Final answer:
The ECG records the heart's electrical activity, indicating conditions like atrial enlargement or myocardial infarction through changes in waveform shapes. It has limitations in assessing mechanical function, which needs additional testing. Modern technology allows for portable ECG monitoring.
Step-by-step explanation:
An electrocardiogram (ECG) or EKG is a diagnostic tool that records the electrical activity of the heart. The ECG shows a graphic representation of the heart's electrical impulse as it travels from the atria to the ventricles. Specific components of the ECG, such as P waves, QRS complex, and T waves, correspond to electrical events in the heart.
The ECG primarily provides information about the heart's electrical function, but it also gives limited indirect information about the heart's mechanical activity based on the timing and shape of the waves. For example, an amplified P wave may indicate atrial enlargement, and an enlarged Q wave can indicate a myocardial infarction (MI).
Abnormal T waves may suggest that insufficient oxygen is reaching the myocardium. If a component of the ECG shows alteration in its normal shape or timing, it could imply that the heart is functioning abnormally.
While the ECG is invaluable in detecting certain heart conditions, it has limitations and won't reveal the effectiveness of the heart's pumping action, which requires further testing like an echocardiogram or nuclear medicine imaging.
Modern technology has advanced to the point where ECG monitoring can be done with portable, wearable devices, providing real-time data outside of clinical settings.