Supraventricular Arrhythmias Claire B. Hunter, M.D.

Adverse Effects of Arrhythmias Depend Upon: Overall Ventricular Rate Too High Too Low Loss of Atrial “Kick” Degree of L.V. Dysfunction

Steps In Arrhythmia Analysis 1. Calculate Rate - Ventricular : Atrial 2. Regularity - QRS : P-Waves 3. Evaluate P-waves a) Presence b) Contour c) Relationship to QRS Complexes 4. P-R Interval 5. Width Of QRS Complex a) Pre-existing Conduction Defect b) Rate Dependent Aberrancy

Tachycardias Sinus Tachycardia Atrial Tachycardia –PAT –MAT AV Nodal Tachycardia Wolff Parkinson White Syndrome Atrial Fibrillation Atrial Flutter

Narrow QRS Tachycardia Supraventricular

Wide QRS Tachycardia Ventricular tachycardia SVT with Conduction Defect Wolff-Parkinson-White

Mechanisms for Supraventricular Tachycardia Re-Entrant Mechanism95% –AV Nodal Re-Entry4060% –Accessory Bypass Tracts2040% –Sinus Node Re-Entry 5% –Intra-Atrial Re-Entry 5% Automatic Atrial Tachycardia5%

Regular Tachycardia Narrow QRS Rate 160

Appendix A

Regular Narrow QRS Tachycardia Rate 160+ Sinus Tachycardia Paroxsymal Supraventricular Tachycardia Atrial Flutter with 2-1 Conduction

Paroxysmal Supraventricular Tachycardia AV nodal reentry Tachycardia (AVRNT) Atrial Tachycardia WPW

AV Nodal Reentrant Tachycardia No p wave seen Normal qrs Sudden onset Most common PSVT

Appendix B

AVNRT Treatment Vagal maneuvers Adenosine 6-12 mg IV Verapamil 5 mg Q 5 min x 3 Diltiazem mg IV (2min) x 2 Digoxin, Beta blockers, Ca C1 blockers Ablation

Appendix C

Atrial Fibrillation Etiology Symptoms ECG Treatment

Atrial Fibrillation Ventricular ratevariable: depends on degree of AV Block Regularity grossly irregular unless complete AV Block QRS Complexnormal (unless P.E.C.D. or R.D.A.) P-wavesnot identifiable: f-waves C-S responseincrease AV Block or none

Appendix D

AF/F: Pathophysiology of Symptoms Decreased diastolic filling time Decreased diastolic coronary perfusion time Exacerbation of angina due to increased oxygen demand (secondary to increase in heart rate) Loss of atrial contribution to ventricular filling

AF/F: Treatment Objectives Relief of symptoms Heart rate control Consider conversion to normal sinus rhythm –Immediate cardioversion if hypotensive or in pulmonary edema Maintenance of sinus rhythm Prevention of embolic complications

Atrial Fibrillation Control rate Cardioversion Anticoagulation

Atrial Flutter Atrial rate250 to 350/min Ventricular ratedepends on degree of AV block; frequently 150/min Regularityregular of irregular depending on AV block QRS complexnormal (unless P.E.C.D. or R.D.A.) P-wavesusually saw-tooth in appearance C-S responseincrease AV block or none

Appendix E

Appendix F

Atrial Flutter Control Rate Cardioversion

Atrial Flutter (1 - 2%) Adverse Effects Evaluation Medical Therapy (Control Ventricular Rate) –Digitalis (Avoid Toxicity) –Propranolol –Verapamil Cardioversion Preventive Therapy

Appendix G

Appendix H

Appendix I

Wolff Parkinson White Pre excitation –Short PR interval –Delta waves Paroxysmal SVT Treatment –Acute –Chronic

Drugs of Choice for Common Arrhythmias Atrial fibrillation or Atrial flutter  -blocker Calcium channel blocker digitalis Supraventricular Tachycardia Adenosine Verapamil  -blocker Digitalis PVC’s or NSVTNo drug if asymptomatic  -blocker