A method for performing ambulatory electrocardiographic monitoring on an adult female is provided. An ambulatory ECG monitor (11), that includes a plurality of sensing electrodes (48) coupled to self-powered sensing circuitry (71), is provisioned. A monitoring site (15) is located on the surface of a patients chest at midline and above the body of the sternum adjacent to the fourth and fifth intercostal spaces between the breasts in the upper portion of the intermammary cleft. The electrodes (48) are aligned and placed along the midline. Interference from breast tissue with placement of the ambulatory monitor (11) at the monitoring site (15) is evaluated. The ambulatory ECG monitor (11) is removably adhered to the monitoring site (15) clear of any breast tissue interference for the duration of monitoring. ECG data is sensed through the sensing electrodes (48) at the monitoring site (15) and the sensed ECG data is recorded into the sensing circuitry (71).
