Adult Congenital Heart Disease In General Echocardiography Practice

The spectrum of adult congenital heart defects seen in echocardiography practice varies according to institutional practice and expertise. Half a century ago, survival with severe congenital heart disease was less common. Today, nearly 80% of such patients in industrialized societies now survive into adulthood. Most are followed up in centers that specialize in adult congenital heart diseases (CHDs), but it is not uncommon for such adults to be seen in general echocardiography practice.

Most CHDs are compatible with survival to adulthood without need for surgical intervention (Table 1). Indeed, some lesions, e.g., mitral valve prolapse, bicuspid aortic valves (BAVs), patent foramen ovale, atrial septal defects, and Marfan syndrome may be completely asymptomatic. More severe or complex defects require interventions early in life (Table 2).

This chapter introduces the fundamentals of echocar-diographic assessment in CHD followed by a concise summary of the more common CHD seen in general adult echocardiography practice. All images shown are from adults who were seen in general echocardiography practice.

From: Contemporary Cardiology: Essential Echocardiography: A Practical Handbook With DVD Edited by: S. D. Solomon © Humana Press, Totowa, NJ

Table 1

Congenital Heart Disease in Adults Compatible With Survival to Adulthood With No Prior Surgery or Intervention

Mitral valve prolapse Bicuspid aortic valve ASD

Marfan syndrome

Isolated restrictive or moderately restrictive ventricular septal defects

Mild aortic stenosis (valvular, supravalvular, subvalvular)

Mild pulmonary valve stenosis

Small patent ductus arteriosus

Ostium primum ASD (AV septal defect)

Ebstein's malformation

Corrected transposition (transposition of the great arteries) (AV-to-ventriculoatrial discordance)

ASD, atrial septal defect; AV, atrioventricular.

Echocardiography in Adult CHD

Echocardiography, both transthoracic (TTE) and transesphageal (TEE), play central roles in the diagnosis and management of CHD (see Chapter 4, Table 15 for Class I indications for echocardiography in adult CHD).

Optimal echocardiography examination and interpretation requires knowledge and experience in the following:

• Normal cardiac anatomy and physiology.

• The spectrum of adult CHDs.

• The segmental approach to echocardiography examination.

• Palliative and corrective surgical and transcatheter interventions and techniques (past and present).

• Postoperative and postintervention residua and complications.

• Superimposed acquired age-related heart disease, e.g., hypertension, coronary artery disease.

Table 2

Spectrum of Congenital Heart Disease

I. Chambers and valves in normal sequence and position {S,D,S} A Shunting predominant

1. Atrial septal defect (Chapter 21)

2. Atrioventricular septal defects (Chapter 21)

3. Isolated ventricular septal defect0

4. Patent ductus arteriosusa

B Stenosis or obstruction predominant

1. Absent AV connections (tricuspid and mitral atresia)

2. Absent or obstructed ventriculoarterial connections (pulmonary atresia, aortic atresia, subaortic obstruction, aortic stenosis)

3. Obstructed great arteries (coarctation of the aortaa, aortic atresia)

4. Obstructed venous flow (total anomalous pulmonary venous return) C Anomalous valve position

1. Ebstein's malformation (anomaly)a

II. Chambers and valves not in normal sequence or relationship A Anomalies of relationships between atria and ventricles

1. Double-inlet left or right ventricle (with univentricular heart)

2. AV discordance (congenitally corrected transposition of great arteries [L-TGA])a B Anomalies of relationships between ventricles and great arteries

1. Tetralogy of Fallot

2. Double-outlet right and left ventricles

3. Truncus arteriosus

4. Ventriculoarterial discordance (transposition of the great vessels D-TGA)a aDiscussed in this chapter.

AV, atrioventricular.

Modified from Kisslo JA, Adams DB, Leech GJ. Essentials of Echocardiography: Congenital Heart Disease. New York: Ceiba-Geigy, 1988.

Cardiac Segmental Anatomy

Fig. 1. The distinguishing characteristics of each cardiac segment—atria, ventricles, and great vessels—are used in the segmental approach to describe cardiac anatomical relationships. IVC, Inferior vena cava; LCA, left coronary artery; LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein; PA, pulmonary artery (right and left); RCA, right coronary artery; RLPV, right lower pulmonary vein; RUPV, right upper pulmonary vein; SVC, superior vena cava.

