Interdisciplinary cardiovascular health research: quantitative methods, heliogeophysical influence, demographics, and spatial trends

Abstract

The study of cardiovascular health involves myriad scientific disciplines associated with diverse factors that contribute to health which further necessitates interdisciplinary endeavors. The current series of studies concern cardiovascular health from multiple interdisciplinary perspectives including biomedical signal processing, heliobiology, and public health, with a particular focus on quantitative methods throughout. The first study examined heart rate variability (HRV) derived from healthy and arrhythmia human electrocardiograph records. Data processed using wavelet entropy was quantitatively novel compared to traditional indices of HRV and also demonstrated significant accuracy for prediction and classification of arrhythmia. Next, heliobiological perspectives of cardiovascular physiology were examined beginning with experimental verification of previous correlational results. Artificially simulated geomagnetic impulses were associated with significant increases in participant HRV, particularly for frequency-based components. An additional pilot case study demonstrated similar effects for natural geomagnetic storms, while a nonlinear relationship was observed overall for HRV and geomagnetic activity. National data regarding mortalities due to hypertensive diseases in Canada from 1979 to 2009 were aggregated and investigated for periodic components and relationships with space weather parameters. Time-lagged linear correlations were observed along with conspicuously overlapping temporal trends, for which geomagnetic activity and solar wind pressures were identified as central sources of variance. Finally, three ecological cross-sectional studies investigated sub-provincial cardiovascular concerns across Canada at the health region level with emphasis on demography and spatial statistics. Hospitalizations due to myocardial infarction demonstrated significant relationships with socioeconomic and behavioral factors as well as significant geospatial clustering of high rates in Northern Ontario and Quebec. Aggregate rates of self-reported hypertension were similarly related to income and demographics with spatial results demonstrating high rates clustered in the North Atlantic, particularly Newfoundland. Furthermore, analyses for hypertension specifically among older adult Canadians (≥ 65 years of age) suggested that education was the strongest contributor at the health region level and there were no significant spatial relationships, in contrast to age-standardized rates. Various implications and other relevant associations are discussed throughout.