From the Guidelines
Ventricular tachycardia is primarily caused by structural heart disease, cardiomyopathies, electrolyte abnormalities, and certain medications, as well as congenital conditions and other factors that disrupt normal electrical conduction in the heart. The causes of ventricular tachycardia can be categorized into several key areas, including:
- Structural heart disease, such as coronary artery disease and previous myocardial infarction, which can create scarring that disrupts normal electrical conduction 1
- Cardiomyopathies, including hypertrophic, dilated, and arrhythmogenic right ventricular cardiomyopathy, which can increase VT risk due to myocardial fiber disarray and fibrosis 1
- Electrolyte abnormalities, especially low potassium, magnesium, or calcium levels, which can trigger VT by altering cardiac cell membrane potentials 1
- Certain medications, including some antiarrhythmics, antipsychotics, antibiotics, and antihistamines, which can prolong the QT interval and precipitate VT 1
- Congenital conditions, such as Long QT syndrome, Brugada syndrome, and catecholaminergic polymorphic VT, which create inherent vulnerability to ventricular arrhythmias 1
- Other causes, including myocarditis, cardiac sarcoidosis, drug toxicity, and severe physical or emotional stress, which can also contribute to the development of VT 1 It is essential to identify the underlying cause of ventricular tachycardia to provide effective treatment, which may include antiarrhythmic medications, implantable cardioverter-defibrillators, catheter ablation, or addressing reversible factors like electrolyte imbalances 1.
From the Research
Causes of Ventricular Tachycardia
- Coronary artery disease is a common cause of ventricular tachycardia, with ischemia-induced electrophysiological changes and genetic factors contributing to its occurrence 2, 3
- Reentry generated in scar tissue is a common mechanism of sustained, monomorphic ventricular tachycardia in patients with coronary artery disease, especially those with lower left ventricular ejection fraction 3
- Other cardiac conditions, such as idiopathic dilated cardiomyopathy, Chagas disease, sarcoidosis, arrhythmogenic cardiomyopathies, and repaired congenital heart disease, can also present with ventricular tachycardia 4
- Nonischemic cardiomyopathy substrate can also be a cause of ventricular tachycardia in patients with coronary artery disease, with catheter ablation being a potential treatment option 5
Underlying Mechanisms
- Ischemia-induced electrophysiological changes can lead to ventricular tachycardia in the acute phase of myocardial infarction 2
- Reentry in scar tissue is a common mechanism of ventricular tachycardia in patients with coronary artery disease 3, 4
- Nonischemic substrate, such as low-voltage zones and epicardial left ventricular scar, can also contribute to ventricular tachycardia in patients with coronary artery disease 5
Diagnostic Approaches
- 12-lead electrocardiogram is essential for diagnosis and can suggest the presence of potential underlying heart disease and identify the location of the ventricular tachycardia circuit 3, 4
- Invasive electrophysiologic study can determine the mechanism of the arrhythmia and provide guidance for ablation 3, 4