OBJECTIVE: Investigate the cardiorespiratory effects of noninvasive neurally adjusted ventilatory assist (NIV-NAVA), nonsynchronized nasal intermittent positive pressure ventilation (NIPPV), and nasal continuous positive airway pressure (NCPAP) shortly after extubation. HYPOTHESIS: Types of noninvasive pressure support and the presence of synchronization may affect cardiorespiratory parameters. STUDY DESIGN: Randomized crossover trial. PATIENT-SUBJECT SELECTION: Infants with birth weight (BW) 1250 g or under, undergoing their first planned extubation were randomly assigned to all three modes using a computer-generated sequence. METHODOLOGY: Electrocardiogram and electrical activity of the diaphragm (Edi) were recorded for 30 min on each mode. Analysis of heart rate variability (HRV), diaphragmatic activity (Edi area, breath area, amplitude, inspiratory and expiratory times), and respiratory variability were compared between modes. RESULTS: Twenty-three infants had full data recordings and analysis: Median (IQR) gestational age = 25.9 weeks (25.2-26.4), BW = 760 g (595-900), and postnatal age 7 (4-19) days. There were no differences in HRV between modes. A significantly reduced Edi area and breath amplitude, and increased coefficient of variation (CV) of breath amplitude were observed during NIV-NAVA and NIPPV compared to NCPAP. A higher proportion of assisted breaths (99% vs. 51%; p < .001) provided a higher mean airway pressure (MAP; 9.4 vs. 8.2 cmH(2) O; p = .002) with lower peak inflation pressures (PIPs; 14 vs. 16 cmH(2) O; p < .001) during NIV-NAVA compared to NIPPV. CONCLUSIONS: NIV-NAVA and NIPPV applied shortly after extubation were associated with lower respiratory efforts and higher respiratory variability. These effects were more evident for NIV-NAVA where optimal patient-ventilator synchronization provided a higher MAP with lower PIPs.