Final answer:
On a 12-lead ECG, when the heart's electrical signal is aimed at the positive electrode, the deflection displayed on the rhythm strip will be positive.
Step-by-step explanation:
When an electrical signal in the heart is aimed directly at the positive electrode, the deflection seen on the 12-lead ECG or rhythm strip will be positive.
An electrocardiogram (ECG or EKG) is a record of the voltages created by the wave of depolarization and subsequent repolarization in the heart.
These voltages are represented as vectors, which when directed towards a positive electrode, produce an upward or positive deflection on the ECG tracing. Conversely, when the vector is directed away from the positive electrode, it will produce a downward or negative deflection.