Two patients (patient 12/13 and patient 23/24) underwent evaluation twice with an interval of at least 6 months. Both patients were surgically palliated (with significant changes in clinical presentation, extent of cyanosis, and shunt volume) between both evaluations. The remaining patients did not undergo surgical corrections. Individual diagnoses are presented in Table 1.
The control group consisted of 101 healthy volunteers aged 16 to 75 years (mean age, 37 years). Forty-five of them were women (mean weight, 60 ± 8 kg; mean height, 165 ± 6 cm), and 56 were men (mean weight, 78 ± 12 kg; mean height, 179 ± 9 cm). All persons were free of any cardiovascular, pulmonary, or other systemic disease, had physiologic resting and exercise ECGs, physical examinations, pulmonary function tests, and had no medications. The results have been published in part elsewhere. website
The functional class of all patients was determined according to the New York Heart Association (NYHA) class and ability index.
In every subject, symptom-limited CPX was performed according to the modified Naughton protocol on a treadmill (Woodway; Boston, MA). A Medical Graphics CPX system was used (Medical Graphics Corporation; St. Paul, MN). Details of the test protocol have been reported previously.
Before starting exercise, FEV1 was measured and multiplied by the factor 41 to estimate maximal voluntary ventilation (MVV) in all subjects. The ratio of maximal ventilation during exercise and MVV provided information about the breathing reserve (maximal Ve/MVV).
CPX was preceded by a resting period of at least 5 min (after reaching a steady state for gas exchange represented by a plateau for Vo2, Vco2, end-tidal oxygen partial pressure [Peto2], end-tidal carbon dioxide partial pressure [Petco2], resting VE, BP, and heart rate). During the resting period, gas exchange, VE, and Ve/Vco2 ratio were calculated as the mean value during the last minute prior to starting exercise.
Table 1—Characteristics of Cyanotic Patients
|PatientNo.||Age, yr||Cardiac Malformation|
|1-4||24-57||Eisenmenger syndrome (VSD)|
|5||49||Eisenmenger syndrome (ASD and partial anomalous pulmonary venous drainage)|
|6-9||25-57||Ebstein anomaly with ASD|
|10, 11||20-25||Pulmonary atresia with Fallot tetralogy|
|12, 13||21||Pulmonary atresia with double-outlet right ventricle|
|14, 15||22-30||Pulmonary atresia with Fallot tetralogy|
|16 -19||18-59||Fallot tetralogy|
|21-23||19-23||Tricuspid valve atresia|
|24||23||Tricupsid valve atresia with double-inlet left ventricle|
|25||18||Complete atrioventricular canal and pulmonary stenosis|
|26||24||Double-outlet right ventricle and atresia of the left pulmonary artery|
|27||29||Congenitally corrected transposition of the great vessels, ASD, VSD, pulmonary stenosis|