The electrocardiogram in primary endocardial fibroelastosis

Endocardial Fibroelastosis: A Comprehensive Review

Endocardial fibroelastosis emerged as a challenging clinical phenomenon in the 1940s. It is characterized by an atypical proliferation of fibrous and elastic tissue within the heart and is primarily observed in childhood, occasionally displaying familial inheritance. While the precise cause remains elusive, various factors, including genetic, infectious, metabolic, autoimmune, oncologic, and medication-related influences, appear to play a role in its pathogenesis. The coexistence of endocardial fibroelastosis with multiple cardiac structural abnormalities manifests in symptoms of congestive heart failure and rhythm abnormalities. Despite its challenging diagnosis, various findings from ECG and imaging have proven beneficial in further evaluation of this condition. Finally, the treatment approach to endocardial fibroelastosis became complex due to addressing its concurrent cardiac abnormalities. Strategies for managing and preventing this condition are still under investigation. In this review, we intend to highlight the existing knowledge and illuminate future considerations regarding the etiology, diagnosis, and management of this disease.

Festschrift for Dr. John M. Opitz: Pathogenesis of cardiac conduction disorders in children genetic and histopathologic aspects

Fetal dysrhythmias are usually transient. Abnormal fetal rates and rhythms during labor are "functional." Fetal dysrhythmias may be associated with congenital heart disease and fetal hydrops. Bradycardia is usually related to fetal distress; supraventricular tachycardia, atrial flutter, and atrial fibrillation may be associated with severe congestive heart failure. Ventricular fibrillation is rare in the fetus and infant and is usually associated with myocardial necrosis with perimembranous septal defect; the nonbranching atrioventricular (AV) bundle may have an aberrant position and result in cardiac arrhythmia. Wolff-Parkinson-White syndrome with conduction abnormalities and left ventricular hypertrophy (LVH) is due to an accessory pathway that bypasses the AV sulcus and results in faster conduction. Carnitine deficiency may be primary or secondary and may result in cardiac arrhythmia. Histiocytoid cardiomyopathy is characterized by cardiomegaly, incessant ventricular tachycardia, and frequently sudden death. Arrhythmogenic right ventricular dysplasia (ARVD) results in ventricular tachycardia and left bundle branch block. Noncompaction of the left ventricle predisposes to potentially fatal arrhythmias. Long Q-T syndromes (LQTS) are a heterogeneous group of disorders with many genetic mutations. Brugada syndrome is an autosomal dominant trait with right bundle branch block and ST elevation. Barth syndrome is an X-linked disorder with dilated cardiomyopathy, cyclic neutropenia and skeletal myopathy. Hypertrophic cardiomyopathy in infancy may be related to metabolic diseases, particularly glycogen storage diseases; the familial form predisposes to sudden death. Arrhythmias following cardiac surgery may occur after closure of a ventricular septal defect (VSD) or damage to the conduction system.

ENDOCARDIAL FIBROELASTOSIS. A CLINICAL AND ANATOMIC STUDY OF 47 PATIENTS WITH EMPHASIS ON ITS RELATIONSHIP TO MITRAL INSUFFICIENCY

A clinical and pathologic study of 47 cases with endocardial fibroelastosis is presented. These cases have been classified according to the associated cardiac anomaly and the anatomic condition of the left ventricle. In so doing, a better understanding is had of the role the cardiac anomaly associated with endocardial fibroelastosis plays in the production of cardiac signs and symptoms.

In each of the specimens available for review, a change of the mitral valve was present that rendered it insufficient. Those cases grouped as primary endocardial fibro-elastosis had this as the only abnormality present, other than the endocardial fibroelastosis. Many of the clinical and laboratory findings in this group could be explained on the basis of mitral insufficiency, and one cannot necessarily assign the cardiac signs and symptoms to the endocardial process itself. In those cases with associated cardiac anomalies the hemodynamic consequences appear to be a summation of the combined effects of the mitral insufficiency, endocardial fibroelastosis, and the associated cardiac anomaly.

In this review, we were unable to distinguish, by either gross or microscopic methods, between primary and secondary endocardial fibroelastosis. Since use of these terms suggests etiologic relations, it is preferable to classify cases of endocardial fibroelastosis on the basis of the structural abnormalities present.

THE MEDICAL MANAGEMENT OF CLINICAL ENDOCARDIAL FIBROELASTOSIS

Fifty-six patients with the clinical diagnosis of primary endocardial fibroelastosis have been reviewed. There was an over-all mortality rate of 44 per cent and a long-term survival of 56 per cent. Of 31 long-term survivors, 27 are without cardiac symptomatology or cardiomegaly. The method and rationale of therapy are reviewed.

