Human adult cardiac autonomic innervation: Controversies in anatomical knowledge and relevance for cardiac neuromodulation.

BACKGROUND: Cardiac sympathetic blockade is a therapeutic approach for arrhythmias and heart failure and may be a beneficial effect of high thoracic epidural anesthesia. These treatments require detailed knowledge of the spatial location and distribution of cardiac autonomic nerves, however, there are controversies on this subject in humans. OBJECTIVE: To provide a systematic overview of current knowledge on human anatomy of the cardiac autonomic nervous system. RESULTS: In contrast to the often claimed assumption that human preganglionic sympathetic cardiac neurons originate mainly from thoracic spinal segments T1-T4 or T5, there is ample evidence indicating involvement of cervical spinal segment C8 and thoracic spinal segments below T5. Whether cervical ganglia besides the stellate ganglion play a role in transmission of cardiac sympathetic signals is unclear. Similarly, there is debate on the origin of cardiac nerves from different thoracic ganglia. Most human studies report thoracic cardiac nerves emerging from the first to fourth thoracic paravertebral ganglia; others report contributions from the fifth, sixth and even the seventh thoracic ganglia. There is no agreement on the precise composition of nerve plexuses at the cardiac level. After years of debate, it is generally accepted that the vagal nerve contributes to ventricular innervation. Vagal distribution appears higher in atria, whereas adrenergic fibers exceed the number of vagal fibers in the ventricles. CONCLUSION: Anatomy of the human cardiac autonomic nervous system is highly variable and likely extends beyond generally assumed boundaries. This information is relevant for thoracic epidural anesthesia and procedures targeting neuronal modulation of cardiac sympathetic innervation.

Risk factors for progression in hand osteoarthritis: a systematic review.

OBJECTIVE: To assess the risk factors for progression of hand osteoarthritis (OA). METHODS: In a systematic review of cohort studies, medical literature databases were searched up to May 2012 for articles reporting data on the association between risk factors and hand OA progression. The quality of these studies was assessed by 2 independent reviewers using a criteria scoring system of 16 items, and studies were dichotomized into those with scores of 69% or over and those with scores under 69%. Best evidence synthesis was used to determine the level of evidence per risk factor. RESULTS: In total, 14 articles that fulfilled the selection criteria were included, of which 8 were high quality. The most frequently investigated risk factors were age, sex, radiographic features (e.g., erosive OA), and scintigraphy. Progression was mostly defined by radiographic criteria, but also clinical progression as an outcome was described. Most of the investigated risk factors showed limited or inconclusive evidence for an association with hand OA progression. Limited evidence according to the best evidence synthesis with most available studies was present for the association between a positive scintigraphic scan and radiographic progression (up to 2.8 times more progression than negative joints). CONCLUSION: Limited evidence is available for a positive association between an abnormal scintigraphic scan and radiographic hand OA progression. These data suggest that a positive scintigraphic scan as an inclusion criterion for studies that aim to show structural modification can increase the power of such studies. Future longitudinal studies with a well-defined baseline population are needed to search for risk factors of hand OA progression.