Infantile histiocytoid cardiomyopathy: three cases and literature review

Case report: high-dose carvedilol as a potential key drug for arrhythmias in histiocytoid cardiomyopathy

Background

Histiocytoid cardiomyopathy is a rare infancy cardiac disorder manifesting as severe cardiac arrhythmias or dilated cardiomyopathy. There is no specific treatment for these arrhythmias. This is the first report of infantile histiocytoid cardiomyopathy whose refractory ventricular arrhythmias were successfully controlled by high-dose carvedilol.

Case summary

A 4-month-old girl presented with asystole, and recurrent ventricular tachycardias. From the histological findings and clinical symptoms, she was diagnosed as histiocytoid cardiomyopathy. Sedatives were the most effective therapy for her arrhythmia, but the cardiac sympathetic denervation was not effective enough. Finally, her ventricular arrhythmias were controlled with high-dose carvedilol, and she was discharged on hospitalization Day 393.

Discussion

Carvedilol is the only beta blocker that directly acts on the ryanodine receptor (RyR2) and inhibits store-overload-induced Ca2+ release (SOICR) in myocardium at high dosage. The arrhythmias did not disappear with bisoprolol, landiolol, or verapamil, but high-dose carvedilol was effective. This clinical course suggested that the arrhythmias in histiocytoid cardiomyopathy might be related with SOICR. High-dose carvedilol might be a key drug for patients with histiocytoid cardiomyopathy.

Histiocytoid cardiomyopathy presenting as sudden death in an 18-month-old infant

Histiocytoid cardiomyopathy (HC) is an arrhythmogenic disorder, usually involving children under two years of age with a strong Caucasian and female predominance. The disease is fatal in the vast majority and diagnosis is nearly always established at autopsy, but this is only possible with adequate myocardial sampling. Meticulous gross and histological examination of the heart in collaboration with a cardiovascular-trained pathologist maximises the opportunity to make specific diagnoses (and therefore rule out the differentials of SIDS, SUDC and child abuse), guide genetic testing, and inform potentially life-saving medical interventions for blood relations. We present a typical HC case presenting as sudden death, without prodrome, in a previously healthy 18-month-old boy. The disease is characterised histologically by discrete groups of enlarged, polygonal histiocyte-like cells with distinct margins and abundant faintly eosinophilic foamy cytoplasm. Cells often contain coarse granules, microvacuoles and irregular, round nuclei. In our case, dysplastic fascicles were predominantly located immediately deep to the endocardium of the left ventricle. We report our own autopsy findings with histological images, and discuss the expected clinical, morphological and ultrastructural features of the disease.

2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Histiocytoid cardiomyopathy and microphthalmia with linear skin defects syndrome: phenotypes linked by truncating variants in NDUFB11

Variants in NDUFB11, which encodes a structural component of complex I of the mitochondrial respiratory chain (MRC), were recently independently reported to cause histiocytoid cardiomyopathy (histiocytoid CM) and microphthalmia with linear skin defects syndrome (MLS syndrome). Here we report an additional case of histiocytoid CM, which carries a de novo nonsense variant in NDUFB11 (ENST00000276062.8: c.262C > T; p.[Arg88*]) identified using whole-exome sequencing (WES) of a family trio. An identical variant has been previously reported in association with MLS syndrome. The case we describe here lacked the diagnostic features of MLS syndrome, but a detailed clinical comparison of the two cases revealed significant phenotypic overlap. Heterozygous variants in HCCS (which encodes an important mitochondrially targeted protein) and COX7B, which, like NDUFB11, encodes a protein of the MRC, have also previously been identified in MLS syndrome including a case with features of both MLS syndrome and histiocytoid CM. However, a systematic review of WES data from previously published histiocytoid CM cases, alongside four additional cases presented here for the first time, did not identify any variants in these genes. We conclude that NDUFB11 variants play a role in the pathogenesis of both histiocytoid CM and MLS and that these disorders are allelic (genetically related).

