The new ACC/AHA/ESC Guidelines outline recommendations on the evaluation and treatment of patients who have or may be at risk for VA. Evaluation includes noninvasive and invasive techniques such as electrocardiography and electrophysiological testing. Possible therapies include pharmacological (drugs), devices, ablation (destruction of the affected area), surgery and revascularization. Acute and chronic therapies are addressed. Prognosis and management are individualized according to symptom burden and severity of underlying heart disease in addition to clinical presentation. In addition to recommendations in patients with specific pathology, cardiomyopathy and heart failure, specific populations are also covered, such as athletes, pregnant women, the elderly and pediatric patients.
One of the key updates in the 2006 document is that the implantation of devices now has a range of ejection fractions. Ejection fraction (EF) measures how effectively the heart's left ventricle pumps blood to the body. A normal, healthy heart has an EF in the range of about 50-70%.
"Prior to this document," says Douglas P. Zipes, M.D., M.A.C.C., F.A.H.A., F.E.S.C. and co-chair of the Guideline Writing Committee, "practitioners faced inconsistent recommendations for prophylactic ICD implantation based on ejection fractions, for example. The inconsistencies occurred because clinical investigators chose different ejection fractions for enrollment in trials of therapy, average values of the ejection fraction have been substantially lower than the cut off value for enrollment and subgroup analysis of clinical trial populations based on ejection fraction have not been consistent in their implications. The result was substantial differences among guidelines."