ECG Key Terms Quiz

Key Terms in ECG

• Electrode: Small sensors placed on the skin to detect the heart's electrical activity.
• Leads: Covered wires conducting electrical impulses from electrodes to the ECG machine.
• Einthoven's Triangle: Configuration of the first three leads (I, II, III) formed by limb electrodes.
• Limb Leads: Four leads used in a 4-lead ECG positioned on the arms and legs.
• Bipolar Leads: Measure electrical current flow in both directions simultaneously, associated with limb leads.
• Augmented Leads: Comprising aVR, aVL, aVF; these leads have amplified tracings for better interpretation.
• Unipolar Leads: Focus on measuring electrical current in one direction, includes augmented leads and precordial leads.

Types of Leads

• Precordial Lead: Leads (V1-V6) placed on the chest to monitor heart activity.
• Multichannel Recorder: ECG machine that monitors all 12 leads, recording three leads at a time.
• Input: Data entered into the ECG machine via electrodes on the skin surface.

ECG Machine Functions

• Signal Processing: Amplifies the electrical pulse and converts it for display.
• Output Display: Shows the heart's electrical activity tracing, typically printed.
• Serial ECG Comparison: Involves frequent ECG tracings to monitor patient changes over time.

ECG Settings and Measurements

• Speed Control: Regulates the paper speed during ECG tracing.
• Normal Speed: Typically set at 25 mm/sec.
• Gain: Adjusts the size of the ECG tracing on the output display.
• Millivolt (mV): Unit for measuring voltage on ECG tracings.
• Hertz (Hz): Unit of frequency equivalent to one cycle per second.

Artifacts and Maintenance

• Artifact: Unwanted traces on ECG caused by non-cardiac activity.
• 40 Hz Filter: Typically employed to minimize artifacts on ECG.

Electrode Types

• Disposable Electrodes: Single-use electrodes commonly employed in ECG.
• Silver Electrodes: Used for patients undergoing multiple or serial ECGs.

ECG Graph Paper and Methods

• ECG Graph Paper: Sensitive to various elements; can be affected by alcohol, sunlight, or pressure.
• 300 Method: Quick heart rate estimation for regular rhythms (count boxes between R waves, divide by 300).
• 1500 Method: Most accurate calculation for heart rate (count boxes between R waves, divide by 1500).
• 6-Second Method: Used for irregular rhythms; count complexes in a 6-second interval and multiply by 10.

Heart Rate and Rhythm

• Tachycardia: Heart rate exceeding 100 bpm; increase paper speed to 50 mm/sec for better representation.
• Bradycardia: Heart rate below 60 bpm; reduce paper speed to 25 mm/sec.

ECG Tracing Questions

• ECG Testing Angles: A 12-lead ECG evaluates heart activity from 12 different perspectives.
• Major Controls of ECG Machine: Include speed, gain, artifact filter, LCD display, lead selector, and heart rate limits.
• Box Representation: A speed of 25 mm/sec means one small box represents 0.04 seconds.

Conclusion

Understanding ECG terms and machine settings is crucial for effective monitoring and interpretation of cardiac activity. Familiarity with lead types, measurement methods, and potential artifacts enhances diagnostic accuracy.