Identification of some forms of congenital heart disease prior to birth may allow for fetal intervention, thereby avoiding progression or development of a more severe anomaly. In this chapter, we ...discuss the current experience with identification of aortic stenosis in the fetus and the effort to avoid development of hypoplastic left heart syndrome by performance of an in-utero balloon valvuloplasty of the aortic valve.
A pseudoaneurysm of the right ventricle was diagnosed postoperatively in 8 patients between 1986 and 1992. One pseudoaneurysm formed after placement of a CarpentierEdwards conduit and the other seven ...arose after placement of a homograft between the right ventricle and the pulmonary artery. Both aortic (n = 3) and pulmonary (n = 4) homografts had been used. In 6 patients, the homografts had been augmented proximally with Dacron, Gore-Tex, or pericardium. Pseudoaneurysms originated between the augmentation patch and the homograft in 4 patients, between the homograft or conduit and the myocardium in 3 patients (1 patient with and 2 without an augmentation patch), and between the patch and the myocardium in 1 patient. The prior operations performed were placement of a palliative conduit for tetralogy of Fallot with pulmonary atresia (n = 5), repair of truncus arteriosus (n = 2), and repair of absent pulmonary valve syndrome (n = 1). Pseudoaneurysms were discovered from 5 weeks to 4 years after the operation. Symptoms were present in 3 patients; in the others, diagnosis was made during follow-up on the basis of routine imaging studies. Symptoms, when present, were due to compression of surrounding mediastinal structures. Pseudoaneurysms ranged in diameter from 1.0 to 5.0 cm. Echocardiography and color-flow mapping reliably identified the pseudoaneurysm in the 6 patients in whom it was performed. Characteristic features included a well-defined, narrow aneurysm neck leading to an extracardiac echo-free space. Color-flow mapping demonstrated to-and-fro flow through the neck of the aneurysm. Right ventricular pressure was half the systemic pressure or less in 2 patients and was the same as or exceeded the systemic pressure in 6 patients. The pseudoaneurysm was surgically repaired in 7 patients; in the eighth patient, the neck of the pseudoaneurysm was closed with a double-umbrella, clamshell device in the catheterization laboratory. A pseudoaneurysm of the right ventricle forms infrequently after the placement of a homograft or conduit between the right ventricle and the pulmonary artery and is probably multifactorial in origin, though it is frequently associated with systemic right ventricular pressure. This defect can be diagnosed easily by echocardiography and successfully treated.
Echocardiographic assessments of ventricular function derived from estimates of the mean dP/dt during isovolumetric contraction (mean dP/dtic) were compared with those obtained from measurements of ...the shortening fraction and the stress‐velocity index (SVI). Mean dP/dtic correlated well with the shortening fraction, r = 0.74, P < 0.0001. Furthermore, 10 out of 11 patients with mean dP/dtic below 800 had a shortening fraction < 0.28, whereas all patients with a mean dP/dtic > 1000 mmHg/sec had a shortening fraction > 0.28. A good correlation also existed between mean dP/dtic and the SVI, r = 0.73, P < 0.0001. Nine out of 11 patients with a mean dP/dtic < 800 mmHg/sec had an SVI > 2 standard deviations below normal, whereas all patients with mean dP/dtic > 1000 mmHg/sec had normal or increased SVI. The correlation between mean dP/dtic and the SVI was strengthened when mean dP/dtic was adjusted for heart rate and preload. Hence, assessments of ventricular function derived from measurements of mean dP/dtic appear to agree well with those provided by the shortening fraction and SVI. Because the determination of mean dP/dtic is not hampered by unusual anatomy or wall motion (conditions which compromise the validity of the shortening fraction and SVI), mean dP/dtic may be a good index of ventricular function in cases where measurements of the shortening fraction and SVI would be unreliable.
Ventricular tachycardia has rarely been diagnosed in the fetus. We describe a 31-week-old fetus with ventricular tachycardia and severely depressed ventricular function. M-mode and 2-dimensional ...Doppler tissue echocardiography were used in this study to assess the nature of the arrhythmia. The complete atrioventricular dissociation inherent to the diagnosis of ventricular tachycardia was particularly easy to detect with M-mode Doppler tissue echocardiography. Moreover, the onset and the pattern of propagation of the ventricular arrhythmia could be easily identified with 2-dimensional Doppler tissue echocardiography. Doppler tissue echocardiography facilitates the diagnosis of ventricular tachycardia and adds new information that is not available by other techniques.
The Pediatric Heart Network trial comparing outcomes in 549 infants with single right ventricle undergoing a Norwood procedure randomized to modified Blalock-Taussig shunt or right ...ventricle-pulmonary artery shunt (RVPAS) found better 1-year transplant-free survival in those who received RVPAS. We sought to compare the impact of shunt type on echocardiographic indices of cardiac size and function up to 14 months of age.
A core laboratory measured indices of cardiac size and function from protocol exams: early after Norwood procedure (age 22.5 ± 13.4 days), before stage II procedure (age 4.8 ± 1.8 months), and at 14 months (age 14.3 ± 1.2 months). Mean right ventricular ejection fraction was <50% at all intervals for both groups and was higher in the RVPAS group after Norwood procedure (49 ± 7% versus 44 ± 8%; P<0.001) but was similar by 14 months. Tricuspid and neoaortic regurgitation, diastolic function, and pulmonary artery and arch dimensions were similar in the 2 groups at all intervals. Neoaortic annulus area (4.2 ± 1.2 versus 4.9 ± 1.2 cm(2)/m(2)), systolic ejection times (214.0 ± 29.4 versus 231.3 ± 28.6 ms), neoaortic flow (6.2 ± 2.4 versus 9.4 ± 3.4 L/min per square meter), and peak arch velocity (1.9 ± 0.7 versus 2.2 ± 0.7 m/s) were lower at both interstage examinations in the RVPAS compared with the modified Blalock-Taussig shunt group (P<0.001 for all), but all were similar at 14 months.
