Maternal hyperoxygenation and foetal cardiac MRI in the assessment of the borderline left ventricle.

Using phase-contrast MRI in a foetus with borderline left ventricular hypoplasia at 37 weeks' gestation we showed an increase in pulmonary blood flow during maternal hyperoxygenation. The associated increase in venous return to the left atrium, however, resulted in reversal of the atrial shunt, with no improvement in left ventricular output. The child initially underwent single ventricle palliation with a neonatal hybrid procedure, but following postnatal growth of the left ventricle tolerated conversion to a biventricular circulation at 5 months of age. We conclude that when there is significant restriction of filling or outflow obstruction across the left heart, neither prenatal nor postnatal acute pulmonary vasodilation can augment left ventricular output enough to support a biventricular circulation. Chronic pulmonary vasodilation may stimulate the growth of the left-sided structures allowing biventricular repair, raising the intriguing question of whether chronic maternal oxygen therapy might obviate the need for neonatal single ventricle pallation in the setting of borderline left ventricular hypoplasia.

The assessment of atrial function in single ventricle hearts from birth to Fontan: a speckle-tracking study by using strain and strain rate.

BACKGROUND: Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques. METHODS: A cross-sectional study of 81 patients with SV (1 day to 6.5 years) at 4 stages of surgical palliation (presurgery, 22; prebidirectional cavopulmonary anastomosis, 23; pre-Fontan, 22; post-Fontan, 14). The dominant atrium was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; strain rate (SR); and εact/εres ratio before each stage of surgical palliation. Findings were compared with the left atrium of 51 healthy children (1 day to 5.5 years). RESULTS: Single ventricle atrial size was increased (P < .01), and atrial εres was decreased (P < .01) compared with healthy controls. SV atrial εcon (P < .01) and SRcon (P < .0001) was decreased, increased εact persisted (P < .05), and εact/εres was increased (P < .001) between surgical stages. Although the expected maturational trend of increasing εcon, decreasing εact, and εact/εres occurred in SV, they lagged behind healthy maturational changes (P < .0001). CONCLUSION: Single ventricle atrium is dilated, has deceased compliance, decreased early diastolic emptying, and increased reliance on active atrial contraction for ventricular filling. This deviates from normal early childhood maturational changes and appears to parallel those of an atrium facing early ventricular diastolic dysfunction.

Role of four-dimensional ultrasound (spatiotemporal image correlation and sonography-based automated volume count) in prenatal assessment of atrial morphology in cardiosplenic syndromes.

OBJECTIVE: To assess the diagnostic role of four-dimensional ultrasound using spatiotemporal image correlation and Sonography-based Automated Volume Count (STIC-SonoAVC) in the identification of the morphology of the atrial appendages in cases with cardiosplenic syndrome. METHODS: This was a retrospective investigation of 22 fetuses with cardiosplenic syndromes seen at our institution over a 5-year period from January 2004. As control groups, 10 normal fetuses, five cases with a non-isomeric atrioventricular septal defect and five cases with other congenital heart diseases were also analyzed. For all fetuses, one or more cardiac volume datasets were available for offline analysis. Two-dimensional and four-dimensional echocardiography was carried out in all cases at the time of diagnosis using high quality three-dimensional equipment. Dedicated software was used to assess chamber morphology using the SonoAVC technique, which allows the creation of casts of hollow structures. Two different operators used the software. The first performed all steps up to positioning of the region of interest box. The second operator, who was blinded to clinical information, then rendered the cardiac chambers using the SonoAVC technique. This operator then used the rendered image to subjectively assess atrial morphology. RESULTS: Suitable rendered images of the cardiac chambers could be produced in 40/42 fetuses. In two cases of left atrial isomerism, advanced (34 weeks) and early (13 weeks) gestational age made it impossible to obtain adequate rendered images. In the remaining 40 cases (13 cases of left atrial isomerism, seven cases of right atrial isomerism, five cases of non-isomeric atrioventricular septal defect, five cases of other congenital heart diseases and 10 normal fetuses), atrial morphology was correctly identified by evaluation of the rendered images. CONCLUSION: Four-dimensional ultrasound with SonoAVC rendering allows correct identification of the morphology of atrial appendages in all cases of cardiosplenic syndromes in which an adequate cardiac volume dataset can be obtained for analysis.

Rare variation in partial anomalous venous drainage in 2 cases: diagnosis, assessment methods, and surgical approach.

Where pulmonary veins drain and their relationship with an atrial septal defect (ASD) are important. A sinus venosus (high venosum) type of defect is the most common pathology accompanying partial anomalous pulmonary venous connection. Typically, the right superior pulmonary vein and occasionally the middle pulmonary vein drain into the junction of the superior vena cava (SVC) and the right atrium (RA), and a sinus venosus type of ASD usually accompanies these anomalies. In this report, we assess a very rare pathology in which 3 right pulmonary veins (superior, middle, and inferior) drain into the SVC-RA junction with respect to diagnostic methods and in the light of 2 cases involving patients in 2 different age groups.

