臨床神経学

<シンポジウム(3)―5―2>神経内科医にとっての筋強直性ジストロフィー診療上の盲点

心伝導障害

田村 拓久

国立病院機構東埼玉病院神経内科〔〒349―0196 埼玉県蓮田市黒浜4147〕

Sudden death is a serious problem in patients with myotonic dystrophy. Atrioventricular blocks (AVBs) and tachyarrhythmias are regarded as a cause of the cardiac sudden death. The increase of QRS width and the deviation of electrical axis are rather important because the main lesion of AVB is located in His-Purkinje system, while the prolongation of PR interval attracts our attention for AVB. The measurement of His-ventricle (HV) interval is indispensable to cardiac electrophysiological testing for the detection of His-Purkinje abnormalities. We measured "HV interval" (BHV) noninvasively, using His bundle potential recorded from the body surface by signal-averaged electrocardiogram. As a result, BHV correlated with QRS width and electrical axis (r=0.769, p<0.0001; r=-0.713, p=0.0004, respectively). Pacemaker implantation (PMI) is performed for the treatment of bradyarrhythmias based on the guideline of each country. Some reports revealed that prophylactic PMI did not improve the prognosis of asymptomatic case with severe muscle involvement, even if HV interval was over 70ms. It is important to assess PMI indication in each case, deliberating the extra-cardiac complications and prognosis.
Full Text of this Article in Japanese PDF (170K)

(臨床神経, 52:1261−1263, 2012)
key words:筋強直性ジストロフィー,房室ブロック,HV時間,加算平均心電図,ペースメーカー植え込み

(受付日:2012年5月25日)