Chapter 25

    This defect is relatively frequent among the cyanotic congenital diseases although not as often as Tetralogy of Fallot or transposition of the great arteries. 30% of the cases will be associated to transposition of the great arteries.

ANATOMY

    The anatomy is characterized by:
    Total atresia of the tricuspid valve.
    Atrial septal defect (patent foremen ovals, ostium secundum.)
    Occasionally a common atrium maybe seen.
    Left ventricular hypertrophy.
    Ventricular septal defect is present in most cases.
    Marked hypoplasia of the right ventricle.

    Transposition of the great arteries and atresia of the pulmonary artery is not unusual in this congenital disease. In other cases the pulmonary artery may be normal or only an hypoplasic vessel.
    Many authors divide tricuspid atresia in two categories depending upon the presence or absence of transposition of the great arteries with subsequent subdivisions in relation to the degree of hypoplasia of the pulmonary artery.

CLINICAL VIEWPOINT

    This is typically a cyanotic congenital heart disease with left ventricular hypertrophy and one of the few situations where the combination of cyanosis and left axis deviation in the electrocardiogram may be seen.
    The patient may present clubbing of the fingers, dyspnea and anoxic crisis.
    Early cardiac insufficiency with cyanosis and cerebral vascular accidents is common finding.
    The auscultation of these patients is rather atypical, having murmurs of different significance depending upon the importance of the associated malformations and shunts present.

ELECTROCARDIOGRAM

    The electrocardiogram is very important in this malformation. As previously observed, it is one of the few congenital heart diseases with cyanosis and hypertrophy of the left ventricle and left axis deviation over the frontal plane of the electrocardiogram.
    Sinus mechanism with giant P wave of right atrial overload is typical. Many times P wave indicative of bilateral hypertrophy is observed. The more typical QRS configuration in the right precordial leads is rS and ST-T changes in relation with left ventricular diastolic overload can be seen at times.

ROENTGENOGRAM

    The chest x-ray will present left ventricular hypertrophy with bilateral atrial hypertrophy. Right ventricular hypoplasia may be demonstrated mainly in the AP and oblique projections.
    The pulmonary blood circulation will depend upon the degree and significance of stenosis or atresia of the pulmonary artery.
    The analysis of the valve level and position of the aortic valve in relation to the pulmonary artery is important in the analysis of the possibility of combination with transposition of the great arteries.

CARDIAC CATHETERIZATION AND ANGIOGRAPHY

    The cardiac catheterization is essential for final diagnosis and study of the associated congenital malformations. The fundamental finding will be the impossibility for the catheter to pass from the right atrium to the right ventricle.
    The catheter will easily pass through the atrial defect to the left atrium and from there to the left ventricle, and occasionally, passing through a ventricular septal defect, to the right ventricle.
    The angiographic study, injecting the contras dye into the right atrium, will show a very typical image with failure of filling of the right ventricle and simultaneous filling of the left atrium and left ventricle. Angiography is essential in the study of patients with associated transposition of the great arteries.
    In general, the diagnosis of these patients is not difficult due to the common association of cyanosis with left ventricular hypertrophy and left axis deviation in the electrocardiogram. However, a complete evaluation by invasive means is essential before surgical treatment.

SURGICAL TREATMENT

    The surgery attempts, in most cases, to alleviate the problem and not pretend a total, complete anatomical correction.

PROCEDURES

    Glenn Operation: Side to side anastomosis at the superior vena cava with the right pulmonary artery. Ligation of the superior vena cava at the junction with the right atrium in necessary. The surgery is usually attempted when the patient is older than six weeks. If surgery is necessary before six weeks of age, side to side anastomosis between the right pulmonary artery and the ascending aorta is preferred. Many times, a right Blalock-Taussig may be performed.

Tricuspid valve and pulmonary valve atresia. Diagrammatic representation of -the anatomy and pattern of circulation. The so called "four chamber view" or -"apex view" in real time echocardiography may be tremendously helpful in tricuspid valve atresia.

Tricuspid atresia with pulmonary artery hypoplasia and ventricular septal defect. Note that the relation between the aorta and the pulmonary arteries is normal.

Variety of tricuspid atresia with incomplete transposition of the great arteries and infundibular pulmonic stenosis.

Roentgenogram in a case of Tricuspid Atresia with normal pulmonary artery and incomplete transposition.