The European Congenital Heart Surgeons Association (ECHSA) Congenital Database (CD) is the second largest clinical pediatric and congenital cardiac surgical database in the world and the largest in Europe, where various smaller national or regional databases exist. Despite the dramatic increase in interventional cardiology procedures over recent years, only scattered national or regional databases of such procedures exist in Europe. Most importantly, no congenital cardiac database exists in the world that seamlessly combines both surgical and interventional cardiology data on an international level; therefore, the outcomes of surgical and interventional procedures performed on the same or similar patients cannot easily be tracked, assessed, and analyzed. In order to fill this important gap in our capability to gather and analyze information on our common patients, ECHSA and The Association for European Paediatric and Congenital Cardiology (AEPC) have embarked on a collaborative effort to expand the ECHSA-CD with a new module designed to capture data about interventional cardiology procedures. The purpose of this manuscript is to describe the concept, the structure, and the function of the new AEPC Interventional Cardiology Part of the ECHSA-CD, as well as the potentially valuable synergies provided by the shared interventional and surgical analyses of outcomes of patients. The new AEPC Interventional Cardiology Part of the ECHSA-CD will allow centers to have access to robust surgical and transcatheter outcome data from their own center, as well as robust national and international aggregate outcome data for benchmarking. Each contributing center or department will have access to their own data, as well as aggregate data from the AEPC Interventional Cardiology Part of the ECHSA-CD. The new AEPC Interventional Cardiology Part of the ECHSA-CD will allow cardiology centers to have access to aggregate cardiology data, just as surgical centers already have access to aggregate surgical data. Comparison of surgical and catheter interventional outcomes could potentially strengthen decision processes. A study of the wealth of information collected in the database could potentially also contribute toward improved early and late survival, as well as enhanced quality of life of patients with pediatric and/or congenital heart disease treated with surgery and interventional cardiac catheterization across Europe and the world.

Substantial progress has been made in the standardization of nomenclature for paediatric and congenital cardiac care. In 1936, Maude Abbott published her Atlas of Congenital Cardiac Disease, which was the first formal attempt to classify congenital heart disease. The International Paediatric and Congenital Cardiac Code (IPCCC) is now utilized worldwide and has most recently become the paediatric and congenital cardiac component of the Eleventh Revision of the International Classification of Diseases (ICD-11). The most recent publication of the IPCCC was in 2017. This manuscript provides an updated 2021 version of the IPCCC.

The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD), in collaboration with the World Health Organization (WHO), developed the paediatric and congenital cardiac nomenclature that is now within the eleventh version of the International Classification of Diseases (ICD-11). This unification of IPCCC and ICD-11 is the IPCCC ICD-11 Nomenclature and is the first time that the clinical nomenclature for paediatric and congenital cardiac care and the administrative nomenclature for paediatric and congenital cardiac care are harmonized. The resultant congenital cardiac component of ICD-11 was increased from 29 congenital cardiac codes in ICD-9 and 73 congenital cardiac codes in ICD-10 to 318 codes submitted by ISNPCHD through 2018 for incorporation into ICD-11. After these 318 terms were incorporated into ICD-11 in 2018, the WHO ICD-11 team added an additional 49 terms, some of which are acceptable legacy terms from ICD-10, while others provide greater granularity than the ISNPCHD thought was originally acceptable. Thus, the total number of paediatric and congenital cardiac terms in ICD-11 is 367. In this manuscript, we describe and review the terminology, hierarchy, and definitions of the IPCCC ICD-11 Nomenclature. This article, therefore, presents a global system of nomenclature for paediatric and congenital cardiac care that unifies clinical and administrative nomenclature.

The members of ISNPCHD realize that the nomenclature published in this manuscript will continue to evolve. The version of the IPCCC that was published in 2017 has evolved and changed, and it is now replaced by this 2021 version. In the future, ISNPCHD will again publish updated versions of IPCCC, as IPCCC continues to evolve.

