SLIDE 1
ACC Rockies 2012
ACC Rockies 2012
Overview
Back to the basics Unraveling the lexicon Bread and Butter
- Wide QRS tachycardia
- Irregular narrow complex tachycardia
Toast and Jam
- Regular narrow QRS tachycardia
Supraventricular Arrhythmias Bread And Butter Or Toast And Jam Derek - - PowerPoint PPT Presentation
Supraventricular Arrhythmias Bread And Butter Or Toast And Jam Derek - - PowerPoint PPT Presentation
Supraventricular Arrhythmias Bread And Butter Or Toast And Jam Derek V Exner , MD, MPH, FRCPC, FACC, FHRS Professor, Libin Cardiovascular Institute of Alberta ACC Rockies 2012 Overview Back to the basics Unraveling the lexicon Bread and
SLIDE 2
SLIDE 3
ACC Rockies 2012
Starting with the Basics
SLIDE 4
ACC Rockies 2012
Common SVT Types & Features
Type
- Freq. Features
AV Node Reentry (AVNRT) # 1
- Pseudo R1 in V1
AV Reentry (AVRT) # 2
- ± Manifest
Atrial Tachycardia (AT) # 3
- Altered P wave
morphology
Medi et al. MJA 2009; 190: 255–260
SLIDE 5
ACC Rockies 2012
Anatomic Lexicon of SVT
AVNRT Slow-Fast Fast-Slow AVRT Orthodromic Antidromic Atrial flutter Counterclockwise Clockwise
SLIDE 6
ACC Rockies 2012
Other Things to Consider
Diagnosis Features Inappropriate Sinus Tachycardia (IST)
- Idiopathic sinus tachycardia
Female healthcare workers Postural Orthostatic Tachycardia Syndrome (POTS)
- ± Other autonomic findings
Medi et al. MJA 2009; 190: 255–260
SLIDE 7
ACC Rockies 2012
Less Common SVTs
Type Features Permanent Junctional Reciprocating Tachycardia (PJRT)
- Children
- Rate related CM
Junctional ectopic tachycardia (JET)
- Children
- Discrete AV node focus
Mahaim tachycardia
- AP involving AVN & His-P
- From RA to RV near RBB
Medi et al. MJA 2009; 190: 255–260
SLIDE 8
ACC Rockies 2012
Bread and Butter
SLIDE 9
ACC Rockies 2012
Eight Nine Steps to Unraveling SVT (1 of 2)
- 1. QRS width & regularity.
- 2. Evidence of atrial activity.
- 3. If distinct P waves
- RP relationship
- P wave morphology in SVT (& NSR)
- AV relationship (1:1, 2:1, dissociated)
- 4. If flutter waves seen or suspected
- Evaluate P morphology (slow R rate)
Kumar & Scheinman. Cardiol Clin 2006:24:427-37
SLIDE 10
ACC Rockies 2012
Approach to Narrow Complex Tachycardia
SLIDE 11
ACC Rockies 2012
Regular WCT: Summary of Four Studies
285 consecutive stable patients (tertiary care centres) – 230 had VT (81%) – 180 with VT had prior MI (78%) – Regular WCT + Prior MI = VT 98% of the time
Tchou, P et al. Am J Med, 1988 Steinman et al. JAMA 1989 Baerman JM et al. Ann Emerg Med 1987 Akhtar M et al. Ann Int Medi 1988
SLIDE 12
ACC Rockies 2012
Know that pre-ECG
- prob. of SVT is 5%
To achieve post-ECG
- prob. of SVT > 90%,
require a LR ~ 200 Even a powerful LR (e.g., > 10) changes post-ECG prob. of SVT to ~ 30% Pre- LR Post- test test
SLIDE 13
ACC Rockies 2012
Brugada P. Circulation 1991;83:1649-59.
