心脏性猝死的防治1课件.ppt

* * Studies have identified several factors that increase a patient’s risk for SCA. Individual risk factors are more predictive of SCA if they are combined with other risk factors. NOTE: Slides are provided on each risk factor if additional information is desired. 1Myerburg, Robert. Sudden Death due to Cardiac Arrhythmias. NEJM, Vol. 345, No. 20; November 15, 2001. This slide reviews our best understanding of the causes of SCD. According to Dr. Myerburg, CAD is the underlying cause for 80% of SCD events. Either an acute ischemic event and/or a reentry pathway from a previous MI can cause an SCD event. According to this diagram, non-ischemic cardiomyopathy accounts for 10-15% of cases of SCD even though non-ischemics account for about 40% of CHF patients. A recent study of 15,041 post-MI patients (GUSTO-III) found 5.7% of the study patients had a VT or VF event within 48 hours of their MI event. The overall mortality rates of these patients were significantly higher than for patients who did not experience a VT or VF event, as shown above. This data also shows that if patients survive to hospital discharge their survival parallels that of patients without VT/VF. Patients with LV dysfunction had higher rates of sudden cardiac death, than patients without LV dysfunction in the GISSI-2 Trial. Patients with more frequent PVBs had a higher rate of sudden cardiac death in patients with and without LV dysfunction. (Source: Maggioni AP. Circulation. 1993;87:312-322). A marked depression of LVEF is the most powerful predictor of SCD. A LVEF 0.30 is the most significant risk factor for SCD. This risk factor, however, has low specificity, since studies have shown more than 50% of SCD victims have a LVEF 0.30. A large registry study (n = 9,258) documented the rate of SCD among patients with varying degrees of left ventricular dysfunction. A strong relationship was found between LVEF and SCD, as shown above. (Source: Vreede-Swagemakers JJ. J Am Coll Cardiol. 19