Effect of kyphosis in ankylosing spondylitis on cardiopulmonary function

Abstract Purpose: To analyze the characteristics of cardiopulmonary function in patients with ankylosing spondylitis (AS), and explore the influence of global kyphosis (GK) on cardiopulmonary function. Method: Clinical data of 46 AS patients with kyphosis admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed. According to the to global kyphosis Angle, they were divided into severe group (GK > 95°), 23 cases in the moderate group (80° ≤ GK ≤ 95°). Cardiac structure, function and lung function parameters were compared between the two groups, and the effects of GK Angle on other parameters were analyzed by Pearson or Spearman correlation analysis. Result: The cardiac structure and function measurements in both groups were within the normal range, and the atrioventricular size in the severe group was significantly smaller than that in the moderate group (P < 0.05), left ventricular diastolic function parameters E/A, e’/a’ were significantly lower than those in moderate group (P < 0.05), and E/e’ was significantly higher than that in moderate group (P < 0.05). The lung function of the two groups was decreased to varying degrees. The restrictive ventilation function, small airway function and ventilation function parameters of the severe group were significantly lower than those of the moderate group (P < 0.05). Correlation analysis showed that GK Angle was significantly negatively correlated with left atrioventricular size (LAD, LVDD, LVSD) and diastolic function parameters (E/A, e’/a’) in AS patients (P < 0.05); GK Angle was negatively correlated with restrictive ventilation parameters in AS patients (P < 0.05). Conclusion: The GK Angle of AS affects the heart structure and diastolic function. The larger the GK Angle is, the smaller the left and right atventricle diameters are. In addition, GK Angle also affects left ventricular diastolic function. GK Angle is related to the degree of lung function impairment, and the larger the GK Angle, the worse the lung function.