Final answer:
An upright pattern on an electrocardiogram (ECG) usually indicates electrical activity moving toward the recording lead. The lead II potential is commonly used to measure heart function. Modern 12-lead ECGs can provide detailed information about the direction and characteristics of the heart's electrical activity.
Step-by-step explanation:
An electrocardiogram (ECG) or EKG is a diagnostic tool that records the electrical activity of the heart. The ECG produces waveforms on paper (or on a screen) which represent the electrical depolarization and repolarization as the heart beats. When an ECG waveform is upright, it typically signifies that the electrical activity is moving toward the lead detecting the activity. An upright pattern in certain leads can indicate normal heart function, while in others, it could signify a problem depending on the context of the lead placement and the waveforms.
The lead II potential, which measures the voltage between the right arm and the left leg, is commonly used to assess heart-muscle function and its correlation with arterial blood pressure. Modern ECG machines use 12 leads to provide a comprehensive view of the heart's direction of electrical flow and can detect abnormalities such as infarcts, or damaged heart tissue.