in 57 patients, aged 1 day to 27 years (mean 6 years); the variables examined included morphology, size and function of the atrioventricular (AV) valves and ventricular septal defect and their relation to pulmonary stenosis, aortic stenosis and aortic arch obstruction. The visceroatrial situs was solitus and the heart was in the left side of the chest in all 57 patients. A d-loop ventricle was present in 21 patients and an l-loop ventricle in 36. The great arteries were normally related (Holmes heart) in 8 patients and transposed in 49. In all hearts, the right AV valve was anterior to the left AV valve. In 53 patients, the tricuspid valve (right valve in d-loop and left valve in l-loop) was closer to and had attachments on the septum. The tricuspid valve straddled the outflow chamber in eight patients. No significant difference was noted in the mean AV valve diameter when comparing mitral and tricuspid valves within the same group or between the groups with a d- or l-loop ventricle. The right AV valve diameter had a significant direct correlation with the aortic valve diameter and the size of the ventricular septal defect regardless of ventricular loop. Both AV valves were functionally normal in 34 patients. Among patients with AV valve dysfunction, the tricuspid valve tended to be stenotic in patients with an l-loop ventricle and regurgitant in patients with a d-loop ventricle. Mitral valve dysfunction was uncommon. The ventricular septal defect (46 patients) was separated from the semilunar valves in 24 patients (muscular defect) and adjacent to the anterior semilunar valve as a result of hypoplasia or malalignment, or both, of the infundibular septum (subaortic defect) in 19 patients. Multiple defects were present in three patients. The defect was unrestrictive in 26 patients, restrictive in 23 and could not be evaluated in 8. Pulmonary artery banding had been performed in 8 of the 26 patients with an unrestrictive defect and in 10 of the 23 patients with a restrictive defect. Only 4 of 19 subaortic defects compared with 16 of 24 muscular defects were restrictive. The size of the defect was significantly correlated with the measured pressure gradient. Among patients with transposition, only 2 of 13 with pulmonary stenosis had a restrictive ventricular septal defect compared with 15 of 30 without pulmonary stenosis. In patients with transposition, the defect size was significantly smaller when coarctation was present.

Common atrioventricular valve guarding double inlet atrioventricular connexion: natural history and surgical results in 76 cases

We describe 76 patients in whom a double inlet atrioventricular connexion was guarded by a common atrioventricular valve. The atriums were connected to a dominant right ventricle in 42, to a left ventricle in 29 and to a solitary indeterminate ventricle in 5. The most common atrial arrangement was isomerism of the right atrial appendages, seen in 46% (35/76). Of these, there was associated anomalous pulmonary venous connexion in 72% and absence of the spleen in 63%. Double outlet right ventricle was the most frequent ventriculoarterial connexion, present in 37 cases. Abnormal atrioventricular valvar function could already be detected in 46% of cases at the time of initial presentation. A decrease of function was observed in 18 patients, in 14 of them 2 weeks to 16 years (mean 5.7 years) after palliative surgery. The majority of the palliative procedures were constructions of shunts, since 75% (57/76) of the patients showed obstruction to flow of pulmonary blood. Patients with double inlet ventricle guarded by a common atrioventricular valve have a high early mortality (37% died in the neonatal period). Management should be designed to protect the integrity of the pulmonary vascular bed. Definitive repair with a Fontan type procedure is the most suitable final approach.

Two-dimensional echocardiographic spectrum of univentricular atrioventricular connection

The spectrum of anomalies in hearts having a univentricular atrioventricular (AV) connection was examined by two-dimensional echocardiography in 183 patients and the anatomic findings were compared with angiography. The mode of AV connection was found to be of three types: double inlet via two AV valves; single inlet via one AV valve with absence of the other (left or right AV valve atresia); and common inlet via a common AV valve. Identification of an accessory chamber by two-dimensional echocardiography was possible with 90% sensitivity, but it was limited compared with angiography in patients with severely hypoplastic anterior chambers and pulmonary valve atresia. All patients with subaortic outlet foramen obstruction were detected. Great artery position and the presence of obstruction to pulmonary flow were correctly predicted in all but one patient. Two-dimensional echocardiography was superior to angiography for the detection of AV valve abnormalities which were present in 27% and included abnormal chordae, hypoplasia or dysplasia of either valve. Two-dimensional echocardiography should play an essential role in the complete preoperative assessment of patients with univentricular AV connection.

