自动复律除颤器在心脏性猝死中应用.pptVIP

* Although the highest risk factor for SCA is a previous cardiac arrest, survival rates are extremely low. It is critical to identify other risk factors so that high-risk patients can be referred for treatment. * Studies for heart failure patients are in progress, including the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), the goal of which is to identify therapy that will significantly reduce death rates in patients with CHF. * Studies for heart failure patients are in progress, including the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), the goal of which is to identify therapy that will significantly reduce death rates in patients with CHF. * A marked depression of LVEF is the most powerful predictor of SCA. A LVEF 0.30 is the most significant risk factor for SCA. This risk factor, however, has low specificity, since studies have shown more than 50% of SCA victims have a LVEF 0.30. A large registry study (n = 9,258) documented the rate of SCA among patients with varying degrees of left ventricular dysfunction. A strong relationship was found between LVEF and SCA, as shown above. (Source: Vreede-Swagemakers JJ. J Am Coll Cardiol. 1997;30:1500-1505) * Interestingly, most patients who suffer from sudden cardiac death (64%) are the patients who are minimally symptomatic with Class II heart failure. The sickest, most symptomatic patient (Class IV) experience heart failure deaths (56%) from pump failure, rather than sudden cardiac death (33%). It is important to remember that although it can be said that a heart failure patient in NYHA class II may have a higher risk of SCD, their relative annual risk of dying is less than the other NYHA classes.  The results from the SCD-HeFT Trial (Sudden Cardiac Death in Heart Failure Trial) which enrolled NYHA II and III patients with a Left Ventricular Ejection Fraction of 35% or less showed that ICDs significantly reduced mortality in this patient population on top of optimal medical therapy. *