Michael J. Godman

Transesophageal echocardiographic monitoring of interventional cardiac catheterization in children

Transesophageal echocardiography was used prospectively in 22 children scheduled for interventional cardiac catheterization (9 with pulmonary valvuloplasty, 5 with aortic valvuloplasty, 1 with pulmonary angioplasty, 2 with aortic angioplasty, 2 with patent ductus arteriosus occlusion and 3 with Mustard baffle dilation) to determine its potential value as a monitoring technique. The patients ranged in age from 0.9 to 14.6 years (mean 5.4) and in weight from 9.5 to 49.2 kg (mean 21.1). Studies were completed in all patients without complications. Preintervention studies provided important new information in two patients, leading to cancellation of the planned procedure. Major contributions of transesophageal monitoring included 1) a real time assessment of catheter placement across either atrioventricular valve and the aortic valve during balloon valvuloplasty; 2) immediate assessment of aortic valve and aortic wall morphology during balloon dilation; and 3) detailed morphologic and hemodynamic information together with enhanced catheter guidance during Mustard baffle dilation. After pulmonary valvuloplasty, partial chordal rupture of the tricuspid valve was documented in one patient. In two patients, balloon catheter position was modified according to the transesophageal findings. The assessment of changes in pulmonary valve morphology and transcatheter occlusion of a patent ductus arteriosus was not enhanced by single-plane transesophageal monitoring. Pulsed wave Doppler studies contributed additional information in the assessment of immediate hemodynamic changes after interventional procedures. Transesophageal echocardiography is a new important guiding and monitoring technique during interventional cardiac catheterization procedures in children. It can provide additional real time imaging information, immediate identification of complications and assessment of hemodynamic changes.

Assessment of atrial septal defect morphology by transthoracic three dimensional echocardiography using standard grey scale and Doppler myocardial imaging techniques: comparison with magnetic resonance imaging and intraoperative findings

Objective To determine whether transthoracic three dimensional echocardiography is an accurate non-invasive technique for defining the morphology of atrial septal defects (ASD). Methods In 34 patients with secundum ASD, mean (SD) age 20 (17) years (14 male, 20 female), the measurements obtained from three dimensional echocardiography were compared to those obtained from magnetic resonance imaging (MRI) or surgery. Three dimensional images were constructed to simulate the ASD view as seen by a surgeon. Measured variables were: maximum and minimum vertical and horizontal ASD dimension, and distances to inferior and superior vena cava, coronary sinus, and tricuspid valve. In each patient two ultrasound techniques were used to acquire three dimensional data: standard grey scale imaging (GSI) and Doppler myocardial imaging (DMI). Results Good correlation was found in maximum ASD dimension (both horizontal and vertical) between three dimensional echocardiography and both MRI (GSI r = 0.96, SEE = 0.05 cm; DMI r = 0.97, SEE = 0.04 cm) and surgery (GSI r= 0.92, SEE = 0.06 cm; DMI r = 0.95, SEE = 0.06 cm). The systematic error was similar for both three dimensional techniques when compared to both MRI (GSI = 0.40 cm (27%); DMI = 0.38 cm (25%)) and surgery (GSI = 0.50 cm (29%); DMI = 0.37 cm (22%)). A significant difference was found in both horizontal and vertical ASD dimension changes during the cardiac cycle. This change was inversely correlated with age. These findings were consistent for both DMI and GSI technique. In children (age ⩽ 17 years), the feasibility of detecting structures and undertaking measurements was similar for both echo techniques. However, in adult ASD patients (age ⩾ 18 years) this feasibility was higher for DMI than for GSI. Conclusions Transthoracic three dimensional imaging using both GSI and DMI accurately displayed the varying morphology, dimensions, and spatial relations of ASD. However, DMI was a more effective technique than GSI in describing ASD morphology in adults.

Comparative values of the precordial and transesophageal approaches in the echocardiographic evaluation of atrial baffle function after an atrial correction procedure

