Presentation on theme: "Congenital Heart Disease and Cardiac Imaging Modalities Congenital Heart Disease and Cardiac Imaging Modalities Riya Chacko, MD May 2008."— Presentation transcript:
Congenital Heart Disease and Cardiac Imaging Modalities Congenital Heart Disease and Cardiac Imaging Modalities Riya Chacko, MD May 2008
Overview Classification of congenital heart disease Brief overview of common simple adult congenital heart diseases: ASD, VSD, PDA, and coarctation Transthoracic echocardiography Fetal echocardiography Transesophageal echocardiography 3D echocardiography Cardiac CT Cardiac MRI
Relevance Congenital heart disease is the most common major birth defect affecting 6-8/1000 live births (Gardiner) Accounts for 40% of perinatal deaths from congenital anomalies, 20% of deaths in 1 st month of life, and majority of congenital defect deaths in childhood (Randall) With improved surgical and medical therapies, now more adults live with congenital heart disease. In 1950s, 20% of congenital heart disease patients lived to adulthood and now 80%. (Crean) Adult population in US with congenital heart disease now 1 million (Russell)
Copyright restrictions apply. Russell, I. A. et al. Anesth Analg 2006;102:694-723 Table 1. Survival Rate from Year of Birth (1940-2000) by Complexity of Congenital Heart Disease
Classification of Congenital Heart Diseases Simple or complex Simple includes ASD, VSD, or singular valvular abnormalities (Ebstein’s anomaly) Simple includes ASD, VSD, or singular valvular abnormalities (Ebstein’s anomaly) Complex includes those with multiple defects, AV canal defects, or “single” ventricle physiology. Complex includes those with multiple defects, AV canal defects, or “single” ventricle physiology. Cyanotic or non-cyanotic Non-cyanotic: ASD, VSD, sinus venosus defect, patent ductus arteriosus, aortic stenosis, pulmonary stenosis, aortic coarctation Non-cyanotic: ASD, VSD, sinus venosus defect, patent ductus arteriosus, aortic stenosis, pulmonary stenosis, aortic coarctation Cyanotic: Tetralogy of Fallot, Ebstein’s anomaly, transposition of the great arteries, Eisenmenger’s syndrome, truncus arteriosus, tricuspid atresia, total anomalous pulmonary venous return “5 Ts and 2 Es” Cyanotic: Tetralogy of Fallot, Ebstein’s anomaly, transposition of the great arteries, Eisenmenger’s syndrome, truncus arteriosus, tricuspid atresia, total anomalous pulmonary venous return “5 Ts and 2 Es”
The heart is formed and septations occur at 50 embryonic days.
Atrial Septal Defects One third of all congenital defects detected in the adult are ASDs. 2-3 times more likely to occur in women 3 varieties: Ostium primum Ostium primum Ostium secundum Ostium secundum Sinus venosus Sinus venosus
PDA 10% of congenital heart disease Rarely closes spontaneously after infancy May become aneurysmal or calcified leading to rupture 1/3 of patients die of heart failure, pulmonary hypertension or endarteritis by age 40. 2/3 die by age 60.