The 2015 WHO Classification of Tumors of the Heart and Pericardium

This article reviews the nomenclature of benign and malignant neoplasm of the heart and pericardium in the 4th edition of the World Health Organization's Classification, with emphasis on differences since the 3rd edition of 2004. The tumours are divided into benign, malignant, and intermediate tumors of uncertain behavior, with separate sections on germ cell tumours and tumors of the pericardium. There are important updates in the sarcoma classification, with emphasis on the most common site, the left atrium. The importance of the new genetic finding in cardiac myxomas, namely somatic mutations in the PRKAR1A gene underscores the importance of this alteration in the pathogenesis of these tumors. Challenges on the classification of each entity are discussed.

Exome sequencing of patients with histiocytoid cardiomyopathy reveals a de novo NDUFB11 mutation that plays a role in the pathogenesis of histiocytoid cardiomyopathy

Histiocytoid cardiomyopathy (Histiocytoid CM) is a rare form of cardiomyopathy observed predominantly in newborn females that is fatal unless treated early in life. We have performed whole exome sequencing on five parent-proband trios and identified nuclear-encoded mitochondrial protein mutations in three cases. The molecular genetic basis of Histiocytoid CM remains unknown despite several hypotheses in medical literature. The findings presented in this manuscript may represent components of genetic etiologies for this heterogeneous disease. Two probands had de novo non-sense mutations in the second exon of the X-linked nuclear gene NDUFB11. A third proband was doubly heterozygous for inherited rare variants in additional components of complex I, NDUFAF2 and NDUFB9, confirming that Histiocytoid CM is genetically heterogeneous. In a fourth case, the proband with Histiocytoid CM inherited a mitochondrial mutation from her heteroplasmic mother, as did her brother who presented with cardiac arrhythmia. Strong candidate recessive or compound heterozygous variants were not found for this individual or for the fifth case. Although NDUFB11 has not been implicated before in cardiac pathology, morpholino-mediated knockdown of ndufb11 in zebrafish embryos generated defective cardiac tissue with cardiomegaly, looping defects, and arrhythmia which suggests the role of NDUFB11 in the pathogenesis of this abnormal cardiac pathology. Taken together, the unbiased whole exome sequencing approach confirms the suspected genetic heterogeneity of Histiocytoid CM. Therefore, the novel NDUFB11 mutation may cause a complex 1 deficiency in synergy with additional unknown mtDNA variants.

MRI of pediatric cardiac masses

OBJECTIVE

The purpose of this article is to describe the characteristic cardiac MRI features of primary and secondary cardiac tumors, including differentiation from masslike lesions, such as thrombus or focal myocardial hypertrophy.

CONCLUSION

The frequency and type of cardiac tumors in children differ from those in adults. Although transthoracic echocardiography is the initial imaging technique of choice for evaluation of cardiac tumors, cardiac MRI is an important complementary modality for characterization of the mass and effect on cardiac function.

Cardiac tumours in infancy

Cardiac tumours in infancy are rare and are mostly benign with rhabdomyomas, fibromas and teratomas accounting for the majority. The presentation depends on size and location of the mass as they tend to cause cavity obstruction or arrhythmias. Most rhabdomyomas tend to regress spontaneously but fibromas and teratomas generally require surgical intervention for severe haemodynamic or arrhythmic complications. Other relatively rare cardiac tumours too are discussed along with an Indian perspective.

Undiagnosed heart disease leading to sudden unexpected death in childhood: a retrospective study

OBJECTIVES

Heart disease accounts for a significant proportion of sudden unexpected deaths among children. We describe here demographic features, pathological conditions, and the frequency of premonitory symptoms in a retrospective series of cases of sudden unexpected cardiac death (SUCD) attributable to undiagnosed structural heart disease.

METHODS

A chart review of autopsies involving children 0 to 17 years of age that were performed at the Hospital for Sick Children (Toronto, Ontario, Canada) between 1984 and 2003 was conducted. Cases of sudden unexpected death within 24 hours after clinical presentation with previously undetected fatal heart disease were included. Cases with multiple or thoracic trauma and chronic or multisystem disease were excluded.

