Final answer:
An ECG captures heart electrical activity, with the P wave, PR Segment, QRS Complex, ST Segment, T Wave, and TP Interval each representing different cardiac events such as atrial depolarization, ventricular depolarization, and repolarization.
Step-by-step explanation:
The Electrocardiogram (ECG) captures the electrical activity of the heart and is crucial for diagnosing heart conditions. Each wave, segment, and interval on the ECG corresponds to specific cardiac events:
- P wave: Represents atrial depolarization, where the atria contract to push blood into the ventricles. This occurs before the atria actually begin to contract.
- PR Segment: This flat line reflects the time delay at the AV node which allows the ventricles to fill with blood from the atria before they contract. It starts at the end of the P wave and ends at the start of the QRS complex.
- QRS Complex: Corresponds to ventricular depolarization, indicating the ventricles contract to pump blood out of the heart. It begins with the Q wave and ends after the S wave.
- ST Segment: This segment, which starts at the end of the S wave and ends at the start of the T wave, reflects the period when the ventricles are depolarized and indicates the beginning of the ventricle's repolarization.
- T Wave: Indicates ventricular repolarization, a recovery phase before the ventricles begin to fill with blood again.
- TP Interval: The time during which the ventricles are at rest and filling with blood before the next contraction; it extends from the end of the T wave until the next P wave.
The PR interval and QT interval are also important in assessing the heart's electrical function. The PR interval is the duration from the beginning of atrial depolarization (the P wave) to the initiation of the QRS complex, while the QT interval starts at the beginning of the QRS complex and ends at the end of the T wave, covering both ventricular depolarization and repolarization.