Date post: | 31-Mar-2015 |
Category: |
Documents |
Upload: | jerome-cullipher |
View: | 223 times |
Download: | 3 times |
Management of the Patient Presenting with Wide Complex Tachycardia
Samir Saba, MD
Director, Cardiac Electrophysiology
Definition
• Heart rate > 100 b/min• QRS > 120 ms
Differential Diagnosis
• Supraventricular tachycardia with aberrancy• Pre-excited tachycardia• Motion artifact• Paced rhythm• Ventricular tachycardia
– Idiopathic– Non-idiopathic
Importance of diagnosing VT
1. Sensitivity versus Specificity
2. In all patients with WCT, VT is the diagnosis in 80% of cases
SVT with aberrancy
• Typical RBBB• Typical LBBB
Typical bundle morphology
LBBB RBBB
LBBB in AVRT
RBBB and AVRT
Pre-excited Tachycardia
• Manifest versus concealed AP
WPW
WPW
Antidromic AVRT
Atrial Flutter with Preexcitation
AF with Preexcitation
Motion artifact
• Failure to recognize artifact is common:
– 94% of internists– 58% of cardiologists– 38% of EP
Motion Artifact
Recognize artifact by:• Marching the high frequency signal across the WCT• Looking at other available leads
Paced ECG
Paced ECG
PacedNot Paced
Ventricular Tachycardia
• Idiopathic– RVOT VT– LVOT VT– Lt fascicular VT
• Non-idiopathic– ICM– NICM– HCM– Channelopathy
(LQTS, Brugada, etc…)
RVOT VT
LVOT VT
Left fascicular VT
Other Classifications for VT
• Morphology:– Monomorphic – Polymorphic– Bidirectional
• Mechanisms:– Reentry– Automaticity– Triggered activity
• Drug susceptibility:– Verapamil sensitive– Adenosine sensitive
Repetitive VT
MMVT
Non-idiopathic VT
Ventricular Tachycardia
Bidirectional VT
Mechanisms of VT
Approach to Management
• History
• Physical Exam
• ECG
• EP Study
History
• Age (if >35 yrs, VT>85%) • Symptoms (palpitations, syncope, LH,
diaphoresis, angina, seizures, CA…)• Circumstances: N/V/D (electrolytes)• PMH: Cardiac disease, MI, CHF, ICD, RF• Family history: SCD, arrhythmias• Medications: QT prolongation, digoxin, diuretics,
etc…• Habits: Drugs
Physical Examination
• Hemodynamic Stability• Signs of acute CHF• Sternal wound• PVD• Stroke• PM/ICD• Evidence of AV dissociation (cannon A waves,
marked fluctuations in BP, variable S1 intensity)• Maneuvers: CSM, pharmacologic interventions
(lidocaine, adenosine, BB, verapamil)
Other tests
• Laboratory tests: K, Mg, plasma concentrations of drugs (dig, procan, etc…)
• CXR: cardiomegaly
• Echo: structural abnormalities
ECG
During WCT:
• AV dissociation• Fusion beats• Capture beats• Morphology
– Width of QRS– Morphology of the
bundles– Electrical axis– Precordial concordance
In NSR:• Ischemia• Acute MI• Old MI• Long QT• Brugada pattern• LVH• Epsilon waves
AV dissociation
Fusion beat
ECG
ECG
Therapy
• Acute Management:– For the Unstable patient:
• Emergent synchronized cardioversion• If QRS and T cannot be distinguished then defibrillation• Cautious use of sedatives and analgesics
– For the Stable patient:• Class I or III AAD• Treatment of associated conditions (ischemia,
electrolytes,…)• Elective cardioversion• Interrogation of ICD or PM if present
Therapy
• Chronic Management:• AAD:
– class IC or III, if structurally normal hearts– class III, if structurally abnormal hearts (with
ICD)
• EPS+/-RFA – Stand alone therapy in idiopathic VT– Adjunctive therapy (+/-AAD) in ischemic VT
• ICD– For primary and secondary prevention of SCD
Indication for EPS
EP Study
• Induce the arrhythmia
• Activation or Pace mapping
• Ablation
Activation Map for VT
RVOT VT: pace map
Special Case: NSVT
• EF≤35%, then ICD
• EF>40%, no ICD
• 35%<EF≤40%, then EPS and ICD if EPS+ (MUSTT trial)
In all these cases, -blockers and other AAD can be used if NSVT is symptomatic.
Summary
• DDX of WCT includes VT, SVT with aberrancy, preexcited tachycardia, artifact, and paced rhythm. VT accounts for 80%
• Diagnosis hinges of good history, PE, ECG• Acute management depends on stability of
patient. In the unstable patient, immediate cardioversion or defibrillation is recommended
• Long term management armamentarium includes: AAD, Ablation, ICD
Holter Monitor in a Mouse
EPS in a Mouse
Question?…