Care of the patient undergoing valvular heart surgery

Corrective cardiac surgery in infants. A review of 136 patients including the contribution of postoperative ventilation

This is a review of 136 patients who have undergone corrective surgery for congenital heart disease with the aid of profound hypothermia in a 6-year period. Almost all patients were less than one year old and less than 10 kg. In 1979 the average age was 3.4 months and the average weight was 4.1 kg in 34 infants. The hypothermic technique consisted of surface cooling followed by cardiopulmonary bypass cooling and circulatory arrest during definitive surgery. The hospital mortality was 26% for the whole period, having decreased from 53% in 1974 to 15% in 1979. After operation 70% of patients with uncomplicated ventricular septal defect or the tetralogy of Fallot were extubated within 4 hours, 65% of all patients were extubated within 12 hours of operation.

The role of echocardiography in the selection of mitral valve prosthesis

Assessment of the left ventricular outflow tract was made echographically in 70 patients who subsequently received a mitral prosthesis. Group A (44 patients) had normal left ventricular outflow tract width (greater than 20 mm.); 13 received the Starr-Edwards prosthesis and nine received the Braunwald-Cutter prosthesis. There were two patients with low cardiac output syndrome and no hospital deaths. Group B (26 patients) had a narrow left ventricular outflow tract (less than 20 mm.). Thirteen patients received the Starr-Edwards prosthesis. One patient had low cardiac output syndrome, and there were no hospital deaths. We conclude that the use of the ball-and-cage prosthesis in the mitral position in patients with a narrowed left ventricular outflow tract (less than 20 mm.) measured echographically is not associated with an increased surgical risk.

Pulmonary hypertension in mitral valve disease: 56 surgical patients reviewed

A total of 392 patients have undergone prosthetic valve surgery including the mitral valve over a four-year period (1972-76). Of these patients 56 (14%) had a pulmonary artery systolic pressure of 70 mmHg or more during preoperative cardiac catheterisation and the hospital mortality of this group was 5.4%. Similarly, the hospital mortality of the remaining 336 patients with a pulmonary artery pressure below 70 mmHg was 5.4%. The presence of pulmonary hypertension in patients with valve disease including the mitral valve does not therefore indicate that the risk of dying in hospital as a consequence of corrective surgery is increased. The absence of a raised hospital mortality in this recent series may be attributed to improved surgical techniques and materials, while the use of droperidol and pentolinium which may reduce pulmonary vascular resistance as well as systemic resistance during surgery could be contributory.