Fig. 1. The distinguishing characteristics of each cardiac segment—atria, ventricles, and great vessels—are used in the segmental approach to describe cardiac anatomical relationships. IVC, Inferior vena cava; LCA, left coronary artery; LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein; PA, pulmonary artery (right and left); RCA, right coronary artery; RLPV, right lower pulmonary vein; RUPV, right upper pulmonary vein; SVC, superior vena cava.

Segmental Approach to CHD

A good relationship between adult and pediatric sonographers and cardiologists can optimize the quality of the echocardiographic examination in patients with adult CHD.

To simplify and standardize the complicated and confusing embryological descriptions of the past, a logical descriptive method called the segmental approach or sequential segmental analysis has been adopted. This method evaluates the sequence of bloodflow throughout the entire cardiac circuit. It is segmental in that it compartmentalizes the heart into three main segments or building blocks—atria, ventricles, and great arteries—that are analyzed separately (Fig. 1). In pediatric cardiology, these are designated by three letters in curly brackets {X,X,X} that describe the arrangement.

Assigning the Segments

The normal segmental arrangement is {S,D,S}.

The first letter "S" means solitus—Latin for normal visceral and atrial position (situs). It describes the positions of the major unpaired abdominal organs (liver, stomach, spleen) and atria that are almost always situated on the same side of the body cavity (concordant) (Fig. 2).

The second letter "D" denotes the normal D-looping or rightward (dextro) folding of the heart tube during cardiac embryonic development (Fig. 3A). This results in the normal atrioventricular (AV) relationship or concordance. L-looping occurs when ventricular folding proceeds in the opposite (levo) direction, resulting in AV discordance (Fig. 3B). This terminology is used to differentiate between the two forms of transposition of the great arteries (TGA).

The third letter "S" means that a normal relationship exists between the great arteries—the main pulmonary artery and the aorta. Parasternal short-axis (PSAX) views at the aortic valve level can define this relationship on echocardiography (Fig. 4; see Chapter 3, Figs. 23-26). These relationships are summarized in Tables 3-5.

Morphological Characteristics of the Connecting Segments

Defining cardiac chambers is important in identification and assignment of segmental situs and describing the connections between the segments. The morphological characteristics of the right and left ventricles (LVs) and the internal cardiac crux can be readily defined on examination (Fig. 5). The major echocardiographic morphological characteristics are summarized in Table 3.

Transthoracic Examination

The standard protocol outlined in Chapter 3 applies to adults with CHD, but pediatric/adult CHD sonogra-phers perform an initial four-step segmental analysis before proceeding with the standard examination (Table 5). Subcostal (subxyphoid) views are used to

Pediatric Echo Subcostal

Fig. 2. The first segment. The most distinctive anatomical features that define the first segment—atrial and visceral situs—are depicted. The distinguishing features of right versus left atrium are highlighted in the lower panel. On echocardiography, the atrial chamber into which the pulmonary veins enter is the morphological left atrium. The chamber into which the vena cavae empty is the morphological right atrium. The right atrial appendage is used by cardiac anatomical pathologists to define atrial situs, but this structure is poorly visualized during echocardiography.

Fig. 2. The first segment. The most distinctive anatomical features that define the first segment—atrial and visceral situs—are depicted. The distinguishing features of right versus left atrium are highlighted in the lower panel. On echocardiography, the atrial chamber into which the pulmonary veins enter is the morphological left atrium. The chamber into which the vena cavae empty is the morphological right atrium. The right atrial appendage is used by cardiac anatomical pathologists to define atrial situs, but this structure is poorly visualized during echocardiography.

Cardiac Situs Definition

Fig. 4. The third segment: the great arteries. The relative positions of the great arteries on the parasternal short-axis view (PSAX, aortic valve level) provides the echocardiographic basis for naming the third segment. The normal "S" (solitus) position and the "I" (inversus) relationships are shown in the upper panels. When the aortic valve is to the right and anterior to the pulmonary valve, it is called D-transposition. When the aortic valve is to the left and anterior to the to the pulmonary valve, it is called L-transposition (lower panels). Two other relationships (not shown) are: the "A" anterior and the "P" posterior positions. These describe the position of the aortic valve relative to the pulmonary valve.

