ECG_V1_V2_2ND_ICS medical runtime_error ai_generated true

AI instructs placement of V1 and V2 ECG leads in the 2nd intercostal space instead of the 4th, leading to misdiagnosis of anterior myocardial infarction

ID: medical/ecg-lead-placement-v1-v2-4th-ics

Also available as: JSON · Markdown · 中文
93%Fix Rate
89%Confidence
1Evidence
2024-09-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
ECG-machine:GE-MAC-5500-2024 active — — —
ECG-machine:Philips-IntelliVue-MP70-2023 active — — —

Root Cause

V1 and V2 must be placed in the 4th intercostal space (ICS) at the right and left sternal borders, respectively. Placement in the 2nd ICS shifts the QRS axis, producing false ST elevation that mimics anterior STEMI.

generic

中文

V1和V2必须分别放置在胸骨右缘和左缘的第四肋间隙。放置在第二肋间隙会改变QRS电轴，产生类似前壁STEMI的假性ST段抬高。

Official Documentation

https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.119.042703

Workarounds

  1. 95% success Use the angle of Louis (sternal angle) as a landmark for the 2nd intercostal space. Palpate the space below the clavicle: the first palpable space is the 2nd ICS. Count down two more spaces to reach the 4th ICS. Place V1 at the right sternal border in the 4th ICS, V2 at the left sternal border in the 4th ICS. Document the intercostal space used on the ECG report. 
    Use the angle of Louis (sternal angle) as a landmark for the 2nd intercostal space. Palpate the space below the clavicle: the first palpable space is the 2nd ICS. Count down two more spaces to reach the 4th ICS. Place V1 at the right sternal border in the 4th ICS, V2 at the left sternal border in the 4th ICS. Document the intercostal space used on the ECG report.
  2. 90% success If the patient is female, place V1 and V2 electrodes on the sternum, not on breast tissue. Lift breast tissue if necessary to access the 4th ICS. Use a skin marker to mark the 4th ICS before placing electrodes. 
    If the patient is female, place V1 and V2 electrodes on the sternum, not on breast tissue. Lift breast tissue if necessary to access the 4th ICS. Use a skin marker to mark the 4th ICS before placing electrodes.
  3. 88% success Use a 15-lead ECG (adding V4R, V8, V9) if there is any doubt about lead placement or if the patient has a history of previous MI. This helps differentiate true anterior ischemia from lead placement artifact. 
    Use a 15-lead ECG (adding V4R, V8, V9) if there is any doubt about lead placement or if the patient has a history of previous MI. This helps differentiate true anterior ischemia from lead placement artifact.

中文步骤

  1. 使用胸骨角（路易氏角）作为第二肋间隙的标志。触摸锁骨下方的间隙：第一个可触及的间隙是第二肋间隙。再向下数两个间隙到达第四肋间隙。将V1放置在胸骨右缘第四肋间隙，V2放置在胸骨左缘第四肋间隙。在心电图报告上记录所使用的肋间隙。
  2. 如果患者为女性，将V1和V2电极放置在胸骨上，而非乳房组织上。如有必要，抬起乳房组织以接触第四肋间隙。在放置电极前用皮肤标记笔标记第四肋间隙。
  3. 如果对导联放置有疑问或患者有既往心梗史，使用15导联心电图（增加V4R、V8、V9）。这有助于区分真正的前壁缺血与导联放置伪影。

Dead Ends

Common approaches that don't work:

  1. Assuming that the 2nd intercostal space is correct because it is easier to palpate (just below the clavicle) 80% fail

    The 2nd ICS is commonly mistaken for the 4th ICS because the angle of Louis (sternal angle) marks the 2nd ICS, not the 4th. Proper technique requires counting down two more spaces to the 4th ICS.

  2. Believing that small variations in lead placement do not significantly affect ECG interpretation 70% fail

    Even a 1-2 intercostal space difference can produce up to 0.2 mV of ST elevation in V2, which meets STEMI criteria in many guidelines, leading to unnecessary catheterization lab activation.

  3. Using a 'one-size-fits-all' approach: placing V1 and V2 at the same level as V3-V6 60% fail

    V3-V6 are placed at the 5th ICS along the left chest; placing V1-V2 at that level is too low and may miss right ventricular involvement.