Ebstein's anomaly

Pulmonary agenesis and hypoplasia may be one of many multisystem anomalies in primary embryologic defect syndrome or may result from decreased intrathoracic space due to other congenital thoracic or spinal defects.[1,2] Klippel-Feil syndrome, resulting from congenitally fused cervical vertebrae, has been cited to be rarely associated with pulmonary agenesis and hypoplasia.[2] Although many congenital cardiac anomalies have been identified with all of these conditions,[3-5] to our knowledge, an accessory to atrioventricular conduction pathways has never been demonstrated together with Klippel-Feil sydrome and pulmonary lobar agenesis and hypoplasia. We report the finding in a patient with such an association.

Case Report

A 23-year-old woman was referred to us for investigation of an abnormal chest roentgenogram, prompted three months ago by a bout of respiratory tract infection. When she presented to us, she had no complaint. The patient had never smoked and never suffered from any chronic pleuropulmonary disease. Her menstrual cycle was normal and regular. She had a low hairline and a short neck with painless restriction of movement, more so on the left side. Examination of the chest revealed signs of volume loss of the right side with ipsilateral shift of the mediastinum. Heart sounds were best heard in the right parasternal region; no added sounds were audible.

The findings on routine investigations of blood and urine were within normal limits. The chest roentgenogram revealed an opaque right hemithorax with ipsilateral shift of the mediastinum and herniation of the contralateral lung (Fig 1). Roentgenograms of the cervical and thoracic spine showed block C6-7 and D3-4 vertebrae with a D2 hemivertebra. Smears and cultures of sputum for pyogenic organisms and Mycobacterium tuberculosis were repeatedly negative. On the fiberoptic bronchoscopy the right main bronchus was narrow and tortuous. The right upper lobe bronchus was absent, and the right intermediate bronchus narrowed progressively, preventing negotiation beyond 4 cm. Bronchography (Fig 1) and CT of the thorax confirmed the absence of right upper and middle lobes, with a hypoplastic right lower lobe. Digital subtraction angiography demonstrated a tiny hypoplastic right pulmonary artery (Fig 2). Findings on CT and untrasonographic examination of the abdomen were essentially normal, and a skeletal survey did not reveal any other bony abnormality.

The electrocardiogram showed normal sinus rhythm with respiratory sinus as arrhythmia. The heart rate varied from 75 to 100 beats per min. The P-R intervals were short ([is less than or equal to] 0.11 s) with normal QRS complexes, suggesting Lown-Ganong-Levine syndrome. The echocardiogram did not reveal any associated congenital cardiac anomaly.

Discussion

Pulmonary agenesis and hypoplasia are said to result from reduced intrathoracic space due to loss of normal spinal curvature in Klipper-Feil syndrome.[1,2] Development of the lung may also be intrinsically related to its blood supply.[4] Reduction in blood flow may either follow or results in pulmonary developmental anomalies. Our patient had a severely underdeveloped right lung and a small vestigial right pulmonary artery. The severity of the anomaly is consistent with the markedly reduced pulmonary blood flow and the absence of the any accessory systemic supply. In a review, Oyamada et al[6] have cited similar cases with small fibrotic lung tissue and vestigial pulmonary artery. Hislop et al[7] also have reported three patients with pulmonary dysplasia and a hypoplastis or absent pulmonary artery. Furthermore, the association of pulmonary hypoplasia with conditions resulting in reduced pulmonary blood flow (such as tetralogy of Fallot, Ebstein's anomaly, hypoplastic right heart, and pulmonary stenosis) also provide evidence to support this.[4,8] Hence, as suggested by Ellis[9] and Page and Stocker,[4] a reduced blood supply to the lung may be the cause, rather than the effect of the pulmonary deficiency. Considering the aforementioned, the relationship between arterial blood flow and development of lung needs further elucidation.

To our knowledge, an association of pulmonary hypoplasia with Klippel-Feil and Lown-Ganong-Levine syndromes has never been reported previously. Furthermore, the suggestion that the James pathway in Lown-Ganong-Levine syndrome is congenital in origin[1] is supported by our case. Considering that women with Klippel-Feil syndrome have a propensity for congenital cardiac anomalies[5] and that Lown-Ganong-Levine syndrome is more common in female subjects,[10] their occurrence together may be a manifestation of an embryologic defect or yet may merely be coincidental.

While agenesis of the lung is a rare conditions, lobar agenesis is even uncommon. Of the 14 cases of lobar agenesis reported until 1954, nine of them had right upper and middle lobes involved together.[11] On the other hand, lobar agenesis associated with a congenital abnormality of the remaining bronchial tree on that side is exceptionally rare.[12] The association of lobar agenesis and hypoplasia and Lown-Ganong-Levine syndrome with Klippel-Feil sydrome makes our case unique. The prognosis in both rightsided pulmonary agenesis and hypoplasia is said to be relatively poor[13] because of a greater shift of the mediastinum and heart, resulting in vascular and tracheobronchial distortion; however, our patient has led a trouble-free life.

Unilateral opaque lung on the chests roentgenogram may also result from pulmonary tuberculosis. Hence, pulmonary hypoplasia may be mistaken for destroyed lung in regions where tuberculosis still remains a significant clinical problem. This is especially so, as tuberculous infection maybe unaccompanied by respiratory symptoms or may have occurred long ago and been forgotten.

References

[1] Currarino G, Williams B. Causes of congenital unilateral pulmonary hypoplasia: a study of 33 cases. Pediatr Radiol 1985; 15:15-24 [2] Landing BH, Dixon LG. State of art: congenital malformations and genetic disorders of the respiratory tract (larynx, trachea, bronchi and lungs). Am Rev Respir Dis 1979; 120:151-85 [3] Maltz DL, Nadas AS. Agenesis of lung: presentation of eight new cases and review of literature. Pediatrics 1968; 42:175-88 [4] Page DV, Stocker JT. Anomalies associated with pulmonary hypoplasia. Am Rev Respir Dis 1982; 125:216-21 [5] Nagib MG, Maxwell RE, Chou SN. Klippel-Feil syndrome in children: clinical features and management. Childs Nerv Sys 1985; 1:255-63 [6] Oyamada A, Gasul BM, Holinger PH. Agenesis of the lung. Am J Dis Child 1953; 85:182-201 [7] Hislop A, Sanderson M, Reid L. Unilateral congenital dysplasia of lung associated with vascular anomalies. Thorax 1973; 28:435-41 [8] Hislop A, Reid L. Structural changes in the pulmonary arteries and veins in tetralogy of Fallot. By Heart J 1973; 35:1178-83 [9] Ellis AG. Error of endogenous origin (congenital absence of lung) based on pulmonary vascular development. Am J Med Sci 1917; 154:33 [10] Schamroth L. The disorders of cardiac rhythm. 2nd ed. Oxford, England: Blackwell Scientific Publications, 1980 [11] Rosenberg DML. Pulmonary agenesis. Dis Chest 1962; 42:68-73 [12] Storey CF, Marrangoni AG. Lobar agenesis of the lung. J Thorac Surg 1954; 28:536-43 [13] Schaeffer AJ, Rider RV. A note on the prognosis of pulmonary agenesis and hypoplasia according to the side affected. J Thorac Surg 1957; 33:379-82

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