Cardiac CT assessment of left atrial accessory appendages and diverticula.

OBJECTIVE: The purpose of this study is to describe the prevalence, morphology, size, and location of left atrial abnormalities including diverticula and accessory appendages in consecutive patients undergoing cardiac-gated CT for coronary artery evaluation. MATERIALS AND METHODS: Routine retrospectively gated contrast-enhanced 64-MDCT angiography (0.75-mm collimation, 330-milliseconds gantry rotation time) was performed in 529 consecutive patients. CT data sets were evaluated using axial, sagittal, coronal, and interactive multiplanar reconstructions; maximum intensity projections (MIPs); and interactive volume rendering. The presence, type, and location of left atrial appendages and diverticula were recorded. RESULTS: One hundred twenty-one patients had left atrial accessory appendages (n = 20) or left atrial diverticula (n = 81) or both (n = 20). One hundred four left atrial diverticula were found in 101 of the 529 patients (20%) and 44 accessory appendages in 41 patients (8%). Of the atrial diverticula, 88% were superior and anterior, 9% were right lateral superior, and 3% were inferior. Of accessory appendages, 34% were inferior posterior, 32% were left inferior, 18% were superior anterior, 14% were inferior posterior, and 2% were right inferior posterior. The average sizes of diverticula were 6.4 +/- 2.5 x 6.2 +/- 2.4 mm, and accessory appendages were 4.9 +/- 2.1 x 3.9 +/- 2.4 mm. CONCLUSION: Left atrial diverticula and accessory appendages are commonly found on cardiac-gated CT.

Three-dimensional echocardiographic assessment of acquired left ventricular to right atrial shunt (Gerbode defect).

A 60-year-old man was readmitted 1 year after bioprosthetic aortic valve replacement for recurrent endocarditis. Transthoracic 2-dimensional color Doppler revealed a novel finding of a left-to-right shunt from the left ventricular outflow tract to the right atrium immediately superior to the septal leaflet of the tricuspid valve consistent with an acquired Gerbode defect. Real-time 3-dimensional echocardiography was used to accurately delineate the course of the shunt. To avoid overestimating right ventricular systolic pressure by mistaking such a shunt for an eccentric jet of tricuspid regurgitation, it is important to accurately differentiate the two. Real-time 3-dimensional echocardiography now provides rapid, detailed 3-dimensional appreciation of the origin and course of such shunts with easy facility of orienting views to the flows of interest by cropping. Such information can help design optimal surgical or catheter-based therapy.

Assessment of intracardiac anomalies in two adults with Ivemark's syndrome.

Ivemark's syndrome consists of intracardiac anomalies, abnormal lobation of the lungs, and abdominal heterotaxy. A frequent intracardiac anomaly seen in Ivemark's syndrome is a common atrium, which is associated with left-to-right shunting. The increased blood flow and resistance within the pulmonary vasculature creates pulmonary hypertension and eventual reversal of the shunt physiology. In the absence of additional cyanotic malformations, survival into adulthood without prior surgical septation of the common atrium depends on the extent of pulmonary hypertension and intracardiac right-to-left shunting. We present two patients with a common atrium in the setting of Ivemark's syndrome who survived into adulthood without prior operation. Two-dimensional echocardiography assessed their intracardiac structures. One patient had right atrial isomerism manifested by asplenia and a common atrium, into which the hepatic veins drained directly, and the other patient had left atrial isomerism manifested by polysplenia, a common atrium, and a ventricular septal defect with a single atrioventricular valve. Neither patient had additional cyanotic malformations, including obstruction to pulmonary venous return, transposition of the great vessels, or pulmonic valve stenosis. The 2-dimensional echocardiogram guides the clinician to refer patients for surgical septation of the common atrium before the right-to-left shunt physiology predominates. The medical and surgical treatment of these patients is discussed.

Diagnostic assessment before Fontan operation in patients with bidirectional cavopulmonary anastomosis: are noninvasive methods sufficient?

