Double outlet right ventricle definition.
Double outlet of the right ventricle is a complex group of congenital cardiac malformations between tetralogy of Fallot and complete transposition of the great arteries. The classical concept is that the two great arteries originate exclusively from the right ventricle, the ventricular septal defect (VSD) is the only exit from the left ventricle, and there is no fibrous connection between the mitral valve and the aorta. From the point of view of facilitating the improvement of the diagnosis and treatment of right ventricular double outlet, it may be more meaningful to consider that more than 90% of the aorta originates from the right ventricle as right ventricular double outlet and less than 90% as tetralogy of Fallot.
Morbidity.
Double outlet of the right ventricle is a rare congenital heart disease with an incidence of about 1% of congenital heart diseases Clinical manifestations.
The clinical presentation is determined by the presence or absence of stenosis of the right ventricular outflow tract and pulmonary valve and the location and relationship of the main pulmonary artery. Patients may present with a septal defect similar to ventricular septal defect combined with pulmonary hypertension or tetralogy of Fallot. There may be a history of cyanosis, squatting, hemoptysis or syncope, and a few patients have a history of heart failure. Physical examination reveals poor development, conjunctival congestion, cyanosis, and rod-shaped fingers (toes). There is a heart murmur on auscultation.
Diagnosis.
Clinical manifestations, physical examination, electrocardiogram and cardiac X-ray plain film are non-specific. Echocardiography can clarify the relationship between ventricular septal defect and large blood vessels, the location and size of ventricular septal defect, the presence of pulmonary hypertension, and whether the atrioventricular valve is abnormal. Right heart catheterization and angiography can confirm the diagnosis and provide insight into the development of the ventricles and great vessels and coronary arteries. Ultrahigh-speed CT or MRI can help with the diagnosis. Simple right ventricular double outlet can be diagnosed definitively based on ultrasound findings and treated surgically accordingly. In complex type of double outlet right ventricle or combined with other cardiac malformations, preoperative cardiovascular angiography is mostly required.
Natural course of disease.
In the case of double outlet right ventricle without pulmonary stenosis, the natural prognosis is the same as that of simple ventricular septal defect. In case of Taussig-bing malformation, it is similar to complete transposition of the great arteries with early onset of pulmonary hypertension and poor prognosis. In case of pulmonary stenosis, it can be similar to tetralogy of Fallot. Children with double outlet right ventricle tend to die from hypoxia and heart failure.
Treatment.
In right ventricular double outlet with ventricular septal defect without other cardiac malformations, the indications for surgery are the same as ventricular septal defect combined with pulmonary hypertension, which should be operated as early as possible, especially if the ventricular defect is located below the pulmonary artery and pulmonary hypertension occurs earlier, and should be operated within 2 years of age. In the case of Taussig-bing malformation, if the condition does not allow for radical treatment, palliative surgery, i.e. pulmonary artery circumferential reduction, can be performed 4-5 years after surgery, and then Raste11i surgery or intra-atrial diversion plus ventricular defect repair surgery can be performed. If possible, ventricular defect repair plus switch should be performed before half a year of age if the condition permits. If the right ventricular double outlet is combined with pulmonary valve and right ventricular outflow tract stenosis, surgery should also be performed as early as possible, with the same indications as for tetralogy of Fallot. If other malformations such as complete endocardial cushion defect and aortic malformation are combined, they should also be corrected in one stage.
Surgical complications.
(a) VSD recanalization.
(ii) III° AV block. (One of the arrhythmias) (iii) Low cardiac output syndrome.
(iv) Pulmonary edema or perfused lung.
(v) Left ventricular outflow tract stenosis.
(vi) Postoperative hemolysis.
(vii) Tricuspid valve closure insufficiency.
(viii) Right ventricular outflow tract stenosis.
(ix) Pericardial tamponade.
(J) Re-opening of the chest to stop the bleeding.
(xi) Subacute bacterial endocarditis.
(xii) Chronic right heart insufficiency.
(xiii) Pleural effusion.
Surgical outcome.
According to the literature, the operative mortality rate is still high, up to 20%-5O%, which is related to the complexity of the cardiac malformation and surgical technique, such as the defect is located below the aortic valve, the success rate of surgery is high. If the defect is located far from the aorta, combined with atrioventricular canal malformation, operated in infancy, using external conduits, and poor left ventricular development, the operative mortality rate is high. Patients still need to pay attention to the maintenance of cardiac function after corrective surgery, and as long as cardiac function allows, they can live and study normally, generally should not engage in heavy work, and can have a family and children.