Which patients are at risk for developing ventricular tachycardia (VTach)?

Risk Factors for Developing Ventricular Tachycardia

Patients at highest risk for developing ventricular tachycardia (VT) include those with structural heart disease, particularly prior myocardial infarction with left ventricular dysfunction, and those with inherited arrhythmogenic conditions. 1

Primary Risk Factors

Structural Heart Disease

• Coronary Artery Disease (CAD)

  • Prior myocardial infarction, especially with:
    • Left ventricular ejection fraction ≤40% 1
    • Scar formation creating reentry circuits 2
  • Acute ischemia (within 48 hours of MI) 1

• Cardiomyopathies

  • Dilated cardiomyopathy (DCM) 1
  • Hypertrophic cardiomyopathy (HCM) 1
  • Arrhythmogenic right ventricular cardiomyopathy (ARVC) 2
  • Infiltrative cardiomyopathies (sarcoidosis, amyloidosis) 1

• Congenital Heart Disease

  • Repaired tetralogy of Fallot (especially with RV outflow tract patch) 1
  • Congenital aortic stenosis 1
  • Transposition of great arteries (after atrial baffle procedures) 1, 3
  • Single ventricle physiology (especially older Fontan patients) 1
  • Ventricular septal defect with pulmonary arterial hypertension 1

Inherited Arrhythmogenic Conditions

• Long QT syndrome 1
• Brugada syndrome 1
• Catecholaminergic polymorphic VT 1
• Familial history of sudden cardiac death 1

Clinical Presentations Associated with VT Risk

• Prior Cardiac Events

  • Cardiac arrest due to VT/VF 1
  • History of sustained VT 1
  • Unexplained syncope in patients with structural heart disease 1
  • Nonsustained VT in patients with coronary disease and LV dysfunction 1, 4

• Electrophysiologic Findings

  • Inducible VT/VF during electrophysiology study 1
  • QRS duration ≥180 ms (particularly in repaired tetralogy of Fallot) 1
  • T-wave alternans 1

Other Risk Factors

• Medication-Related

  • QT-prolonging medications (antiarrhythmics, certain antibiotics, antipsychotics) 5
  • Drug-drug interactions with amiodarone 5

• Metabolic/Electrolyte Abnormalities

  • Electrolyte imbalances (hypokalemia, hypomagnesemia) 1
  • Hypoxia 1

• Hemodynamic Factors

  • Advanced heart failure (NYHA class II-III) 6
  • Pulmonary arterial hypertension 1

Clinical Implications and Warning Signs

• Palpitations (present in 57% of patients with VT) 7
• Chest pain (27% of VT patients) 7
• Dyspnea (25% of VT patients) 7
• Lightheadedness (35% of VT patients) 7
• Near-syncope or syncope (30% of VT patients) 7

Important Caveats

• The absence of severe symptoms does not rule out VT. Approximately 35% of patients with sustained VT have no cerebral symptoms 7
• VT can be misdiagnosed as supraventricular tachycardia when symptoms are mild 7
• Patients with newly diagnosed non-ischemic cardiomyopathy (<9 months) who develop ventricular arrhythmias are at particularly high risk 1
• In congenital heart disease, VT risk increases with age and time from surgical repair 1

Recognizing these risk factors allows for appropriate monitoring, risk stratification, and consideration of preventive therapies such as implantable cardioverter-defibrillators in high-risk populations.