Atrioventricular block as the initial manifestation of cardiac sarcoidosis in middle-aged adults.

Introduction: Atrioventricular block (AVB) can be caused by several conditions, including cardiac sarcoidosis (CS). The prevalence of CS causing this presentation in a North American population has not been investigated and was the purpose of this study.

Methods: We prospectively evaluated patients aged 18-60 years presenting with unexplained 2nd or 3rd degree AVB and no previous history of sarcoidosis in any organ.

Sampling state and process variables on coral reefs.

Contemporary coral reefs are forced to survive through and recover from disturbances at a variety of spatial and temporal scales. Understanding disturbances in the context of ecological processes may lead to accurate predictive models of population trajectories. Most coral-reef studies and monitoring programs examine state variables, which include the percentage coverage of major benthic organisms, but few studies examine the key ecological processes that drive the state variables.