Indices of cardiac size and function after the Norwood procedure are similar for modified Blalock-Taussig shunt and RVPAS by 14 months of age. Interstage differences between shunt types can likely be explained by the physiology created when the shunts are in place rather than by intrinsic differences in cardiac function.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.
Infants with coarctation of the aorta may have obstructions at other sites within the left heart which are not always apparent on the initial echocardiogram. The magnitude of the risk of having the ...additional obstructions is not well described, with few reliable quantitative criterions for identifying patients at the highest risk. We determined the frequency of additional, late appearing, stenotic lesions within the left heart, and the predictive morphologic features on the initial cross-sectional echocardiogram. We identified all patients with coarctation of the aorta diagnosed by 3 months of age, excluding those with complex cardiac disease or definite additional stenotic lesions at presentation, leaving 101 patients for study. At follow-up, 31 stenotic lesions were diagnosed in 23 patients, 15 of whom had at least 1 intervention. Mitral stenosis was diagnosed in 11 patients, aortic stenosis in 10, subaortic stenosis in 8, and supravalvar aortic stenosis in 2. The probability for freedom from obstructive lesions was 81% at 1 year, 74% at 3 years, and 70% at 5 years. Echocardiographic predictors of mitral stenosis included smaller mitral valvar annuluses, presence of a mean transmitral gradient between 2.5 and 5.0 mmHg, and elongation of the area of intervalvar fibrous continuity. Predictors of aortic stenosis were smaller mitral valvar annuluses, an initial aortic valvar gradient between 15 and 20 mmHg, and obliteration of the commissure between the right and non-coronary leaflets of the aortic valve. Predictors of subaortic stenosis were smaller mitral valvar annuluses and elongation of the area of intervalvar fibrous continuity. Patients with Z-scores for the diameter of the mitral valve of less than -1 were at the highest risk for manifesting obstructive lesions at any level. Associated stenoses in the left heart are common in the setting of aortic coarctation. When Doppler data is equivocal, features of the cross-sectional echocardiogram can identify the sub-group of infants at increased risk.
Common atrioventricular (AV) canal consist of a group of structural heart malformations that share some common features but can vary widely with respect to anatomic features and physiologic ...manifestations. High quality, non-invasive evaluation can define the anatomic features of the disease and give cardiologists a full appreciation of the hemodynamic issues. Patients with common AV canal frequently require surgical intervention and the importance of non-invasive evaluation in the intra-operative, peri-operative and post-operative periods has grown along with the technology. Echocardiographic technology has progressed rapidly over the last 25 years, revolutionizing the evaluation of structural heart disease. Patients with suspected common AV canal can now be completely evaluated non-invasively in most cases. Using two-dimensional imaging, color and spectral Doppler, the cardiologist can fully assess cardiac anatomy, hemodynamics and ventricular function. The smaller, high resolution transducers introduced in recent years allow for excellent imaging in newborns. The availability of small transesophageal transducers has made intraoperative study available to patients as small as 2.5 kg. The contribution of three-dimensional echocardiography is still in the investigational stages, but it is likely that it will be important for the further delineation of valve anatomy and for the quantitative assessment of valve and ventricular function. This article reviews the current use of echocardiography in the evaluation of common AV canal, including the initial diagnostic evaluation as well as the intra-operative, post-operative and prenatal evaluation.
Patients (pts) presenting with aortic coarctation (COA) can subsequently develop left sided obstruction at other sites. We sought, retrospectively, to identify morphologic predictors for the ...development of late obstruction. Pts diagnosed with COA before age 3 months (from 1988—1992) were included (N=101). Pts with aortic stenosis, mitral stenosis, subaortic stenosis or complex heart disease on initial presentation were excluded. A VSD was present in 53%, an LSVC in 18% and a bicuspid aortic valve in 59% (53%—intercoronary cusp fusion and 6%—right/non-coronary cusp fusion). At the initial study, left ventricular volume tended to be larger than normal while other left sided structures were smaller. The probability of freedom from new left sided lesions was 81% at 1 yr, 74% at 3 yrs and 70% at 5yrs. Mitral stenosis developed in 11 pts. Multivariate analysis revealed that these pts had smaller mitral valve annulus diameter (MV) (p=0.027), higher mean transmitral gradients (p=0.043) and longer intervalvular fibrosa (p=0.017). Ten pts developed aortic stenosis. They had smaller MV (p=0.006), higher initial aortic valve velocities (p=0.007), and were more likely to have fusion of the right/non-coronary cusp (p=0.001). Eight pts developed subaortic stenosis. They had smaller MV (p=0.027) and longer intervalvular fibrosa (p=0.025). Risk factors for the development of any stenosis were: small MV (p<0.001). presence of a VSD (p=0.004), initial aortic valve gradient > 14mmHg (p=0.01), right/non-coronary cusp fusion (p=0.022) and longer intervalvular fibrosa (p=0.008).Measurements-1 st studyMean Z-scoreMitral valve diameter–0.70Aortic valve diameter–092Distal transverse arch–2.6Isthmus diameter–3.9End systolic volume+0.76End diastolic volume+0.73
Late left sided stenoses are common in isolated neonatal COA and often develop by 1 yr of age. Echocardiography can identify patients at increased risk for these progressive lesions.
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