Abstract 14952: Hemodynamic Comparison of Left Ventricular Function in Pressure Overload- versus Volume Overload-Induced Heart Failure Models by Invasive Pressure-Volume Analysis

Introduction: Both sustained left ventricular (LV) pressure overload (PO) and volume overload (VO) induces LV remodeling and eventually development of heart failure (HF). Using rat models, the present study aimed to provide a detailed comparison of distinct aspects of LV function in PO- and VO-induced HF. Methods: PO and VO was induced by transverse aortic constriction (TAC, n=12) and aortocaval shunt (AV-shunt, n=12) creation respectively. Controls underwent corresponding sham operations (n=11). LV remodeling was characterized by echocardiography, histology, qRT PCR, and western blot. LV function was assessed by invasive pressure-volume (P-V) analysis. Results: Both sustained PO and VO resulted in the development of HF, as evidenced by increased LV BNP mRNA expression, pulmonary edema, and characteristic symptoms. While the extent of LV hypertrophy was comparable between the HF models, PO induced concentric while VO evoked eccentric LV remodeling. P-V analysis revealed impaired systolic function in both HF models. Accordingly, decreased ejection fraction and impaired ventriculo-arterial coupling (calculated as the ratio of arterial elastance/LV contractility [VAC]: 0.38±0.05 vs. 1.30±0.13, ShamTAC vs. TAC and 0.52±0.08 vs. 1.17±0.13, ShamAV-Shunt vs. AV-shunt; p<0.05) was detected in both HF models. However, in case of VO the severely reduced LV contractility (slope of end-systolic P-V relationship: 1.79±0.19 vs. 0.52±0.06, ShamAV-Shunt vs. AV-shunt, p<0.05 and 2.14±0.28 vs. 2.03±0.21, ShamTAC vs. TAC p>0.05) underpinned the contractility-afterload mismatch, while in case of PO the increased afterload (arterial elastance: 0.77±0.07 vs. 2.64±0.28, ShamTAC vs. TAC and 0.80±0.07 vs. 0.54±0.05, ShamAV-Shunt vs. AV-shunt; p<0.05) was the main determinant. Furthermore, prolongation of active relaxation occurred to a greater extent in case of PO. In addition, increased myocardial stiffness was only observed in PO-induced HF. Conclusion: Systolic function was reduced in both HF models. However, different factors underpinned the impaired VAC in case of VO (reduced LV contractility) and PO (increased arterial elastance). Furthermore, although diastolic function deteriorated in both models, it occurred to a greater extent in case of PO.

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Characterizing preclinical models of ischemic heart failure: differences between LAD and LCx infarctions

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00797.2013 ◽

2014 ◽

Vol 307 (10) ◽

pp. H1478-H1486 ◽

Cited By ~ 24

Author(s):

Kiyotake Ishikawa ◽

Jaume Aguero ◽

Lisa Tilemann ◽

Dennis Ladage ◽

Nadjib Hammoudi ◽

...

Keyword(s):

