1. How Should We Optimally Describe Complex Congenitally Malformed Hearts? 
Robert H. Anderson, MD 
The Annals of Thoracic Surgery 
Volume 62, Issue 3, Pages (August 1996)
DOI: /S (96)
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

2. Fig. 1
The three segments of the heart are made up of strictly limited components. At the atrial level, as judged by the extent of the pectinate muscles (shown by the bracket lines) within the appendages, atrial chambers can be of only right or left morphology, although the venoatrial connections (not shown) can vary markedly. According to the nature of apical trabeculations, ventricles may be of right, left, or indeterminate morphology. Four types of arterial trunk can be recognized according to the pattern of branching, the solitary variant existing only in the setting of complete absence of the intrapericardial pulmonary arteries.
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

3. Fig. 2
Hearts with usually arranged or mirror-imaged atrial appendages can be joined to the ventricles in either concordant or discordant fashion. (LV = 5 left ventricle; RV = 5 right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

4. Fig. 3
When the appendages are isomeric, then irrespective of how the atrial chambers are joined each to their own ventricle the arrangement must be biventricular and ambiguous, as of necessity half of the heart will always show a concordant union whereas the other half will be joined in discordant fashion. (LV = left ventricle; RV = right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

5. Fig. 4
Hearts with all patterns of arrangement of the atrial appendages (upper row) can exist with the atrial chambers joined to only one ventricle, this arrangement being produced by either double-inlet connection or absence of one atrioventricular (AV) connection (middle row). The ventricle to which the atrial chambers are joined can be a dominant left ventricle (LV), with an anterosuperior rudimentary right ventricle (RV), a dominant left ventricle with a posteroinferior rudimentary left ventricle, or a solitary and indeterminate ventricle (Ind. V) lacking a second chamber within the ventricular mass (bottom row). The rudimentary ventricles can be right- or left-sided irrespective of their morphology.
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

6. Fig. 5
Double-inlet ventricle exists when both segments of atrial myocardium (right-sided or left-sided) are joined to the same ventricle, shown in this diagram as a dominant left ventricle (LV). As shown, this arrangement can be found irrespective of whether the two junctions (right-sided and left-sided) are guarded by separate right and left atrioventricular (AV) valves (R and L) or by a common atrioventricular valve. (RV = rudimentary and incomplete right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

7. Fig. 6
The heart exhibits complete absence of the left-sided atrioventricular connection, with the right atrial myocardium joined to both the left and right ventricles because of overriding of its orifice. (AV = atrioventricular; LV = left ventricle; RV = right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions

8. Fig. 7
The arrangement shown in Figure 6 gives a uniatrial but biventricular union between the atrial and ventricular myocardial segments. Both ventricles are incomplete and rudimentary in that they possess less than all their normal component parts. According to the specific atrial arrangement and ventricular topology in any individual case, various combinations must be anticipated with this uniatrial but biventricular junctional pattern.
The Annals of Thoracic Surgery  , DOI: ( /S (96) )
Copyright © 1996 The Society of Thoracic Surgeons Terms and Conditions