Heterotaxy Syndrome With Severe Pulmonary Hypertension in an Adult

Vincent M. Brandenburg, MD, Stefan Krueger, MD, Patrick Haage, MD, Peter Mertens, MD, Jochen Riehl, MD

Disclosures

South Med J. 2002;95(5) 

In This Article

Discussion

In heterotaxy syndrome, the predominant malformations occur in the cardiovascular system, the lungs (symmetric lobulation), the spleen (polysplenia, asplenia, or hypoplastic spleen), and the gastrointestinal tract (situs ambiguus, other forms of malrotations, liver and pancreatic malformation).[1,2,3] Moreover, the syndrome includes a wide variety of clinical manifestations, and no single anomaly is pathognomonic. Most cases are sporadic, but familial cases have been reported. The overall prognosis of children with heterotaxy syndrome is significantly reduced, due to early manifestations in childhood or infancy. Mortality and morbidity are usually related to the degree of CHD.[2] The anatomy of CHD is highly variable. Abnormal localization of the cardiac apex, a common atrioventricular canal, anomalous systemic venous return (eg, bilateral superior vena cava, interruption of the inferior vena cava with azygos continuation), atrial and ventricular malformations and septal defects, absent coronary sinus, malposition or transposition of the great arteries, pulmonic stenosis, pulmonary atresia, patent ductus arteriosus, and anomalous pulmonary venous connection have often been described.[1,2,3] The most likely reason that our patient with heterotaxy syndrome was asymptomatic and felt well until he was 30 years old was that he had no relevant structural or functional cardiac defect. Overall, the presentation of heterotaxy syndrome in adulthood as an incidental finding is rare.[4,5,6]

Our patient presented with symptoms of severe pulmonary hypertension. To the best of our knowledge, pulmonary hypertension has not been previously described as the prominent clinical feature of patients with heterotaxy syndrome. The development of pulmonary hypertension in heterotaxy syndrome is possible (eg, in the setting of left-right blood shunting); however, a significant cardiac shunt volume was ruled out in our patient. We suggest that the development of pulmonary hypertension in our patient may be pathophysiologically linked to heterotaxy syndrome by the presence of severe visceral malformations.

Patients with liver cirrhosis or portal hypertension are at greater risk of having pulmonary hypertension (portopulmonary hypertension).[7,8] Altered hemodynamics or incomplete metabolism of vasoactive substances in the liver are possible mechanisms for the development of pulmonary hypertension in these patients.[9] Although parenchymal liver disease was excluded by biopsy results, a portocaval shunt was present in our patient, with drainage of the mesenteric blood into the inferior vena cava. As a result, blood ammonia levels were constantly elevated.

On the other hand, an increased risk for pulmonary hypertension has also been found in patients with functional asplenia or after splenectomy.[10,11] It has been hypothesized that the lack of splenic filter function predisposes patients to increased thrombocyte aggregation, due to persistence of abnormal erythrocytes in the circulation, which leads to widespread chronic pulmonary microthromboembolisms. The abnormally high number of Howell-Jolly bodies in our patient was indicative of altered splenic function.

There are a broad variety of clinical manifestations in heterotaxy syndrome, which can present late in adulthood if substantial cardiovascular defects are absent. The number of asymptomatic patients with heterotaxy syndrome diagnosed in adulthood may rise with the increased utilization of CT and magnetic resonance imaging. Pulmonary hypertension may develop in heterotaxy syndrome as a consequence of underlying splenic, hepatic, or vascular malformations.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....