Which lead is most effective for determining anterior and posterior infarction of the left ventricle?

Which lead is most effective for determining anterior and posterior infarction of the left ventricle?

• A. Lead I
• B. Lead II
• C. Lead V2
• D. Lead V5

Answer: (C)

Lead V2 is particularly effective in determining anterior and posterior infarction of the left ventricle due to its strategic placement on the chest. Lead V2 is located in the 4th intercostal space at the left sternal border, which allows it to capture electrical activity from the anterior wall of the heart. This positioning enables it to provide critical information regarding changes associated with ischemia or infarction in that region.

In cases of anterior infarction, changes such as ST-segment elevation or the development of Q waves are typically first noticed in leads that view the anterior wall, including V2. Conversely, if there is evidence of a posterior infarction, leads like V2 can help indicate reciprocal changes. For example, when a posterior wall ischemia occurs, it may present with ST depression in V1 or V2, which are directly opposite the posterior aspect of the heart.

Other leads mentioned, such as Lead I, Lead II, and Lead V5, while useful in detecting various cardiac conditions, do not provide the same level of specificity for anterior and posterior infarction as Lead V2. This makes V2 a key lead in identifying changes consistent with such infarctions, marking it as the most effective choice for this purpose.