We present the surgical implantation of the Edwards Inspiris Resilia® aortic valve in mitral position for mechanical mitral valve failure in a severely ill infant after valve replacement because of anomalous origin of the left coronary artery from the pulmonary artery. The biological valve was chosen because the child could not receive oral anticoagulation and was for several months on heparin infusion. The procedure was safely performed with good haemodynamic result.

An internationally approved and globally used classification scheme for the diagnosis of CHD has long been sought. The International Paediatric and Congenital Cardiac Code (IPCCC), which was produced and has been maintained by the International Society for Nomenclature of Paediatric and Congenital Heart Disease (the International Nomenclature Society), is used widely, but has spawned many “short list” versions that differ in content depending on the user. Thus, efforts to have a uniform identification of patients with CHD using a single up-to-date and coordinated nomenclature system continue to be thwarted, even if a common nomenclature has been used as a basis for composing various “short lists”. In an attempt to solve this problem, the International Nomenclature Society has linked its efforts with those of the World Health Organization to obtain a globally accepted nomenclature tree for CHD within the 11th iteration of the International Classification of Diseases (ICD-11). The International Nomenclature Society has submitted a hierarchical nomenclature tree for CHD to the World Health Organization that is expected to serve increasingly as the “short list” for all communities interested in coding for congenital cardiology. This article reviews the history of the International Classification of Diseases and of the IPCCC, and outlines the process used in developing the ICD-11 congenital cardiac disease diagnostic list and the definitions for each term on the list. An overview of the content of the congenital heart anomaly section of the Foundation Component of ICD-11, published herein in its entirety, is also included. Future plans for the International Nomenclature Society include linking again with the World Health Organization to tackle procedural nomenclature as it relates to cardiac malformations. By doing so, the Society will continue its role in standardising nomenclature for CHD across the globe, thereby promoting research and better outcomes for fetuses, children, and adults with congenital heart anomalies.

Interventional cardiology for paediatric and congenital cardiac disease is a relatively young and rapidly evolving field. As the profession begins to establish multi-institutional databases, a universal system of nomenclature is necessary for the field of interventional cardiology for paediatric and congenital cardiac disease. The purpose of this paper is to present the results of the efforts of The International Society for Nomenclature of Paediatric and Congenital Heart Disease to establish a system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease, focusing both on procedural nomenclature and the nomenclature of complications associated with interventional cardiology. This system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease is a component of The International Paediatric and Congenital Cardiac Code. This manuscript is the second part of the two-part series. Part 1 covered the procedural nomenclature associated with interventional cardiology as treatment for paediatric and congenital cardiac disease. Part 2 will cover the nomenclature of complications associated with interventional cardiology as treatment for paediatric and congenital cardiac disease.

Interventional cardiology for paediatric and congenital cardiac disease is a relatively young and rapidly evolving field. As the profession begins to establish multi-institutional databases, a universal system of nomenclature is necessary for the field of interventional cardiology for paediatric and congenital cardiac disease. The purpose of this paper is to present the results of the efforts of The International Society for Nomenclature of Paediatric and Congenital Heart Disease to establish a system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease, focusing both on procedural nomenclature and on the nomenclature of complications associated with interventional cardiology. This system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease is a component of The International Paediatric and Congenital Cardiac Code. This manuscript is the first part of a two-part series. Part 1 will cover the procedural nomenclature associated with interventional cardiology as treatment for paediatric and congenital cardiac disease. This procedural nomenclature of The International Paediatric and Congenital Cardiac Code will be used in the IMPACT Registry™ (IMproving Pediatric and Adult Congenital Treatment) of the National Cardiovascular Data Registry® of The American College of Cardiology. Part 2 will cover the nomenclature of complications associated with interventional cardiology as treatment for paediatric and congenital cardiac disease.

