Which of the following is a CORRECT placement of V1 ECG lead?

Appeared in: NORCET-7 Mains-2024

Explanation

The V1 lead is one of the six precordial (chest) leads in a standard 12-lead ECG.
Its correct anatomical position is at the fourth intercostal space (ICS), to the right of the sternum (the right sternal border).
To locate the fourth ICS, first palpate the sternal angle (Angle of Louis), which is the ridge where the manubrium meets the body of the sternum. This corresponds to the second rib.
From there, count down two spaces to find the fourth intercostal space.

Option A: This describes the placement for the V2 lead, not the V1 lead. The V2 lead is a mirror image of the V1 lead on the opposite side of the sternum.
Option B: This describes the placement for the V3 lead. V3 is placed after V2 and V4 are positioned.
Option C: This describes the placement for the V4 lead. It is located in the fifth intercostal space, not the fourth.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain ECG Precordial Lead Placement as background academic context rather than a clinical decision trigger.
Accurate ECG lead placement is a fundamental nursing skill essential for correct diagnosis of cardiac conditions. Misplacement is a common error that can lead to significant diagnostic confusion.
For example, placing the V1 and V2 leads too high (in the 2nd or 3rd ICS instead of the 4th) is a frequent mistake that can create a 'pseudo-infarction' pattern on the ECG, potentially leading to unnecessary and invasive cardiac procedures.
What if the patient has dextrocardia (heart on the right side)? In this rare case, the precordial leads should be placed in a mirror-image position on the right side of the chest to accurately capture the heart's electrical activity.

How to Approach the Question

First, identify the core of the question, which is asking for the specific location of the 'V1' ECG lead.
Recall the standard placement for the six precordial (chest) leads. A helpful mnemonic is to remember that V1 and V2 are in the 4th intercostal space, and V4, V5, and V6 are in the 5th intercostal space.
Visualize the sternum as the dividing line. V1 is on the right side of the sternum, and V2 is on the left.
Evaluate each option against this knowledge. Option A (left sternum) is V2. Option B (between V2/V4) is V3. Option C (5th ICS) is V4.
Conclude that Option D (fourth intercostal space on the right sternum) correctly describes the placement of V1.

Concept Tested & Keywords

QXQpsUqWkkDSYO4XAin3yD

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

E6 Medicine Macleod Clinical Examination 15e p. 75-77

E6 Anatomy Applied Ashalatha 4e p. 453-455

Practise the full NORCET-7 Mains-2024

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