OBJECTIVES: This study was designed to determine if a subset of patients who have undergone bidirectional cavopulmonary anastomosis could be identified in which catheterization was of little benefit before completion of the Fontan procedure. BACKGROUND: Diagnostic evaluation before Fontan procedure has typically included cardiac catheterization. However, the overall management strategy for patients with functional single ventricle has evolved to include staging bidirectional cavopulmonary anastomosis in most, and it has become uncommon to exclude patients from Fontan based on catheterization data. METHODS: Patients who underwent bidirectional cavopulmonary anastomosis and had complete echocardiograms and catheterizations within three months of each other between January 1992 and October 1997 were evaluated with a series of clinical and echocardiographic characteristics to identify a subset in whom catheterization was predicted to be of little added value ("no-cath" group). The predictive value and sensitivity of these criteria in excluding patients who required additional intervention, were excluded from Fontan, or died within 30 days of Fontan was determined. RESULTS: A total of 99 patients who underwent bidirectional cavopulmonary anastomosis at 6.7 months (range 2.9 months to 14 years) were studied; 46 met criteria for the "no-cath" group. Noninvasive criteria stratified all patients who died (n = 5) or did not proceed to Fontan (n = 1) and 9 of 11 who required additional interventions to the "cath" group. Thus, the negative predictive value of these criteria was 93%. CONCLUSIONS: Our data suggest that catheterization before Fontan could be avoided in a large percentage of patients without adversely affecting outcome; prospective evaluation of this strategy is warranted.

Comparative assessment of Fontan operation in modifications of atriopulmonary and total cavopulmonary anastomoses.

OBJECTIVES: The optimal technique of the Fontan operation remains disputable. This investigation was aimed at the comparison of atriopulmonary and total cavopulmonary anastomoses. METHODS: The results of 81 operations of total cavopulmonary and 69 operations of atriopulmonary anastomosis, performed from 1983 to 1995 were analysed. A control study was carried out 1-10 (3.7 + 0.2) years after the operation in 80 patients (36 after total cavopulmonary and 44 after atriopulmonary anastomoses). 70 patients were studied several times. Cardiac catheterization was done in 70 patients. In 78 patients central hemodynamical indices were studied during exercise. RESULTS: Preoperative hemodynamical indices were not reliably different in the two groups. Early mortality after total cavopulmonary anastomosis was 15%, after atriopulmonary anastomosis 23%. The highest mortality was seen when the criteria of Choussat et al. (Choussat et al. Pediatric Cardiology. Edinburgh: 1977:559-566) were surpassed. In the early postoperative period after total cavopulmonary anastomosis circulatory insufficiency was less marked, transsudation from pleural cavities was reliably lower (15.3 + 1.2 versus 25.5 + 1.8 ml/kg/day, P < 0.01). Arrhythmias were more common after total cavopulmonary anastomosis (18.5 versus 12%). Late mortality after total cavopulmonary anastomosis was 6%, after atriopulmonary anastomosis 12%. 82% of patients after atriopulmonary anastomosis and 81% after total cavopulmonary anastomosis were in NYHA classes 1 and 2.7% of patients after total cavopulmonary anastomosis and 11% after atriopulmonary anastomosis were reoperated. Physical tolerance rose stepwise in both groups and by the third post-operative year reached 75% of normal level. At this time we saw the most optimal hemodynamical indices during exercise. However, the best hemodynamics during exercise were seen after atriopulmonary anastomosis. CONCLUSIONS: Total cavopulmonary anastomosis is accompanied by lower mortality rate and a more favourable course of early postoperative period. However, the best long-term functional results are obtained after atriopulmonary anastomosis.

The spectrum of left ventricular-right atrial communications in the adult: essentials of echocardiographic assessment.

Left ventricular-right atrial communication may be a congenital defect or can result from trauma, endocarditis, or valve replacement. Traditionally the preoperative diagnosis of this entity was made during cardiac catheterization, but recent advances in echocardiography, particularly color Doppler imaging, have greatly facilitated the noninvasive diagnosis of left ventricular-right atrial communication. We present four cases of left ventricular-right atrial communication, each identified by two-dimensional and color Doppler imaging. One case is a congenital defect, two were identified years after cardiac surgery, and one presents as an unusual complication of myocardial infarction. Optimal views for identifying this defect are discussed along with clues to quantifying its hemodynamic significance.

Usefulness of magnetic resonance imaging in the assessment of venoatrial connections, atrial morphology, bronchial situs, and other anomalies in right atrial isomerism.

