Summary
Definition
History and exam
Key diagnostic factors
- history of CAD
- history of hypertrophic cardiomyopathy
- history of idiopathic dilated cardiomyopathy
- presence of other risk factors
- asymptomatic presentation
- tachycardia
Other diagnostic factors
- palpitations
- dizziness
- lightheadedness
- pre-syncope
- syncope
Risk factors
- CAD
- left ventricular systolic dysfunction
- hypertrophic cardiomyopathy
- idiopathic dilated cardiomyopathy
- long QT syndrome
- Brugada's syndrome
- electrolyte imbalance
- drug toxicity
- Chagas' disease and other cardiomyopathies
- catecholaminergic polymorphic VT
- family history of sudden death
- mental or physical stress
Diagnostic investigations
1st investigations to order
- ECG
- electrolyte panel
- troponin
- CK-MB
Investigations to consider
- 24-hour ambulatory ECG monitoring
- echocardiogram
- cardiac catheterisation
- cardiac MRI with gadolinium
- electrophysiological testing
- stress testing
- genetic screening
Treatment algorithm
no cardiac comorbidity: asymptomatic
no cardiac comorbidity: symptomatic
post-MI
idiopathic dilated or hypertrophic cardiomyopathy
Contributors
Authors
Fred Kusumoto, MD

Professor of Medicine
Mayo Medical School
Division of Cardiovascular Diseases
Department of Medicine
Mayo Clinic Florida
Jacksonville
FL
Disclosures
FK declares that he has no competing interests.
Acknowledgements
Professor Kusumoto would like to gratefully acknowledge Dr Ronald R. Butendieck Jr, a previous contributor to this topic. RRB declares that he has no competing interests.
Peer reviewers
Sarabjeet Singh, MD
Cardiology Fellow
Adult Cardiovascular Fellowship
Department of Cardiology
Chicago Medical School (CMS) and affiliated hospitals
Chicago
IL
Disclosures
SS declares that he has no competing interests.
Vias Markides, MB(Hons), BS(Hons), MD, FRCP
Consultant Cardiologist and Chair
Arrhythmias
Royal Brompton & Harefield NHS Trust
Hon. Senior Lecturer
Imperial College
London
UK
Disclosures
VM declares that he has no competing interests.
Differentials
- SVT with aberrant conduction
- Electrical artifact
More DifferentialsGuidelines
- 2022 AHA/ACC/HFSA guideline for the management of heart failure
- 2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias
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