Aric Baumann was born on December 7, 1993, at St. Boniface General Hospital. He was born prematurely at 36 weeks gestation and weighed five pounds two ounces. He was the second child born to Curtis and Deanna Baumann. Shortly after his birth, Aric was noted to be cyanotic and to have a heart murmur.

Giddins examined Aric at the St. Boniface Hospital soon after his birth. Deanna Baumann testified that Giddins told her and her husband that Aric had a hole in his heart, but that he would likely not need surgery for a number of years.

Giddins subsequently saw the family at the Heart Centre on January 3, 1994. Giddins observed that Aric's chest was clear, although his breathing was shallow with mild in-drawing. Aric's oxygen saturation level was 96 per cent; however, this value dropped when he exerted himself. The results of an electrocardiogram suggested that Aric had:

• enlargement of his right atrium
• hypertrophy of his right ventricle.

These results, together with the clinical findings, suggested that Aric had a partial atrioventricular canal defect with overload of the right side of his heart. A partial atrioventricular canal defect is similar to a complete atrioventricular canal defect, except that the child still has separate valves between the left collecting chamber and the left ventricle and between the right collecting chamber and the right ventricle.

An echocardiogram confirmed the diagnosis of a large degree of atrial shunting, with moderate to severe right atrioventricular valve regurgitation and a moderate elevation of pulmonary pressures. In other words, Aric had what is termed a primum atrial septal defect. This is a hole between the top chambers of the heart. The hole was thought to be large, due to the amount of blood that was shunting. This condition is usually associated with minor valve problems and leakage.

Giddins said it was his approach to attempt to surgically correct the defects that Aric was suffering from when the child was between two and three years of age. Therefore he did not recommend sending Aric to surgery at that time.

In a January 3, 1994, letter to Dr. Cheryl Simmonds, Aric's doctor, Giddins confirmed that Aric had tachypnea (rapid breathing) with mild in-drawing, which were symptoms of mild right-heart volume overload and pulmonary edema. Since Aric was thriving, his liver was normal, and his peripheral pulses and perfusion were good, Giddins advised that there be no specific intervention at that time and that a follow-up visit take place in three months. However, he cautioned that with such a large atrial septal defect and valve regurgitation, a heart catheterization followed by a definitive repair would be necessary if Aric's condition deteriorated.

At Aric's follow-up appointment on April 13, Giddins found Aric's condition to have remained relatively stable, although there had been some deterioration. Aric's oxygen saturation level was 86 per cent. Both ventricles were hypertrophied, and an echocardiogram revealed moderate to severe left atrioventricular valve regurgitation. Considering the changes and the continued atrial shunting, Giddins arranged for Aric to undergo a heart catheterization in May. It was becoming apparent that a surgical repair might be required in the near future.

Before the catheterization took place, however, Aric became very ill. When his parents took him to hospital on April 30, he was diagnosed with heart failure and treated with diuretics. He also required treatment with antibiotics for ten days for an ear infection. During his stay in hospital, an echocardiogram was done on May 2. This showed:

• a partial atrioventricular canal defect
• a torrential left to right shunt through a large primum atrial septal defect
• severe right atrioventricular valve regurgitation
• moderate pulmonary hypertension.

The shunt was diagnosed as torrential because four hundred per cent more blood was flowing into Aric's lungs than was normal. A cardiac catheterization performed on May 5 confirmed those findings and indicated that there was also mitral stenosis. Aric's heart failure was brought under control and he was discharged home on May 8.

One of the issues in Aric's case was the fact that the defect Giddins identified did not normally create the degree of hypertension that Aric was suffering from, so early in life. Odim attributed the hypertension to the mitral stenosis, and to the hole in part of the atrial septum above Aric's valves.

Healthy heart

Diagram 7.1 Aric Baumann - pre-operative heart 1 - Right stenotic pulmonary vein (not detected prior to surgery) 2 - Partial atrioventricular canal defect (septum primum defect) 3 - Deficient tricuspid (right atrioventricular) valve (not detected prior to surgery) 4 - Right ventricular hypertrophy 5 - Left stenotic pulmonary veins (not detected prior to surgery) 6 - Deficient mitral (left atrioventricular) valve (not detected prior to surgery)