Final answer:
Lead V3 for a Holter monitor is placed at the fifth intercostal space along the left anterior axillary line for continuous heart electrical activity monitoring.
Step-by-step explanation:
In placing leads of a Holter monitor on the patient, lead V3 is placed at the fourth intercostal space, right sternal border - option A).
The 12-lead electrocardiograph uses 10 electrodes placed in standard locations on the patient's skin. Lead V3 is one of these electrodes and is positioned in this specific location to record the electrical activity of the heart from a certain perspective. Placing the electrode in the correct location ensures accurate readings.
For example, a Holter monitor continuously monitors heart electrical activity, typically for a period of 24 hours. By placing lead V3 on the fourth intercostal space, right sternal border, healthcare professionals can gather important information about the patient's heart health and detect any abnormalities.