Research
Interests
Dr. Lapu-Bula has had a long-standing interest in the clinical
applications of echo-Doppler techniques to the evaluation
and risk stratification of patients with left ventricular
dysfunction and chronic heart failure. As lead investigator
in the NASA human cardiovascular studies at Morehouse School
of Medicine, he has been working on the implementation of
ultrasound protocols for use in human SMLSRC/NSBRI research
on the effects of acute (12 h) and chronic (over 2 weeks)
bed rest deconditioning on the cardiovascular system. The
purpose is to evaluate the relative contribution of cardiac
compliance and peripheral vasculature to orthostatic intolerance
following exposure to long-term bed rest and to provide potential
countermeasures. This work has been critical from the view
point of NASA cardiovascular research, as it provides rapid
non-invasive means to monitor cardiac volumetric and structural
changes in humans during simulated microgravity, where other
conventional imaging modalities could not efficiently be
used. This research has also provided much needed data on
the variability of cardiac mass and volumes to blood pressure
changes under conditions of bed rest, with salt manipulations
as countermeasures. Using this human model of blood pressure
sensitivity to salt (salt sensitivity), subsequent experiments
are currently being conducted to explore further the role
of nitric oxide in the systemic vascular adaptation to changes
in sodium intake that will help bridge the gap between animal
models and human subjects in our understanding of post-flight
and bed rest-induced orthostasis.
Relevant
Publications
Lapu-Bula, R ., Quarshie, A., Lyn, D., Oduwole, A., Pack, C., Morgan, J., Onwuanyi, A., Igho-Pemu, P., Li, R., Ofili, E. The 894T allele of the endothelial nitric oxide synthase gene is related to left ventricular mass in African Americans with high-normal blood pressure. Journal of National Medical Association 2005; 97:197-205.
Li, R., Lyn, D., Lapu-Bula, R., Oduwole, A., Igho-Pemu, P., Lankford, B., Morgan, J., Nkemdechi, S., Liu, G., Pack, C., Silvestrov, N., von Deutsch, D.A., Song, Q., Abukhalaf, I.K., Ofili, E. Relation of endothelial nitric oxide synthase gene to plasma nitric oxide level, endothelial function, and blood pressure in African Americans. American Journal of Hypertension 2004; 17:560-567.
Lapu-Bula, R., Robert, A., Van Craehnest, D., D’Hondt, A-M., Gerber, B.L., Pasquet, A., Melin, J.A., De Kock, M., Vonoverschelde, J.L. Contribution of exercise-induced mitral regurgitation to exercise stroke volume and exercise capacity in patients with left ventricular systolic dysfunction. Circulation 2002; 106:1342-1348.
Lapu-Bula, R., Robert, A., De Kock, M., D’Hondt, A-M., Detry, J.M., Melin, J.A., Vanoverschelde, J.L. Relation of exercise capacity to left ventricular systolic function and diastolic filling in ischemic and idiopathic dilated cardiomyopathy. American Journal of Cardiology 1999; 83:728-734.
Lapu-Bula, R., Robert, A., De Kock, M., D’Hondt, A-M., Detry, J.M., Melin, J.A., Vanoverschelde, J.L. Risk stratification in patients with dilated cardiomyopathy: Contribution of Doppler-derived left ventricular diastolic filling. American Journal of Cardiology 1998; 82:779-785.
[Selected article highlighted for its clinical contribution in the Journal Watch Cardiology 1998 Dec; 4(12):102 ].
Keywords Orthostatic intolerance, Bed rest, Salt-sensitivity, Cardiac hemodynamic and structure
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