Yue-Cheng Hu, Zuo-Cheng Li, Xi-Ming Li, Yuan David Zhe, Dong-Xia Jin, Ying-Yi Zhang, Hui-Ming Yang, Hong-Liang Cong
Department of Cardiology, Tianjin Chest Hospital, Tianjin, China.
Pacing Clin Electrophysiol. 2013 Jan;36(1):86-93. doi: 10.1111/pace.12016. Epub 2012 Oct 18.
Pacing has been proposed as a treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM), but there are few studies with long-term follow-up. We evaluated the long-term effects of dual-chamber pacing therapy for patients with HOCM, and to identify the most prognosis-specific factors for predicting outcome in such treating methods.
A total of 37 HOCM patients implanted with dual-chamber pacemakers were enrolled consecutively and followed-up. Thirty-seven cases were followed for 1 year, 26 cases for 2 years, 10 cases for 3 years, and eight cases for 4 years. At each annual point of follow-up after pacemaker implantation, the pacing frequency, pacing threshold, impedance, atrioventricular delay, and cumulative percentage of atrial and ventricular pacing were tested, respectively. In addition, left atrial dimension (LAD), left ventricular end diastolic dimension (LVEDd), left ventricular posterior wall thickness (LVPW), interventricular septum thickness (IVS), left ventricular outflow tract dimension (LVOTd), peak velocity of left ventricular outflow tract (VLVOT), left ventricular outflow tract pressure gradient (LVOTPG), left ventricular ejection fraction (LVEF), and pulmonary artery systolic pressure (PASP) were measured. Mitral valve systolic anterior motion (SAM) was also observed. Pacing parameters and echocardiography indexes before and after pacemaker implantation were dynamically compared.
Pacing frequency and atrioventricular delay were adjusted to 60-70 beats per minute and 90-180 ms, respectively, in order to ensure the ratio of ventricular pacing was more than 98%. Pacing threshold and pacing impedance were kept in normal ranges. The differences of various pacing parameters were of no statistical significance within the 4 years of follow-up (P > 0.05). Compared with prior to pacing, it was observed that the IVS, VLVOT, and LVOTPG declined significantly (P < 0.01), the LVOTd widened significantly (P < 0.01), and the SAM phenomenon improved obviously (P < 0.01) at 1, 2, 3, and 4 years after pacemaker implantation. Additionally, the changes in LAD, LVEDd, LVPW, LVEF, and PASP were statistically insignificant (P > 0.05).
The cardiac structural reconstruction in patients with HOCM can be chronically improved by dual-chamber pacing therapy. The IVS, LVOTd, VLVOT, and LVOTPG can be used as sensitive and specific factors in evaluating the long-term effects of dual-chamber pacing therapy for HOCM.
起搏已被提议作为肥厚性梗阻性心肌病（HOCM）患者的一种治疗方法，但长期随访研究较少。我们评估了双腔起搏治疗对HOCM患者的长期影响，并确定在此治疗方法中预测预后的最具预后特异性的因素。
连续纳入37例植入双腔起搏器的HOCM患者并进行随访。37例随访1年，26例随访2年，10例随访3年，8例随访4年。在起搏器植入后的每年随访点，分别测试起搏频率、起搏阈值、阻抗、房室延迟以及心房和心室起搏的累积百分比。此外，测量左心房内径（LAD）、左心室舒张末期内径（LVEDd）、左心室后壁厚度（LVPW）、室间隔厚度（IVS）、左心室流出道内径（LVOTd）、左心室流出道峰值速度（VLVOT）、左心室流出道压力阶差（LVOTPG）、左心室射血分数（LVEF）和肺动脉收缩压（PASP）。还观察二尖瓣收缩期前向运动（SAM）。动态比较起搏器植入前后的起搏参数和超声心动图指标。。
为确保心室起搏比例超过98%，将起搏频率和房室延迟分别调整为每分钟60 - 70次和90 - 180毫秒。起搏阈值和起搏阻抗保持在正常范围内。在4年的随访中，各种起搏参数的差异无统计学意义（P > 0.05）。与起搏前相比，观察到起搏器植入后1、2、3和4年时，IVS、VLVOT和LVOTPG显著下降（P < 0.01），LVOTd显著增宽（P < 0.01），SAM现象明显改善（P < 0.01）。此外，LAD、LVEDd、LVPW、LVEF和PASP的变化无统计学意义（P > 0.05）。
双腔起搏治疗可长期改善HOCM患者的心脏结构重构。IVS、LVOTd、VLVOT和LVOTPG可作为评估双腔起搏治疗HOCM长期效果的敏感且特异的因素。
