Intraoperative ECG Lead Placement

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Intraoperative ECG Lead Placement

• Brian Matthews SRNA
• Nicholas Stoddard SRNA
• David Perkins SRNA

2
Monitoring Basics

• Impulse toward positive is an up swing away from
  positive is down.
• J point, or junction point, is located at
  junction of S wave and start of ST segment.
• ST segment is Measured 60 milliseconds from
• the J point.
• 1mm change from baseline suggests myocardial
  injury.

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Leads Bipolar and Augmented Placement(Frontal
plane)

• Bipolar leads read from negative to positive.
• Bipolar leads are Lead I, II, and III also
  referred to as the limb leads.
• Augmented leads read from center to specific
  lead and are unipolar.
• Augmented leads are aVR, aVL, and aVF.

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Precordial Lead placement (Horizontal plane)

• Unipolar leads, reading from center to outward.
• V1 right sternal boarder 4th intercostal space
• V2 left sternal border 4th intercostal space
• V3 halfway between V2 and V4
• V4 left 5th intercostal space, mid-clavicular
  line
• V5 horizontal to V4, anterior axillary line
• V6 horizontal to V5, mid-axillary line

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Which lead(s) is/are best?
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Incidence/Indications

• The pooled results from the studies evaluating
  patients who had or were at risk of cardiac
  disease suggest that 3.9 (95 CI 3.34.6) of
  these patients experience major perioperative
  cardiac events.

7
Cardiac Events in Noncardiac Surgery
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London et al 1988

• n-105 with CAD
• Single lead monitoring unacceptable low
• Leads II and V5 had 80 sensitivity
• Leads II, V4, and V5 had a sensitivity of 96 for
  detecting ischemic events

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Landesberg et al 2002

• n-185 major vascular surgery
• Continual 12 lead monitoring during surgery
• We conclude that as a single lead, V4 discloses
  ischemia earlier, more frequently, and with a
  greater relative ST depression than the
  conventional V5
• Two lead monitoring is required to approach 95
  sensitivity.

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Martinez et al 2003

• n-149 Post-op ICU
• The majority of ischemia occurred in leads V2,
  V3, and V4, suggesting that the routine practice
  of monitoring leads II and V5 may not be optimal.

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Martinez et al 2003

• Given that in routine ICU care leads II and V5
  are usually monitored, we estimated that if all
  ischemic episodes occurring in either or both of
  these leads were detected, the maximal possible
  sensitivity of standard monitoring is 41 for
  detecting the first
• episode of ECG evidence suggestive of prolonged
• Ischemia

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12-lead Fingerprinting

• First and foremost, if a preoperative 12-lead
  ECG has been done, fingerprinting of the
  tracing should serve as the primary guide for
  lead selection during the perioperaive period.
  If the baseline 12-lead shows significant primary
  ST-segment changes in leads V3,V4 and V5, then
  this lead set should be prioritized for
  continuous display in the operating room.
  (Nagelhout, Plaus, 2010)
• A preoperative resting 12-lead ECG is
  recommended for patients with at least one
  clinical risk factor who are undergoing vascular
  surgical procedures and for patients with known
  CAD, peripheral arterial disease, or
  cerebrovascular disease who are undergoing
  intermediate-risk surgical procedures. A
  perioperative ECG is reasonable in persons with
  no clinical risk factors who are about to undergo
  vascular surgical procedures and may be
  reasonable in patients with at least one clinical
  risk factor who are undergoing intermediate-risk
  operative procedures (Barash, et al. 2009)

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Recommendations

• If no pre-op 12 lead then monitor Leads II and
  V3/V4.
• With pre-op 12 lead available and normal then
  the electrocardiographic lead with the most
  isoelectric ST level out of leads V3, V4, and V5
  on the preoperative electrocardiogram is
  recommended or monitoring of ischemia.
• If 12 lead available with ST changes,
  fingerprinting, monitor those specific leads.

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Works Cited

• Barash, P, Bruce, C, Robert, S, Cahalan, M,
  Stock, M. (2009). Clinical anesthesia.
  Philidelphia Lippincott Williams Wilkins.
• Devereaux, P, Goldman, L, Yusurf, S, Gilbert, K,
  Leslie, K. et al (2005). Surveillance and
  prevention of major perioperative ischemic
  cardiac events in patients undergoing noncardiac
  surgery a review. JMAC, 173(7), 779-788.
• Landesberg, G, Mosseri, M, Wolf, Y, Vesselov, Y,
  Weissman, C. (2002). Perioperative myocardial
  ishecmia and infarction. Anesthesiology, 96,
  264-270.
• London, M, Hollenberg, M, Wong, M, Levenson, L,
  Tubau, J. et.al.(1988). Intraoperative myocardial
  ishemia localization by continuous 12-lead
  electrocardiography. Anesthesiology, 69, 232-241.
  
• Martinez, E, Kim, L, Faraday, N, Rosenfeld, B,
  Bass, E. (2003). Sensitivity of routine intensive
  care unit surveillance for detecting myocardial
  ischemia. Critical care medicine, 31(9),
  2302-2308.
• Nagelhout, J, Plaus, K. (2009). Nurse
  anesthesia. St. Louis, Missouri W B Saunders Co.