RESULTS

During the 20-year study period, 4926 autopsies were performed. A total of 103 cases (2.1%), involving 51 male patients and 52 female patients 1 day to 15 years of age (mean: 2.9 ± 4.2 years), were diagnosed as having SUCD. The most common diagnoses were myocarditis (n = 37 [35.9%]), hypoplastic left heart syndrome (HLHS) (n = 19 [18.4%]), dilated cardiomyopathy (DCM) (n = 16 [16.5%]), coronary artery anomalies (n = 6 [5.8%]), and aortic stenosis (n = 5 [4.9%]). There was a significant difference in the mean age of presentation between leading causes of SUCD (6.5 days for HLHS, 1.7 years for DCM, and 5.4 years for myocarditis; P < .0001). Of 103 cases, 27 (26.2%) had premonitory symptoms documented.

CONCLUSION

SUCD accounted for 2.1% of all autopsies, and HLHS, DCM, and myocarditis were the 3 most common diagnoses, which presented at increasing ages.

[A rare cause of sudden cardiac failure: histiocytoid cardiomyopathy]

Histiocytoid cardiomyopathy is a rare disease which occurs predominantly in the first two years of life, with a female preponderance. We report the cases of two girls (11 and 15-month-old) which were respectively referred to our institution for ventricular tachycardia and ventricular fibrillation without prodroma. Etiologic findings only showed mild cardiomyopathy. Autopsy and histologic examination led to the diagnosis of histiocytoid cardiomyopathy. Furthermore, in the first observation, agenesis of the corpus callosum was found.

Oncocytic mania: a review of oncocytic lesions throughout the body

Oncocytic lesions are characterized pathologically by an abundance of oncocytes, that is by enlarged, eosinophilic, and finely granular cells enriched in mitochondria. They can arise in numerous organs and tissues, often in endocrine glands, and have been associated with hyperplasia, autoimmunity, and neoplasia. The causes and mechanisms that transform a normal cell into an oncocyte remain to be elucidated. Aim of this article is to review the most common oncocytic lesions, highlighting their key pathological features and clinical significance.

Histiocytoid cardiomyopathy: a mitochondrial disorder

Histiocytoid cardiomyopathy (HICMP) is a rare, genetic, cardiac disorder of infancy or childhood, predominantly affecting girls, and clinically manifesting as severe cardiac arrhythmias or dilated cardiomyopathy. Pathoanatomically, HICMP is characterized by subendocardial, epicardial, or valvular yellow-tan nodules, which are histologically built up of abnormal Purkinje fibers and multiple, scattered clusters of histiocytoid myocytes, which are filled with an increased number of normal or abnormal mitochondria. Within the myocardium, yellowish areas with irregular outlines are found and are histologically built up of enlarged, polygonal, histiocyte-like cells with foamy granular cytoplasm. Since HICMP is frequently found in patients with mitochondrial deoxyribonucleic acid (DNA) mutations, HICMP cardiomyocytes carry an increased number of normal or abnormal mitochondria, and may show markedly decreased succinate-cytochrome c reductase or NADH-cytochrome c reductase activity; HICMP should be regarded as mitochondrial cardiomyopathy.

Histiocytoid cardiomyopathy and ventricular non-compaction in a case of sudden death in a female infant

A case of sudden infant death with histiocytoid cardiomyopathy and ventricular non-compaction was investigated with immunohistochemical methods. Histiocytoid cardiomyopathy is thought to be a developmental defect of the cardiomyocytes of the conduction system. In contrast to mature cardiomyocytes, the histiocytoid cells showed only weak reactions to desmin and myosin antibodies. They lacked cross-striation but reacted strongly to enolase and myoglobin antibodies. The protein Pax-7, seen only in cells undergoing differentiation, and the proliferation marker Ki-67 were not expressed in the histiocytoid cells. In areas of altered myocardium, clusters of CD4-, CD8-, and CD68-positive inflammatory cells were seen as well an abundance of mast cells. With the TUNEL method, it was found that many of the histiocytoid cells were undergoing apoptosis. Our results confirm that the histiocytoid cells are defective cardiomyocytes. The apoptotic and inflammatory changes point to a degenerative process rather than defective maturation of cardiomyocytes as has been suggested in some earlier studies. Ventricular non-compaction is a developmental defect of the subendocardial tissue with hypertrabeculation and weak development of the papillary muscles. Only one case combined with histiocytoid cardiomyopathy has been described previously. A causal connection between the two conditions cannot be established until more cases have been analyzed.