Multiple complex venous and intracardiac anomalies are frequently seen in patients with right atrial isomerism, and complete anatomic information may not always be obtained from combined echocardiography and angiography. Twenty patients with right atrial isomerism were prospectively studied with use of magnetic resonance imaging (MRI); satisfactory imaging was obtained in 18 patients, aged 6 days to 12 years (median 3 months). All patients had undergone echocardiography, cardiac catheterization, and angiocardiography. The purpose of this study was to assess the usefulness of MRI in the evaluation of venoatrial connections, atrial morphology, bronchial situs, and additional anomalies. Bilateral superior venae cavae were documented in 12 patients and anomalous hepatic venous drainage in 11. The pulmonary venous system was imaged in all 18 patients, of whom 12 had total anomalous pulmonary venous connection: 9 supracardiac, 2 infracardiac, and 1 mixed type. Some obstruction to pulmonary venous return was present in 9 of the 12 patients, and the site of obstruction was demonstrated by MRI in 6. Bilateral morphologic right atrial appendages were imaged in 7 patients. Bilateral morphologic right bronchi were identified in 17 patients, asplenia was confirmed in 17 of 18 patients by the absence of splenic tissue on imaging, and hiatal hernia was imaged in 4. Compared with angiography and echocardiography, MRI more clearly defined the pulmonary venous connections in 10 patients with pulmonary venous obstruction. Anomalous hepatic venous connections were better defined by MRI in 2. Therefore, MRI provided valuable supplementary information on the cardiovascular and visceral anomalies in these patients.

[Assessment of long-term systemic ventricular function after the surgical repair in patients with atrioventricular discordance].

Long-term systemic ventricular function at rest and during supine bicycle exercise was studied in 12 patients with atrioventricular discordance (AVD group) using multigated radionuclide blood pool imaging. For comparison, similar measurements were made in eight children (control group). The mean age at the exercise test was 12.3 years in AVD group and was 14.8 years in the control group. In AVD group, ages at the operation ranged from three to 21 years (mean 12.3 years), and the exercise test was performed from one to 9.8 years after the operation (mean 5.3 years). The operative procedures in AVD group consisted of closure of the ventricular septal defect in 11 patients, extracardiac conduit between the left ventricle and the pulmonary artery in nine patients, postero-lateral left ventricular outflow reconstruction in two patients, tricuspid annuloplasty in one patient, and tricuspid valve replacement in one patient. Exercise tolerance of AVD group was less than that of the control group. Heart rate and blood pressure were significantly increased during exercise in both groups. In the control group, end-diastolic count index (EDCI) (= end-diastolic volume) remained unchanged and end-systolic count index (ESCI) (= end-systolic volume) decreased during exercise. In contrast, both EDCI and ESCI were decreased in AVD group. As a consequence, systemic right ventricular ejection fraction (RVEF) increased during exercise in the control group, but remained unchanged in AVD group. Although stroke count index (SCI) (= stroke volume index) did not increased during exercise in AVD group, output count index (OCI) (= cardiac index) increased with the increase of heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

The assessment of juxtaposed atrial appendages by transoesophageal echocardiography.

As part of a prospective study into the diagnostic role of transoesophageal echocardiography in children with complex congenital heart disease, the atrial morphology was assessed in 62 children. Using the direct visualization of atrial appendage morphology, 58 were shown to have usual atrial arrangement, two were documented to have isomerism of the right and two isomerism of the left appendages. Of those with usual arrangement, four children were demonstrated to have left juxtaposition of the atrial appendages. Only two of these patients were identified during praecordial echocardiographic re-evaluation, and three on angiocardiographic examination. Surgical confirmation was obtained in three, and juxtaposition was excluded in the remaining cases. The transoesophageal cross-sectional imaging features of left juxtaposition of the atrial appendages are unique and readily diagnostic of this entity. They include, first, a lateral deviation of the acid-portion of the atrial septum and, second, a frontal orientation of the antero-superior portion forming the floor and the posterior wall of the junction of the right-sided atrial appendage with the venous component of the atrial cavity. The knowledge of these morphologic characteristics is important, as, otherwise, this malformation may be misinterpreted as representing an atrial septal defect. The results suggest that transoesophageal echocardiography will be the most sensitive preoperative diagnostic technique in detecting or excluding juxtaposed atrial appendages.

Cross-sectional echocardiographic assessment of conditions with atrioventricular valve leaflets attached to the atrial septum at the same level.

Ninety two patients with both atrioventricular valves attached to the atrial septum, roofing a perimembranous inlet ventricular septal defect, were assessed by cross-sectional echocardiography. In the group, 42 had an isolated perimembranous inlet ventricular septal defect, 31 had atrioventricular discordance, nine an atrioventricular septal defect with intact interatrial septum, and 10 a straddling atrioventricular valve. In all but those with an atrioventricular septal defect the left atrioventricular valve had the appearance of a morphologically mitral valve. In the former lesion the atrioventricular junction was "sprung" and a cleft between the anterior and posterior bridging leaflets was identified in all. A straddling valve was identified by tensor apparatus from one atrioventricular valve in both ventricular chambers. Atrioventricular discordance was diagnosed by identifying the systemic and pulmonary venous atria and then assessing the morphology of the draining atrioventricular valves. Thus, with cross-sectional echocardiography, the constellation of abnormalities that give rise to lack of offsetting of the atrioventricular valves can be reliably identified.