Regarding the placement of leads when recording ECG all of the following are correct, EXCEPT:

Appeared in: AIIMS Jodhpur SNO-2023

Explanation

This option incorrectly states that the V4 lead is placed in the 7th intercostal space (ICS).
The correct anatomical landmark for the V4 lead is the 5th intercostal space at the mid-clavicular line.
Placing the V4 lead two spaces too low results in an inaccurate representation of the heart's electrical activity, particularly of the anterior wall and apex, potentially leading to misdiagnosis.

Option B: This is a correct statement. The V3 lead is placed exactly midway on a straight line between the V2 and V4 leads.
Option C: This is a correct statement. The V2 lead is correctly placed in the 4th intercostal space at the left sternal margin.
Option D: This is a correct statement. The V1 lead is correctly placed in the 4th intercostal space at the right sternal margin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomical placement of precordial ECG leads as background academic context rather than a clinical decision trigger.
Accurate lead placement is fundamental for a diagnostic-quality ECG. Misplacement is a common error that can create pseudo-pathological patterns (e.g., mimicking ischemia or bundle branch block) or mask true abnormalities, leading to incorrect clinical decisions.
A key landmarking technique is to first find the Angle of Louis (sternal angle), which is the junction of the manubrium and the body of the sternum. This bony ridge is level with the 2nd rib, and the space just below it is the 2nd ICS. From there, the nurse can accurately count down to the 4th and 5th intercostal spaces.
What if? If a patient has large breasts, the electrode should be placed under the breast tissue in the 5th ICS, not on top of it, to ensure proper skin contact and an accurate signal. The patient's chart should note that this modification was made.

How to Approach the Question

First, recognize that the question uses the word 'EXCEPT', which means you must find the single incorrect statement among the options.
The question is a factual recall question about the standard procedure for placing precordial ECG leads.
Mentally review or visualize the placement of each lead: V1 and V2 are in the 4th ICS; V4, V5, and V6 are in the 5th ICS.
Evaluate each option against this standard: Option A places V4 in the 7th ICS, which is incorrect. Options B, C, and D describe the correct placements for V3, V2, and V1, respectively.
Since Option A is the only false statement, it is the correct answer to the 'EXCEPT' question.

Concept Tested & Keywords

QAJzBaL2d4pce_rLCKbGr4

E6 Medicine Harrison 22e Part 1 p. 1910-1912

E6 Physiology Ganong 27e Vol 2 Part 1 p. 73-75

Practise the full AIIMS Jodhpur SNO-2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.