Pulse Oximetry and EKG Monitoring

Depolarization

Electrical activation/contraction of heart muscle. Seen as P wave (atria) & QRS (ventricles). Important for RTs to recognize on cardiac monitor.

Repolarization

Recovery/relaxation phase of heart cells. Seen as T wave. Abnormalities can signal ischemia or electrolyte problems in patients with respiratory distress.

PVC (Premature Ventricular Complex)

Early beat from ventricles disrupting rhythm. Can occur with hypoxemia, suctioning, or electrolyte imbalance. May indicate worsening patient status.

Sinus Tachycardia

A normal heart rhythm that starts in the SA node, but with a heart rate faster than normal (>100 bpm in adults). Often due to hypoxemia, fever, anxiety, or ↑ work of breathing.

V-Fib (Ventricular Fibrillation)

Chaotic rhythm with no cardiac output. Life-threatening emergency. RTs assist with CPR, defibrillation, and airway management.

Precordial Leads

Chest leads V1–V6 on EKG. Show ventricular activity. RTs may place/assist with proper placement for accurate readings.

Pulse Oximetry (SpO₂)

Non-invasive measurement of oxygen saturation. Essential for monitoring oxygenation during therapy, weaning, and emergencies.

Plethysmograph

Waveform on a pulse oximeter showing blood flow. Verifies signal quality. Poor pleth may mean motion artifact or poor perfusion.

Lead Placement (EKG)

Proper electrode positioning on chest/limbs. Required for accurate rhythm interpretation.

Artifact

Distorted/false EKG signal from movement or loose leads. Can mimic or hide arrhythmias. RTs must recognize difference.