Excerpt

We previously reported that exertional oscillatory ventilation (EOV) during cardiopulmonary exercise test (CPET) was a frequent phenomenon among Fontan patients, and that a lack of EOV was related to lower peak oxygen uptake (VO₂), which was a contrary result in adult patients with chronic heart failure and biventricular circulation [1]. Herein, we show additional data about the late clinical outcomes of these Fontan patients. We studied 43 Fontan patients who underwent symptom-limited CPET. Age at CPET was 9 (6–30) years and interval after Fontan operation was 4 (1.8–15) years. We studied NYHA functional class at 20 (15–34) years of age among these patients. Peak VO₂ and corrected values were 31.8 (18.8–48.1) ml/min/kg and 72(41–92)%, respectively. EOV was noted in 23 patients (53%), peak VO₂ and %peak VO₂ were significantly higher in the patients with EOV than those without EOV (35.5 vs 28.4 ml/min/kg, p < 0.001; 74 vs 59%, p = 0.001). There was no significant difference in other CPET parameters and invasive hemodynamic data between two groups (Table 1). At the last follow-up, 20 patients (87%) with EOV were in NYHA functional class I and the rest 3 patients (13%) were in class II, whereas 15 (75%), 2 (10%) and 3 patients (15%) without EOV were in NYHA functional class I, II and III, respectively (no statistical difference). There is no patient with protein-losing enteropathy or heart transplantation during the follow-up period. The occurrence of EOV in Fontan patients was responsible for an inappropriate increase of cardiac output due to a lack of pulmonary ventricle, ventilation–perfusion mismatch, an increase of ventricular afterload, chronotropic incompetence, autonomic nerve disturbance and hyperactivity of central nervous chemoreflex [1]. We noted that some of the patients without EOV had worse NYHA functional classes in the last follow-up. A recent report by Nathan et al. from Boston Children’s Hospital described that the presence of EOV was associated with increased risk of death or transplant among Fontan patients, which differed from our result [2]. The majority of population in Nathan et al.’s report consisted of adults (24 years of age), whereas out study population consisted of young children. It is supposed that a lack of EOV among young Fontan patients may suggest the adverse outcome during the follow-up period. …