Abnormal Ventilatory Response to Exercise in Adults With Congenital Heart Disease Relates to Cyanosis and Predicts Survival

Abstract

Background— Limited data exist with which to stratify risk in adult congenital heart disease (ACHD). An increased ventilatory response to exercise, expressed as ventilation per unit of carbon dioxide production (V̇ e /V̇ co 2 slope), is an established predictor of impaired survival in acquired heart disease. We sought to establish the distribution, relation to cyanosis, and prognostic value of the V̇ e /V̇ co 2 slope across a wide spectrum of ACHD patients. Methods and Results— Five hundred sixty ACHD patients of varying diagnoses and 50 healthy controls underwent cardiopulmonary exercise testing at a single laboratory between 2001 and 2004. Patient age was 33.2±12.9 years (mean±SD). Peak oxygen consumption was 23.5±9.0 mL · kg −1 · min −1 . V̇ e /V̇ co 2 slope for all patients was 36.3±15.3. The slope was raised in all ACHD groups compared with controls and was 73% higher in cyanotic patients. Cyanosis, with or without pulmonary arterial hypertension, was the strongest predictor of abnormal V̇ e /V̇ co 2 slope. The V̇ e /V̇ co 2 slope was the most powerful univariate predictor of mortality in the noncyanotic group and the only independent predictor of mortality among exercise parameters on multivariate analysis. In cyanotic patients, no parameter was predictive of death. Conclusions— Ventilatory response to exercise is abnormal across the spectrum of ACHD. Cyanosis is a powerful stimulus for such exaggerated ventilatory patterns irrespective of the presence of pulmonary arterial hypertension. Increased V̇ e /V̇ co 2 slope is the strongest exercise predictor of death in noncyanotic ACHD patients.

Normal values for cardiopulmonary exercise testing in children

“…13 An increase of this variable has been attributed to maldistribution of pulmonary blood flow with increased physiological dead space ventilation. The values obtained in this study are higher when compared with their normal values, although this difference is less prominent in our older children.…”

Eisenmenger syndrome: current perspectives

“…In ES, the chronic hypoxemia, together with a low cardiac output and PAH, has significant multisystem effects, resulting in a vast spectrum of complications (Table 2). 5,[12][13][14][15] Cardiac arrhythmias, hemoptysis, infections, and right heart failure are important late complications and are a frequent cause of death. Other complications such as pulmonary artery (PA) dilatation and in situ thrombosis are frequently encountered in this cohort (Figure 1).…”

The spectrum of pulmonary arterial hypertension in adults with congenital heart disease: management from a physician and nurse specialist perspective

“…Chronic cyanosis, together with PAH and the underlying congenital heart defect is responsible for the significant morbidity and mortality of this condition. Exercise intolerance is the most important symptom of ES and affects patients' quality of life [12][13][14]. Tolerance to effort is extremely limited in these patients, with an average peak oxygen consumption well below 15 ml/kg/min, frequently less than half that predicted for healthy individuals.…”