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Abstract This consensus of nomenclature and classification for congenital bicuspid aortic valve and its aortopathy is evidence-based and intended for universal use by physicians (both pediatricians and adults), echocardiographers, advanced cardiovascular imaging specialists, interventional cardiologists, cardiovascular surgeons, pathologists, geneticists, and researchers spanning these areas of clinical and basic research. In addition, as long as new key and reference research is available, this international consensus may be subject to change based on evidence-based data1.
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BACKGROUND: As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT. METHODS: Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors. RESULTS: In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases. CONCLUSIONS: Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.
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Rejeição de Enxerto , Sobrevivência de Enxerto , Cardiopatias Congênitas , Transplante de Coração , Humanos , Criança , Masculino , Feminino , Pré-Escolar , Lactente , Adolescente , Cardiopatias Congênitas/cirurgia , Cardiopatias Congênitas/patologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento , Seguimentos , Cardiomiopatias/cirurgia , Cardiomiopatias/patologia , Reoperação , Recém-Nascido , Análise de SobrevidaRESUMO
Objective: This study aimed to describe the histomorphologic characteristics of resected (unroofed) common wall tissue from repair of anomalous aortic origin of a coronary artery and to determine whether the histologic features correlate with clinical and imaging findings. Methods: The histology of resected tissue was analyzed and reviewed for the presence of fibrointimal hyperplasia, smooth muscle disarray, mucoid extracellular matrix accumulation, mural fibrosis, and elastic fiber disorganization and fragmentation using hematoxylin and eosin and special stains. Clinical, computed tomography imaging, and surgical data were correlated with the histopathologic findings. Results: Twenty specimens from 20 patients (age range, 7-18 years; 14 males) were analyzed. Anomalous aortic origin of a coronary artery involved the right coronary in 16 (80%), and a slit-like ostium was noted in 18 (90%). By computed tomography imaging, the median proximal coronary artery eccentricity index was 0.4 (range, 0.20-0.90). The median length of intramural course was 8.2 mm (range, 2.6-15.2 mm). The anomalous vessel was determined to be interarterial in 14 patients (93%, 15 had evaluable images). The median distance from a commissure was 2.5 mm above the sinotubular junction (STJ) (range: 2 mm below the STJ-14 mm above the STJ). Prominent histopathologic findings included elastic fiber alterations, mural fibrosis, and smooth muscle disarray. The shared wall of the aorta and intramural coronary artery is more similar to the aorta histologically. Mural fibrosis and elastic fiber abnormalities tended to be more severe in patients >10 years of age at the time of surgery, but this did not reach statistical significance. The extent of vascular changes did not appear to have a clear relationship with the imaging features. Conclusions: The findings confirm the aortic wall-like quality of the intramural segment of the coronary artery and the presence of pathologic alterations in the wall microstructure.
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Spontaneous coronary artery dissection in infants is a rare phenomenon. We present 2 neonates with severe ventricular dysfunction due to coronary artery dissection. Neither patient had evidence of extracardiac fibromuscular dysplasia or other comorbidities that would explain the presentation. (Level of Difficulty: Advanced.).
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A 2-month-old male infant, born premature with a birth weight of 865 g, was found to have a tricuspid valve mass mimicking thrombus and vegetation by echocardiogram on the fourth day of life. The patient was treated with antibiotics and anticoagulation with no change in the size of the mass on serial follow-up echocardiography. The patient died of severe pulmonary vein stenosis and complex neurological disability. Postmortem cardiac examination revealed numerous cardiac blood cysts with two dominant ones (1.6 and 1.5 mm) on the septal leaflet of the tricuspid valve, which based on the location and position corresponded to the suspected vegetation and thrombus on imaging. Cardiac blood cysts on valve leaflets are a common incidental finding during autopsy within the first 6 months of life; however, they are rarely detected on imaging because of their minute size, often < 0.5 mm. In this case, the sizable blood cysts were thought to represent thrombus or vegetation on echocardiogram, which influenced the patient management.
