此心电图案件博客我们来看看7例右束支阻滞和潜在的缺血症状。其中有右束支阻滞闭塞MI?

Written by Jesse McLaren; Peer Reviewed and edited by Anton Helman. August 2020

七例存在潜在的缺血症状。其中有闭塞MI?

情况1:70yo胸痛。HR 140,BP 150,RR20,饱和98%。老那么新的心电图:

案例2: 70yo with syncope. AVSS. Old then new ECG:

案例3:75yo胸痛一个小时。HR 90,BP 85/50。老那么新的心电图:

案例4: 40yo prior CABG with 2hr chest pain. AVSS. Old then new ECG:

案例5:85yo用2小时胸痛。AVSS,事先没有心电图

案例6:45yo消化不良和出汗。AVSS,事先没有心电图

案例7:65yo具有恒定的胸痛一天。边缘性心动过速与正常BP / SATS。事先没有心电图

右束支阻滞和闭塞MI

当右束支被阻断,隔膜去极化(左到右),随后由左心室的去极化迅速经由左束支,然后右心室去极化缓慢。So QRS is prolonged >120ms (incomplete RBBB if <120ms), right-sided precordial leads have RsR’ in V1 (R from septal depolarization, S from LV depolarization, and R’ from delayed RV depolarization), and left-side precordial leads have RS wave (with rapid R from LV depolarization, and slurred S from slower RV depolarization). Axis should be normal in RBBB, and an abnormal axis could be the clue to a concomitant left anterior fascicular block (left axis, qR in I/aVL and rS in II/III/aVF) or left posterior fascicular block (right axis, rS in I/aVL, qR in III/aVF), or another reason for altered axis.

右束不仅顺着室间隔,并得到其大部分血液供应从LAD。所以急性右束支阻滞可以开发,如果隔膜是由急性RV株(从PE)拉伸,或者选自急性冠状动脉闭塞(尤其是LAD)。右束支阻滞在急性冠状动脉闭塞可预先存在的(更可能在老年患者有合并症),也可以是急性的,在那里它与更大的梗死,心脏衰竭和心脏传导阻滞的更高的速率和更高的死亡率。虽然“新发LBBB”不再被认为是一个“STEMI等价物”,有急性冠脉闭塞的情况下日益认识新RBBB的危险。从STEMI死亡率相比新LBBB在新RBBB更高,和更高的仍然在bifascicular块最常用RBBB + LAFB,左前分册更薄且具有缺血比左后分册[1]更敏感的,因为。虽然与互惠STE-AVR弥漫STD曾经与左主干闭塞划等号,它现在认识到有多少更广泛的鉴别诊断的,但新的RBBB + LAFB + STEMI已经与左主阻塞有关[2]。

As with other causes of abnormal depolarization, RBBB causes repolarization abnormalities that can mask or mimic ischemic changes (especially in right-sided precordial leads that have RSR’), but the concept of appropriate discordance can help. As a review summarized: “The major, terminal portion of the QRS complex and the initial portion of the ST segment/T wave are discordant, meaning that they are located on opposite sides of the isoelectric baseline. Thus, in the right to mid precordial leads, the largely positive QRS complex will be associated with ST-segment depression and an inverted T wave. A ‘violation’ of this concept will manifest as ST-segment elevation, which is concordant with the major, terminal portion of the QRS complex; the T-wave findings are often variable with either continued inversion or disappearance (lost within the greater ST segment itself). Anterior wall STEMI is therefore usually quite obvious if the clinician is comfortable with the appropriate appearance of the ST segment in RBBB.”[3] But sometimes ECG changes can be subtle or non-existent. As with the guideline for PCI in patients with refractory ischemia, the 2017 European Society of Cardiology advises, “Patients with MI and right bundle branch block (RBBB) have a poor prognosis.这可能是难以检测患者胸痛和右束支阻滞透缺血。Therefore, a primary PCI strategy (emergent coronary angiography and PCI if indicated) should be considered when persistent ischaemic symptoms occur in the presence of RBBB.”[4]

回到案件

情况1:不必要导管室激活

Old RBBB+LAFB, new rapid atrial fibrillation and rate-related ST changes. Cath lab activated based on mild inferior ST elevation, but ST changes resolved with rate control. Mild troponin elevation from non-occlusive MI.

