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
Investigations to consider
- 24-hour ambulatory ECG monitoring
- echocardiogram
- cardiac catheterisation
- cardiac MRI with gadolinium
- electrophysiological testing
- stress testing
- genetic screening
Treatment algorithm
Contributors
Authors

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.
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
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.
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.
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