This week we review the answers to the last 6 cases from the 4th annual UMEM Residency ECG Competition.
Make sure to attempt to answer the questions before you watch the video!
Video review of each ECG Case:
Key Teaching Points
ECG 7 Answer
Hypertrophic obstructive cardiomyopathy (HOCM)
- ECG abnormalities present in 85-93%
- High left ventricular voltages
- Left atrial enlargement is most common
- Tall R wave in V1 (mimics posterior MI)
- Deep narrow Q waves in inferior, lateral leads
- Definitive diagnosis – Doppler ECHO
- Can also help to assess severity of obstruction at rest and with provocative maneuvers
- Beta blockers, calcium channel blockers
- Amiodarone for ventricular dysrhythmias
For more on HOCM, review the case from November 16, 2015.
ECG 8 Answer
Impressive Syndrome, treat for hyperkalemia!
Hyperkalemic Periodic Paralysis (HYPP) a.k.a Impressive Syndrome
- Inherited autosomal dominant condition that affects Na+ channels in muscle tissues and affects the ability to regulate K+ in the blood.
- Produces significant muscle weakness and paralysis, can cause death because of diaphragmatic paralysis
- Episodic, usually caused by medications, K+ rich foods, or significant stressors to the body
- Bizarre rhythm? Wide QRS? Think tox/metabolic & get your Calcium and Bicarb ready!
For more on this topic, review the case from December 28, 2015.
ECG 9 Answer
Sinus rhythm with junctional trigemeny, left axis deviation, and WPW
Differential Diagnosis for Short PR interval
- Junctional rhythm
- Pre-excitation syndromes
- WPW (Wolff-Parkinson-White syndrome)
- LGL (Lown-Ganong-Levine syndrome)
- Normal variant (EAVNC – enhanced AV nodal conduction)
Differential diagnosis of leftward axis
- Left ventricular hypertrophy (LVH)
- Left bundle branch block (LBBB)
- Paced rhythm
- Ventricular beats/ectopy
- Pre-excitation (e.g. WPW)
- Inferior MI (from Q-waves)
- Left anterior fascicular block (LAFB)
- Normal Variant
ECG 10 Answer
TCA/ Na+ channel blocker toxicity. Treat with Sodium Bicarbonate.
Na+ channel blocker toxicity ECG
- Tall R wave in aVR
- Rightward axis
- QRS-interval widening
To learn more about Na+ channel blocker toxicity review the case from March 14, 2016.
ECG 11 Answer
Calcium for Hyperkalemia
ECG findings in Hyperkalemia
- Peaked T-waves
- Widening of the QRS (often marked)
- Prolonged PR-interval
- Flattening and eventual loss of P-waves
- Advanced AV Blocks and sinus pauses
- Fascicular & Bundle Branch Blocks
- Pseudo ACS with ST-segment changes (can mimic STEMI)
- Pseudo Brugada syndrome pattern
- Sine wave morphology
Causes of Rightward Axis Deviation
- Na+channel blocker toxicity
- Pulmonary HTN – Acute (PE) & chronic lung disease (COPD)
- Right ventricular hypertrophy
- Left posterior fascicular block
- Lateral MI (from Q-waves in lead I)
- Ventricular ectopy (VT)
- Lead misplacement / Dextrocardia
- Normal thin adults with horizontally positioned hearts
Pearl: When you see a wide QRS rhythm with a rightward axis, think of HYPERKALEMIA or other sodium channel blocker toxicities.
For more practice on this topic, review the case from Jan 12, 2015.
ECG 12 Answer
Hypokalemia causing Himalayan T-waves and a prolonged QT interval. Watch out for Torsades!
- Very tall, broad-based T-waves
- Market prolongation of QTc
- ST-segment elevation
- May have camel hump due to large U-waves
Differential for Prolonged QTc Interval
- Medications/Drugs (Type Ia, TCA’s, & many others)
- ACS / cardiac ischemia
- Elevated intracranial pressures
For more practice on this topic, review the case from March 28, 2016.