A 60 year old male presents with an overdose. Below is the patients ECG:
Describe and interpret the ECG
What drugs can cause these changes on an ECG
Answer:
Rate: 90 beats/min
Rhythm: Normal sinus
Axis: Normal
Intervals
- PR 200ms
- QRS 140ms
- QTc 400ms (Bazettes)
Additional:
RBBB morphology
Dominant R wave aVR
Artefact
The above ECG shows signs of sodium channel blockade – near tachycardia, prolonged QRS and terminal R wave >3mm
Drugs that cause sodium channel blockade include:
TCA
Class 1a and 1c antidysrhythmic agents
Local Anaesthetics
Diltiazam
Propranolol
Hydroxychloroquine
Chloroquine
Quinine
Carbamazepine
Phenothiazines
ECG from John Larkins ECG of the Week 18th Feb 2019
Further Reading Toxicology Hand Book Murray,L et al