The incidence of sustained ventricular tachycardia (VT) is approximately 3 percent in patients who survive an acute myocardial infarction (MI), usually occurring 48 hours to six weeks after the event . The majority of such patients have had a large MI, typically associated with a substantial reduction in left ventricular ejection fraction and often with a left ventricular aneurysm [2-4]. (See "Sustained monomorphic ventricular tachycardia in patients with a prior myocardial infarction: Treatment and prognosis".)
Advances in early revascularization for acute MI as well as increasing use of beta blockers and angiotensin-converting enzyme (ACE) inhibitors post-MI have led to a reduction in the frequency of these complications. For left ventricular aneurysm, for example, the incidence following an MI in which Q waves develop has fallen from 30 to 35 percent to 8 to 15 percent. (See "Left ventricular aneurysm and pseudoaneurysm following acute myocardial infarction".)
Surgery was once a prominent component of the treatment of post-MI VT. However, because of proven efficacy and ease of implantation, an implantable cardioverter-defibrillator (ICD) is currently the most common strategy for treating serious ventricular arrhythmias in these patients. (See "General principles of the implantable cardioverter-defibrillator" and "Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy".)
Although an ICD can treat VT and usually prevent the consequences of untreated sustained VT (ie, syncope, sudden death), surgery remains an important procedure since it offers the potential for cure . Catheter mapping of the arrhythmia plays an integral role in localizing all potential tachycardias circuits and planning the surgical approach. Arrhythmia surgery is particularly useful when surgical revascularization (coronary bypass grafting) is also necessary, since it offers added hemodynamic benefits, including improvement in left ventricular ejection fraction and alleviation of symptoms of heart failure.
Another method for potential control or cure of VT is catheter ablation of myocardial tissue using a radiofrequency source of energy; other modes of ablation, such as thermal (hot or cold), light (laser), mechanical (ultrasound), and chemical methods have been developed and are being investigated. Radiofrequency ablation is highly effective for many supraventricular tachycardias and has replaced surgery as a first-line therapy in their management. It has not advanced sufficiently to be a primary therapy for VT associated with coronary disease. (See "Catheter ablation for ventricular arrhythmias".)