Fig. 4. The third segment: the great arteries. The relative positions of the great arteries on the parasternal short-axis view (PSAX, aortic valve level) provides the echocardiographic basis for naming the third segment. The normal "S" (solitus) position and the "I" (inversus) relationships are shown in the upper panels. When the aortic valve is to the right and anterior to the pulmonary valve, it is called D-transposition. When the aortic valve is to the left and anterior to the to the pulmonary valve, it is called L-transposition (lower panels). Two other relationships (not shown) are: the "A" anterior and the "P" posterior positions. These describe the position of the aortic valve relative to the pulmonary valve.

Loop Transposition Great VesselsLoop Transposition Great Vessels

Fig. 3. The second segment. (A) The basis of the atrioventricular concordance lies in the folding (ventricular looping) of the tubular embryonic heart to form a folded four-chamber heart. Initially, the cardiac apex is on the right, but final looping of the tube swings the apex to the left and places the right ventricle anterior and rightward to the left ventricle. This is the normal or D-loop pattern. (B) Rarely, an L-loop folding pattern lands the right ventricle to the left of the left ventricle. This is seen in "congenitally corrected" transposition of the great arteries.

Fig. 3. The second segment. (A) The basis of the atrioventricular concordance lies in the folding (ventricular looping) of the tubular embryonic heart to form a folded four-chamber heart. Initially, the cardiac apex is on the right, but final looping of the tube swings the apex to the left and places the right ventricle anterior and rightward to the left ventricle. This is the normal or D-loop pattern. (B) Rarely, an L-loop folding pattern lands the right ventricle to the left of the left ventricle. This is seen in "congenitally corrected" transposition of the great arteries.

Table 3

Echocardiography Features of Cardiac Segments and Connections

Morphological right atrium

Receives right-sided inferior vena cava and superior vena cava Morphological right atrial appendage (triangular, broad-based, with pectinate muscles extending outside appendage lumen) Tricuspid valve Trileaflet

Septal leaflet (attached to ventricular septum) Septal insertion more apical than mitral valve Morphological right ventricle Coarse trabeculations Moderator (septo-marginal) band Trileaflet (tricuspid) valve "Triangular" ventricular cavity Septal chordae Infundibular muscle band Morphological main pulmonary artery

Branch pattern: main trunk with right and left branches

Morphological left atrium

Receives four pulmonic veins Attached to left atrial appendage—smaller tubular with pectinate muscles confined to appendage lumen

Mitral valve

Bileaflet

No septal leaflet or chordae

Morphological left ventricle

Less coarse trabeculations Two clearly defined papillary muscles Ellipsoid ventricular cavity Bileaflet (mitral) valve

Morphological aorta

Coronary arteries (with coronary sinuses) Aortic arch with arteries to head and neck

Coarse trabeculations

Smoother apical trabeculations

Moderator (septomarginal band)

LV i

Papillary * muscle

Apical Prominent Trabeculation

Diastole

Tricuspid Septal Leafl** RA

Diastole

Anterior Mitral Leaflet

Systole

Internal Cardiac Crux

Fig. 5. Morphological left and right ventricle. What defines right vs left ventricle are the morphological characteristics. On echocardiography, the defining features of the right ventricle are the heavy trabeculation and apical-ward septal insertion of the atrioventricular valve leaflet. Smoother apical trabeculations, a more basal septal insertion of the atrioventricular valve leaflet, and a pair of prominent papillary muscles are the most reliable defining characteristics of the left ventricle. The confluence of the septal leaflets to the interatrial and interventricular septal is called the internal cardiac crux (cross). Examination of this relationship is important in congenital heart disease. Loss of the normal pattern (circled) can provide valuable clues in congenital heart disease.

Table 4

The Segmental Set (Pediatric Cardiac Pathology)

Relationship Letter

Segment variants designation

Table 4

The Segmental Set (Pediatric Cardiac Pathology)

Relationship Letter

Segment variants designation

First (atrial and

Situs solitus

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