Show simple item record

dc.contributor.authorCotton, James M.
dc.contributor.authorKearney, Mark T.
dc.contributor.authorMacCarthy, Philip A.
dc.contributor.authorGrocott-Mason, Richard M.
dc.contributor.authorMcClean, Dougal R.
dc.contributor.authorHeymes, Christophe
dc.contributor.authorRichardson, Peter J.
dc.contributor.authorShah, Ajay M.
dc.date.accessioned2008-06-04T09:02:29Z
dc.date.available2008-06-04T09:02:29Z
dc.date.issued2001
dc.identifier.citationCirculation, 104(19): 2318-2323
dc.identifier.issn1524-4539
dc.identifier.pmid11696472
dc.identifier.doi10.1161/hc4401.098515
dc.identifier.urihttp://hdl.handle.net/2436/29435
dc.description.abstractBACKGROUND: Nitric oxide (NO) exerts autocrine/paracrine effects on cardiac function, including alterations of the inotropic state. In vitro studies suggest that NO modulates the myocardial force-frequency relationship. Basal left ventricular (LV) contractility is depressed and the force-frequency relationship is blunted in human heart failure, and it is speculated that an increase in NO production is involved. METHODS AND RESULTS: We compared the effects of intracoronary NO synthase inhibition with N(G)-monomethyl-L-arginine (L-NMMA; 25 micromol/min) on basal LV function and the response to incremental atrial pacing in patients with dilated cardiomyopathy (n=11; mean age, 51 years) and in control subjects with atypical chest pain and normal cardiac function (n=7; mean age, 54 years). In controls, L-NMMA significantly reduced basal LV dP/dt(max) (from 1826 to 1578 mm Hg/s; P<0.002), but had no effect on heart rate, mean aortic pressure, or right atrial pressure. Pacing-induced increases in LV dP/dt(max) were unaltered by L-NMMA. In patients with dilated cardiomyopathy, L-NMMA had no effect on baseline LV dP/dt(max) (from 1313 to 1337 mm Hg/s; P=NS). The blunted pacing-induced rise in LV dP/dt(max) in these patients was unaltered by L-NMMA. CONCLUSION: Endogenous NO has a small baseline positive inotropic effect in the normal human heart, which is lost in heart failure patients. NO does not significantly influence the force-frequency relationship in either the normal or failing human heart in vivo. Because this study was performed in patients with moderate heart failure, whether the findings apply to subjects with more severe heart failure requires further investigation.
dc.language.isoen
dc.publisherAmerican Heart Association Inc
dc.relation.urlhttp://circ.ahajournals.org/cgi/content/full/104/19/2318
dc.subjectContractility
dc.subjectHeart failure
dc.subjectMyocardial contraction
dc.subjectNitric oxide
dc.subjectNitric oxide synthase
dc.subject.meshAdult
dc.subject.meshAged
dc.subject.meshCardiac Pacing, Artificial
dc.subject.meshCardiomyopathy, Dilated
dc.subject.meshEnzyme Inhibitors
dc.subject.meshFemale
dc.subject.meshHeart
dc.subject.meshHeart Atria
dc.subject.meshHeart Catheterization
dc.subject.meshHemodynamics
dc.subject.meshHumans
dc.subject.meshMale
dc.subject.meshMiddle Aged
dc.subject.meshMyocardial Contraction
dc.subject.meshMyocardium
dc.subject.meshNitric Oxide
dc.subject.meshNitric Oxide Synthase
dc.subject.meshVentricular Function, Left
dc.subject.meshomega-N-Methylarginine
dc.titleEffects of nitric oxide synthase inhibition on Basal function and the force-frequency relationship in the normal and failing human heart in vivo.
dc.typeJournal article
dc.identifier.journalCirculation
html.description.abstractBACKGROUND: Nitric oxide (NO) exerts autocrine/paracrine effects on cardiac function, including alterations of the inotropic state. In vitro studies suggest that NO modulates the myocardial force-frequency relationship. Basal left ventricular (LV) contractility is depressed and the force-frequency relationship is blunted in human heart failure, and it is speculated that an increase in NO production is involved. METHODS AND RESULTS: We compared the effects of intracoronary NO synthase inhibition with N(G)-monomethyl-L-arginine (L-NMMA; 25 micromol/min) on basal LV function and the response to incremental atrial pacing in patients with dilated cardiomyopathy (n=11; mean age, 51 years) and in control subjects with atypical chest pain and normal cardiac function (n=7; mean age, 54 years). In controls, L-NMMA significantly reduced basal LV dP/dt(max) (from 1826 to 1578 mm Hg/s; P<0.002), but had no effect on heart rate, mean aortic pressure, or right atrial pressure. Pacing-induced increases in LV dP/dt(max) were unaltered by L-NMMA. In patients with dilated cardiomyopathy, L-NMMA had no effect on baseline LV dP/dt(max) (from 1313 to 1337 mm Hg/s; P=NS). The blunted pacing-induced rise in LV dP/dt(max) in these patients was unaltered by L-NMMA. CONCLUSION: Endogenous NO has a small baseline positive inotropic effect in the normal human heart, which is lost in heart failure patients. NO does not significantly influence the force-frequency relationship in either the normal or failing human heart in vivo. Because this study was performed in patients with moderate heart failure, whether the findings apply to subjects with more severe heart failure requires further investigation.


This item appears in the following Collection(s)

Show simple item record