The Congenital Cardiac Anesthesia Society was formed in 2005 by representatives from many of the busiest congenital cardiac surgical programs in North America and is now in the process of partnering with The Society of Thoracic Surgeons to create a joint congenital cardiac surgery and congenital cardiac anaesthesia database. Even the busiest of congenital cardiac programs have a low frequency of anaesthesia-related cardiac complications and deaths. One of the only mechanisms for accurately determining the incidence and outcomes of low frequency events is to aggregate large amounts of data from multiple sources. To that end, the Congenital Cardiac Anesthesia Society has joined with the Society of Thoracic Surgeons Congenital Database Task Force to incorporate anaesthesia-specific data points into their surgical registry, which is now the largest single reporting site for children and adults undergoing surgical repair of congenital cardiac malformations in North America. The Joint Congenital Cardiac Anesthesia Society – Society of Thoracic Surgeons Database will therefore become an optional module of The Society of Thoracic Surgeons Congenital Heart Surgery Database. Initial data fields have been selected and are presented in this article.

Efforts are ongoing to make this initiative a global project. Initial collaborative discussions have taken place about the possibility of linking this initiative with the European Association of Cardiothoracic Anesthesiologists. It is certainly possible and desirable that the planned anaesthesia module of The Society of Thoracic Surgeons Congenital Heart Database has an identical module in the congenital heart database of The European Association for Cardio-Thoracic Surgery and The European Congenital Heart Surgeons Association. This project should also ideally spread beyond North America and Europe. Efforts to involve Africa, Asia, Australia, and South America are necessary and already underway. The creation of a joint cardiac surgery and anaesthesia database is another step towards the ultimate goal of creating a database for congenital heart disease that spans both geographical and subspecialty boundaries.

Clinicians working in the field of congenital and paediatric cardiology have long felt the need for a common diagnostic and therapeutic nomenclature and coding system with which to classify patients of all ages with congenital and acquired cardiac disease. A cohesive and comprehensive system of nomenclature, suitable for setting a global standard for multicentric analysis of outcomes and stratification of risk, has only recently emerged, namely, The International Paediatric and Congenital Cardiac Code. This review, will give an historical perspective on the development of systems of nomenclature in general, and specifically with respect to the diagnosis and treatment of patients with paediatric and congenital cardiac disease. Finally, current and future efforts to merge such systems into the paperless environment of the electronic health or patient record on a global scale are briefly explored.

On October 6, 2000, The International Nomenclature Committee for Pediatric and Congenital Heart Disease was established. In January, 2005, the International Nomenclature Committee was constituted in Canada as The International Society for Nomenclature of Paediatric and Congenital Heart Disease. This International Society now has three working groups. The Nomenclature Working Group developed The International Paediatric and Congenital Cardiac Code and will continue to maintain, expand, update, and preserve this International Code. It will also provide ready access to the International Code for the global paediatric and congenital cardiology and cardiac surgery communities, related disciplines, the healthcare industry, and governmental agencies, both electronically and in published form. The Definitions Working Group will write definitions for the terms in the International Paediatric and Congenital Cardiac Code, building on the previously published definitions from the Nomenclature Working Group. The Archiving Working Group, also known as The Congenital Heart Archiving Research Team, will link images and videos to the International Paediatric and Congenital Cardiac Code. The images and videos will be acquired from cardiac morphologic specimens and imaging modalities such as echocardiography, angiography, computerized axial tomography and magnetic resonance imaging, as well as intraoperative images and videos.

Efforts are ongoing to expand the usage of The International Paediatric and Congenital Cardiac Code to other areas of global healthcare. Collaborative efforts are underway involving the leadership of The International Nomenclature Committee for Pediatric and Congenital Heart Disease and the representatives of the steering group responsible for the creation of the 11th revision of the International Classification of Diseases, administered by the World Health Organisation. Similar collaborative efforts are underway involving the leadership of The International Nomenclature Committee for Pediatric and Congenital Heart Disease and the International Health Terminology Standards Development Organisation, who are the owners of the Systematized Nomenclature of Medicine or “SNOMED”.

The International Paediatric and Congenital Cardiac Code was created by specialists in the field to name and classify paediatric and congenital cardiac disease and its treatment. It is a comprehensive code that can be freely downloaded from the internet (http://www.IPCCC.net) and is already in use worldwide, particularly for international comparisons of outcomes. The goal of this effort is to create strategies for stratification of risk and to improve healthcare for the individual patient. The collaboration with the World Heath Organization, the International Health Terminology Standards Development Organisation, and the healthcare industry, will lead to further enhancement of the International Code, and to its more universal use.

