Acute Management of Stable Narrow Complex Tachycardia

1. Acute Management of Stable Narrow Complex Tachycardia Mini Lecture 2013

2. Objectives • Review the initial approach to diagnose and treat narrow complex tachycardia • Review examples of AVNRT, AVRT, Atrial Tachycardia • This is not a comprehensive review of all the narrow complex tachycardias • You are not expected to manage these patients on your own, always ask for back up

3. Case • Nurse calls to inform you that bed 10’s heart rate just went up to 200s on telemetry. Which of the following information should you obtain asap? A. Blood pressure B. Mental status C. EKG D. Focused Physical Exam E. All of the above

4. Case • Nurse calls to inform you that bed 10’s heart rate just went up to 200s on telemetry. Which of the following information should you obtain asap? A. Blood pressure B. Mental status C. EKG D. Focused Physical Exam E. All of the above

5. Narrow Complex Tachycardia • Rate >100 (often 150-250) • QRS <120 msec • Regular • Sinus tachycardia (usually <150) • AVNRT • AVRT • Atrial Tachycardia • Atrial Flutter with regular block (150, 100, 75) • Irregular • Atrial Fibrillation • MAT

6. Initial Assessment for Tachycardia Questions • Symptomatic? • Hypotensive? • 12 lead EKG • IV access • Stable or Unstable? • Altered Mental Status • Hypotension • Chest Pain • Acute SOB • Hypoxia

7. Unstable? • Crash Cart • ACLS • Call for backup • Senior resident • Cardiology fellow • Nocturnist • Code blue

8. Stable?Initial Assessment • Focused H&P • Talk to the patient to assess mental status • Reason for admission (sepsis, ACS) • Cardiac Hx (CAD, HF, Afib, SVT) • Recent electrolytes • Medications (AV nodal agents, digoxin) • Listen to heart and lungs • Volume status • JVD

9. EKG shows..

10. Too fast to interpret rhythm? • Vagal Maneuvers and Adenosine • Slow down the rhythm • Terminate certain SVTs which conduct through the AV node • If possible obtain 12 lead EKG recording during intervention

11. Vagal maneuvers • Bearing down • Face in ice cold water • Carotid Massage • Blowing into a folded straw • Cough • Adenosine • May avoid if bronchospasm/asthma/COPD? • Caution if history of pre-exitation/ WPW?* • Warn them about the symptoms • 6mg IV push followed by NS flush followed by • 12mg IV push followed by NS flush

12. Cause Dual AV nodal pathways with differing refractory periods Often initiated by a PAC 60% SVT DX Rate 150-250 Inverted p or “psuedo S” Tx Vagal Adenosine BB: Metoprolol 5mg q5min x3 CCB: Diltiazem 10mg IV, repeat 10-30mg IV in 5-10 min AVNRT

13. AVNRT PSUEDO S WAVES

14. Cause Re-entrant tachycardic circuit with conduction down AV node and back up a bypass tract (i.e. WPW) 30% SVT Dx: Rate 150-250 Retrograde P inferior leads Tx: Vagal Adenosine BB: Metoprolol 5mg min q5 x 3 CCB: Diltiazem 10mg IV, repeat 10-30mg IV in 5-10 min AVRT

15. AVRT

16. Cause Enhanced Automaticity of atrial tissue or ectopic atrial pacemaker 10% SVT Dx P wave precedes each QRS Unusual p wave axis Adenosine may show continued atrial beats, without AV conduction Tx: BB: metoprolol 5mg q5 x 3 CCB: Diltiazem 10mg IV, repeat 10-30mg IV in 5-10 min Atrial Tachycardia

17. Atrial Tachycardia ADENOSINE Unusual p wave axis Continued atrial automaticity

18. General Principles • Note the common theme: Vagal Maneuvers, Adenosine, Beta Blockers, Calcium Channel Blockers, caution in WPW • Check vitals (BP) frequently during acute setting to make sure a stable situation does not become unstable • Again, this is meant to be a review of the initial management of SVT you are not expected to independently manage these patients- Call for backup!

19. Case Follow Up • Nurse calls: “ Bed 10’s heart rate just went up to 200s” • You reply: • What is his blood pressure? • Is his arousable and oriented? • Please get a 12 lead EKG now • Does he have IV access? • I’ll be right there..

20. References • UpToDate • Med Res UCLA http://medres.med.ucla.edu/ • FP Notebook http://www.fpnotebook.com/ • Images sited previously