Cardiac function changes in patients with ankylosing spondylitis kyphosis after pedicle subtraction osteotomy

English Keywords:Ankylosing spondylitis kyphosis  Cardiac function  Resting heart rate  Pedicle subtraction osteotomy

English Abstract:

  【Abstract】 Objectives: To observe the postoperative changes in cardiac function of patients with ankylosing spondylitis(AS) kyphosis after the pedicle subtraction osteotomy(PSO). Methods: The original cohort consisted of 36 patients(31 males and 5 females) treated in our hospital from October 2011 to October 2013. The age was 21 to 50 years(39±10 years) and the duration of AS was 5 to 27 years(17±6 years). Echocardiographic measurements, resting heart rate(RHR), active capacity score(ACS), and full-length spine X-ray films in natural standing position were obtained before surgery and at 1-year follow-up. Echocardiographic parameters were measured as follows: left ventricular ejection fraction(LVEF) and left ventricular fraction shortening(LVFS)， mitral early diastolic velocity(E), late diastolic velocity(A), E/A ratio, E deceleration time(DT) and isovolumetric relaxation time(IVRT). And the left ventricular(LV) diastolic function was assessed by the recommendations of American and European Society of Echocardiography. Results: 32 patients(28 males and 4 females) completed the follow-up and 4(3 males and 1 female) patients lost. The preoperative RHR was 85.9±12.5 beats per minute, whereas it was reduced to 71.8±9.7 beats per minute at 1-year follow-up(P=0.0000). The ACS was improved from 47.4±18.2 points preoperatively to 78.3±12.6 points at 1-year follow-up(P=0.0000). 14 patients(2 patients were turned into mild LV diastolic dysfunction at 1-year follow-up) had normal LV diastolic function before operation while there were 25 patients at 1-year follow-up. The clinical improvement rate was 72.2%(13/18). The preoperative DT was 234.84±32.46ms, and it was reduced to 211.56±26.74ms at 1-year follow-up(P=0.0027). The IVRT before PSO was 102.50±19.86ms, while it decreased to 87.92±13.12ms at 1-year follow-up(P=0.0010). The E/A ratio increased from 1.02±0.36 preoperatively to 1.24±0.27 at 1-year follow-up(P=0.0075). Conclusions: The postoperative cardiac function in patients with AS kyphosis is significantly improved at 1-year follow-up.