Absence of RS in all precordial ? VT RS > 100 ms ? VT AV Dissociation ? VT VT Morphology in V1-2 & V6 ? VT SVT No Yes No Yes No Yes No Yes
Regular Wide Complex Tachycardia
SLIDE 14
ACC Rockies 2012
QRS Morphology Versus Brugada Algorithm 102 consecutive patients, 69 (68%) had VT – VT is the default unless match for typical BBB Sensitivity Specificity Brugada Criteria 83% (57/69) 67% (22/33) Typical BBB Criteria 91% (63/69) 85% (28/33)
Griffith MJ et al. Lancet 1994
SLIDE 15
ACC Rockies 2012
Kindwall 1988
“Down Hill Mogul ” in Leads V1 & V2
VT Favoured if A is > 30 ms Notching (B) C is > 70 ms
- Wellens. Heart 2001;86:579-85
SLIDE 16
ACC Rockies 2012
58 year old man: lightheaded; BP 108/62
“Regular Narrow Complex Tachycardia”
SLIDE 17
ACC Rockies 2012
58 year old man: lightheaded; BP 108/62
“Regular Narrow Complex Tachycardia”
Wide
SLIDE 18
ACC Rockies 2012
Regular WCT
History of MI: > 95% will be VT Evidence for VT – AV Relationship
- Dissociated P-waves, Fusion & Capture
– QRS morphology
- Brugada Criteria, others
Adenosine may be helpful Require adequate data (12 lead / old ECG)
SLIDE 19
ACC Rockies 2012
Toast and Jam
SLIDE 20
ACC Rockies 2012
Eight Nine Steps to Unraveling SVT (1 of 2)
- 1. QRS width & regularity.
- 2. Evidence of atrial activity.
- 3. If distinct P waves
- RP relationship
- P wave morphology in SVT (& NSR)
- AV relationship (1:1, 2:1, dissociated)
- 4. If flutter waves seen or suspected
- Evaluate P morphology (slow R rate)
Kumar & Scheinman. Cardiol Clin 2006:24:427-37
SLIDE 21
ACC Rockies 2012
Where do you look for P Waves ?
Needle in the Haystack Principle
SLIDE 22
ACC Rockies 2012
Simple Clues
SLIDE 23
ACC Rockies 2012
- 5. If no P waves
–
- Irreg. & non-isoelectric (AF) / pseudo R (AVNRT)
- 6. Assess underlying A & V rates.
- 7. Initiation & termination
– Starts with PAC, PVC / Ends with P / QRS
- 8. Response to adenosine.
– Terminates? How? AV block? Δ in atrial rhythm?
- 9. Δ in rate (cycle length) with & without BBB?
Eight Nine Steps to Unraveling SVT (2 of 2)
Kumar & Scheinman,. Cardiol Clin 2006:24:427-37
SLIDE 24
ACC Rockies 2012
ECG Clues
Morphology Termination Onset
SLIDE 25
ACC Rockies 2012
Simple Clues
Orthodromic
SLIDE 26
ACC Rockies 2012
Widening of QRS in Patient with WPW
SLIDE 27
ACC Rockies 2012
SLIDE 28
ACC Rockies 2012
SLIDE 29
ACC Rockies 2012
SLIDE 30
ACC Rockies 2012
Pharmacological Intervention
Response to Adenosine / Vagal Maneuvers
SLIDE 31
ACC Rockies 2012
Adenosine as a Diagnostic Maneuver
Appears safe in VT (based on a few small series) Does not terminate scar related reentrant VT May terminate some idiopathic VTs Never appropriate for IRREGULAR WCT Terminates most AVN dependent SVT Slows ventricular response to AVN independent SVT Smart when SVT is suspected
SLIDE 32
ACC Rockies 2012
SVT Does Not Rule Out Other Problems
SLIDE 33
ACC Rockies 2012
When to Refer to EP Specialist ?
Wide QRS tachycardia Narrow SVT Severe symptoms Drug resistant or intolerant Non-pharmacological approach preferred Occupational Pre-excitation
SLIDE 34
ACC Rockies 2012
Summary
Keep it simple Wide QRS tachycardia
- VT until proven otherwise
Regular narrow QRS tachycardia
- Simple, step-by-step algorithm