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Terrifying Tachycardias. Susan P. Torrey, MD, FACEP, FAAEM Associate Professor of Emergency Medicine UMass Medical School – Baystate Medical Center Springfield, Mass. I have no disclosures TorreyEKG.com. Objectives. Consider the diagnostic grid Answer several interesting questions
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Terrifying Tachycardias Susan P. Torrey, MD, FACEP, FAAEM Associate Professor of Emergency Medicine UMass Medical School – Baystate Medical Center Springfield, Mass
I have no disclosures TorreyEKG.com
Objectives • Consider the diagnostic grid • Answer several interesting questions • What’s the scariest atrial fib you’ll ever see? • How DO you know it is ventricular tach?
Rate Rate = 300 ÷ # “big boxes” between R-R 300 – 150 – 100 – 75 – 60 – 50
Diagnostic grid - tachycardias Cherchez le P
Sinus tachycardia • normal P before every QRS • upright P in lead II
Sinus tachycardia • Emergency Department differential: • compensation for shock - dehydration, hemorrhage, sepsis • fever • drugs (cocaine, anticholinergic) • acute pulmonary embolism • thyrotoxicosis • anxiety - only as a dx of exclusion
Atrial flutter • atrial activity – regular deflections (F waves) - F waves usually 300/minute • rate and regularity of QRS variable - in purest form, multiple of 300
Atrial flutter • untreated, flutter usually has 2:1 AV block regular rhythm at 150/minute
Rate of 150… • when the rate is 140 – 150/minute always consider 2:1 atrial flutter
Supraventricular tachycardia • Regular, narrow tachycardia due to re-entry • AV nodal re-entry vs. AV re-entry (WPW) • Onset and termination is abrupt • Heart rate 140-220/minute • Differential: sinus tach, 2:1 flutter, ? a fib
Atrial fibrillation • no discernible P waves - atrial activity is fibrillatory waves (f) - fibrillatory waves – II and V1 • ventricular rhythm is irregularly irregular - untreated ventricular rate 100 – 180/min
Multifocal atrial tachycardia • P waves of varying morphology (≥ 3 foci) - absence of single dominant P wave • Variable PP, RR, PR intervals - theother irregularly irregular rhythm • Seen with COPD, elderly, seriously ill
Diagnostic grid - tachycardias • aberrancy • pre-existing BBB • bypass tract
Ventricular tachycardia • Abnormal wide QRS • Regular rhythm – “dead regular” • Rate usually 140-200/minute
Diagnostic grid - tachycardias • aberrancy • pre-existing BBB • bypass tract
What is the scariest tachycardiayou will ever see? 38-year-old man with history of palpitations
Scary atrial fib • Atrial fib with… - aberrancy - pre-existing bundle, or… - bypass tract with Wolff-Parkinson-White! - changing QRS shape and rapid conduction
Atrial fib with WPW • most AV node blockers ↑ bypass conduction • must avoid A – B – C – D • A – adenosine • B – beta-blockers • C – calcium-channel blockers • D – digoxin • treat with electricity or procainamide
What about amiodarone? • 2005 ACLS – rec: amiodarone • 2010 ACLS – returns to procainamide Simonian S Inter Emerg Med 2010 • Literature review challenges superiority and safety of amiodarone for atrial fib with WPW • Complex drug with effects on Na+, K+, and Ca++ channels, as well as α- and β-blocking effects
rapid atrial fib with wide complex after cardioversion after ablation of bypass tract
How do you know if it’s V. tach? • EKG criteria favoring V. Tach • AV dissociation
How do you know if it’s V. tach? • EKG criteria favoring V. Tach • AV dissociation • QRS concordance • all chest leads (V1-6) predominantly negative
How do you know if it’s V. tach? • algorithms • Brugada’s four-step algorithm 98% sens / 96% spec • Circ 1991 • Vereckei’s new “simplified” algorithm • Euro Heart J 2007
How do you know if it’s V. tach? • clinical predictors • association with heart disease or MI 98% positive predictive value • Aktar Ann Intern Med 1988
In conclusion… • Remember, tachycardias are easy… • Narrow or wide complex? • Regular or irregular?
In conclusion… • Remember, tachycardias are easy… • Narrow or wide complex? • Regular or irregular? • If the rate is around 150 think 2:1 flutter.
In conclusion… • Remember, tachycardias are easy… • Narrow or wide complex? • Regular or irregular? • If the rate is around 150 think 2:1 flutter. • Rapid wide-complex atrial fib think WPW… • Avoid A – B – C – D
In conclusion… • Remember, tachycardias are easy… • Narrow or wide complex? • Regular or irregular? • If the rate is around 150 think 2:1 flutter. • Rapid wide-complex atrial fib think WPW… • Treat wide-complex tachycardia per ACLS