SNCA and Alzheimer disease: Thus, while the present study shows a greater extent of abnormal P wave parameters in LBD compared to AD, it is not possible to conclude whether these are due to extrinsic (e.g. due to autonomic dysfunction and/or denervation potentially mediated by neuroinflammation) or intrinsic (e.g. due to cardiac structural alterations such as alpha-synuclein deposition or cytokine-mediated remodeling) factors, or a combination.