WIDENED QRS

Question 1

DDx

Answer 1

DRUGS
Sodium Channel Blockers

METABOLIC
Kyperkalemia
Kypercalcemia
Hypothermia

Question 2

Hyperkalemia

Answer 2

Peaked T Waves
Widening of the QRS
Flattening with eventual loss of the Ps;
Bradycardia

Other:
Tachycardias, , AV blocks, sinus pause,

Question 3

Hypercalcemia

Answer 3

Short QT (<400)
Prolonged PR
Bradycardia
AV blocks
QRS Widening
BBB
ST-segment changes can mimic ACS

Question 4

Sodium Channel Blocker Toxicity

Answer 4

Tachycardia
R-wave amplitude in aVR ≥3 mmRightward axis
QRS Widening
QT Prolongation
Possible Brugada Pattern

Question 5

Hypothermia

Answer 5

1. Bradyarrythmias: sinus brady, afib with slow ventricular response, slow junctional rhythm, varying AV block
2. Osborne Waves (J waves): positive deflection at the J point, amplitude proportional to degree of hypothermia
3. Prolonged PR, QRS, and QT intervals
4. Shivering Artifact: fuzziness at the ECG baseline
5. Ventricular Ectopics
6. Cardiac arrest due to VT, AF or asystole