Noninvasive imaging in congenital heart disease

The use of echocardiography in congenital heart surgery and intervention

Echocardiography has revolutionized the management of pediatric and adult heart disease, especially in the diagnosis of congenital heart defects. Although the early methods of echocardiography (M-mode and Doppler imaging) were limited in their ability to define the defect in question, the advent of 2D, and now 3D, imaging have clearly equaled or surpassed traditional methods of diagnosis (e.g., noninvasively obtained plain chest radiographs and electrocardiograms) and invasive tests (e.g., cardiac catheterization and angiography). Confidence in the images obtained using echocardiography has continued to increase, with many patients referred for corrective or palliative surgery on the basis of echocardiographic imaging alone. Echocardiography has eliminated the need, decreased the frequency, or improved the timing or performance of invasive studies in other patients. Specifically, it is used to definitively diagnose a cardiac defect and any associated lesions. It will also provide quantitative information for the assessment of the hemodynamic severity of the lesion. This review outlines the manner in which echocardiography is used to plan and guide congenital heart surgery or intervention, along with some of the advantages and disadvantages (pitfalls) of which to be aware. The use of echocardiography within the cardiac catheterization or surgical theater, as well as in the intensive care unit, is discussed, as is the use of echocardiography as a means of monitoring recovery and follow-up following cardiac surgery. Finally, the authors discuss who is best qualified or suited to perform these tests.

A prospective study of dobutamine stress echocardiography for the assessment of cardiac allograft vasculopathy in pediatric heart transplant recipients

Transplant CAV is the leading cause of graft loss beyond one yr post-heart transplant. Diagnosis can be challenging and the previous "gold standard," coronary ANG, tends to underestimate disease. The purpose of this study was to relate DSE to ANG for the diagnosis of CAV. Prospective annual DSE at a single centre on all heart transplant patients (1999-2006) were compared with results from routine coronary angiograms. Progression of CAV over time as determined by DSE and ANG and associated factors were sought through logistic regression models adjusted for repeated measures. There were 102 heart transplant patients (54 males) transplanted between 1989 and 2006. Median age at transplant was 17 months (0-16.6 yr). The initial DSE was at a median of 10-months post-transplantation. There was a high correlation between an abnormal DSE and an abnormality on ANG (p = 0.002). There was an increased probability of an abnormal DSE with increasing grade of CAV as assessed by ANG (p < 0.001). Factors associated with an abnormal DSE included older age at transplant (p = 0.04), higher grade of rejection (p = 0.002), higher total cholesterol (p = 0.04), higher LDL (p < 0.05), and older age at the time of DSE (p = 0.002). DSE result was not related to HDL, triglyceride or homocysteine levels, or to steroid or statin use. The probability of an abnormal DSE result increases with increasing angiographic grade of CAV, and thus DSE may be used for initial screening for CAV with ANG reserved for confirmation and grading. Patients transplanted at an older age and those with a greater history of rejection were at higher risk of a positive DSE and may require increased surveillance for CAV.

Contrast-enhanced magnetic resonance angiography of the great arteries in patients with congenital heart disease: an accurate tool for planning catheter-guided interventions

BACKGROUND

Catheter-guided interventions are increasingly used for relief of lesions in patients with congenital heart disease. Exact anatomical imaging with measurement of the vascular structures is crucial in the planning of such interventions. This can be provided non-invasively and without radiation by contrast-enhanced MR angiography (CE-MRA).

AIM

To evaluate the accuracy of the measurements of the vessels obtained by CE-MRA in comparison to those obtained by conventional X-ray angiography (XRA).

METHODS

Measurements of the diameters of aorta and pulmonary arteries were performed retrospectively and blinded on the CE-MRA and XRA images, in comparable locations. The limits of agreement between the two methods were calculated.

RESULTS

Twenty-one CE-MRA and XRA were performed in 20 children with congenital heart disease, median age 4 years (1 day-13 years), weight 18 kg (3.2-74 kg). The time interval between CE-MRA and XRA was 2.6 +/- 2.3 months. A total of 98 measurements, 38 of the aorta and 60 of the pulmonary arteries were performed on the images obtained by each technique. The correlation between CE-MRA and XRA measurements was excellent, r = 0.97, p < 0.0001. The mean difference between the two techniques was 0.018 +/- 1.1 mm; the limits of agreement -2.14 and + 2.18 mm. Similar agreement was found for measures of the aorta (r = 0.97, mean difference 0.20 +/- 1.08 mm) and of the pulmonary arteries (r = 0.97, mean difference 0.048 +/- 0.89 mm).

CONCLUSIONS

CE-MRA provides accurate quantitative anatomical information, which highly agrees with XRA data, and can therefore be used for planning catheter-guided procedures.

Contrast-enhanced magnetic resonance angiography of the great arteries in patients with congenital heart disease: an accurate tool for planning catheter-guided interventions

BACKGROUND

Catheter-guided interventions are increasingly used for relief of lesions in patients with congenital heart disease. Exact anatomical imaging with measurement of the vascular structures is crucial in the planning of such interventions. This can be provided non-invasively and without radiation by contrast-enhanced MR angiography (CE-MRA).

AIM

To evaluate the accuracy of the measurements of the vessels obtained by CE-MRA in comparison to those obtained by conventional X-ray angiography (XRA).

METHODS

Measurements of the diameters of aorta and pulmonary arteries were performed retrospectively and blinded on the CE-MRA and XRA images, in comparable locations. The limits of agreement between the two methods were calculated.

RESULTS

Twenty-one CE-MRA and XRA were performed in 20 children with congenital heart disease, median age 4 years (1 day-13 years), weight 18 kg (3.2-74 kg). The time interval between CE-MRA and XRA was 2.6 +/- 2.3 months. A total of 98 measurements, 38 of the aorta and 60 of the pulmonary arteries were performed on the images obtained by each technique. The correlation between CE-MRA and XRA measurements was excellent, r = 0.97, p < 0.0001. The mean difference between the two techniques was 0.018 +/- 1.1 mm; the limits of agreement -2.14 and + 2.18 mm. Similar agreement was found for measures of the aorta (r = 0.97, mean difference 0.20 +/- 1.08 mm) and of the pulmonary arteries (r = 0.97, mean difference 0.048 +/- 0.89 mm).

CONCLUSIONS

CE-MRA provides accurate quantitative anatomical information, which highly agrees with XRA data, and can therefore be used for planning catheter-guided procedures.