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Cistos , Trombose , Lactente , Recém-Nascido , Masculino , Humanos , Valva Tricúspide/diagnóstico por imagem , Ecocardiografia , Cistos/diagnóstico por imagem , Trombose/diagnóstico por imagem , Coagulação SanguíneaRESUMO
AIMS: Bioprosthetic heart valves (BHVs), made from glutaraldehyde-fixed heterograft materials, are subject to more rapid structural valve degeneration (SVD) in paediatric and young adult patients. Differences in blood biochemistries and propensity for disease accelerate SVD in these patients, which results in multiple re-operations with compounding risks. The goal of this study is to investigate the mechanisms of BHV biomaterial degeneration and present models for studying SVD in young patients and juvenile animal models. METHODS AND RESULTS: We studied SVD in clinical BHV explants from paediatric and young adult patients, juvenile sheep implantation model, rat subcutaneous implants, and an ex vivo serum incubation model. BHV biomaterials were analysed for calcification, collagen microstructure (alignment and crimp), and crosslinking density. Serum markers of calcification and tissue crosslinking were compared between young and adult subjects. We demonstrated that immature subjects were more susceptible to calcification, microstructural changes, and advanced glycation end products formation. In vivo and ex vivo studies comparing immature and mature subjects mirrored SVD in clinical observations. The interaction between host serum and BHV biomaterials leads to significant structural and biochemical changes which impact their functions. CONCLUSIONS: There is an increased risk for accelerated SVD in younger subjects, both experimental animals and patients. Increased calcification, altered collagen microstructure with loss of alignment and increased crimp periods, and increased crosslinking are three main characteristics in BHV explants from young subjects leading to SVD. Together, our studies establish a basis for assessing the increased susceptibility of BHV biomaterials to accelerated SVD in young patients.
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Bioprótese , Calcinose , Próteses Valvulares Cardíacas , Animais , Ratos , Ovinos , Valvas Cardíacas , Materiais Biocompatíveis , ColágenoRESUMO
BACKGROUND: Outcomes following congenital aortic valve (AoV) repair are plagued by progressive dysfunction of currently available leaflet substitute materials. OBJECTIVES: We compared the long-term outcomes of congenital AoV repair using porcine intestinal submucosa vs autologous pericardium (AP). METHODS: This was a single-center retrospective review of all patients who underwent congenital AoV repair with either porcine intestinal submucosa or AP from October 2009 to March 2013. The primary outcome was postdischarge (late) unplanned AoV reintervention. Secondary outcomes included number of late AoV reinterventions and a composite of at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention. Associations between leaflet repair material and outcomes were assessed using multivariable regression models, adjusting for prespecified patient-related and operative variables. RESULTS: Of 26 porcine intestinal submucosa and 49 AP patients who met entry criteria, the median age was 11.0 years (IQR: 4.7-16.6 years). At a median follow-up of 8.5 years (IQR: 4.4-9.6 years), 17 (65.4%) porcine intestinal submucosa and 22 (44.9%) AP patients underwent at least 1 AoV reintervention. On multivariable analysis, porcine intestinal submucosa use was significantly associated with unplanned AoV reintervention (HR: 4.6; 95% CI: 2.2-9.8; P < 0.001), number of postdischarge AoV reinterventions (incidence rate ratio: 1.7; 95% CI: 1.0-2.9; P = 0.037), and at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention (OR: 5.0; 95% CI: 1.2-21.0; P = 0.027). CONCLUSIONS: Aortic valvuloplasty with porcine intestinal submucosa is associated with earlier time to reintervention compared with autologous pericardium. The search for the ideal AoV leaflet repair material continues.
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Insuficiência da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Assistência ao Convalescente , Animais , Valva Aórtica , Insuficiência da Valva Aórtica/cirurgia , Constrição Patológica/complicações , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Alta do Paciente , Pericárdio , Reoperação/efeitos adversos , Estudos Retrospectivos , Suínos , Resultado do TratamentoRESUMO
BACKGROUND: Neurodevelopmental impairment is common in survivors of congenital diaphragmatic hernia (CDH). Altered cerebral perfusion in utero may contribute to abnormal brain development in CDH patients. METHODS: 5 fetal lambs with surgical left-CDH and 5 controls underwent transuterine cranial Doppler and contrast enhanced ultrasound (CEUS). Global and regional perfusion metrics were obtained. Biometric and perfusion data were compared between groups via nonparametric Mann Whitney U test and Spearman's rank order correlation. RESULTS: No significant differences in cerebral Doppler measurements were identified between groups. By CEUS, CDH animals demonstrated significantly decreased global brain perfusion and increased transit time. With focal regions-of-interest (ROIs), there was a tendency towards decreased perfusion in the central/thalamic region in CDH but not in the peripheral brain parenchyma. Transit time was significantly increased in both ROIs in CDH, whereas flux rate was decreased in the central/thalamic region but not the peripheral brain parenchyma. Biometric CDH severity was correlated to perfusion deficit. There was no difference in cardiomyocyte histology. CONCLUSION: The fetal lamb model of CDH shows altered cerebral perfusion as measured by CEUS, correlating to disease severity. This suggests a physiological abnormality in fetal cerebrovascular perfusion that may contribute to abnormal brain development and neurodevelopmental impairment in survivors.