The diagnosis and treatment for paediatric and congenital cardiac disease has undergone remarkable progress over the last 60 years. Unfortunately, this progress has been largely limited to the developed world. Yet every year approximately 90% of the more than 1,000,000 children who are born with congenital cardiac disease across the world receive either suboptimal care or are totally denied care.

While in the developed world the focus has changed from an effort to decrease post-operative mortality to now improving quality of life and decreasing morbidity, which is the focus of this Supplement, the rest of the world still needs to develop basic access to congenital cardiac care. The World Society for Pediatric and Congenital Heart Surgery [http://www.wspchs.org/] was established in 2006. The Vision of the World Society is that every child born anywhere in the world with a congenital heart defect should have access to appropriate medical and surgical care. The Mission of the World Society is to promote the highest quality comprehensive care to all patients with pediatric and/or congenital heart disease, from the fetus to the adult, regardless of the patient’s economic means, with emphasis on excellence in education, research and community service.

We present in this article an overview of the epidemiology of congenital cardiac disease, the current and future challenges to improve care in the developed and developing world, the impact of the globalization of cardiac surgery, and the role that the World Society should play. The World Society for Pediatric and Congenital Heart Surgery is in a unique position to influence and truly improve the global care of children and adults with congenital cardiac disease throughout the world [http://www.wspchs.org/].

Accurate, complete data is now the expectation of patients, families, payers, government, and even media. It has become an obligation of those practising congenital cardiac surgery. Appropriately, major professional organizations worldwide are assuming responsibility for the data quality in their respective registry databases.

The purpose of this article is to review the current strategies used for verification of the data in the congenital databases of The Society of Thoracic Surgeons, The European Association for Cardio-Thoracic Surgery, and The United Kingdom Central Cardiac Audit Database. Because the results of the initial efforts to verify data in the congenital databases of the United Kingdom and Europe have been previously published, this article provides a more detailed look at the current efforts in North America, which prior to this article have not been published. The discussion and presentation of the strategy for the verification of data in the congenital heart surgery database of The Society of Thoracic Surgeons is then followed by a review of the strategies utilized in the United Kingdom and Europe. The ultimate goal of sharing the information in this article is to provide information to the participants in the databases that track the outcomes of patients with congenitally malformed hearts. This information should help to improve the quality of the data in all of our databases, and therefore increase the utility of these databases to function as a tool to optimise the management strategies provided to our patients.

The need for accurate, complete and high quality Congenital Heart Surgery outcome data has never been more pressing. The public interest in medical outcomes is at an all time high and “pay for performance” is looming on the horizon. Information found in administrative databases is not risk or complexity adjusted, notoriously inaccurate, and far too imprecise to evaluate performance adequately in congenital cardiac surgery. The Society of Thoracic Surgeons and European Association for Cardio-Thoracic Surgery databases contain the elements needed for assessment of quality of care provided that a mechanism exists within these organizations to guarantee the completeness and accuracy of the data. The Central Cardiac Audit Database in the United Kingdom has an advantage in this endeavour with the ability to track and verify mortality independently, through their National Health Service.

A combination of site visits with “Source Data Verification”, in other words, verification of the data at the primary source of the data, and external verification of the data from independent databases or registries, such as governmental death registries, may ultimately be required to allow for optimal verification of data. Further research in the area of verification of data is also necessary. Data must be verified for both completeness and accuracy.

A complication is an event or occurrence that is associated with a disease or a healthcare intervention, is a departure from the desired course of events, and may cause, or be associated with, suboptimal outcome. A complication does not necessarily represent a breech in the standard of care that constitutes medical negligence or medical malpractice. An operative or procedural complication is any complication, regardless of cause, occurring (1) within 30 days after surgery or intervention in or out of the hospital, or (2) after 30 days during the same hospitalization subsequent to the operation or intervention. Operative and procedural complications include both intraoperative/intraprocedural complications and postoperative/postprocedural complications in this time interval.