Heart Failure ◽

Systolic Function ◽

Left Ventricular ◽

Ischemic Heart ◽

Volume Index ◽

Lv Function ◽

Large Animal ◽

Ischemic Heart Failure ◽

Left Circumflex Artery ◽

Lv Remodeling

Large animal studies are an important step toward clinical translation of novel therapeutic approaches. We aimed to establish an ischemic heart failure (HF) model with a larger myocardial infarction (MI) relative to previous studies, and characterize the functional and structural features of this model. An MI was induced by occluding the proximal left anterior descending artery (LAD; n = 15) or the proximal left circumflex artery (LCx; n = 6) in Yorkshire pigs. Three pigs with sham procedures were also included. All pigs underwent hemodynamic and echocardiographic assessments before MI, at 1 mo, and 3 mo after MI. Analyses of left ventricular (LV) myocardial mechanics by means of strains and torsion were performed using speckle-tracking echocardiography and compared between the groups. The proximal LAD MI approach induced larger infarct sizes (14.2 ± 3.2% vs. 10.6 ± 1.9%, P = 0.03), depressed systolic function (LV ejection fraction; 39.8 ± 7.5% vs. 54.1 ± 4.6%, P < 0.001), and more LV remodeling (end-systolic volume index; 82 ± 25 ml/m2 vs. 51 ± 18 ml/m2, P = 0.02, LAD vs. LCx, respectively) compared with the LCx MI approach without compromising the survival rate. At the papillary muscle level, echocardiographic strain analysis revealed no differences in radial and circumferential strain between LAD and LCx MIs. However, in contrast with the LCx MI, the LAD MI resulted in significantly decreased longitudinal strain. The proximal LAD MI model induces more LV remodeling and depressed LV function relative to the LCx MI model. Location of MI significantly impacts the severity of HF, thus careful consideration is required when choosing an MI model for preclinical HF studies.

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Contractile protein phosphorylation predicts human heart disease phenotypes

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00957.2012 ◽

2013 ◽

Vol 304 (12) ◽

pp. H1644-H1650 ◽

Cited By ~ 12

Author(s):

Lori A. Walker ◽

David A. Fullerton ◽

Peter M. Buttrick

Keyword(s):

Heart Failure ◽

Heart Disease ◽

Protein Phosphorylation ◽

Protein Phosphatase ◽

Human Heart ◽

Troponin I ◽

Systolic Function ◽

Left Ventricular ◽

Control Group ◽

Lv Function

Human heart failure has been associated with a low level of thin-filament protein phosphorylation and an increase in calcium sensitivity of contraction relative to both “control” human heart tissue and tissue from small animal models. However, diverse strategies of human tissue procurement and the reliance on tissue obtained from subjects with end-stage heart failure suggest this may be an incomplete characterization. Therefore, we evaluated cardiac left ventricular (LV) biopsy samples from patients with aortic stenosis undergoing valve replacement who presented either with LV hypertrophy and preserved systolic function (Hyp) or with LV dilation and reduced ejection fraction (Dil). In Hyp, total troponin I (TnI) phosphorylation was markedly increased and myosin light chain 2 (MLC2) phosphorylation was unchanged relative to a control group of patients with normal LV function. Conversely, in Dil, total TnI phosphorylation was significantly reduced compared with control subjects and MLC2 phosphorylation was increased. Site-specific analysis of TnI phosphorylation revealed phenotype-specific differences such that Hyp samples demonstrated significant increases in phosphorylation at serine 22/23 and Dil samples had significant decreases at serine 43. The ratio of phosphorylation at the two sites was biased toward serine 22/23 in Hyp and toward serine 43/45 in Dil. Western blot analysis showed that protein phosphatase-1 was reduced in Hyp and protein phosphatase-2 was reduced in Dil. These data suggest that posttranslational modifications of sarcomeric proteins, both singly and in combination, are stage specific. Defining these changes in progressive heart disease may provide important diagnostic and treatment information.

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Abstract 3295: De-induction of the Maladaptive Fetal Gene Program During Chronic Monotherapy with Metoprolol Succinate is Retained Following Withdrawal of Therapy in Dogs with Chronic Heart Failure

Circulation ◽

10.1161/circ.116.suppl_16.ii_742-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Rasha Bazari ◽

Sharad Rastogi ◽

Valerio Zaca ◽

Sidney Goldstein ◽

Hani N Sabbah

Keyword(s):