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Hérnias Diafragmáticas Congênitas , Animais , Circulação Cerebrovascular , Feto , Hérnias Diafragmáticas Congênitas/patologia , Humanos , Pulmão , Perfusão , Ovinos , Ultrassonografia DopplerRESUMO
BACKGROUND: In patients with congenitally corrected transposition of the great arteries (ccTGA) with an intact ventricular septum (IVS) or d-looped transposition of the great arteries (DTGA) with IVS after an atrial switch operation, left ventricular dysfunction often develops after anatomic repair despite previous retraining of the morphologically left ventricle (mLV) by using pulmonary artery banding (PAB). This study examined histopathologic changes in such mLVs. METHODS: Capillary density, myocyte diameter, and interstitial fibrous area in the mLV were retrospectively evaluated in postmortem or explanted heart specimens obtained from patients with ccTGA with IVS or DTGA with IVS after atrial switch operations after PAB for retraining and were compared with those of patients with normal cardiac anatomy, ccTGA with IVS or DTGA with IVS without PAB, and ccTGA or DTGA with high mLV pressure by using generalized estimating equations models. RESULTS: Adjusting for age, capillary density in 4 patients with ccTGA with IVS or DTGA with IVS after PAB was approximately 20% lower than that in 8 patients with normal cardiac anatomy (3149 ± 863/µm2 vs 3978 ± 1206/µm2 [mean, SD]; P = .039), whereas myocyte diameter was approximately 50% larger (16.2 ± 4.0 µm vs 11.7 ± 2.4 µm [mean, SD]; P < .001). The interstitial fibrous area did not differ between the 2 groups (803 ± 422 µm2 vs 789 ± 480 µm2; P = .92). CONCLUSIONS: The study investigators observed significant cardiomyocyte hypertrophy but lower capillary density in patients with ccTGA with IVS or DTGA with IVS after PAB for retraining compared with normal control subjects. This finding suggests that inadequate capillary growth is a potential pathologic basis for mLV dysfunction occurring after retraining or anatomic repair.
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Transposição dos Grandes Vasos , Transposição das Grandes Artérias Corrigida Congenitamente , Ventrículos do Coração/cirurgia , Humanos , Artéria Pulmonar/cirurgia , Estudos Retrospectivos , Transposição dos Grandes Vasos/cirurgia , Resultado do TratamentoRESUMO
This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes. © 2021 Jointly between the RSNA, the European Association for Cardio-Thoracic Surgery, The Society of Thoracic Surgeons, and the American Association for Thoracic Surgery. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. All rights reserved. Keywords: Bicuspid Aortic Valve, Aortopathy, Nomenclature, Classification.
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This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.
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Estenose da Valva Aórtica , Doença da Válvula Aórtica Bicúspide , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Consenso , Humanos , FenótipoRESUMO
This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.
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Estenose da Valva Aórtica , Doença da Válvula Aórtica Bicúspide , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Consenso , Humanos , FenótipoRESUMO
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.
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Cardiopatias Congênitas , Classificação Internacional de Doenças , Criança , Feminino , Humanos , Sistema de Registros , Sociedades MédicasRESUMO
This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.
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Doença da Válvula Aórtica Bicúspide/classificação , Doença da Válvula Aórtica Bicúspide/cirurgia , Pesquisa Biomédica , Humanos , Systematized Nomenclature of MedicineRESUMO
This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.
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Doença da Válvula Aórtica Bicúspide/classificação , Doença da Válvula Aórtica Bicúspide/genética , Humanos , Fenótipo , Systematized Nomenclature of MedicineRESUMO
This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.
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Aorta , Doenças da Aorta/classificação , Valva Aórtica/anormalidades , Doença da Válvula Aórtica Bicúspide/classificação , Terminologia como Assunto , Aorta/diagnóstico por imagem , Aorta/cirurgia , Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/cirurgia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Aortografia , Doença da Válvula Aórtica Bicúspide/diagnóstico por imagem , Doença da Válvula Aórtica Bicúspide/cirurgia , Técnicas de Imagem Cardíaca , Consenso , Humanos , Fenótipo , Valor Preditivo dos Testes , PrognósticoRESUMO
This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.