The MultiSocietal Database Committee for Pediatric and Congenital Heart Disease has set forth a comprehensive list of complications associated with the treatment of patients with congenital cardiac disease, related to cardiac, pulmonary, renal, haematological, infectious, neurological, gastrointestinal, and endocrinal systems, as well as those related to the management of anaesthesia and perfusion, and the transplantation of thoracic organs. The objective of this manuscript is to examine the definitions of operative morbidity as they relate specifically to the haematological system and to infectious complications. These specific definitions and terms will be used to track morbidity associated with surgical and transcatheter interventions and other forms of therapy in a common language across many separate databases.

The MultiSocietal Database Committee for Pediatric and Congenital Heart Disease has prepared and defined a near-exhaustive list of haematological and infectious complications. Within each subgroup, complications are presented in alphabetical order. Clinicians caring for patients with congenital cardiac disease will be able to use this list for databases, quality improvement initiatives, reporting of complications, and comparing strategies for treatment.

This review discusses the historical aspects, current state of the art, and potential future advances in the areas of nomenclature and databases for the analysis of outcomes of treatments for patients with congenitally malformed hearts. We will consider the current state of analysis of outcomes, lay out some principles which might make it possible to achieve life-long monitoring and follow-up using our databases, and describe the next steps those involved in the care of these patients need to take in order to achieve these objectives. In order to perform meaningful multi-institutional analyses, we suggest that any database must incorporate the following six essential elements: use of a common language and nomenclature, use of an established uniform core dataset for collection of information, incorporation of a mechanism of evaluating case complexity, availability of a mechanism to assure and verify the completeness and accuracy of the data collected, collaboration between medical and surgical subspecialties, and standardised protocols for life-long follow-up.

During the 1990s, both The European Association for Cardio-Thoracic Surgery and The Society of Thoracic Surgeons created databases to assess the outcomes of congenital cardiac surgery. Beginning in 1998, these two organizations collaborated to create the International Congenital Heart Surgery Nomenclature and Database Project. By 2000, a common nomenclature, along with a common core minimal dataset, were adopted by The European Association for Cardio-Thoracic Surgery and The Society of Thoracic Surgeons, and published in the Annals of Thoracic Surgery. In 2000, The International Nomenclature Committee for Pediatric and Congenital Heart Disease was established. This committee eventually evolved into the International Society for Nomenclature of Paediatric and Congenital Heart Disease. The working component of this international nomenclature society has been The International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, also known as the Nomenclature Working Group. By 2005, the Nomenclature Working Group crossmapped the nomenclature of the International Congenital Heart Surgery Nomenclature and Database Project of The European Association for Cardio-Thoracic Surgery and The Society of Thoracic Surgeons with the European Paediatric Cardiac Code of the Association for European Paediatric Cardiology, and therefore created the International Paediatric and Congenital Cardiac Code, which is available for free download from the internet at [http://www.IPCCC.NET].

This common nomenclature, the International Paediatric and Congenital Cardiac Code, and the common minimum database data set created by the International Congenital Heart Surgery Nomenclature and Database Project, are now utilized by both The European Association for Cardio-Thoracic Surgery and The Society of Thoracic Surgeons. Between 1998 and 2007 inclusive, this nomenclature and database was used by both of these two organizations to analyze outcomes of over 150,000 operations involving patients undergoing surgical treatment for congenital cardiac disease.

Two major multi-institutional efforts that have attempted to measure the complexity of congenital heart surgery are the Risk Adjustment in Congenital Heart Surgery-1 system, and the Aristotle Complexity Score. Current efforts to unify the Risk Adjustment in Congenital Heart Surgery-1 system and the Aristotle Complexity Score are in their early stages, but encouraging. Collaborative efforts involving The European Association for Cardio-Thoracic Surgery and The Society of Thoracic Surgeons are under way to develop mechanisms to verify the completeness and accuracy of the data in the databases. Under the leadership of The MultiSocietal Database Committee for Pediatric and Congenital Heart Disease, further collaborative efforts are ongoing between congenital and paediatric cardiac surgeons and other subspecialties, including paediatric cardiac anaesthesiologists, via The Congenital Cardiac Anesthesia Society, paediatric cardiac intensivists, via The Pediatric Cardiac Intensive Care Society, and paediatric cardiologists, via the Joint Council on Congenital Heart Disease and The Association for European Paediatric Cardiology.

