EKG Technical Aspects and Troubleshooting

Introduction

• Focus on the technical aspects and troubleshooting of EKGs.
• Aim to identify and correct incorrect EKG readings.

Electrical Principles

• Heart as a transmitter, EKG machine as a receiver.
• Electrical impulses from the heart travel through the body.
• Electrodes capture impulses, sending them via leads to the EKG machine.
• Amplifier magnifies the signal, which is converted from analog to digital for display.

Chart Speed

• Normal chart speed: 25 mm/sec (25 small blocks per second).
• Speed changes must be noted on the EKG.
• Altered speed can lead to misinterpretation; useful for analyzing fast heartbeats.

Gain

• Gain controls amplitude (height) of QRS complexes.
• Default gain: 10 mm (10 small blocks upward).
• Adjusting gain helps when the EKG appears flat but the patient is alive.

Frequency Response

• Filters out noise and artifacts like jitter.
• Document any EKG setting changes.

Electrical Safety

• Ensuring patient safety is critical.
• Macroshock: High-voltage shock from poor grounding (frayed wires, faulty outlets).
  • 10 volts can cause serious damage.
• Microshock: Smaller shock through a heart conduit (e.g., pacemaker), equally dangerous.
  • Regular equipment inspection is vital.

Artifacts

• Various causes and types:
  • Somatic Tremor: Jittery lines from shaking or cold; solution: warm blanket or patient stillness.
  • Baseline Sway: Caused by lotion/sweat on skin; baseline appears unsteady.
  • 60-Cycle Interference: Thick lines between spikes; caused by electrical devices, remove them.
  • Broken Recording: Gaps due to frayed wires or poor electrode connection; check connections.

Troubleshooting Artifacts

• Identify affected limbs and leads.
• Replace loose electrodes.
• Check specific leads if artifacts appear.

Artifacts Mimicking Rhythms

• Some artifacts resemble dangerous rhythms.
• Assess the patient before trusting EKG readings:
  • Asystole Mimic: Loose monitor patch causes flat line.
  • Toothbrush Tachycardia: Movement mimics dangerous rhythms.
  • CPR Artifact: Chest compressions resemble ventricular rhythms.
  • Defibrillation/Cardioversion Artifact: Electrical surges alter rhythm pattern.

Three-Lead Monitoring Artifacts

• All leads should record the same rhythm simultaneously.
• Different rhythm in one lead suggests an artifact.

Differentiating Real Rhythms from Artifacts

• Check symptoms and compare rhythm to criteria.
• Assess other leads for consistency.
• Check for loose wires and observe patient for movements.

Conclusion

• Understanding EKG aspects and artifacts is crucial for accurate interpretation.
• Consider patient condition and check for errors before making decisions.

Troubleshooting Examples

• Example 1: Right arm lead issues cause artifacts on right arm leads.
• Example 2: Left leg lead issues cause artifacts on left leg leads.
• Example 3: Problems in 12 and AVR indicate right arm issues.