Cardiac tumours in children

Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10-20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT) and Magnetic Resonance Imaging (MRI) of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

Tumors associated with sudden infant and childhood death

Tumors are rare causes of sudden death in infancy and early childhood. The goals of this study were to determine the types and frequency of the tumors associated with sudden death occurring in cases between birth and age 3 years. The San Diego Sudden Infant Death Syndrome/sudden unexplained death in childhood (SUDC) Research Project database and the literature were reviewed retrospectively. Sixty-eight cases, with the most (84%) affecting the heart and brain, were identified. Tumors are a rare but significant cause of sudden death in infancy and early childhood, and their diagnosis may have significant genetic implications for planning future pregnancies. The diagnosis of these lesions can be established only after thorough postmortem examination.

A case of sporadic infantile histiocytoid cardiomyopathy caused by the A8344G (MERRF) mitochondrial DNA mutation

The A8344G mitochondrial DNA (mtDNA) mutation is best known for the MERRF phenotype (myoclonic epilepsy, myopathy, and ragged red fibers). We describe a sporadic case of an infant with the A8344G mtDNA mutation who presented with failure to thrive and sudden unexpected death at 11 months of age. The autopsy revealed a histiocytoid cardiomyopathy, diffuse steatosis of the liver, and bilateral retinal hypoplasia. Electron micrographs of cardiac myocytes showed striking mitochondrial hyperplasia, dispersing the sarcomeres. Special stains of frozen heart muscle showed an absence of complex IV (cytochrome c oxidase) in many of the myocytes. Both complexes I and IV of the respiratory chain were reduced in cardiac muscle. The A8344G mtDNA mutation was detected in both liver and cardiac muscle tissue. To our knowledge, this is the first description of the A8344G mtDNA mutation presenting as a sporadic case of fatal infantile cardiomyopathy and the first occurrence of this mutation associated with histiocytoid cardiomyopathy.

Orthotopic heart transplantation in a child with histiocytoid cardiomyopathy

We report a case of histiocytoid cardiomyopathy in a 30-month-old child. This rare disorder has been identified in <100 patients worldwide and no previous reports of cardiac transplantation with this condition have been identified. We reviewed the clinical and pathologic findings and compared them to previous studies.

Fetal and neonatal cardiac tumors

Primary tumors of the heart are uncommon in the fetus and neonate. Nevertheless, the widespread use of new imaging techniques has contributed significantly to earlier diagnosis, treatment, and thus improved survival. The clinical findings, imaging studies, pathology, and outcome of 224 fetuses and neonates with cardiac tumors collected from the literature are evaluated and discussed. Most tumors are benign, and of these rhabdomyoma is the most common, followed by teratoma, fibroma, oncocytic cardiomyopathy, vascular tumors, and myxoma. Malignant and metastatic tumors are described but are rare. Murmurs, arrhythmias, cyanosis, respiratory distress, and cardiac failure are the main presenting signs of cardiac tumors in the perinatal period. Disturbances in hemodynamic function are correlated with the size and location of the tumor. Cardiac vascular tumors have the best outcome, whereas malignant tumors have the worst. The purpose of this review is to concentrate on the fetus and neonate in an attempt to determine the various ways cardiac tumors differ clinically and morphologically in this age group from those occurring in older children and adults and to show that certain types of tumors have a better prognosis than others.

Demonstration of MyoD1 expression in oncocytic cardiomyopathy: report of two cases and review of the literature

Oncocytic cardiomyopathy is a rare arrhythmogenic disorder usually associated with female sex, difficult-to-control arrhythmias, or sudden death of infants and children. Morphologically, it is characterized by the presence of oncocytic cells, which are diffusely distributed or form the nodular structures within the myocardium, occasionally involving the valves, with a large number of mitochondria in cytoplasms. We present two cases of oncocytic cardiomyopathy. The first case had a fatal clinical outcome, and the other case was surgically treated. The nuclear expression of skeletal muscle transcription factor MyoD1 was demonstrated in the first case, supporting the theory that oncocytic cardiomyopathy is a conduction system developmental disorder. To confirm this hypothesis, it is necessary to further investigate myogenic transcription factor program in human cardiac conduction system cells.