In finalising our review, we emphasise that analysis of outcomes must move beyond mortality, and encompass longer term follow-up, including cardiac and non cardiac morbidities, and importantly, those morbidities impacting health related quality of life. Methodologies must be implemented in these databases to allow uniform, protocol driven, and meaningful, long term follow-up.

This review includes a brief discussion, from the perspective of cardiac surgeons, of the rationale for creation and maintenance of multi-institutional databases of outcomes of congenital heart surgery, together with a history of the evolution of such databases, a description of the current state of the art, and a discussion of areas for improvement and future expansion of the concept. Five fundamental areas are reviewed: nomenclature, mechanism of data collection and storage, mechanisms for the evaluation and comparison of the complexity of operations and stratification of risk, mechanisms to ensure the completeness and accuracy of the data, and mechanisms for expansion of the current capabilities of databases to include comparison and sharing of data between medical subspecialties. This review briefly describes several European and North American initiatives related to databases for pediatric and congenital cardiac surgery the Congenital Database of The European Association for Cardio-Thoracic Surgery, the Congenital Database of The Society of Thoracic Surgeons, the Pediatric Cardiac Care Consortium, and the Central Cardiac Audit Database in the United Kingdom. Potential means of approaching the ultimate goal of acquisition of long-term follow-up data, and input of this data over the life of the patient, are also considered.

When designed in 2000, the Aristotle Complexity Score was entirely based on subjective probability. This approach, based on the opinion of experts, was considered a good solution due to the limited amount of data available. In 2008, the next generation of the complexity score will be based on observed data available from over 100,000 congenital cardiac operations currently gathered in the congenital cardiac surgery databases of the Society of Thoracic Surgeons and the European Association for Cardio-Thoracic Surgery.

A mortality score is created based on 70,000 surgeries harvested in the congenital databases of The Society of Thoracic Surgeons and The European Association for Cardio-Thoracic Surgery. It is derived from 118 congenital cardiovascular operations, representing 91% of the operations and including 97% of the patients. This Mortality Index of the new Aristotle Complexity Score could further be stratified into 5 levels with minimal within-group variation and maximal between-group variation, and may contribute to the planned unification of the Aristotle Complexity Score with the Risk Adjustment for Congenital Heart Surgery system.

Similarly, a score quantifying morbidity risk is created. Due to the progress of congenital cardiac surgery, the mortality is today reduced to an average of 4%. No instrument currently exists to measure the quality of care delivered to the survivors representing 96% of the patients. An objective assessment of morbidity was needed. The Morbidity Index, based on 50,000 operations gathered in the congenital databases of The Society of Thoracic Surgeons and The European Association for Cardio-Thoracic Surgery, is derived from 117 congenital cardiovascular operations representing 90% of the operations and including 95% of the patients. This morbidity indicator is calculated on an algorithm based on length of stay in the hospital and time on the ventilator.

The mortality and morbidity indicators will be part of the next generation of the complexity score, which will be named the Aristotle Average Complexity Score. It will be based on the sum of mortality, morbidity, and subjective technical difficulty. The introduction of objective data in assessment of mortality and morbidity in congenital cardiac surgery is a significant step forward, which should allow a better evaluation of the complexity of the operations performed by a given centre or surgeon.

In 2000, The International Nomenclature Committee for Pediatric and Congenital Heart Disease was established. This committee eventually evolved into the International Society for Nomenclature of Paediatric and Congenital Heart Disease. The working component of this international nomenclature society has been The International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, also known as the Nomenclature Working Group. The Nomenclature Working Group created the International Paediatric and Congenital Cardiac Code, which is available for free download from the internet at [http://www.IPCCC.NET].

