{"id":"https://openalex.org/W2154473109","doi":"https://doi.org/10.1161/circheartfailure.108.785501","title":"Determinants of Ventilatory Efficiency in Heart Failure","display_name":"Determinants of Ventilatory Efficiency in Heart Failure","publication_year":2008,"publication_date":"2008-11-01","ids":{"openalex":"https://openalex.org/W2154473109","doi":"https://doi.org/10.1161/circheartfailure.108.785501","mag":"2154473109","pmid":"https://pubmed.ncbi.nlm.nih.gov/19808296","pmcid":"https://www.ncbi.nlm.nih.gov/pmc/articles/2806812"},"language":"en","primary_location":{"id":"doi:10.1161/circheartfailure.108.785501","doi":"https://doi.org/10.1161/circheartfailure.108.785501","is_oa":false,"landing_page_url":"https://doi.org/10.1161/circheartfailure.108.785501","pdf_url":null,"source":{"id":"https://openalex.org/S8311976","display_name":"Circulation Heart Failure","issn_l":"1941-3289","issn":["1941-3289","1941-3297"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-b","doyens","jufo-2","ki-jl-2","medline","norway-1","poland-140","russia-white-list-1"],"host_organization":"https://openalex.org/P4310315671","host_organization_name":"Lippincott Williams & Wilkins","host_organization_lineage":["https://openalex.org/P4310315671","https://openalex.org/P4310318547"],"host_organization_lineage_names":["Lippincott Williams & Wilkins","Wolters Kluwer"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Circulation: Heart Failure","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["crossref","pubmed"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/2806812","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5028473973","display_name":"Gregory D. Lewis","orcid":"https://orcid.org/0000-0001-8108-8240","observed_orcids":["https://orcid.org/0000-0001-8108-8240","https://orcid.org/0000-0002-3673-0182"]},"institutions":[{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]},{"id":"https://openalex.org/I4210087915","display_name":"Massachusetts General Hospital","ror":"https://ror.org/002pd6e78","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I4210087915","https://openalex.org/I48633490"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Gregory D. Lewis","raw_affiliation_strings":["From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","Gregory D. Lewis From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]},{"raw_affiliation_string":"Gregory D. Lewis From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5013418419","display_name":"Ravi V. Shah","orcid":"https://orcid.org/0000-0002-4471-7156","observed_orcids":["https://orcid.org/0000-0002-4471-7156"]},"institutions":[{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]},{"id":"https://openalex.org/I4210087915","display_name":"Massachusetts General Hospital","ror":"https://ror.org/002pd6e78","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I4210087915","https://openalex.org/I48633490"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Ravi V. Shah","raw_affiliation_strings":["From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","Ravi V. Shah From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]},{"raw_affiliation_string":"Ravi V. Shah From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5076940031","display_name":"Paul P. Pappagianopolas","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]},{"id":"https://openalex.org/I4210087915","display_name":"Massachusetts General Hospital","ror":"https://ror.org/002pd6e78","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I4210087915","https://openalex.org/I48633490"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Paul P. Pappagianopolas","raw_affiliation_strings":["From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","Paul P. Pappagianopolas From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]},{"raw_affiliation_string":"Paul P. Pappagianopolas From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5090845445","display_name":"David M. Systrom","orcid":"https://orcid.org/0000-0002-9610-6330","observed_orcids":["https://orcid.org/0000-0002-9610-6330"]},"institutions":[{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]},{"id":"https://openalex.org/I4210087915","display_name":"Massachusetts General Hospital","ror":"https://ror.org/002pd6e78","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I4210087915","https://openalex.org/I48633490"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"David