Usually distal to left subclavian at site of ligamentum arteriosum. 2-5 times more common in men Associated with Turner’s syndrome, bicuspid aortic valve, ventricular septal defect, patent ductus arteriosus, mitral stenosis or regurgitation, or aneurysms of the circle of Willis
Imaging Protocols for Congenital Heart Disease Position of the cardiac apex and aortic arch Levocardia Left-sided cardiac apex Dextrocardia Right-sided cardiac apex MesocardiaMidline/indistinct cardiac apex Aortic archLeft or right aortic arch, branches
Defining Atria and Ventricles Left atrium– by finger-like appendage Right atrium – larger, wider appendage Usually concordance with abdominal situs 70- 80% (IVC on right, RA on right) Right ventricle – triangular with 3 components (inlet, trabeculated, outlet). Moderator band, septal attachments of TV Left ventricle – elliptical, fine trabeculae, no septal attachment of MV (inlet, tension apparatus, and outlet zone for AV valve)
Situs of the atrium Situs solitus Normal atrial arrangement Situs inversus Reverse atrial arrangement (LA–RV, RA–LV) Situs ambiguous Often LA isomerism (usual with abnormal venous drainage from azygous/hemi-azygous veins)
Atrioventricular (AV) arrangement AV concordance RA–RV, LA–LV AV discordance RA–LV, LA–RV Double inlet RA and LA to LV or RV Absent Right or left AV valve atresia
Ventriculoarterial (VA) arrangement VA concordance RV–PA, LV–aorta VA discordance RV–aorta, LV–PA Double outlet RV or LV giving off both PA and aorta Solitary or common arterial trunk Truncus or A–P window
Other defects ASD VSD AVSD Common in Trisomy 21 (Down's syndrome) Valvular defects, atresia, abnormal number of cusps Shunts Blalock–Taussig or Glenn shunts Venous drainage Anomalous systemic or pulmonary venous connections Vascular rings Nicol ED. Clin Rad 2007;62(6
Coronary anatomy Normal configuration Normal or congenital heart Rotation Rotation common in AV and VA discordance Aberrant origin i.e., RCA off left coronary sinus Single coronary artery Beware left main coronary artery atresia Malignant course i.e., between RVOT and aorta Abnormal morphology i.e., Kawasaki's disease
Echocardiography Preferred method for initial assessment of congenital heart disease Also the preferred imaging modality in babies Limitations – Chest wall deformities, median sternotomies, relation to extracardiac structures and post-surgical assessment Poor assessment of RV size and function
Fetal Echocardiography Two forms: basic and extended “Four chamber view” the most basic Color-flow and spectral Doppler imaging M-mode available Sensitivity from 60-100% Limited by body habitus and fetal age (11 to 14 weeks transvaginal ultrasound). 16 weeks by abdominal. Reported specificity up to 100% in babies without congenital heart disease
Transabdominal view of the 4 chambers of the heart at 13 weeks' gestation.
Transvaginal view of atrioventricular septal defect at 13 weeks' gestation in a fetus with trisomy 21 (case 2).
(A)A full examination of the fetal heart may be obtained by five transverse sections through the abdomen and chest of the fetus. The first section shows abdominal situs (B) with the aorta (Ao) to the left of the spine and the inferior caval vein (IVC) anterior and to the right. The normal fetal stomach (St) and heart lie on the left side. The second section (C) illustrates the four chambers of the heart with the left atrium (LA) in front of the spine and the right ventricle (RV) just below the sternum. The third cut (D) shows the aorta arising centrally in the heart from the left ventricle (LV) and the fourth the pulmonary trunk (PV) arising from the anteriorly placed right ventricle and crossing to the fetal left over the ascending aorta (E). The fifth section shows the anteriorly positioned ductal arch (D) and the transverse aortic arch (Ao) to be of equal size traversing back to the fetal spine (F). A normal variant "three vessel" view is shown with a right sided aortic arch and persistent left superior caval vein (LSVC). The trachea (T) can be seen lying between the aortic (Ao) and ductal (D) arches (G). Gardiner.
Transvaginal 3-vessel view of the great arteries at 13 weeks' gestation. PA, Main pulmonary artery; Ao, aorta; SVC, superior vena cava; BPA, right branch pulmonary artery. McAuliffe F.
In 1992, only 8% of infants with congenital heart disease undergoing cardiac surgery had a prenatal diagnosis. With fetal echo, this number rose to 57% in 2002.(Mohan) In one study assessing use of early fetal echo (prior to 14 weeks gestation) in a high-risk population, sensitivity of 70% and specificity of 98% This resulted in 79% of patients terminating their pregnancy prior to their 18-20 week follow up.