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Aorta , Doenças da Aorta/classificação , Valva Aórtica/anormalidades , Doença da Válvula Aórtica Bicúspide/classificação , Terminologia como Assunto , Aorta/diagnóstico por imagem , Aorta/cirurgia , Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/cirurgia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Aortografia , Doença da Válvula Aórtica Bicúspide/diagnóstico por imagem , Doença da Válvula Aórtica Bicúspide/cirurgia , Técnicas de Imagem Cardíaca , Consenso , Humanos , Fenótipo , Valor Preditivo dos Testes , PrognósticoRESUMO
The histological spectrum of the central fibrous body (CFB) of the heart, particularly in humans, is not fully characterized. Herein, we describe the presence of cartilage and bone within the CFB of 2 explanted heart specimens from patients with known mutation-driven cardiomyopathy involving the TNNI3 and TNNT2 genes, review the existing literature on the identified variants particularly TNNI3 (p.Asn185Thrfs*14) and TNNT2 (p.Arg141Trp), and provide insights into the plausible nature of such histopathological observation based on animal studies and the few reported cases in humans.
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Cardiomiopatias/patologia , Cartilagem , Coristoma/patologia , Miocárdio/patologia , Ossificação Heterotópica/patologia , Troponina I/genética , Troponina T/genética , Adolescente , Cardiomiopatias/diagnóstico , Cardiomiopatias/genética , Cardiomiopatias/cirurgia , Coristoma/diagnóstico , Coristoma/genética , Coristoma/cirurgia , Feminino , Transplante de Coração , Humanos , Masculino , Metaplasia , Mutação , Ossificação Heterotópica/diagnóstico , Ossificação Heterotópica/genética , Ossificação Heterotópica/cirurgiaRESUMO
In this issue of World Journal for Pediatric and Congenital Heart Surgery, Kari and colleagues present a case of anatomically corrected malposition {S, L, L} with ventricular septal defect and complex subaortic stenosis managed by staged biventricular repair. This rare case with interesting management strategy provides an opportunity to clarify this and related unusual ventriculo-arterial alignments.
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Estenose Aórtica Subvalvar , Cardiomiopatia Hipertrófica , Comunicação Interventricular , Artérias , Criança , HumanosRESUMO
OBJECTIVES: This study sought to evaluate for the presence of and characterize the interdigitating and entrapped myocardium within cardiac fibromas (CF) and correlate tissue findings with symptoms and surgical outcomes. BACKGROUND: The mechanism of ventricular tachycardia (VT) in CF is unclear. The authors hypothesized that CF harbor tongues of interdigitating myocardium, which could be a substrate for episodes of arrhythmia analogous to peri-infarct zones. METHODS: A total of 29 patients (14 boys) with CF were identified; all subjects had undergone at least partial tumor resection. A semiquantitative grading system was used to assess the degree of myocardial interdigitation and entrapment, myocyte morphology (hematoxylin and eosin stain and immunohistochemical stain for desmin), tumor collagen density, and cellularity (trichrome stain). The subjects' ages at presentation, types of arrhythmia, and responses to surgery were correlated with histology. RESULTS: CF consistently demonstrated interdigitating and entrapped myocardium, and the extent correlated negatively with age at surgery, as did cellularity, whereas collagen increased with age. Median age at arrhythmia recognition was 8 months. Sustained VT was present in 18 of 29 patients (62%), and 5 of 6 patients with prenatally diagnosed conditions developed VT before 8 months. All 8 patients who experienced cardiac arrest had clinically significant arrhythmia events. Sustained arrhythmia episodes correlated with more diffuse myocyte interdigitation. Ten patients had abnormal karyotype: chromosomes 9 (n = 3) and 3 (n = 1) deletions; isolated translocations: t(4;13), t(5;11) and t(1;9); and undefined aberrations (n = 3). All patients who underwent complete resection were cured of arrhythmias, whereas 2 of 14 patients who had subtotal resections had recurrence, with resolution following re-resection in 1 patient. CONCLUSIONS: Interdigitating myocardium represents a potential histopathologic substrate for VT and cardiac arrest in CF, which may also explain the occasional recurrence of arrhythmia following incomplete resection.