Pulmonary Determinants of Cardiorespiratory Fitness in Fontan Patients

CPET, the gold standard, will be used in the assessment of cardiorespiratory fitness. The cardiopulmonary exercise test system (Cosmed Quark CPET, Rome, Italy) is a safe method in which the patient can be monitored via ECG during the execution of the individual on a treadmill, and simultaneously lactate measurement, maximal O2 consumption, and CO2 production are evaluated. The Bruce protocol is the most commonly used method for KPET applied with a treadmill. However, since the Bruce protocol prefers high workload preferences, the Modified Bruce/half Bruce protocol with intermediate increments will be used. In addition, dyspnea, leg fatigue, and general fatigue at rest, during the test, and during the recovery phases after the test will be recorded with a sphygmomanometer using the Modified Borg Scale.

Pulmonary function testing will be performed with a spirometer (Cosmed Quark CPET, Rome, Italy) connected to the CPET system using standard procedures. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC, peak expiratory volume measured at 25% and 75% of forced expiratory time (FEF 25-75%), and peak expiratory volume (PEF) parameters will be saved.

Intraoral maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) will be used as indicators of respiratory muscle strength. A portable intraoral pressure gauge (MicroRPM, Micromedical, Kent, UK) and nose clip will be used during MIP and MEP assessments. MIP and MEP measurements will be obtained using standard procedures. 3 measurements will be made where the difference between each measurement is not more than 10% and the maximum value of MIP and MEP will be recorded.