What type of abnormal finding is identified in ECG during myocardial ischemia?

RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Medical & Surgical Nursing

Easy

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Explanation

Myocardial ischemia disrupts the normal sequence of ventricular repolarization, the electrical resetting of the heart muscle after contraction.
This electrical disturbance causes the T wave, which represents repolarization on the ECG, to become inverted in the leads facing the ischemic area.
Ischemic T waves are often deep (appearing 'larger' in negative amplitude) and symmetrical, which helps distinguish them from T-wave changes due to other causes.

Option B: 'Ectopic' is a term used to describe the origin of a heartbeat (e.g., an ectopic beat from the ventricles), not the shape or morphology of a T wave within a beat.
Option C: 'W pattern T wave' is not a standard or recognized term in electrocardiography for describing ischemic changes.
Option D: While T waves can become flat or 'smaller' in ischemia, this is a non-specific finding. The term 'horizontal' is more accurately used to describe ST-segment depression, which is a different sign of ischemia, not the T wave itself.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain ECG interpretation in myocardial ischemia as background academic context rather than a clinical decision trigger.
Recognizing T-wave inversion on an ECG is a critical nursing skill for identifying patients with potential myocardial ischemia, allowing for prompt intervention to prevent progression to infarction (heart attack).
Nurses must report these changes to the provider, anticipate orders for cardiac biomarker testing (e.g., troponin), and prepare the patient for potential further interventions like cardiac catheterization.
What if? If the ECG showed ST-segment elevation instead of T-wave inversion, it would signify a more acute and severe condition (myocardial injury/infarction). This is a medical emergency requiring immediate reperfusion therapy (e.g., percutaneous coronary intervention or thrombolysis) to restore blood flow.

How to Approach the Question

First, identify the keywords in the question: 'ECG', 'myocardial ischemia', and 'abnormal finding'.
Recall the basic pathophysiology: ischemia (reduced blood flow) affects the heart's electrical repolarization.
Remember that the T wave on an ECG represents ventricular repolarization.
Evaluate the options based on classic ECG patterns. T-wave inversion is a hallmark sign of ischemia.
Eliminate options that use non-standard terminology ('Ectopic T wave', 'W pattern T wave') or describe findings less specifically or accurately ('Horizontal and smaller T'). The most characteristic and well-known sign among the choices is T-wave inversion.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 1 pp. 1914-1916, 148-150

E6 Medicine Davidson Principles Practice 24e p. 516-518