M. Systrom","raw_affiliation_strings":["From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","David M. Systrom From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]},{"raw_affiliation_string":"David M. Systrom From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5111431724","display_name":"Marc J. Semigran","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I136199984","display_name":"Harvard University","ror":"https://ror.org/03vek6s52","country_code":"US","type":"education","lineage":["https://openalex.org/I136199984"]},{"id":"https://openalex.org/I4210087915","display_name":"Massachusetts General Hospital","ror":"https://ror.org/002pd6e78","country_code":"US","type":"healthcare","lineage":["https://openalex.org/I4210087915","https://openalex.org/I48633490"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Marc J. Semigran","raw_affiliation_strings":["From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","Marc J. Semigran From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]},{"raw_affiliation_string":"Marc J. Semigran From the Cardiology Division (G.D.L., M.J.S.), Department of Medicine (R.V.S.), and Pulmonary and Critical Care Unit (P.P.P., D.M.S.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass","institution_ids":["https://openalex.org/I136199984","https://openalex.org/I4210087915"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":6.9048,"has_fulltext":false,"cited_by_count":166,"citation_normalized_percentile":{"value":0.96955377,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":93,"max":100},"biblio":{"volume":"1","issue":"4","first_page":"227","last_page":"233"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10728","display_name":"Pulmonary Hypertension Research and Treatments","score":0.6420999765396118,"subfield":{"id":"https://openalex.org/subfields/2740","display_name":"Pulmonary and Respiratory Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},"topics":[{"id":"https://openalex.org/T10728","display_name":"Pulmonary Hypertension Research and Treatments","score":0.6420999765396118,"subfield":{"id":"https://openalex.org/subfields/2740","display_name":"Pulmonary and Respiratory Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T11209","display_name":"Cardiovascular and exercise physiology","score":0.326200008392334,"subfield":{"id":"https://openalex.org/subfields/2737","display_name":"Physiology (medical)"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10198","display_name":"Heart Failure Treatment and Management","score":0.011300000362098217,"subfield":{"id":"https://openalex.org/subfields/2705","display_name":"Cardiology and Cardiovascular Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/ventilatory-efficiency","display_name":"ventilatory efficiency","score":0.828000009059906},{"id":"https://openalex.org/keywords/heart-failure-with-reduced-ejection-fraction","display_name":"heart failure with reduced ejection fraction","score":0.8029999732971191},{"id":"https://openalex.org/keywords/secondary-pulmonary-hypertension","display_name":"secondary pulmonary hypertension","score":0.8019999861717224},{"id":"https://openalex.org/keywords/right-ventricular-function","display_name":"right ventricular function","score":0.9359999895095825},{"id":"https://openalex.org/keywords/ve-vco2-slope","display_name":"VE/VCO2 slope","score":0.9480000138282776},{"id":"https://openalex.org/keywords/pulmonary-vascular-resistance","display_name":"pulmonary vascular resistance","score":0.878000020980835},{"id":"https://openalex.org/keywords/sildenafil","display_name":"sildenafil","score":0.8980000019073486},{"id":"https://openalex.org/keywords/pulmonary-vasodilation","display_name":"pulmonary vasodilation","score":0.8149999976158142},{"id":"https://openalex.org/keywords/exercise-hemodynamics","display_name":"exercise hemodynamics","score":0.5170000195503235},{"id":"https://openalex.org/keywords/pulmonary-capillary-wedge-pressure","display_name":"pulmonary capillary wedge pressure","score":0.8859999775886536},{"id":"https://openalex.org/keywords/right-ventricular-ejection-fraction","display_name":"right ventricular ejection