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 Mechanism 95%– AV Nodal Re-Entry 40

60%– Accessory Bypass Tracts 20 40%– Sinus Node Re-Entry 5%– Intra-Atrial Re-Entry 5%

• Automatic Atrial Tachycardia 5%

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

• 150-250

• 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 15-20 mg IV (2min) x 2

• Digoxin, Beta blockers, Ca C1 blockers

• Ablation

Appendix C

Atrial Fibrillation

• Etiology

• Symptoms

• ECG

• Treatment

Atrial Fibrillation

Ventricular rate variable: depends on

degree of AV Block

Regularity grossly irregular unless

complete AV Block

QRS Complex normal (unless P.E.C.D. or

R.D.A.)

P-waves not identifiable: f-waves

C-S response increase 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 rate 250 to 350/min Ventricular rate depends on degree of AV block; frequently 150/min Regularity regular of irregular depending on AV block QRS complex normal (unless P.E.C.D. or R.D.A.) P-waves usually saw-tooth in appearance C-S response increase 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 NSVT •No drug if asymptomatic-blocker