FUNCTIONAL ADAPTATIONS OF THE RIGHT VENTRICULAR OUTFLOW TRACT IN CONGENITAL HEART DISEASE

Acquired infundibular pulmonary stenosis associated with a congenital membranous ventricular septal defect (Gasul phenomenon) in a dog and discussion regarding causes of infundibular stenosis

An aclinical Havanese dog was diagnosed with a membranous restrictive ventricular septal defect. The patient was represented later in their natural history due to the development of syncope. At that time the patient was diagnosed with acquired pulmonary infundibular stenosis. Balloon dilation of the stenosis was performed successfully twice over the patient's lifetime. The patient died suddenly approximately 14 months after the second balloon dilation. A discussion regarding primary infundibular pulmonary stenosis versus causes of acquired infundibular pulmonary stenosis including anomalous muscle bundles (double chamber right ventricle), tetralogy of Fallot, and infundibular stenosis is presented.

The Gasul Phenomenon Still Alive in the Developing World: A Case Report

Background

In child, ventricular septal defect is the most prevalent congenital cardiac disease. Some ventricular septal defects have the potential for spontaneous closure. In poor nations closure based on indications may not be feasible. The patient's natural course may therefore be observed. The Gasul phenomenon, a right ventricular outflow obstruction, is one of the complications.

Case Presentation

A 7-year-old child who had recurrent pneumonia, poor weight gain, and excessive sweating eventually had these symptoms go away. A large peri membranous ventricular septal defect and a small patent ductus arteriosus was detected on echocardiography during infancy. Later, the patient acquired a muscular ridge across the right ventricular outflow tract. Muscular ridge excision and closure of patent ductus arteriosus and ventricular septal defect were done. Patient was discharged in stable condition.

Conclusion

Right ventricular outflow tract blockage can be avoided by performing early surgical closure of a ventricular septal defect.

A classical case of the Gasul phenomenon

This case demonstrates the development of secondary infundibular stenosis in a 10-year-old male child with documented large non-restrictive perimembranous ventricular septal defect in infancy - the classical Gasul phenomenon.

The pathogenesis of tetralogy of Fallot

A pathogenetic mechanism for the formation of tetralogy of Fallot is postulated. We propose that the right ventricular ejection stream is divided into a transseptal aortic stream and an infundibular pulmonary stream during embryonic life before the ventricular septum is closed. The surgically unaltered hearts from 77 cases of tetralogy of Fallot were examined, and measurements made of certain morphologic features. A malformed, stenotic pulmonary valve was found in most all cases and accounts for a divided ejection stream. Infundibular stenosis is shown to be a postnatally acquired, progressive lesion. The detailed anatomic features of the heart and great vessels in tetralogy of Fallot are explained as a response of the developing heart and great vessels to the abnormal blood flow pattern of a divided right ventricular ejection stream. This pathogenetic mechanism, compared to previously proposed hypotheses, appears better able to account for the malformation complex of tetralogy of Fallot.

Natural history of ventricular septal defect with right-sided aortic arch

The natural history of 14 patients with ventricular septal defect and right-sided aortic arch is reviewed. Patients are divided into two groups. Group A consisted of 10 patients, all of whom developed progressive infundibular stenosis; group B consisted of 4 patients, none of whom developed infundibular stenosis. The clinical features, x-rays, electrocardiograms, haemodynamic data, and angiocardiograms in these two groups are compared. The right ventricular cine-angiocardiogram seems to be helpful in differentiating the course of the two groups. The patients who developed progressive infundibular stenosis showed an abnormal right ventricular cine-angiocardiogram even in the absence of obstruction. Various aetiological factors for the development of infundibular stenosis are discussed. The importance of medical management in group A patients is emphasized, even though all of them presented in infancy in congestive heart failure. The role of propranolol in preventing cyanotic spells in group A patients is also discussed.

Long-term treatment with propranolol in selected cases of Fallot's tetralogy

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Increasing obstruction to the outflow tract in Fallot's tetralogy

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Electrode catheters and the diagnosis of Ebstein's anomaly of the tricuspid valve

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