Transesophageal Echocardiography Good for evaluation of venous return, atria, AV valves, and the left ventricular outflow tract Mid-esophageal (ME) four-chamber and bicaval views good for atrial septum by 2D ME 4-chamber and transgastric mid-short axis to assess for VSDs Also essential in intra-operative repair Limited for evaluation of the right ventricular outflow tract and pulmonary arteries
Preferred method in the following cases: ASD, secundum ASD, secundum Mitral valve regurgitation Mitral valve regurgitation Ebstein’s anomaly Ebstein’s anomaly Fontan – assessing for right atrial thrombus, obstruction Fontan – assessing for right atrial thrombus, obstruction
Coronary sinus defect Superior sinus venosus defect Inferior sinus venosus defect AV septal defect
3D Echocardiography In a small, non-randomized comparison of 3D echo evaluation of congenital abnormalities as compared to anatomical specimens, Vogel et al. found a close association. The key difference is in thickness of supporting structures (overestimated on 3D echo). Salustri et al reported additional information gathered by 3D versus 2D echo on 36% of patients screened with known congenital heart disease. Advantage of being able to view en face both sides of a septal defect versus 2D echo
Cardiac CT 10% of MDCT patients at Royal Brompton Hospital in London have congenital heart disease. Multi-detector CT scans (MDCT) are able to identify those with congenital heart disease and anomalous coronary arteries. In a retrospective review of 85 patients with congenital heart disease at Ohio State University, authors Cook and Raman was found that 19% had detectable anomalous coronary anatomy by MDCT both 16 and 64 slice.
Not as useful due to poorer image quality if the patient has frequent beat-to-beat variation or atrial fibrillation. Flow data is not available and thus information on physiologic effects of valvular abnormalities. Inadequate assessment of RV function
Regional wall motion as compared to TTE may be inferior due to lower temporal resolution. Radiation exposure should be considered as compared to cardiac MR or TTE especially if repeat examinations are required throughout a lifetime.
Cardiac CT Advantages over cardiac MRI include: Shorter breath-hold sequences that may not be tolerated in a congenital heart disease population Shorter breath-hold sequences that may not be tolerated in a congenital heart disease population Better tolerability for those with pacemakers/ICDs or those with claustrophobia Better tolerability for those with pacemakers/ICDs or those with claustrophobia More robust coronary artery imaging especially when involvement of fistulous communication More robust coronary artery imaging especially when involvement of fistulous communication Rapid image acquisition time Rapid image acquisition time
Cardiac MRI 1 st described to assess congenital heart disease in 1984. Also utilizes contrast-enhanced MR angiography (CE-MRA) Allows better visualization of mediastinal vessels (small central pulmonary arteries) and better to assess the left pulmonary artery than echo. Best to visualize proximal and mid pulmonary arterial stenosis but not distal to the hila.
Crean. Heart 2007. (A and B) ALCAPA syndrome (anomalous left coronary artery from PA). (C) Large RCA with fistulous connection. CT at bottom (E) shows anomalous LCX draining into coronary sinus
Favored to evaluate coarctation in children. Accurately measures pulmonary blood flow and assesses the aorta. Ultrasound better to assess valvular pathology but MR better to assess systemic and venous malformations. Because of wider field of view, better to assess larger cardiac chambers (ie Ebstein’s anomaly) May also be used to estimate left-to-right shunts by measuring flow to calculate Qp:Qs Probably most effective to assess post-surgically as well
Allows better assessment of RV size and function (critical in cases such as Tetralogy of Fallot post-surgery). With delayed enhancement technique, it is useful to assess prognosis in congenital heart disease as well.
Disadvantage compared to cardiac catheterization: inability to measure pressures and obtain O2 saturations Examination time is long (up to 90 minutes) which is difficult in a pediatric population. Faster heart rates in infant population make MRI less helpful and accurate. Images are obscured by metallic stents in those with stent-corrected coarctation
Components of a congenital CMR exam Axial steady state free precession (SSFP) cine sequence from aortic arch to diaphragm 10 mm thick, no gap Short axis oblique SSFP from ventricular apex to atrioventricular (AV) groove, 8 mm thick, no gap Fast cine phase contrast through ascending aorta, main and left and right pulmonary arteries Three dimensional contrast enhanced magnetic resonance angiography (CE-MRA): coronal plane, sternum to spine, slice thickness 2–2.5 mm, arterial and venous phase Additional thin slices (SSFP or black blood) and cine phase contrast studies (for example, for flow through shunts, collaterals, anomalous veins or arteries, etc) as directed by monitoring physician Multiplanar reformations, maximum intensity projections and volume rendered image preparation (ideally by reporting physician) Creon A.
Summary Classification of congenital heart disease Overview of common adult congenital heart diseases: ASD, VSD, PDA, and coarctation Transthoracic echocardiography Fetal echocardiography Transesophageal echocardiography 3D echocardiography Cardiac CT Cardiac MRI
Regardless of imaging modality, one requires the expertise of an experienced specialist…
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