Previous methods used to assess atrial baffle function after correction of transposition of the great arteries have included precordial echocardiography and cardiac catheterization. To evaluate whether single plane transesophageal echocardiography might provide additional information, its findings were correlated with information derived from both precordial echocardiography and cardiac catheterization in 15 patients (14 Mustard procedures, 1 Senning procedure) aged 4.2 to 33 years (mean 16.3). Precordial ultrasound with combined imaging, color flow mapping and pulsed Doppler ultrasound visualized the supramitral portion of the common systemic venous atrium in every case but could identify only superior limb obstruction in three of six patients, mid-baffle obstruction in zero of two and inferior limb obstruction in zero of two patients. Transesophageal studies with use of the same range of ultrasound methods demonstrated superior limb obstruction (severe in four, mild in two) in six of six patients, mid-baffle obstruction in two of two and inferior limb obstruction in two of two patients. The entire pulmonary venous atrium was equally well interrogated by either ultrasound approach, with both identifying three cases (two mild, one moderate) of mid-pulmonary venous atrium obstruction. However, individual pulmonary vein velocity profiles could only be recorded by transesophageal pulsed Doppler ultrasound. Precordial studies identified baffle leaks (1 large, 2 small) in only three patients, whereas transesophageal studies identified 11 such baffle leaks (1 large, 10 small), which were multiple in two patients. It is concluded that transesophageal echocardiography provides a more detailed and accurate assessment of atrial baffle morphology and function than is provided by either precordial ultrasound or cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Medium-term follow up of residual shunting and potential complications after transcatheter occlusion of the ductus arteriosus.

OBJECTIVES--To determine the causes and outcome of residual shunting after transcatheter occlusion of persistent ductus arteriosus with the Rashkind double umbrella occluder, and to determine the potential of the device to produce obstruction to flow in the aorta and left pulmonary artery. DESIGN--Angiographic examination of morphology of ductus followed by prospective clinical and ultrasound evaluation (including cross sectional imaging, colour flow mapping, and pulse wave Doppler) of all patients undergoing occlusion of persistent ductus arteriosus between October 1987 and July 1992. PATIENTS--140 patients with ages between 0.5 and 78 (median 3.8) years and weights between 6.8 and 74 (median 13.8) kg. INTERVENTIONS--Attempted implantation of the Rashkind double umbrella ductus occluder under angiographic control through a transvenous (n = 136) or transarterial (n = 4) approach. MAIN OUTCOME MEASURES--Successful occlusion of ductus; frequency, pattern, and prognosis of residual shunts; Doppler velocities in left pulmonary artery and aorta; volume loading of the left heart. RESULTS--Including reocclusions the overall rate of successful occlusion was 96%. A total of six devices embolised at the time of operation (4.3%) with no sequelae. There were no anatomical factors that predicted a poor outcome, but suboptimal positioning of the device led to a significantly higher incidence of residual shunts (p < 0.001). Colour flow mapping correctly identified shunts that were unlikely to close spontaneously (n = 9) and to date seven have undergone successful closure with a second device. Encroachment of device legs produced statistically (p < 0.001) but not clinically significant increases in left pulmonary artery Doppler velocities that diminished with time. CONCLUSIONS--Transcatheter occlusion provides a safe and effective means of closing a persistent ductus arteriosus. Doppler colour flow mapping is necessary for follow up and shows those ducts requiring reocclusion. The device did not produce significant disturbance to flow in the pulmonary arteries or aorta.

Transthoracic three-dimensional echocardiography in the preoperative assessment of atrioventricular septal defect morphology

A prospective study of 3-dimensional (3-D) transthoracic echocardiographic definition of atrioventricular septal defect (AVSD) morphology and its dynamic changes during the cardiac cycle was performed. The information obtained from 2-D and 3-D transthoracic echocardiography (TTE) was compared with intraoperative findings in an unselected group of 15 patients with AVSD (median age 22 months). In all study patients, 3-D reconstructions provided anatomic views of the atrioventricular valve(s) en face from either atrial or ventricular perspectives that allowed comprehensive assessment of dynamic valve morphology and the mechanism of valve reflux. Left-sided valve function was correctly assessed by 2-D TTE in 11 of 15 patients (73%) and in 14 of 15 (93%) by 3-D TTE. In 6 of 15 patients (40%), the severity of right-sided valve reflux was described precisely by 2-D TTE and in 12 of 15 patients (80%) by 3-D TTE. Additionally, 3-D TTE supplemented the diagnostic information to that available from 2-D TTE on atrial and ventricular septal defects. Although primum atrial septal defects were depicted by 2-D and 3-D TTE in all 15 patients, the description of defect size was more precise by the 3-D TTE (80% vs. 100%, respectively). The presence of secundum atrial septal defect was correctly diagnosed by both TTE techniques in 10 of 15 patients. Disagreement regarding the size of the defect was present only in 2 of 10 patients by 2-D TTE. In another 2 patients, 3-D TTE described multiple defect fenestrations that were missed by 2-D TTE. Thus, the agreement score was 73% for 2-D and 100% for 3-D echo. The agreement for the presence and sizing of ventricular septal defects was 67% for 2-D and 93% for 3-D echo. We conclude that 3-D TTE provided accurate anatomic reconstructions of the common atrioventricular junction and that the use of dynamic 3-D TTE enhanced the anatomic diagnostic capability of standard 2-D TTE. Medica, Inc.