fraction","score":0.7549999952316284}],"concepts":[{"id":"https://openalex.org/C164705383","wikidata":"https://www.wikidata.org/wiki/Q10379","display_name":"Cardiology","level":1,"score":0.777753472328186},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.7709651589393616},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.7633644342422485},{"id":"https://openalex.org/C78085059","wikidata":"https://www.wikidata.org/wiki/Q641303","display_name":"Ejection fraction","level":3,"score":0.7272067070007324},{"id":"https://openalex.org/C2778198053","wikidata":"https://www.wikidata.org/wiki/Q181754","display_name":"Heart failure","level":2,"score":0.6325832009315491},{"id":"https://openalex.org/C58245268","wikidata":"https://www.wikidata.org/wiki/Q456026","display_name":"Vascular resistance","level":3,"score":0.6176137328147888},{"id":"https://openalex.org/C2778535784","wikidata":"https://www.wikidata.org/wiki/Q7281300","display_name":"Radionuclide ventriculography","level":4,"score":0.5960097908973694},{"id":"https://openalex.org/C139940330","wikidata":"https://www.wikidata.org/wiki/Q596579","display_name":"Cardiac output","level":3,"score":0.5116296410560608},{"id":"https://openalex.org/C146556889","wikidata":"https://www.wikidata.org/wiki/Q1414127","display_name":"Pulmonary wedge pressure","level":3,"score":0.48877760767936707},{"id":"https://openalex.org/C2776768464","wikidata":"https://www.wikidata.org/wiki/Q191521","display_name":"Sildenafil","level":2,"score":0.4771299362182617},{"id":"https://openalex.org/C2780930700","wikidata":"https://www.wikidata.org/wiki/Q1128595","display_name":"Pulmonary hypertension","level":2,"score":0.4379589557647705},{"id":"https://openalex.org/C178853913","wikidata":"https://www.wikidata.org/wiki/Q1642137","display_name":"Hemodynamics","level":2,"score":0.42996761202812195},{"id":"https://openalex.org/C79959777","wikidata":"https://www.wikidata.org/wiki/Q754333","display_name":"Respiratory minute volume","level":3,"score":0.4126274585723877},{"id":"https://openalex.org/C534529494","wikidata":"https://www.wikidata.org/wiki/Q7891","display_name":"Respiratory system","level":2,"score":0.20521420240402222}],"mesh":[{"descriptor_ui":"D000068677","descriptor_name":"Sildenafil Citrate","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000368","descriptor_name":"Aged","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D002245","descriptor_name":"Carbon Dioxide","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D004311","descriptor_name":"Double-Blind Method","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005080","descriptor_name":"Exercise Test","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006333","descriptor_name":"Heart Failure","qualifier_ui":"Q000150","qualifier_name":"complications","is_major_topic":false},{"descriptor_ui":"D006333","descriptor_name":"Heart Failure","qualifier_ui":"Q000175","qualifier_name":"diagnosis","is_major_topic":false},{"descriptor_ui":"D006333","descriptor_name":"Heart Failure","qualifier_ui":"Q000503","qualifier_name":"physiopathology","is_major_topic":true},{"descriptor_ui":"D006439","descriptor_name":"Hemodynamics","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006976","descriptor_name":"Hypertension, Pulmonary","qualifier_ui":"Q000175","qualifier_name":"diagnosis","is_major_topic":false},{"descriptor_ui":"D006976","descriptor_name":"Hypertension, Pulmonary","qualifier_ui":"Q000188","qualifier_name":"drug therapy","is_major_topic":false},{"descriptor_ui":"D006976","descriptor_name":"Hypertension, Pulmonary","qualifier_ui":"Q000209","qualifier_name":"etiology","is_major_topic":false},{"descriptor_ui":"D006976","descriptor_name":"Hypertension, Pulmonary","qualifier_ui":"Q000503","qualifier_name":"physiopathology","is_major_topic":true},{"descriptor_ui":"D008297","descriptor_name":"Male","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008875","descriptor_name":"Middle Aged","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D009129","descriptor_name":"Muscle Tonus","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D009131","descriptor_name":"Muscle, Smooth, Vascular","qualifier_ui":"Q000503","qualifier_name":"physiopathology","is_major_topic":true},{"descriptor_ui":"D010879","descriptor_name":"Piperazines","qualifier_ui":"Q000627","qualifier_name":"therapeutic use","is_major_topic":false},{"descriptor_ui":"D011652","descriptor_name":"Pulmonary