Martin A B, Garson A, Perry J C
Lillie Frank Abercrombie Section of Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston.
Am Heart J. 1994 Jan;127(1):64-70. doi: 10.1016/0002-8703(94)90510-x.
When the QT interval is prolonged in a patient with structural heart disease, there is a question of whether the QT interval prolongation is the result of coexistent long QT interval syndrome or ventricular hypertrophy. The purpose of this study was to assess whether QT interval prolongation can be attributed to ventricular hypertrophy/dilation alone. Electrocardiograms (ECGs) of 25 children in each of six echocardiographically proven groups (right ventricular hypertrophy, left ventricular hypertrophy, biventricular hypertrophy, hypertrophic cardiomyopathy, dilated cardiomyopathy, and normals) were analyzed. All patients had QRS interval durations < 100 msec, and patients with ventriculotomies were excluded. No patients in the normal group had a QTc interval > or = 0.45 sec. Eight (32%) of 25 patients with dilated cardiomyopathy had a QTc interval > or = 0.45 sec (p = 0.007 vs normal), 6 (24%) of 25 patients with hypertrophic cardiomyopathy had a QTc interval > or = 0.45 sec (p = 0.03 vs normal), and 2 of 25 patients each with right ventricular hypertrophy, left ventricular hypertrophy, and biventricular hypertrophy had a QTc interval > or = 0.45 sec (p = NS vs normal). There was no relation of the QTc interval to age, QRS duration, T-wave axis, or heart rate in any group. In the dilated cardiomyopathy group, there was no relationship of QTc interval to age, shortening fraction, or left ventricular end diastolic dimension. In conclusion, (1) a significant number of patients (24% to 32%) with dilated or hypertrophic cardiomyopathy may have a long QTc interval on the surface ECG, and (2) ventricular hypertrophy/dilation may be additional rare causes of acquired prolongation of the QT interval.
在患有结构性心脏病的患者中，QT间期延长时，存在QT间期延长是并存的长QT间期综合征还是心室肥厚所致的问题。本研究的目的是评估QT间期延长是否可单独归因于心室肥厚/扩张。分析了六个经超声心动图证实的组（右心室肥厚、左心室肥厚、双心室肥厚、肥厚型心肌病、扩张型心肌病和正常组）中每组25名儿童的心电图（ECG）。所有患者的QRS间期时长<100毫秒，接受心室切开术的患者被排除。正常组中没有患者的QTc间期≥0.45秒。25例扩张型心肌病患者中有8例（32%）的QTc间期≥0.45秒（与正常组相比，p=0.007），25例肥厚型心肌病患者中有6例（24%）的QTc间期≥0.45秒（与正常组相比，p=0.03），25例右心室肥厚、左心室肥厚和双心室肥厚患者中各有2例的QTc间期≥0.45秒（与正常组相比，p=无显著性差异）。在任何组中，QTc间期与年龄、QRS时长、T波电轴或心率均无关联。在扩张型心肌病组中，QTc间期与年龄缩短分数或左心室舒张末期内径均无关联。总之，（1）相当数量（24%至32%）的扩张型或肥厚型心肌病患者体表心电图上可能有长QTc间期，（2）心室肥厚/扩张可能是获得性QT间期延长的额外罕见原因。