Differentiating anomalous left main coronary artery originating from the pulmonary artery in infants from myocarditis and dilated cardiomyopathy by electrocardiogram

Anomalous left main coronary artery (ALMCA) originating from the pulmonary artery is an important cause of morbidity from heart failure and mortality in infants. Discriminating ALMCA from myocarditis or other forms of dilated cardiomyopathy (DC) in infants is critical for proper early management of this treatable disease. This study was performed to characterize electrocardiographic (ECG) patterns in infants with ALMCA, and to identify features that would allow differentiation of these infants from those with myocarditis/DC. Presenting electrocardiograms from 28 patients with ALMCA < 2 years of age were analyzed for 103 variables, and compared with electrocardiograms from 28 aged-matched infants with myocarditis/DC using the t test, Fisher's exact test, and discriminant analysis using stepwise logistic regression techniques. ECG findings characteristic of infants with ALMCA were confirmed, including deep (> or = 3 mm) and wide (> or = 30 ms) Q waves and a QR pattern in at least 1 of the following leads: I, aVL, V5 to V7. Also, the complete absence of Q waves from leads II, III, and aVF in all infants with ALMCA was noted. These and other ECG patterns were more common in infants with ALMCA than in those with myocarditis/DC (p < 0.05), but were also noted in some patients with myocarditis/DC. Stepwise logistic regression analysis identified 3 ECG variables that best discriminated ALMCA from myocarditis/DC, including Q wave width (w) in lead I, and Q-wave depth (d) and ST-segment amplitude (s) in lead aVL.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent left ventricular disease in clinically "cured" primary endocardial fibroelastosis

We studied by serial cardiac catheterisation eight patients with the dilated form of primary endocardial fibroelastosis in whom congestive heart failure disappeared with treatment. All remained without symptoms for at least three years before recatheterization. Four patients showed regression of the abnormal electrocardiographic findings, three showed persistence, and one showed progression of electrocardiographic left ventricular overload pattern. On first cardiac catheterisation all patients had a dilated left ventricle with a mean ejection fraction of 0.36. In six of the patients repeat cardiac catheterisation showed left ventricular dilatation with a diminished ejection fraction (mean 0.32). Left ventricular end-diastole pressure was raised (12 to 28 mmHg, mean 19 mmHg). In this group were included the three patients with persistence and one with progression of the abnormal electrocardiographic findings, and two of the four patients with regression of these findings. The highest left ventricular end-diastolic pressure was found in a patient in whom the abnormal electrocardiographic findings almost reverted to normal. In the two remaining patients with reversion of the electrocardiographic abnormalities repeat cardiac catheterisation showed nothing abnormal. Our findings indicate that "cure" in primary endocardial fibroelastosis is incomplete. These findings may be the cause of sudden death or late clinical deterioration in some reported patients with "cured" primary endocardial fibroelastosis. The electrocardiogram is of little value in assessing these processes.

The clinical course of primary myocardial disease in infants and children

A total of 161 infants and children, ranging in age from 1 day to 17 years at initial encounter (mean, 3.7 years), was seen over a 30 year period with primary myocardial disease (idiopathic myocarditis, nonobstructive cardiomyopathy, endocardial fibroelastosis, and an anatomically unknown category). These patients were observed from 1 hour to 23 years after initial encounter and cardiac disease has resolved in 27 per cent, resulted in death in 35 per cent, and continues in 38 per cent. The majority were first referred to us with congestive heart failure; all exhibited ST-T changes and cardiomegaly, 67 of 150 had left ventricular hypertrophy, 23 of 151 arrhythmias, and 55 of 153 pulmonary vascular congestion. Initial ventricular depolarization abnormalities were very frequent. Significant clinical predictors of fatal outcome included pulmonary vascular congestion, "northwest" axis deviation, and a cardiac index less than three L./min./M.2. Death occurred during the first year after initial encounter in 44 of 57 who died, and in all 13 with proved myocarditis. Primary myocardial disease is a serious disease of infancy and childhood, resulting in death or residual cardiac disease in three fourths of those affected.

