Short-term effects of elongated soft palate correction on cardiovascular function and heart rate variability (HRV) were studied in eleven French Bulldogs with brachycephalic obstructive airway syndrome (BOAS). The oxygen saturation (SpO2), blood pressure (BP), electrocardiography (ECG), echocardiography, short-term HRV, and modified BOAS questionnaire were carried out before and one month after surgical correction of BOAS. Significant reduction in the respiratory rate was reported after surgery (P < 0.05, 95% CI -16, -2). No significant differences were observed in SpO2, BP, ECG, and echocardiographic parameters both before and after surgery. Most of the questionnaire scores were improved after surgery. The HRV results after surgery showed a significant reduction in vagally mediated indices and a relative shift toward low frequency (LF) components. These changes were correlated to the clinical improvement from modified BOAS questionnaire. Although surgery improved questionnaire scores, the short-term changes in HRV likely reflect altered breathing patterns rather than definitive relief of ‘parasympathetic overactivity’. Longer follow-up with better respiratory control, or comparison among brachycephalic breeds is needed to clarify the direct impact of surgery on autonomic function.
Widyanjaya et al. (Tue,) studied this question.