The univentricular heart: combined 2-dimensional-pulsed Doppler (duplex) echocardiographic evaluation

Two-dimensional echocardiographic-pulsed Doppler (2D-PD) evaluation was performed in 14 patients with a univentricular heart. Accurate information on ventricular structure, atrioventricular valve status, and great vessel anatomy and function was obtained. The characteristic morphologic features were verified in each case by angiography or autopsy, or both. In several patients, 2D-PD evaluation provided more accurate anatomic and functional information than did cardiac angiography in standard views, particularly with regard to atrioventricular valve function. Four children with pulmonary atresia and 4 with pulmonary stenosis were identified prospectively. No patient had 2D-PD evidence of aortic obstruction. Four children had typical 2D-PD patterns consistent with atrioventricular valve regurgitation. Thus, 2D echocardiography coupled with a range-gated Doppler system will improve recognition of patients with a univentricular heart and permit thorough evaluation of specific anatomic details.

Two dimensional echocardiographic categorisation of the univentricular heart. Ventricular morphology, type, and mode of atrioventricular connection

Most univentricular hearts have two chambers in their ventricular mass, only one of which possesses an atrioventricular connection. Categorisation into univentricular heart of right, left, or indeterminate type, using two dimensional echocardiography has been successfully achieved in 122 out of 132 patients to whom this technique has been applied. Thus, right ventricular rudimentary chambers in 84 univentricular hearts of left ventricular type were shown to be anterosuperior and either to the right or left. In contrast, left ventricular rudimentary chambers in 25 univentricular hearts of right ventricular type were posteroinferior and to the right, left, or directly posterior. Thirteen univentricular hearts of indeterminate morphology were characterised by absence of rudimentary chamber on angiography and echocardiography. The trabecular pattern of both main and rudimentary chambers were separately identified in some of the patients with univentricular hearts of right and left ventricular type and two dimensional echocardiography also illustrated the mode of atrioventricular connection, either via two atrioventricular valves, a common valve, or a valve straddling or overriding the trabecular septum. Finally it was also possible to distinguish absent atrioventricular connection from an imperforate valve in 10 patients.

Detection and assessment of straddling and overriding atrioventricular valves by two dimensional echocardiography

Sixteen patients with a straddling tricuspid and two with a straddling mitral valve were identified by two dimensional echocardiography. In all but one the atrioventricular valves appeared at the same level, indicating absence of the ventriculoatrial septum. A straddling valve was diagnosed by identifying subvalvular apparatus from one atrioventricular valve in both chambers, independent of whether they were ventricles or rudimentary chambers. Further confirmation was obtained during real time study where the valve leaflets appeared to fly through the ventricular septal defect. Overriding of the valve annulus was greater than 50% in 12 and less than 50% in five, with one other patient having none detectable. The relation of the central fibrous body to the tip of the interventricular septum was reliable in assessing overriding of greater than 50%, but where it was less than 50% other views were necessary to detect its presence. The diagnosis of straddling with or without overriding of an atrioventricular valve can be reliably made by two dimensional echocardiography, and carries important implications relating to the type of surgical intervention possible, and in those with a straddling tricuspid valve, the position of the atrioventricular node.

Two-dimensional echocardiographic assessment of common atrioventricular valves in univentricular hearts

Twelve patients with univentricular heart and common atrioventricular valve were identified by two-dimensional echocardiography. Seven had an ostium primum atrial septal defect and five a common atrium. The common atrioventricular valve had the appearance of a free floating anterior leaflet flanked by two lateral leaflets. The position of the rudimentary chamber in relation to the atrioventricular valve was posterior in six and anterior in two; no chamber was identified in four. Two-dimensional echocardiography provides a reliable method for the identification of common atrioventricular valve in univentricular heart.

Nomenclature and classification of congenital heart disease

At present there is no universally accepted nomenclature for congenital cardiac malformations. Much of the controversy results from failure to distinguish the structural connections of the heart from the morphology and spatial relations of its components. The confusion is compounded by an abundance of individual definitions, many of them speculative. The present article proposes a totally descriptive nomenclature. It describes in turn the connections of the cardiac segments, their morphology, their relations, and additional anomalies in any segment. Each step in the segmental approach is discrete. The overall effect is to force a succinct and comprehensive description of any cardiac malformation, no matter how complex.

Diagnosis of ventriculo-arterial discordance (transposition of the great arteries) by contrast echocardiography

The constant anatomical relation of the aortic arch and the pulmonary artery bifurcation permits echocardiographic differentiation of the two great arteries when viewed from the suprasternal notch. When this technique was employed with contrast echocardiography in 12 infants, 6 of whom had ventriculo-arterial discordance (transposition of the great arteries), it was possible to establish with certainty in all but 1 case which great artery was most directly connected to the systemic venous return.