Clinical course in adults with ventricular septal defect.

The 38 adult patients admitted to the Natural History Study with a small ventricular defect had a generally favorable course, similar to that noted in children and adolescents. None died under medical or surgical management, and none deteriorated. Among patients treated medically, complete closure was demonstrated during the course of follow-up in one, and in the others, wo were catheterized, the shunt remained the same or decreased slightly. Significant vascular disease did not develop in any of the patients. Among seven surgically-treated patients for whom data were complete, the defect was completely closed in six. In 18 patients who had large ventricular septal defects and mild or moderate pulmonary vascular disease, no significant change occurred in the four who were managed medically. Of 14 who underwent surgery, two died; six of eight who were recatheterized had normal pulmonary arterial pressure, with no residual shunt in four and a trivial shunt in two. Two patients who had had moderate vascular disease preoperatively (RP/RS was 0.4 in both) had open defects and slightly higher resistance ratios at final catheterization. Of the 18 patients with Eisenmenger's syndrome, eight died during the study, including one of two who underwent surgery. The other surgical patient survived and showed significant hemodynamic improvement at final catheterization.

Opitmal age and results in repair of large ventricular septal defects.

The hospital mortality rate was 9.1 per cent (three deaths) in 33 patients less than 2 years old undergoing primary repair of single large ventricular septal defects (VSD's) since January 1972, and was not related to age; it was zero in 50 patients older than 2 years (Group A). The mortality rate with multiple VSD's was 36.4 per cent, not related to age. Age at operation, preoperative pulmonary vascular resistance, and pulmonary artery pressure were directly related to mean pulmonary artery pressure 5 or more years later in 74 patients (Group B) operated upon between 1955 and 1968. Over-all probability of "surgical cure" for single large VSD (surviving the early and late postoperative period with normal or near-normal pulmonary artery pressure 5 years later) is 92 per cent when pulmonary vascular resistance is 4 units - sq. M. and operation performed at age 27 months, 87 per cent when resistance is 8 and operation done at age 6 months, and 80 per cent when resistance is 12 and operation done at less than 6 months of age. These and other probability curves are examined and compared with natural history to determine optimal age for elective repair for large VSD's.

Computer interpretation of Frank vectorcardiogram in normal infant: Longitudinal and cross-sectional observations from birth to 2 years of age.

The evolution of the Frank vectorcardiogram (VCG) was studied from longitudinal observations (60 normal infants) and from cross-sectional observations (231 normal infants) from birth to two years of age. Age specific normal values for the Cartesian coordinates of 14 vectors including maximal QRS-T and timed vectors in the horizontal and frontal plane were determined with both methods of analysis. In longitudinally followed infants the most significant involution of right ventricular forces occurred between the newborn period and 7-14 weeks of age. These changes included disappearance of clockwise horizontal loop rotation and a leftward shift of maximal and terminal forces as well as a rightward shift of initial vectors. Longitudinal observations were useful for prediction of the normal Frank VCG in the 7 to 14-week-old infant from values observed in the newborn period and for prediction of the horizontal loop rotation throughout infancy. Cross-sectional data showed a wider range of normal values than longitudinal data in the same 7 to 14-week-old infants, but age specific normal values were well reflected between 4 and 24 months of age from cross-sectional data.

Cardiac monitoring and demand pacemaker in Guillain-Barré syndrome.

Life-threatening alterations of respiratory and cardiovascular functions may complicate the course of severe Guillain-Barre syndrome. Cardiac arrest, fore-warned by episodes of bradycardia or other arrhythmia, may occur despite adequately assisted respirations. A patient with Guillain-Barre syndrome required tracheostomy and ventilatory assistance. Continuous cardiac monitoring revealed that tracheal aspiration provoked an idioventricular rhythm of 40 beats per minute, which reverted to sinus rhythm after the procedure. To prevent cardiac arrest during the transition from idioventricular to sinus rhythm, a demand pacemaker was inserted into the right ventricle. Set to activate if the rate fell below 65 beats per minute, the pacemaker functioned both during and between tracheal aspiration procedures. Cardiac monitoring in severe cases of Guillain-Barre syndrome may detect potentially lethal arrhythmias that may then be avoided by a demand pacemaker.