What position is modified chest lead (MCL1) placed in?

The correct placement for the modified chest lead (MCL1) is indeed in the right upper chest at the 4th intercostal space. This positioning is essential for optimal recording of electrical activity in the heart, particularly from the right side, allowing for better detection of potential abnormalities such as those found in right ventricular hypertrophy or issues with the right coronary artery circulation.

This position serves to capture the heart's electrical signals more effectively than other locations, which may not provide as clear or accurate readings. The choice of the 4th intercostal space is aligned with traditional placements in ECG practices that aim to standardize electrode positions for reliable interpretations. This modified lead is particularly beneficial in cases where standard limb leads may not provide the required information, such as during certain clinical situations or when assessing specific heart conditions.