Circulation","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D011687","descriptor_name":"Purines","qualifier_ui":"Q000627","qualifier_name":"therapeutic use","is_major_topic":false},{"descriptor_ui":"D012119","descriptor_name":"Respiration","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D013450","descriptor_name":"Sulfones","qualifier_ui":"Q000627","qualifier_name":"therapeutic use","is_major_topic":false},{"descriptor_ui":"D014655","descriptor_name":"Vascular Resistance","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D014665","descriptor_name":"Vasodilator Agents","qualifier_ui":"Q000627","qualifier_name":"therapeutic use","is_major_topic":false},{"descriptor_ui":"D015331","descriptor_name":"Cohort Studies","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015646","descriptor_name":"Ventriculography, First-Pass","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016278","descriptor_name":"Ventricular Function, Right","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true}],"locations_count":4,"locations":[{"id":"doi:10.1161/circheartfailure.108.785501","doi":"https://doi.org/10.1161/circheartfailure.108.785501","is_oa":false,"landing_page_url":"https://doi.org/10.1161/circheartfailure.108.785501","pdf_url":null,"source":{"id":"https://openalex.org/S8311976","display_name":"Circulation Heart Failure","issn_l":"1941-3289","issn":["1941-3289","1941-3297"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-b","doyens","jufo-2","ki-jl-2","medline","norway-1","poland-140","russia-white-list-1"],"host_organization":"https://openalex.org/P4310315671","host_organization_name":"Lippincott Williams & Wilkins","host_organization_lineage":["https://openalex.org/P4310315671","https://openalex.org/P4310318547"],"host_organization_lineage_names":["Lippincott Williams & Wilkins","Wolters Kluwer"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Circulation: Heart Failure","raw_type":"journal-article"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.553.440","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.553.440","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"http://circheartfailure.ahajournals.org/content/1/4/227.full.pdf","raw_type":"text"},{"id":"pmid:19808296","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/19808296","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Circulation. Heart failure","raw_type":"Journal Article"},{"id":"pmh:oai:pubmedcentral.nih.gov:2806812","doi":null,"is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/2806812","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":"Circ Heart Fail","raw_type":"Text"}],"best_oa_location":{"id":"pmh:oai:pubmedcentral.nih.gov:2806812","doi":null,"is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/2806812","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":"Circ Heart Fail","raw_type":"Text"},"sustainable_development_goals":[{"display_name":"Good health and well-being","score":0.9763000011444092,"id":"https://metadata.un.org/sdg/3"}],"study_designs":[],"awards":[{"id":"https://openalex.org/G6482853390","display_name":"RIGHT VENTRICULAR DYSFUNCTION  AND TREATMENT","funder_award_id":"K24HL004021","funder_id":"https://openalex.org/F4320337338","funder_display_name":"National Heart, Lung, and Blood Institute"},{"id":"https://openalex.org/G7800297562","display_name":"Metabolic Profiling of Acute Myocardial Injury in Humans","funder_award_id":"K23HL091106","funder_id":"https://openalex.org/F4320337338","funder_display_name":"National Heart, Lung, and Blood Institute"}],"funders":[{"id":"https://openalex.org/F4320337338","display_name":"National Heart, Lung, and Blood Institute","ror":"https://ror.org/012pb6c26"}],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":32,"referenced_works":["https://openalex.org/W1567859570","https://openalex.org/W1965619184","https://openalex.org/W1975062807","https://openalex.org/W1977354362","https://openalex.org/W1985936920","https://openalex.org/W2009740367","https://openalex.org/W2016709367","https://openalex.org/W2026839530","https://openalex.org/W2028536331","https://openalex.org/W2033852098","https://openalex.org/W2035496727","https://openalex.org/W2040767893","https://openalex.org/W2045710135","https://openalex.org/W2053775321","https://openalex.org/W2053911569","https://openalex.org/W2057558