Antiarrhythmic Therapy Empiric Pathophysiologic Arrhythmia Diagnosis Arrhythmia Diagnosis Known or suspected mechanisms BLACK BOX Critical components Vulnerable parameters Targeted subcellular units Interventions Interventions Clinical Outcomes Clinical outcomes
Antiarrhythmic Therapy Empiric Arrhythmia Diagnosis Interventions Clinical Outcomes Interventions Clinical Outcomes Pathophysiologic Arrhythmia Diagnosis Known or suspected mechanisms Critical components Vulnerable parameters Targeted subcellular units BLACK BOX
Antiarrhythmic Therapy Pathophysiologic AV node reentrant tachycardia Arrhythmia Diagnosis Known or suspected AV node reentry mechanisms Anatomical fast/slow Critical components pathway Vulnerable parameters Targeted subcellular units L-type Ca** channel Interventions Cat+ channel blocker B-blocker L→ Clinica| Outcomes Sinus rhythm
Antiarrhythmic Therapy Pathophysiologic Arrhythmia Diagnosis Interventions Clinical Outcomes Known or suspected mechanisms Critical components Vulnerable parameters Targeted subcellular units AV node reentrant tachycardia AV node reentry Anatomical fast/slow pathway AV node (slow conduction) AV nodal action potential L-type Ca++ channel Ca++ channel blocker -blocker Sinus rhythm
Vaughn-Williams Classification Based on cellular properties of normal His-Purkinje cells Classified on drug's ability to block specific ionic currents (i.e. Nat, K*+, Ca**) and beta-adrenergic receptors Advantages: Physiologically based Highlights beneficialldeleterious effects of specific drugs
Vaughn-Williams Classification • Based on cellular properties of normal His-Purkinje cells • Classified on drug’s ability to block specific ionic currents (i.e. Na+ , K+ , Ca++) and beta-adrenergic receptors • Advantages: – Physiologically based – Highlights beneficial/deleterious effects of specific drugs
Antiarrhythmic Therapy Empiric Goals Arrhythmia Diagnosis .dentify the type of dysrhythmia . Be familiar with more common BLACK BOX antiarrhythmics and their Vaughn-Williams Classification Interventions Clinical outcomes
Antiarrhythmic Therapy Empiric Arrhythmia Diagnosis Interventions Clinical Outcomes BLACK BOX Goals •Identify the type of dysrhythmia •Be familiar with more common antiarrhythmics and their Vaughn-Williams Classification
Arrhythmia Types Slow Fast Fast wide Fast narrow Too fast
Arrhythmia Types • Slow • Fast Fast wide Fast narrow Too fast
Arrhythmia-focused Therapy Fast Narrow Supraventricular tachycardias Re-entry type OrthodromiC SVT Automatic A.E.T Atrial Flutter JET
Arrhythmia-focused Therapy • Fast Narrow • Supraventricular tachycardias – Re-entry type • Orthodromic SVT – Automatic • A.E.T. , Atrial Flutter • J.E.T
Arrhythmia-focused Therapy Fast Wide (rare) Antidromic SVT or SVT with abberancy Ventricular tachycardia Inappropriate automaticity of ventricular or His-Purkinje tissue
Arrhythmia-focused Therapy • Fast Wide – (rare) Antidromic SVT or SVT with abberancy – Ventricular tachycardia • Inappropriate automaticity of ventricular or His-Purkinje tissue
Arrhythmia-focused Therapy Select one antiarrhythmic or a limited group of antiarrhythmics to treat the disorder
Arrhythmia-focused Therapy • Select one antiarrhythmic or a limited group of antiarrhythmics to treat the disorder
Antiarrhythmic Agents Vaughn-Williams Classification Class -Nat-channel blockers(direct membrane action) Class -Sympatholytic agents Class ll-Prolong repolarization Class IV- Cat+- channel blockers Purinergic agonists Digitalis glycosides
Antiarrhythmic Agents Vaughn-Williams Classification • Class I - Na+ - channel blockers (direct membrane action) • Class II - Sympatholytic agents • Class III - Prolong repolarization • Class IV- Ca++ - channel blockers • Purinergic agonists • Digitalis glycosides