Wide & IrRegular tachycardia dDx

Remember there are only 3 main causes of narrow & regular tachycardias, aberrant conduction will cause these rhythms to have a wide complex QRS

Remember there are only 3 main causes of narrow & irregular tachycardias, aberrant conduction will cause these rhythms to have a wide complex QRS

• • Looks closely for P waves in all leads (especially V1 & II) to differentiate between the different potential rhythms

Anything that causes aberrant conduction will turn your narrow complex DDx into your wide complex DDx. Main causes of aberrancy include:

• • Bundle branch blocks, pacemakers, LVH

  • Electrolyte, metabolic causes (Hyperkalemia, acidosis, etc.)

  • Toxicologic causes, medications (e.g. TCA's)

  • Accessory pathways

  • Ventricular rhythms

Wide & regular complex tachycardias should be considered to be VT until proven otherwise

Wide & irregular complex tachycardias should scrutinized for evidence of afib with WPW

• • Avoid all AV nodal blockers unless certain that patient has afib with bundle branch block similar in morphology to baseline

  • Use electrical cardioversion when in doubt, and procainamide when hemodynamically stable