A missense mutation in the mitochondrial cytochrome b gene in a revisited case with histiocytoid cardiomyopathy

We describe a pathogenic mutation in the mitochondrial cytochrome b gene in a patient with a multisystem disorder presenting as histiocytoid cardiomyopathy in whom a defect of ubiquinol cytochrome c oxidoreductase of the electron transport chain had been documented biochemically. The mutation, a G to A transition at nucleotide 15498, results in the substitution of glycine with aspartic acid at amino acid position 251. The mutation, which is heteroplasmic and fulfills all accepted criteria for pathogenicity, is likely to impair the function of the holoenzyme as deduced from its effects on the crystal structure of ubiquinol cytochrome c oxidoreductase. This is the first molecular defect associated with histiocytoid cardiomyopathy.

Ventricular arrhythmias

A spectrum of distinctive clinical presentations and electrocardiographic patterns have been recognized in neonates with ventricular arrhythmias. These may range from an incidental finding on a routine physical to cardiovascular collapse due to ventricular fibrillation. It has become increasingly important that the clinician considers ventricular tachycardia in the neonate with tachycardia when the QRS normal does not appear normal. In general, isolated premature ventricular depolarizations, couplets and non-sustained ventricular tachycardia in the absence of heart disease are associated with a favorable prognosis. Most of these arrhythmias tend to resolve during the first month of life. Conversely, sustained ventricular arrhythmias associated with ischemia, myocarditis or ventricular tumors are associated with a guarded prognosis. Treatment is based on the definition of associated cardiovascular disease, support of hemodynamic status and the judicious use of antiarrhythmic agents. Finally, there has been an increased recognition of idiopathic forms of ventricular tachycardia in the neonate which are associated with a favorable prognosis and may not require pharmacologic treatment. This review will discuss these arrhythmias in neonates, associated forms of cardiovascular disease, current treatment options and long-term prognosis.

Sudden cardiac death in infancy due to histiocytoid cardiomyopathy

Detailed post-mortem is crucial in infants who die suddenly and without a known cause. We report a rare case of histiocytoid cardiomyopathy with endocardial fibroelastosis, the second case in the world literature. The infant presented with sudden death, but the cardiac histological appearance was initially believed to be caused by Pompes disease.

Histiocytoid cardiomyopathy: three new cases and a review of the literature

Histiocytoid cardiomyopathy (HC), a rare arrhythmogenic disorder, presents as difficult-to-control arrhythmias or sudden death in infants and children, particularly girls. Three cases are described with autopsy findings. In two cases, yellow-tan nodules were grossly visible in the myocardium; in the third case, no gross lesions were identified. Microscopic examination in all three cases revealed multiple, scattered clusters of histiocytoid myocytes which on ultrastructural examination were filled with abnormal mitochondria, scattered lipid droplets, and scanty myofibrils. These pathologic findings are similar to those previously described. The pathogenesis of this entity remains controversial. It was recently proposed that this disorder is X-linked dominant with the associated gene located in the region of Xp22.

Histiocytoid cardiomyopathy: a cause of sudden death in infancy

We report the case of an infant aged of 14 months deceased of sudden death. The diagnosis of histiocytoid cardiomyopathy was made on a necropsic basis. The pathologic examination showed a cardiac hypertrophy characterized by yellowish areas with irregular outlines, disseminated in the myocardium, and made of histiocyte-like cells with foamy or granular cytoplasm. These cells reacted positively with desmin and myoglobin labels, and had rare and disorganised myofibrils in electron microscopy, proving their muscular origin. The illness affects infants and usually causes severe cardiac troubles leading to death without treatment. This case is the fourteenth associated with sudden death.

[Cardiac involvement in neuromuscular diseases]

Many neuromuscular disorders involve the heart, occasionally with overt clinical disease. Muscular dystrophies (dystrophinopathies, limb girdle muscular dystrophy, Emery-Dreifuss muscular dystrophy, Steinert's myotonic dystrophy), congenital myopathies, inflammatory myopathies and metabolic diseases (glycogenosis, periodic paralysis, mitochondrial diseases) may produce dilated or hypertrophic cardiomyopathy and heart rhythm or conduction disturbances. Furthermore the heart is commonly involved in some hereditary and degenerative diseases (Friedreich's ataxia and Kugelberg-Welander syndrome) and acquired (Guillain-Barré syndrome) or inherited (Refsum's disease and Charcot-Marie-Tooth syndrome) polyneuropathies. A cardiologist's high clinical suspicion and a simple but systematic skeletal muscle and peripheral nerve investigation, including muscle enzymes quantification, neurophysiological study and muscle biopsy, are necessary for an accurate diagnosis. In selected patients, more sophisticated biochemical and genetic analysis will be necessary. In most cases, endomyocardial biopsy is not essential for the diagnosis.

