Jim Man-Hong, Ho Hee-Hwa, Siu Chung-Wah, Miu Raymond, Chan Carmen Wing-Sze, Lee Stephen Wai-Luen, Lau Chu-Pak
Cardiac Medical Unit, Grantham Hospital Hong Kong, 125 Wong Chuk Hang Road, Hong Kong.
Clin Cardiol. 2007 Jan;30(1):36-41. doi: 10.1002/clc.4.
Lead V(4R) faces the right ventricular free wall; it also reflects ischemia in the posterolateral wall lying opposite and manifests as ST-segment depression.
The aim of this study was to evaluate the usefulness of V(4R) ST-segment depression in distinguishing proximal from distal left circumflex artery occlusion in acute inferoposterior wall myocardial infarction.
We retrospectively analyzed 239 patients who had first acute inferoposterior myocardial infarction, were admitted within 6 h from onset of symptom, and had coronary angiography performed within 4 weeks. Patients who had bundle-branch block or concomitant significant stenoses in the proximal and distal segments of the same vessel or of both vessels were excluded. The electrocardiographic and angiographic findings were reviewed by two independent groups of investigators.
V(4R) ST-segment depression > or =1.0 mm was found in 8 of 46 patients (17.4%) with left circumflex artery occlusion but none (0%) with right coronary artery occlusion. Among the group with left circumflex artery occlusion, the mean magnitude of V(4R) ST-segment depression was greater in proximal than distal occlusion (0.82 +/- 0.65 vs. 0.03 +/- 0.12 mm, p < 0.0001). V(4R)ST-segment depression > or =1.0 mm was found in 8 of 14 patients (57.1%) with proximal occlusion but none (0%) in 32 patients with distal occlusion. The sensitivity and specificity to predict proximal occlusion were 57.1 and 100%, respectively.
V(4R) ST-segment depression > or =1.0 mm was not useful for differentiating left circumflex and right coronary artery occlusion because of its low sensitivity. It is a fairly sensitive and very specific sign of proximal left circumflex artery occlusion.
V(4R)导联面对右心室游离壁;它还反映相对的后外侧壁的缺血情况,表现为ST段压低。
本研究的目的是评估V(4R)导联ST段压低在鉴别急性下后壁心肌梗死时左回旋支近端闭塞与远端闭塞中的作用。
我们回顾性分析了239例首次发生急性下后壁心肌梗死、症状发作后6小时内入院且在4周内行冠状动脉造影的患者。排除有束支传导阻滞或同一血管或两支血管的近端和远端节段伴有明显狭窄的患者。两组独立的研究人员对心电图和血管造影结果进行了评估。
46例左回旋支闭塞患者中有8例(17.4%)V(4R)导联ST段压低≥1.0mm,而右冠状动脉闭塞患者中无一例(0%)出现这种情况。在左回旋支闭塞组中,近端闭塞时V(4R)导联ST段压低的平均幅度大于远端闭塞(0.82±0.65 vs. 0.03±0.12mm,p<0.0001)。14例近端闭塞患者中有8例(57.1%)V(4R)导联ST段压低≥1.0mm,而32例远端闭塞患者中无一例(0%)出现这种情况。预测近端闭塞的敏感性和特异性分别为57.1%和100%。
V(4R)导联ST段压低≥1.0mm由于其低敏感性,对鉴别左回旋支和右冠状动脉闭塞无用。它是左回旋支近端闭塞的一个相当敏感且非常特异的征象。