& x20;Given above is an ECG of a patient with chest pain due to ischemic heart disease. The ECG shows: - AIIMS Jodhpur SNO-2023

AIIMS Jodhpur SNO-2023

Medical Surgical Nursing

Medium

Appeared in: AIIMS Jodhpur SNO-2023

Explanation

The image clearly shows a downward displacement of the ST segment relative to the isoelectric baseline (the dotted line).
This specific finding on an ECG is defined as ST-segment depression.
ST depression is a hallmark sign of myocardial ischemia, particularly subendocardial ischemia, where the inner layer of the heart muscle is deprived of adequate blood flow.
The clinical context of a patient with chest pain due to ischemic heart disease makes ST depression a highly expected finding.

Option A: The T-wave, which is the wave following the QRS complex, is clearly upright in the provided diagram. T-wave inversion would show the wave pointing downwards.
Option B: The PR interval is a measure of time (horizontal axis on the ECG). The abnormality shown is a vertical displacement (voltage change).
Option D: The QRS interval represents the duration of ventricular depolarization and is a measure of time (horizontal width). The image shows a vertical drop, not a widening of the QRS complex.

Visual 1: Diagram: Comparison of a normal ECG waveform, an ECG with ST depression (ischemia), and an ECG with ST elevation (infarction).
Visual 2: Animation: Illustrating the electrical conduction pathway in the heart and how subendocardial ischemia causes the ST vector to shift, resulting in ST depression on the surface ECG.

Clinical Relevance

Nursing practice connection: Use the key finding related to ECG interpretation in myocardial ischemia to guide bedside assessment, documentation, and the next nursing action.
Prompt recognition of ST depression in a patient with chest pain is a critical nursing skill. It indicates active myocardial ischemia and requires urgent intervention to prevent progression to a full-blown heart attack (myocardial infarction).
Immediate nursing actions include administering oxygen, providing sublingual nitroglycerin as prescribed, obtaining a full 12-lead ECG, establishing IV access, and notifying the physician.
What if the ECG showed ST elevation instead of depression? This would signify a STEMI (ST-Elevation Myocardial Infarction), a more urgent emergency indicating full-thickness heart muscle injury. The patient would need immediate reperfusion therapy, such as percutaneous coronary intervention (PCI) or thrombolytics.

How to Approach the Question

First, analyze the clinical context: a patient with chest pain from ischemic heart disease. This immediately directs your focus to ECG changes associated with ischemia.
Second, carefully examine the ECG image. Identify the baseline (isoelectric line) and the different components (P, QRS, T waves).
Third, note the primary abnormality. The segment between the QRS and T wave (the ST segment) is clearly below the baseline. This is ST depression.
Fourth, differentiate between time measurements (intervals, measured horizontally) and voltage measurements (segment deviation, measured vertically). The options include both types.
Fifth, evaluate the options. 'Increased PR Interval' and 'increased QRS interval' are time-based and incorrect as the image shows a vertical change. 'T-wave inversion' is incorrect as the T-wave is upright.
Finally, conclude that the finding is 'ST depression', which perfectly matches both the visual evidence and the clinical scenario of ischemia.

Concept Tested & Keywords

Concept Tested: ECG interpretation in myocardial ischemia
Stem keywords: ECG, chest pain, ischemic heart disease
Lead-in keywords: The ECG shows
Clinical cues: Patient with chest pain due to ischemic heart disease, which strongly suggests an ECG abnormality related to myocardial oxygen supply and demand imbalance.

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