Longitudinal Strain Reflects Ventriculoarterial Coupling Rather Than Mere Contractility in Rat Models of Hemodynamic Overload–Induced Heart Failure - 30/09/20
Abstract |
Background |
Longitudinal strain (LS) is a sensitive marker of systolic function. Recent findings suggest that both myocardial contractility and loading conditions determine LS. The aim of this study was to investigate whether LS reflects the connection of cardiac contractility to afterload (termed ventriculoarterial coupling [VAC]) rather than mere contractility in rat models of hemodynamic overload–induced heart failure (HF).
Methods |
Pressure overload–induced HF was evoked by transverse aortic constriction (TAC; n = 14). Volume overload–induced HF was established by an aortocaval fistula (ACF; n = 12). Age-matched sham-operated animals served as controls for TAC (n = 14) and ACF (n = 12), respectively. Pressure-volume analysis was carried out to compute contractility (slope of end-systolic pressure-volume relationship [ESPVR]), afterload (arterial elastance [Ea]), and VAC (Ea/ESPVR). Preload was evaluated by meridional end-diastolic wall stress. Speckle-tracking echocardiography was performed to assess LS.
Results |
The TAC group presented with maintained ESPVR, increased Ea, and enhanced meridional end-diastolic wall stress. In contrast, the ACF group was characterized by reduced ESPVR, decreased Ea, and enhanced meridional end-diastolic wall stress. VAC increased in both HF groups. Furthermore, LS was also impaired in both HF models (−5.9 ± 0.6% vs −12.9 ± 0.5%, TAC vs Shamt [P < .001], and −11.7 ± 0.7% vs −13.5 ± 0.4%, ACF vs Shama[P = .048]). Statistical analysis revealed that strain parameters were determined predominantly by afterload in the TAC group and by contractility in the ACF group, while preload had a minor effect. In the entire study population, LS showed a correlation with VAC (R = 0.654, P < .001) but not with ESPVR (R = 0.058, P = .668).
Conclusions |
Under pathophysiologic conditions when both contractility and afterload become altered, LS reflects VAC rather than mere contractility.
Le texte complet de cet article est disponible en PDF.Highlights |
• | LV contractility and afterload are both major determinants of LS and LSSr. |
• | In hemodynamic overload–induced HF, contractility and afterload are both altered. |
• | Thus, under these conditions, LS and LSSr reflect VAC rather than mere contractility. |
Keywords : Longitudinal strain, Hemodynamic overload–induced heart failure, Pressure-volume analysis, Ventriculoarterial coupling, Contractility
Abbreviations : 2D, ACF, AS, AWT, Ea, EF, ESPVR, FS, HF, LS, LSSr, LV, LVEDD, LVEDV, PO, P-V, PWT, σED, STE, TAC, VAC, VO
Plan
This study was supported by the Higher Education Institutional Excellence Program of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development thematic program of Semmelweis University and the National Research, Development and Innovation Office of Hungary (NVKP-16-1-2016-0017, National Heart Program). |
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Conflicts of interest: None. |
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Drs. Kovács and Radovits contributed equally to this work. |
Vol 33 - N° 10
P. 1264 - octobre 2020 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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