Patient 2:不必要导管室激活

有那些d LAFB and new RBBB which was misinterpreted as showing anterior ST elevation, but this is within the prolonged depolarization of RBBB

Patient 3:LAD闭塞,推迟导管室激活

在V4-5新的右束支阻滞+ LAFB +超急性T波最初错过。一个重复的心电图一个小时后完成,现在显示与倒数劣质ST段压低ST段抬高V2-4和I / AVL和导管室激活。近端LAD闭塞,在导管室被捕。

Patient 4: diagonal occlusion, rapid cath lab activation

有那些d RBBB/LPFB with new ST elevation and pseudonormalized T waves in I/aVL, with reciprocal inferior ST depression. Cath lab activated: occlusion of graft to diagonal artery.

Patient 5:LAD闭塞,串行ECG然后导管室激活

First degree heart block and RBBB/LAFB unknown age. V2 has RBBB depolarization changes and should have discordant ST depression but instead there is mild concordant ST elevation.

重复心电图检查:

现在有在V2-3 ST段抬高和V4-5超急性T波。导管室激活:LAD闭塞。

Patient 6:MI后,迅速导管实验室激活

Incomplete RBBB and LAFB age indeterminate. V3-4 have ST depression and T wave inversion (and V3 has no RSR’ so this is not simply discordant changes), and there is inferior ST depression and T wave inversion (reciprocal to the electrocardiographically silent lateral wall). 15 lead ECG:

Only minimal ST elevation in V8, but 12 lead shows后闭塞MI直到证明并非如此。导管室激活:闭塞的回旋钝缘支。出院诊断“NSTEMI”。正火ST / T上放电ECG:

Patient 7:闭塞MI症状不典型,没有诊断心电图改变

胸痛伴窦转速,右束支阻滞,S1Q3T3。在等待CT胸部排除PE,肌钙蛋白回来后在10000,与正在进行的胸痛。导管室激活:RCA闭塞。出院诊断“STEMI”。

Take home points on RBBB and Occlusion MI

  1. 右束支阻滞is a high risk feature in occlusion MI, especially if new and accompanied by LAFB. If a patient has ischemic symptoms and RBBB, compare with prior to see if this is new, and look for associated fascicular blocks and ST changes
  2. 与RSR”前导线应具有不和谐的ST / T改变,所以一致抬高或过度抑郁不和谐可以遮挡的标志,而其他的线索会不会有复极异常。寻找QRS结束可以识别ST段改变。

References for ECG Cases 11: RBBB + Occlusion MI

  1. 诺伊曼JT,索伦森NA,Rubsamen N,等人。患者疑似心肌梗塞右束支传导阻滞。EUR心脏杂志急性心血管护理2019月; 8(2):161-166
  2. Widimsky P,ROhac楼Stasek J,等。急性心肌梗死伴右束支传导阻滞血管成形术:应新发右束支传导阻滞被添加到未来的指导方针,作为再灌注的指征?EUR心脏杂志2012年1月; 33(1):86-95
  3. Horton CL and Brady JB. Right bundle branch block in acute coronary syndrome: diagnostic and therapeutic implications for the emergency physician. Am J Emerg Med2009年11月; 27(9):1130至1141年。
  4. 伊瓦涅斯B,詹姆斯·S,Agewall S. 2017年ESC指南急性心肌梗死患者ST段抬高的管理:在患者的欧洲社会的ST段抬高的专责小组急性心肌梗死的管理心脏病学(ESC)。EUR心脏杂志2018扬; 39(2):119-177
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