Issued April 2008 Authors & Reviewers: Karen L Johnson, RN, MSN, PhD Kate M. Moore, RN, MS, ND, CCRN, ACNP Practice Alert ST Segment Monitoring.

Issued April 2008Issued April 2008

Authors & Reviewers:Authors & Reviewers:

Karen L Johnson, RN, MSN, PhDKaren L Johnson, RN, MSN, PhDKate M. Moore, RN, MS, ND, CCRN, ACNPKate M. Moore, RN, MS, ND, CCRN, ACNP

Practice AlertPractice AlertST Segment MonitoringST Segment Monitoring

Practice Alert - ST Segment Monitoring2

Lecture Content

Skin preparation Lead placement and selection Patient positioning Measuring the ST segment Pediatric specific Recommendations

Practice Alert - ST Segment Monitoring3

Skin Preparation

Clip excessive hair before placing electrodes

Clean skin with alcohol or washcloth to remove skin oils and/or debris

Mark locations with indelible ink to assure that if electrodes are moved they can be replaced in their original locations.

Practice Alert - ST Segment Monitoring4

Electrode Placement

Limb leads (I,II,III)Place to decrease muscle artifact during limb

movementPlacement

Right Arm (RA) infra-clavicular fossa close to right shoulder

Left Arm (LA) infra-clavicular fossa close to left shoulder

Left Leg (LL) below rib cage on left side of abdomenGround (RL)

Precordial Leads - depends on patient’s needs

Practice Alert - ST Segment Monitoring5

ST Segment Monitoring

ST segment monitoring can detect silent ischemia in asymptomatic patients.

Although the impact of ST segment monitoring on patient outcomes is not known, when ST segment monitoring is used, it is imperative that accurate data are obtained.

Practice Alert - ST Segment Monitoring6

Lead Selection

Monitoring ST segment changes in 12 leads provides the most accurate data for identification of ischemic events.

If only two leads are available for ST segment monitoring, use leads III and V3 (unless otherwise indicated)

Practice Alert - ST Segment Monitoring7

ST Segment Fingerprint

If 12 lead monitoring is not available, use the patient’s “ST Fingerprint”.

Defined as the pattern of ST segment elevation and/or depression unique to a particular patient based on the anatomic site of coronary occlusion

Can be obtained during STEMI or PCI

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Other Considerations

If the ST fingerprint is not known, use leads III and V3.

For patients without definitive ACS, with suspected of having or being ruled out for ACS, use leads III and V5.

For non-cardiac surgical patients lead V5 is valuable for identifying demand-related ischemia.

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Patient Positioning

Evaluate ST segment with the patient in the supine position.

Change in body position can alter ST segment, mimic ischemia.

If ST alarm sounds with patient in side-lying position, return patient to supine. If deviation persists in supine may indicate ischemia.

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Measuring the ST Segment

J PointThe junction of

the QRS complex with the ST segment

Measure ST segment changes 60 ms beyond the J point

Flanders SA. Continuous ST-segment monitoring: Raising the bar. Crit Care Nurs Clin N Am 2006;18(3):172

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Alarm Parameters

Patients at high risk for ischemiaSet ST segment alarm

parameters 1 above and below baseline ST segment

Stable PatientsSet ST segment alarm

parameters 2 mm above and below baseline ST segment

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Cause for Concern

ST depression or elevation of 1-2 mm that lasts for at least one minute can be clinically significant and warrants further patient assessment.

Flanders SA. Continuous ST-segment monitoring: Raising the bar. Crit Care Nurs Clin N Am 2006;18(3):172

5 mm depression5 mm depression 4 mm elevation4 mm elevation

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Pediatric Specific Information

For neonates and infants the TP segment may be a more accurate isoelectric point than the PR segment.

For neonates and infants an ST elevation or depression of 1 mm or greater is considered clinically significant.

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Need Further Assistance?

For more information or further assistance, please contact a clinical practice specialist with the AACN Practice Resource Network.

Email:[email protected]

Phone:

(800) 394-5995