Oxygen Availability in Respiratory Muscles During Exercise in Children Following Fontan Operation

Abstract

Introduction: As survival of previously considered as lethal congenital heart disease forms is the case in our days, issues regarding quality of life including sport and daily activities emerge. In patients with Fontan circulation, there is no pump to propel blood into the pulmonary arteries since the systemic veins are directly connected to the pulmonary arteries. The complex hemodynamics of Fontan circulation include atrial function, peripheral muscle pump, integrity of the atrioventricular valve, absence of restrictive, or obstructive pulmonary lung function. Therefore, thoracic mechanics are of particular importance within the complex hemodynamics of Fontan circulation. Methods: To understand the physiology of respiratory muscles, the aim of this study was to examine the matching of auxiliary respiratory muscle oxygen delivery and utilization during incremental exercise in young male Fontan patients ( n = 22, age = 12.04 ± 2.51) and healthy Controls ( n = 10, age = 14.90 ± 2.23). All subjects underwent a cardiopulmonary exercise test (CPET) to exhaustion whereas respiratory muscle oxygenation was measured non-invasively using a near-infrared spectrometer (NIRS). Results: CPET revealed significantly lower peak power output, oxygen uptake and breath activity in Fontan patients. The onset of respiratory muscle deoxygenation was significantly earlier. The matching of local muscle perfusion to oxygen demand was significantly worse in Fontans between 50 and 90% . Findings: The results indicate that (a) there is high strain on respiratory muscles during incremental cycling exercise and (b) auxiliary respiratory muscles are worse perfused in patients who underwent a Fontan procedure compared to healthy Controls. This might be indicative of a more general skeletal muscle strain and worse perfusion in Fontan patients rather than a localized-limited to thoracic muscles phenomenon.

Exercise Capacity and Training Programs in Paediatric Fontan Patients: A Systematic Review

“…Oxygen consumption. Reported mean VO 2peak values ranged from 14.4 AE 6.1 mL/kg/min 17 to 35.97 AE 6.84 mL/kg/min, 18 and mean percent-predicted VO 2peak values ranged from 54.3% AE 9.2% 19 to 86% AE 19% 20 (Table 1). Multiple studies reported significantly lower VO 2peak , 17,18,[21][22][23][24] VO 2 at anaerobic threshold, 17,23,25 and O 2 pulse 17,21 relative to healthy individuals.…”

“…Reported mean VO 2peak values ranged from 14.4 AE 6.1 mL/kg/min 17 to 35.97 AE 6.84 mL/kg/min, 18 and mean percent-predicted VO 2peak values ranged from 54.3% AE 9.2% 19 to 86% AE 19% 20 (Table 1). Multiple studies reported significantly lower VO 2peak , 17,18,[21][22][23][24] VO 2 at anaerobic threshold, 17,23,25 and O 2 pulse 17,21 relative to healthy individuals. Although reductions in both maximal and submaximal exercise capacity have been reported, 26 submaximal exercise parameters are typically less reduced than those for maximal exercise.…”

Oxigenación de músculos respiratorios y locomotores durante el test cardiopulmonar en pacientes con circulación de Fontan: serie de casos

“…para realizar CPET 15 protocolo utilizado previamente por nuestro grupo de investigación (Figura 1b) 18 . Vastus-Laterallis (Figura 2b), la asociación fue débil (rho=0.28), y por tanto, es necesario aumentar el número de pacientes evaluados para sostener que el incremento en el WOB es la principal limitación muscular al ejercicio en PCF, y no así el factor muscular periférico 13 .…”

“…Utilizando esta tecnología, en PCF se ha evaluado la SmO 2 en m.Vastus-Laterallis encontrando una disminución total de la oxigenación posterior al ejercicio físico máximo (∆SmO 2 = 4.5±2.1%) 12 . Hallazgo similar se ha reportado recientemente en m.Serratus-Anterior (∆HHb= 48±5%), en donde además se encontró asociación directa con el rendimiento físico (VO 2 -peak) 13 . Considerando los resultados de estos estudios, se infiere que durante el esfuerzo físico intenso, como ocurre en la valoración del test cardiopulmonar (Cardiopulmonary Exercise Testing, CPET), los PCF presentan incrementos del trabajo muscular locomotor y respiratorio, reflejado en la desoxigenación de m.Vastus-Laterallis y m.Serratus-Anterior.…”

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratio in Univentricular Patients From Birth to Follow-Up After Fontan—Predicting Lymphatic Abnormalities

“…The Fontan procedure is a palliative surgical strategy for patients with functional single ventricle malformations. The Fontan circulation is characterized by a non-pulsatile pulmonary blood flow leading to increased central venous pressure and low cardiac output and a series of physiologic changes typical for the univentricular circulation (1)(2)(3). Treatment and care of patients with univentricular heart defects has undeniably made great progress in recent years.…”