Sudden cardiac death is a major cause of death in patients with ischaemic cardiomyopathy and mostly caused by ventricular tachyarrhythmias. Risk stratification has become of paramount importance especially after the development of implantable cardioverter defibrillators that terminate life-threatening ventricular tachyarrhythmic episodes very reliably. Numerous attempts have been performed to identify accurate risk stratification tools. Unfortunately, the success of these attempts has been rather limited. A severely reduced left ventricular ejection fraction has been convincingly shown to be associated with significantly increased mortality and risk for sudden cardiac death in ischaemic cardiomyopathy. For this reason, it is the main parameter used for risk stratification and for the decision to implant a cardioverter defibrillator for primary prevention of sudden cardiac death. However, left ventricular ejection fraction has several limitations as a stand-alone risk stratifier and has limited sensitivity and specificity. Several other tools have been proposed to improve risk prediction such as the patient’s clinical profile, ventricular ectopy, microvolt T-wave alternans, signal-averaged electrocardiogram, markers of autonomic tone, and also invasive programmed ventricular stimulation. However, none of these techniques has managed to establish itself in clinical practice as a major method for risk stratification.
Prognosis and risk stratification in cardiac sarcoidosis patients with preserved left ventricular ejection fraction