Myocardial infarction and ischaemic heart disease in infants and children. Analysis of 29 cases and review of the literature

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Anomalous origin of the left coronary artery from the pulmonary trunk. Its clinical spectrum, pathology, and pathophysiology, based on a review of 140 cases with seven further cases

The congenital anomaly in which the left coronary artery arises from the main pulmonary artery is infrequent, but lethal, and since it can be alleviated surgically, its recognition and hemodynamic consequences are important. On the basis of 140 reported cases and our seven cases, it seems to present in one of four ways: (1) in infancy with angina-like symptoms or as cardiomyopathy, and later (2) as mitral insufficiency, (3) continuous murmur, or in adults (4) by sudden death. Visualization of the coronary arteries provides the definitive diagnosis, and the problem is the selection for this procedure. The electrocardiogram, the most helpful laboratory aid, is diagnostic of infarction in 80% of the infant group; in the remainder other forms of cardiomyopathy may be confused. Although blood flows directly into the pulmonary artery in the majority of cases, it flows in the reverse direction in a few and this must be determined preoperatively. Some unanswered questions are the subject of discussion: Why the majority of infants have onset of symptoms at about 8 weeks of age, and why some survive to childhood and adult life. The pathological findings are reviewed. Although the greatest surgical therapy experience has been with obliteration of the anomalous left coronary artery (ALCA) at its connection with the pulmonary artery, anastomosis between aorta and ALCA provides an additive supply for both the present and the future.

The Diagnosis of Primary Endocardial Fibroelastosis

A comparison has been made of the clinical features of a group of autopsy-proved cases of endocardial fibroelastosis and a clinically diagnosed group with similar findings. It has been possible to make a diagnosis of endocardial fibroelastosis before death in all cases showing a characteristic clinical and electrocardiographic pattern. The characteristic features are (a) appearance of congestive heart failure; (b) absence of organic heart murmurs; (c) onset of signs or symptoms in the first 8 months of life (85 per cent) and rarely after 1½ years; (d) a period of observation under therapy during which is ruled out the conditions that simulate endocardial fibroelastosis, such as an anomalous coronary artery arising from the pulmonary artery, glycogen-storage disease, coronary artery necrosis, or myocarditis; (e) an abnormal increase in voltage of R in V 6 , S in V 1 , or both together; (f) a flat or inverted T wave in V 6 (85 per cent have a T wave 1 mm. or deeper); (g) a Q wave in V 6 (present in 60 per cent).

All the cases proved at autopsy that fulfilled these criteria during life were correctly diagnosed before death. Approximately 85 per cent of the total group were thus recognized. Fifteen per cent were not identified because electrocardiographic tracings showed an atypical right loading pattern. An occasional case with right loading may be suspected by history of a previous sibling with endocardial fibroelastosis.

Since the differential diagnosis between endocardial fibroelastosis and acute myocarditis has been considered difficult in the past, a group of infants and children with myocarditis were reviewed. The majority were proved at autopsy. Such children were also correctly diagnosed during life in most instances. The patients who were diagnosed clinically as having endocardial fibroelastosis and who survived had electrocardiographic patterns that were similar to those in the autopsy-proved group and unlike those in the myocarditis group. The chief differences were in voltages of R and S waves in precordial leads V 6 or V 1 , T waves in V 6 , and Q waves in V 6 .

Cases of endocardial fibroelastosis associated with mitral or aortic valvular disease usually had a similar age of onset or a little earlier. The electrocardiographic pattern was similar. The presence of an aortic or mitral systolic murmur made it difficult to be certain about the underlying pathology. The left loading pattern, however, with increased voltage in the pertinent precordial leads accompanied by a flat or inverted T wave in V 6 in a baby with a large heart or with congestive heart failure, provides suggestive evidence of endocardial fibroelastosis.

The contracted type of endocardial fibroelastosis reported by Edwards is a relatively rare finding. When it does occur, it may or may not be associated with a right loading pattern in the electrocardiogram. The right loading pattern in endocardial fibroelastosis is more likely to be due to heart failure with pulmonary congestion and overloading of the right ventricle, which in an infant may then overshadow the left. This pattern may revert to the more characteristic one of left loading after digitalization has been completed.

The mumps antigen skin test is proving to be a useful diagnostic tool, since it is found to be positive in primary endocardial fibroelastosis in the first 2 years of life. In our experience this occurs without a positive serum antibody reaction to mumps virus. Normal children, or those with congenital heart disease in the same age group, rarely have a positive skin reaction unless they have a recent history of mumps. Further work is needed to clarify this relationship, but on the evidence to date its diagnostic value in primary endocardial fibroelastosis shows considerable promise.

Primary endocardial fibroelastosis: a review of 15 cases

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Diffuse endomyocardial sclerosis

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