Right Ventricular Contractile Reserve and Pulmonary Circulation Uncoupling During Exercise Challenge in Heart Failure: Pathophysiology and Clinical Phenotypes

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• 作者：Marco Guazzi ; MD ; PhD^a ; ^{marco.guazzi@unimi.it" class="auth_mail" title="E-mail the corresponding author} ; Simona Villani ; PhD^b ; Greta Generati ; MD^a ; Ottavia Eleonora Ferraro ; PhD^b ; Marta Pellegrino ; MD^a ; Eleonora Alfonzetti ; RN^a ; Valentina Labate ; MD^a ; Maddalena Gaeta ; PhD^b ; Tadafumi Sugimoto ; MD^a ; Francesco Bandera ; MD^a
• 关键词：exercise ; heart failure ; pulmonary circulation ; right ventricular function
• 刊名：JACC: Heart Failure
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：4
• 期：8
• 页码：625-635
• 全文大小：1093 K

文摘

Right ventricular (RV) exercise contractile reserve (RVECR), its phenotypes, and its functional correlates are among the unresolved issues with regard to the role of the right ventricle in heart failure (HF) syndrome, and understanding these issues constitutes the objective of this study.

Background

Although the role of the right ventricle in HF syndrome might be fundamental, the pathophysiology of the failing right ventricle has not been extensively investigated.

Methods

Ninety-seven patients with HF (mean age 64 years, 70% men, mean left ventricular ejection fraction 33 ± 10%) underwent maximal exercise stress echocardiographic and cardiopulmonary exercise testing. RVECR and RV–to–pulmonary circulation (PC) coupling were assessed using the length-force relationship (tricuspid annular plane systolic excursion [TAPSE] vs. pulmonary artery systolic pressure) and the slope of mean pulmonary artery pressure versus cardiac output. On the basis of TAPSE, patients were categorized into 3 groups: those with TAPSE at rest ≥16 mm (group A, n = 60) and those with TAPSE at rest <16 mm, who were divided according to median TAPSE at peak exercise (15.5 mm) into 2 subgroups (group B, ≥15.5 mm, n = 19; group C, <15.5 mm, n = 18).

Results

Although they had similar left ventricular ejection fractions and rest RV impairment, compared with patients in group C, those in group B showed some degree of RVECR (upward shift of the length-force relationship), better RV-to-PC coupling (lower mean pulmonary artery pressure vs. cardiac output slope), and greater ventilatory efficiency (lower slope of minute ventilation to carbon dioxide output). Rest mitral regurgitation and net changes in pulmonary artery systolic pressure were the variables retained in the best regression model as correlates of RVECR.

Conclusions

In patients with HF, RVECR unmasks different phenotypes. Impaired RV function at rest might not invariably lead to unfavorable RVECR and exercise RV-to-PC coupling. Testing these variables appears useful even in more advanced stages of HF to define various clinical conditions and, most likely, to define different levels of risk.