364","https://openalex.org/W2062140554","https://openalex.org/W2069442524","https://openalex.org/W2092761402","https://openalex.org/W2099733156","https://openalex.org/W2099984876","https://openalex.org/W2105278937","https://openalex.org/W2107880459","https://openalex.org/W2121376498","https://openalex.org/W2122188617","https://openalex.org/W2132948786","https://openalex.org/W2138162621","https://openalex.org/W2147200652","https://openalex.org/W2157368160","https://openalex.org/W2160368886","https://openalex.org/W2163859066","https://openalex.org/W2402014769"],"related_works":["https://openalex.org/W3186125597","https://openalex.org/W2034716156","https://openalex.org/W2013653398","https://openalex.org/W3021617015","https://openalex.org/W2236629120","https://openalex.org/W4381598409","https://openalex.org/W2438883243","https://openalex.org/W1602776433","https://openalex.org/W3022192186","https://openalex.org/W1884659472"],"abstract_inverted_index":{"BACKGROUND:":[0],"Ventilatory":[1],"efficiency,":[2],"right":[3],"ventricular":[4,23,92],"(RV)":[5],"function,":[6],"and":[7,56,70,112,117,138,144,147,157,181,200,202,208,220,232],"secondary":[8,67,221],"pulmonary":[9,68,127,140,149,195,222,233],"hypertension":[10,69],"are":[11],"each":[12],"prognostic":[13],"indicators":[14],"in":[15,73,187,193],"patients":[16,82,215],"with":[17,83,108,123,179,184,191,216],"heart":[18,74,85,218],"failure":[19,86,219],"due":[20],"to":[21,136,161,229],"left":[22,91],"systolic":[24,84,217],"dysfunction,":[25],"but":[26],"the":[27,170],"relationships":[28],"among":[29],"these":[30],"variables":[31],"have":[32],"not":[33],"been":[34],"comprehensively":[35],"investigated.":[36],"In":[37,214],"this":[38],"study,":[39],"we":[40],"hypothesized":[41],"that":[42],"inefficient":[43],"ventilation":[44,55],"during":[45,236],"exercise,":[46],"as":[47],"defined":[48],"by":[49],"an":[50],"abnormally":[51],"steep":[52],"relationship":[53],"between":[54],"carbon":[57],"dioxide":[58],"output":[59],"(Ve/Vco(2)":[60],"slope),":[61],"may":[62],"be":[63],"a":[64,125],"marker":[65],"of":[66,81,121],"RV":[71,164,204,230],"dysfunction":[72],"failure.":[75],"METHODS":[76],"AND":[77],"RESULTS:":[78],"A":[79],"cohort":[80],"(mean+/-SD":[87],"age,":[88],"58+/-13":[89],"years;":[90],"ejection":[93,165,205],"fraction,":[94],"0.27+/-0.05;":[95],"peak":[96,162],"oxygen":[97],"uptake,":[98],"11.2+/-3.2":[99],"mL":[100],"kg(-1)":[101],"min(-1))":[102],"underwent":[103],"incremental":[104],"cardiopulmonary":[105],"exercise":[106,139,163,194,203],"testing":[107],"simultaneous":[109],"hemodynamic":[110],"monitoring":[111],"first-pass":[113],"radionuclide":[114],"ventriculography":[115],"before":[116],"after":[118],"12":[119],"weeks":[120],"treatment":[122],"sildenafil,":[124],"selective":[126],"vasodilator,":[128],"or":[129],"placebo.":[130,185],"Ve/Vco(2)":[131,174,188],"slope":[132,175,189],"was":[133,182],"positively":[134],"related":[135,160,228],"rest":[137,148,201],"vascular":[141,196,234],"resistance":[142,197],"(R=0.39":[143],"R=0.60,":[145],"respectively)":[146],"capillary":[150],"wedge":[151],"pressure":[152],"(R=0.49,":[153],"P<0.005":[154],"for":[155],"all)":[156],"weakly":[158],"indirectly":[159],"fraction":[166,206],"(R=-0.29,":[167],"P=0.03).":[168],"Over":[169],"12-week":[171],"study":[172],"period,":[173],"fell":[176],"8+/-3%":[177],"(P=0.02)":[178],"sildenafil":[180],"unchanged":[183],"Changes":[186],"correlated":[190],"changes":[192],"(R=0.69,":[198],"P<0.001)":[199],"(R=-0.58":[207],"-0.40,":[209],"respectively,":[210],"both":[211],"P<0.05).":[212],"CONCLUSIONS:":[213],"hypertension,":[223],"ventilatory":[224],"efficiency":[225],"is":[226],"closely":[227],"function":[231],"tone":[235],"exercise.":[237]},"counts_by_year":[{"year":2026,"cited_by_count":3},{"year":2025,"cited_by_count":18},{"year":2024,"cited_by_count":6},{"year":2023,"cited_by_count":2},{"year":2022,"cited_by_count":9},{"year":2021,"cited_by_count":13},{"year":2020,"cited_by_count":13},{"year":2019,"cited_by_count":6},{"year":2018,"cited_by_count":7},{"year":2017,"cited_by_count":14},{"year":2016,"cited_by_count":12},{"year":2015,"cited_by_count":10},{"year":2014,"cited_by_count":8},{"year":2013,"cited_by_count":5},{"year":2012,"cited_by_count":16}],"updated_date":"2026-11-06T12:05:46.655746","created_date":"2016-06-24T00:00:00"}