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@article{vermeulen_influence_2018,
 abstract = {It remains unclear if the human coronary vasculature is inherently sensitive to changes in arterial PO2and PCO2or if coronary vascular responses are the result of concomitant increases in myocardial O2consumption/demand (MVO2). We hypothesized that the coronary vascular response to PO2and PCO2would be attenuated in healthy men when MVO2was attenuated with β1-adrenergic receptor blockade. Healthy men (n=11; age: 25 plus minus 1 years) received intravenous esmolol (β1-adrenergic receptor antagonist) or volume-matched saline in a double-blind, randomized, crossover study, and were exposed to poikilocapnic hypoxia, isocapnic hypoxia, and hypercapnic hypoxia. Measurements made at baseline and following 5-min of steady state at each gas manipulation included left anterior descending coronary blood velocity (LADV; Doppler echocardiography), heart rate and arterial blood pressure. LADVvalues at the end of each hypoxic condition were compared between esmolol and placebo. Rate pressure product (RPP) and left-ventricular mechanical energy (MELV) were calculated as indices of MVO2. All gas manipulations augmented RPP, MELV, and LADVbut only RPP and MELVwere attenuated (4-18%) following β1-adrenergic receptor blockade (P\textless0.05). Despite attenuated RPP and MELV responses, β1-adrenergic receptor blockade did not attenuate the mean LADV vasodilatory response when compared to placebo during poikilocapnic hypoxia (29.4plus minus2.2 vs. 27.3plus minus1.6 cm/s) and isocapnic hypoxia (29.5plus minus1.5 vs. 30.3plus minus2.2 cm/s). Hypercapnic hypoxia elicited a feed-forward coronary dilation that was blocked by β1-adrenergic receptor blockade. These results indicate a direct influence of arterial PO2on coronary vascular regulation that is independent of MVO2.},
 author = {Vermeulen, <NAME> Boulet, <NAME> and Stembridge, <NAME> Williams, <NAME> and Anholm, <NAME> and Subedi, Prajan and Gasho, <NAME>, Ainslie and Feigl, <NAME> and Foster, <NAME>},
 doi = {10.1152/ajpheart.00689.2017},
 file = {Full Text:/Volumes/Samsung_T5/Zotero/storage/RBDPV73V/Vermeulen et al. - 2018 - Influence of myocardial oxygen demand on the coron.pdf:application/pdf;Vermeulen et al. - 2018 - Influence of myocardial oxygen demand on the coron.pdf:/Volumes/Samsung_T5/Zotero/storage/YHLYIAY7/Vermeulen et al. - 2018 - Influence of myocardial oxygen demand on the coron.pdf:application/pdf},
 journal = {American Journal of Physiology. Heart and Circulatory Physiology},
 keywords = {hypercapnia, hypoxia, coronary blood flow, myocardial oxygen demand, β1-adrenergic blockade},
 language = {English},
 month = {March},
 pmid = {29600897},
 title = {Influence of myocardial oxygen demand on the coronary vascular response to arterial blood gas changes in humans.},
 url = {http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=29600897&retmode=ref&cmd=prlinks},
 year = {2018}
}

