[Ventricular tachycardia of ischemic cardiomyopathies]

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Surgery

Context:

• Ventricular tachycardia (VT) frequently occurs in patients with ischemic heart disease post-myocardial infarction, particularly when border zones are not preserved.
• Monomorphic VT is associated with permanent electrophysiological substrates and slow conduction zones, often triggered by extrasystoles or sympathetic activation.

Purpose:

• To analyze the prognostic value of left ventricular ejection fraction (LVEF) and treatment strategies in patients with ischemic heart disease and ventricular tachycardia.
• To evaluate factors influencing mortality, including LVEF, syncopal episodes, inducible VT, and response to antiarrhythmic therapy.

Summary:

• Cardiac mortality, primarily sudden death, follows sustained monomorphic VT. LVEF is a critical prognostic indicator: 5-year mortality is 30% with LVEF > 0.3 versus 51% with LVEF < 0.3.
• While spontaneous or induced VT frequency doesn't alter prognosis, syncopal VT episodes increase mortality risk. Persistence of inducible VT despite therapy elevates mortality, highlighting the need for effective antiarrhythmic drugs.
• Treatment choice is crucial for patients with LVEF ≤ 0.30; Class I antiarrhythmics correlate with higher mortality, whereas beta-blockers demonstrate reduced mortality. Polymorphic VT with inducible VT/VF carries a very high mortality risk.

Impact:

• This study underscores the critical role of LVEF in stratifying mortality risk in ischemic VT patients.
• It emphasizes the importance of clinical history and effective antiarrhythmic therapy, particularly beta-blockers, in managing patients with reduced ejection fraction.
• Findings guide therapeutic decisions, aiming to reduce sudden cardiac death and improve survival rates in this vulnerable patient population.