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

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