Background-Clinical impact of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) is largely unresolved.Thus, we analyzed the prognostic implications of AF in a large, community-based HCM population assembled from Italian and US cohorts. Methods and Results-Occurrence of AF and outcome were assessed in 480 consecutive HCM patients (age at diagnosis, 45Ϯ20 years; 61% male) who were followed up for 9.1Ϯ6.4 years. AF occurred in 107 patients (22%; incidence, 2%/y) and was independently predicted by advancing age, congestive symptoms, and increased LA size at diagnosis. Patients with AF had increased risk for HCM-related death (OR, 3.7; PϽ0.002) because of excess heart failure-related mortality but not sudden, unexpected death. This risk associated with AF was substantially greater in patients with outflow obstruction or with earlier development of AF (Յ50 years of age). AF patients were also at increased risk for stroke (OR, 17.7; Pϭ0.0001) and severe functional limitation (OR for NYHA class III or IV, 2.8; PϽ0.0001). Compared with those with exclusively paroxysmal AF, patients developing chronic AF showed higher combined probability of HCM-related death, functional impairment, and stroke (PϽ0.0001). In a subgroup of 37 patients with AF (35%), the clinical course was largely benign in the absence of stroke and severe symptoms. Conclusions-In a community-based HCM population, AF (1) was common, with 22% prevalence over 9 years; (2) was associated with substantial risk for heart failure-related mortality, stroke, and severe functional disability, particularly in patients with outflow obstruction, those Յ50 years of age, or those developing chronic AF; and (3) was nevertheless compatible with benign outcome in 35% of patients.

In an unselected regional population, hypertrophic cardiomyopathy had a relatively benign prognosis inconsistent with its prior characterization as a generally progressive disorder, based primarily on the experience of selected referral institutions. Sudden unexpected cardiac death was distinctly uncommon, although a sizable proportion of patients (particularly the subset prone to atrial fibrillation), did experience clinical deterioration.

A hypotensive blood pressure response during exercise occurred in over 20% of a community-based patient cohort with HCM, and was associated with adverse long-term prognosis in patients <50 years old. However, the positive predictive accuracy of this blood pressure response is too low to justify modifications of clinical management or to allow identification of the high-risk patient based solely on an abnormal test result. By virtue of its high negative predictive accuracy for HCM-related mortality, the blood pressure response to exercise appears to be most valuable (in conjunction with the absence of other well recognized risk factors) as a screening test for the identification of low-risk subsets of patients.

Increased CSF glutamate may originate within the CNS and may play a pathogenetic role in HIV dementia, thus supporting the treatment of these patients with glutamate receptor antagonists.

7In this paper an artificial neural network for photovoltaic plant energy fore-8 casting is proposed and analyzed in term of its sensitivity with respect to the 9 input data sets.