Cardiac Dysrhythmias
Rhythm interpretation is one of the highest-scoring topics on paramedic exams and a frequent AEMT topic. The trick isn't memorizing every strip — it's recognizing the four categories fast and matching them to a treatment pathway.
AEMT · Paramedic
The four questions to ask every strip
Rate, rhythm regularity, P-wave presence, and QRS width. Answer those four and you've narrowed 90% of rhythms to a specific bucket.
- Rate: bradycardia (<60), normal (60–100), tachycardia (>100)
- Regular vs. irregular
- P before every QRS?
- QRS narrow (<0.12) or wide (≥0.12)?
Life-threatening rhythms to know cold
V-fib and pulseless V-tach: shock. Asystole and PEA: high-quality CPR, epi, find the H's and T's. Symptomatic bradycardia: atropine, then pacing. Unstable tachycardia: synchronized cardioversion.
AV blocks in one paragraph
First-degree: PR > 0.20, benign. Second-degree Mobitz I (Wenckebach): PR lengthens until a QRS drops. Second-degree Mobitz II: PR constant, random dropped QRS — dangerous. Third-degree: P's and QRS's march independently — pace it.
Frequently asked
- How do I tell V-tach from SVT with aberrancy?
- Wide QRS + hemodynamic instability + history of cardiac disease favors V-tach. When unsure, treat it as V-tach.
- When do I pace a bradycardia?
- When it's symptomatic (hypotension, altered mental status, chest pain, signs of shock) and atropine has failed or isn't appropriate.
Test yourself
Practice on this topic.
Free 10-question sample or build a custom quiz on cardiac dysrhythmias.