In previous publications from the Nomenclature Working Group, unity has been produced by cross-mapping separate systems for coding, as for example in the treatment of the functionally univentricular heart, hypoplastic left heart syndrome, or congenitally corrected transposition. In this manuscript, we review the nomenclature, definition, and classification of heterotaxy, also known as the heterotaxy syndrome, placing special emphasis on the philosophical approach taken by both the Bostonian school of segmental notation developed from the teachings of Van Praagh, and the European school of sequential segmental analysis. The Nomenclature Working Group offers the following definition for the term “heterotaxy”: “Heterotaxy is synonymous with ‘visceral heterotaxy’ and ‘heterotaxy syndrome’. Heterotaxy is defined as an abnormality where the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. By convention, heterotaxy does not include patients with either the expected usual or normal arrangement of the internal organs along the left-right axis, also known as ‘situs solitus’, nor patients with complete mirror-imaged arrangement of the internal organs along the left-right axis also known as ‘situs inversus’.” “Situs ambiguus is defined as an abnormality in which there are components of situs solitus and situs inversus in the same person. Situs ambiguus, therefore, can be considered to be present when the thoracic and abdominal organs are positioned in such a way with respect to each other as to be not clearly lateralised and thus have neither the usual, or normal, nor the mirror-imaged arrangements.”

The heterotaxy syndrome as thus defined is typically associated with complex cardiovascular malformations. Proper description of the heart in patients with this syndrome requires complete description of both the cardiac relations and the junctional connections of the cardiac segments, with documentation of the arrangement of the atrial appendages, the ventricular topology, the nature of the unions of the segments across the atrioventricular and the ventriculoarterial junctions, the infundibular morphologies, and the relationships of the arterial trunks in space. The position of the heart in the chest, and the orientation of the cardiac apex, must also be described separately. Particular attention is required for the venoatrial connections, since these are so often abnormal. The malformations within the heart are then analysed and described separately as for any patient with suspected congenital cardiac disease. The relationship and arrangement of the remaining thoraco-abdominal organs, including the spleen, the lungs, and the intestines, also must be described separately, because, although common patterns of association have been identified, there are frequent exceptions to these common patterns. One of the clinically important implications of heterotaxy syndrome is that splenic abnormalities are common. Investigation of any patient with the cardiac findings associated with heterotaxy, therefore, should include analysis of splenic morphology. The less than perfect association between the state of the spleen and the form of heart disease implies that splenic morphology should be investigated in all forms of heterotaxy, regardless of the type of cardiac disease. The splenic morphology should not be used to stratify the form of disease within the heart, and the form of cardiac disease should not be used to stratify the state of the spleen. Intestinal malrotation is another frequently associated lesion that must be considered. Some advocate that all patients with heterotaxy, especially those with isomerism of the right atrial appendages or asplenia syndrome, should have a barium study to evaluate for intestinal malrotation, given the associated potential morbidity. The cardiac anatomy and associated cardiac malformations, as well as the relationship and arrangement of the remaining thoraco-abdominal organs, must be described separately. It is only by utilizing this stepwise and logical progression of analysis that it becomes possible to describe correctly, and to classify properly, patients with heterotaxy.

Congenitally corrected transposition is a complex cardiac lesion that is often associated with ventricular septal defect, obstruction of the outflow tract of the morphologically left ventricle, and abnormalities of the morphologically tricuspid valve.1,2 Nomenclature for this lesion has been variable and confusing.1 In this review, we define, and hopefully clarify this terminology. The lesion is a combination of discordant union of the atrial chambers with the ventricles, and the ventricles with the arterial trunks.1,2 In rare circumstances, discordant atrioventricular connections can be associated with concordant ventriculo-arterial connections. This malformation has been called “isolated ventricular inversion”. The term is less than precise, and the descriptive approach using the phrase “discordant atrioventricular connections with concordant ventriculo-arterial connections” is preferred, as discussed below.