The variable clinical presentation of, and outcome for, noncompaction of the ventricular myocardium in infants and children, an under-diagnosed cardiomyopathy

Noncompaction of the ventricular myocardium is increasingly recognized as an important cause of cardiomyopathy. Its echocardiographic definition, however, is not yet clearly refined, and differentiation from other conditions with hypertrabeculation can be difficult. We report a prospective short-term follow-up of 15 children with noncompaction, excluding those with associated complex congenital cardiac disease. The clinical presentation and outcome were variable, with 2 patients being asymptomatic. For 5 patients, presentation was with cardiac failure due to depressed myocardial function. The function deteriorated in two, remained the same in two, and improved in the other patient. Cardiac failure due to mitral regurgitation was the mode of presentation in 2 patients with preserved myocardial function, one of whom needed replacement of the mitral valve. In 6 patients (40%), symptoms of cardiac failure were due to noncomplex congenital cardiac disease. All of them had ventricular septal defects. In addition, two had cleft mitral valves, and one had a large persistently patent arterial duct. The diagnosis of noncompaction was initially missed on more than one echocardiographic study in one-third of our patients. We conclude that noncompaction is under-diagnosed, and is not as rare as is thought. In children, it is often associated with other cardiac lesions that can cause cardiac failure in the presence of preserved myocardial function.

Effect of Catheter Device Closure of Atrial Septal Defect on Diastolic Mitral Annular Motion

Atrial septal defect closure with the Amplatzer septal occluder has a negative effect on diastolic mitral annulus motion in terms of decreasing longitudinal septal annular motion and changing the relation between the annulus motion and mitral inflow.

Prolonged QT interval and the cardiac conduction tissues

Abstract The QT interval, which marks the “vulnerable” period of ventricular repolarization, is related to heart rate and can be affected by a broad range of physiopathologic conditions. The interval is considered to be prolonged when, once normalized for heart rate (QTc), it exceeds 0.44 to 0.45 second [American Heart Association criterion 1956). In view of its association with sudden death, particularly in young children, there has been a call for a collective prospective registry to assess the efficacy of therapeutics available to patients with the long QT syndrome.1 Since the long QT syndrome is recognized as a clinical entity, general interest has focused on its causes. Anomalies of the cardiac conduction tissues have been suggested,2–4 as have conditions such as metabolic disorders5 and neurologic imbalance.6 The conduction tissues were implicated after clinicopathologic investigations that concentrated on the specialized myocardium and its neurons and ganglia. Some studies pointed to degenerative processes within and in the immediate environs of the conduction system.3,4

Left ventricular function in adolescents and adults with restrictive ventricular septal defect and moderate left-to-right shunting

BACKGROUND The long-term haemodynamic effects of a restrictive ventricular septal defect permitting moderate left-to-right shunting are not known. PATIENTS AND METHODS Echocardiographic measurements of left heart dimensions and function were compared between a group of 9 older children and adults (median age 21 years, range 12-24.5 years) having restrictive ventricular septal defects (median Qp/Qs 1.7, range 1.4-2.1) and a group of 10 age matched controls. RESULTS Left ventricular mass indexed to body surface area was significantly greater in subjects than in controls (102+/-29 vs. 75+/-13 g/m2, p=0.02), although there was no significant difference in the ratio of mass to volume. There were no significant differences between indexes of left ventricular systolic function. Ratios of peak early to late diastolic ventricular filling were lower in those with septal defects (1.5+/-0.3 vs. 1.8+/-0.3, p=0.03), but there were no differences in other indexes of diastolic function. CONCLUSIONS Resting left ventricular function does not appear to have deteriorated by early adult life in patients with restrictive ventricular septal defects and moderate volume loading. This would support a continued conservative approach to management in these patients.

Pulmonary Atresia, VSD in Association with Coronary-Pulmonary Artery Fistula

Congenital coronary-pulmonary artery fistula is rare in patients with pulmonary atresia and ventricular septal defect. The nomenclature, physiological, clinical, and surgical implications of these fistulas are yet to be defined. We report a one-year-old child with pulmonary atresia, ventricular septal defect, and a right coronary-pulmonary artery fistula who also had a diminutive, disconnected left pulmonary artery in addition to aortopulmonary collaterals. The patient underwent corrective surgery. However, the fate of diminutive pulmonary arteries is unknown. The literature was reviewed to explore the clinical or surgical implications of such fistulas for improved understanding and management in the future.