[Incessant ventricular tachycardia and myocardial hamartomas in childhood: long-term remission after surgical treatment]

Incessant ventricular tachycardia in children 2 years old or younger is usually caused by a well-localized myocardial lesion that has been termed myocardial hamartoma. Its major clinical manifestation is a rapid and potentially fatal tachyarrhythmia that does not respond to antiarrhythmic drugs. We report a patient who underwent successful surgical excision of the hamartoma and we describe the clinical features, pathologic findings and longterm follow-up.

Results of combined pulmonary resection and cardiac operation

BACKGROUND

Concomitant lesions of the heart and lung are uncommon, but when present they pose a therapeutic challenge for thoracic surgeons. A combined procedure avoids the need for a second major thoracic procedure and may improve outcomes and provide economic benefit. However, cardiopulmonary bypass may adversely affect the natural history of pulmonary malignancies.

METHODS

The clinical records of 30 patients were reviewed who underwent simultaneous lung resection and cardiac operations between January 1982 and July 1995. Follow-up was obtained on all 30 patients (mean follow-up, 22 months; range, 1 to 100 months).

RESULTS

Twenty-four patients underwent coronary artery bypass grafting in conjunction with pulmonary resection. Six patients underwent aortic (n = 4) or mitral (n = 2) valve replacement. The pulmonary resections consisted of pneumonectomy (n = 3), lobectomy (n = 14), wedge excision (n = 12), and tracheal resection (n = 1). Twenty-one patients had pathologic findings that confirmed adenocarcinoma (n = 10), squamous cell carcinoma (n = 5), small cell carcinoma (n = 2), or other malignancy (n = 4). Tumor stage of primary lung cancers was stage I, n = 12; stage II, n = 3; and stage IIIa, n = 2. Pathologic examination revealed benign disease in 9 patients. There were two operative deaths, one due to aspiration and one due to stroke. There were three late deaths, two cardiac and one of metastatic disease. Overall late survival was 85% +/- 7% and 73% +/- 16% at 1 and 5 years, respectively. Actuarial survival for patients with malignant disease was 64% at 5 years.

CONCLUSIONS

Simultaneous cardiac operation and lung resection was not associated with increased early or late morbidity or mortality. Cardiopulmonary bypass does not adversely affect survival in patients with malignant disease. Cardiac valve replacement can be performed safely in conjunction with pulmonary resection.

Histiocytoid cardiomyopathy and sudden death

We present a case of histiocytoid cardiomyopathy resulting in sudden and unexpected death in a 4-month-old infant with Peter's Anomaly and congenital glaucoma. At autopsy, the granular histiocytoid cells that define this entity were found predominantly involving the conduction system, with encasement and partial replacement the His' Bundle. Large aggregates of these cells formed atrioventricular and nodoventricular connections, indicating a possible mechanism for the arrhythmias characteristic of the condition. The striking propensity for involvement of the conduction system in this case lends further support to the view that this disorder represents a developmental anomaly of the Purkinje cell system of the heart.

Clinical spectrum, therapeutic management, and follow-up of ventricular tachycardia in infants and young children

We reviewed 40 infants and young children with VT. Median maximum VT rate was 214 beats/min (range 152 to 375 beats/min). A cause was defined in 20 (50%), the most common being cardiomyopathy or myocarditis in 8 (20%). There were six deaths (15%) related to VT, three of which occurred at diagnosis and in patients less than 1 week old. In 5 of 6 deaths related to VT, a cause was defined. At follow-up, 31 (91%) of 34 survivors did not have VT. The presence of symptoms was a predictor of death related to VT. The outlook for asymptomatic patients and those who survived more than 6 months after diagnosis and who do not have progressive myocardial disease appears good.