Heart Failure ◽

Chronic Heart Failure ◽

Mrna Expression ◽

Natriuretic Peptide ◽

Left Ventricular ◽

Lv Function ◽

Metoprolol Succinate ◽

Myosin Heavy Chain Isoform ◽

Chronic Therapy ◽

Lv Remodeling

Background: Chronic therapy with extended release metoprolol succinate (MET), a selective β1 adrenergic receptor blocker, improves left ventricular (LV) function and attenuates global LV remodeling in dogs with chronic heart failure (HF). We previously showed that chronic therapy with β-blockade results in de-induction of the fetal gene program (FGP) in LV myocardium of dogs with HF. In this study, we tested the hypothesis that in dogs with HF withdrawal of chronic MET does not lead to re-induction of FGP. Methods: Studies were performed in 17 intracoronary microembolization-induced HF dogs randomized to 3 months oral therapy with MET (100 mg, once daily, n=11) or no therapy at all (Controls, n=6). In dogs randomized to MET, 6 were sacrificed after 3 months of therapy and in the remaining 5, MET was withdrawn after 3 months of therapy and dogs were observed for 6 weeks after withdrawal of MET (MET-W) and then sacrificed. LV tissue was also obtained from 6 normal (NL) dogs for comparison. mRNA expression of the FGP genes namely, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), sarcoplasmic reticulum calcium ATPase (CAA), cardiac β-1 adren-ergic receptor (AR) and α-myosin heavy chain isoform (α-MHC) was measured using reverse transcriptase polymerase chain reaction (RT-PCR) and bands were quantified in densitometric units (du). Results: In Controls, mRNA expression of ANP and BNP increased and expression of CAA, β 1-AR and α-MHC decreased. Treatment with MET decreased expression of ANP and BNP and increased expression of CAA, β 1-AR and α-MHC. Except for α-MHC, the improvement in FGP seen during MET treatment was preserved in MET-W dogs. Conclusions: Withdrawal of MET is associated with sustained de-induction of the FGP in LV myocardium of dogs with HF. This observation supports the concept that chronic β-blockade therapy in HF confers lasting reversal of LV remodeling and molecular recovery of the failing myocardium.

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Plasma cardiotrophin-1 following acute myocardial infarction: relationship with left ventricular systolic dysfunction

Clinical Science ◽

10.1042/cs1020009 ◽

2001 ◽

Vol 102 (1) ◽

pp. 9-14 ◽

Cited By ~ 18

Author(s):

Suneel TALWAR ◽

Iain B. SQUIRE ◽

Russell J. O'BRIEN ◽

Paul F. DOWNIE ◽

Joan E. DAVIES ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Failure ◽

Acute Myocardial Infarction ◽

Left Ventricular Systolic Dysfunction ◽

Systolic Function ◽

Systolic Dysfunction ◽

Clinic Visit ◽

Left Ventricular ◽

Lv Function ◽

Ventricular Remodelling

The glycoprotein 130 (gp130) signalling pathway is important in the development of heart failure. Cardiotrophin-1 (CT-1), a cytokine acting via the gp130 pathway, is involved in the process of ventricular remodelling following acute myocardial infarction (AMI) in animals. The aims of the present study were to examine the profile of plasma CT-1 following AMI in humans, and its relationship with echocardiographic parameters of left ventricular (LV) systolic function. Serial measurements of plasma CT-1 levels were made in 60 patients at 14-48h, 49-72h, 73-120h and 121-192h following AMI and at a later clinic visit. LV function was assessed using a LV wall motion index (WMI) score on admission (WMI-1) and at the clinic visit (WMI-2). Compared with values in control subjects (29.5±3.6fmol/ml), the plasma CT-1 concentration was elevated in AMI patients at 14-48h (108.1±15.1fmol/ml), 49-72h (105.2±19.7fmol/ml), 73-120h (91.2±14.9fmol/ml) and 121-192h (118.8±22.6fmol/ml), and at the clinic visit (174.9±30.9 fmol/ml) (P < 0.0001). Levels were higher following anterior compared with inferior AMI. For patients with anterior AMI, CT-1 levels were higher at the clinic visit than at earlier times. WMI-1 correlated with CT-1 at all times prior to hospital discharge (P < 0.05). On best subsets analysis, the strongest correlate with WMI-1 was CT-1 level at 49-72h (R2 = 20%, P < 0.05). In conclusion, plasma levels of CT-1 are elevated soon after AMI in humans and rise further in the subsequent weeks in patients after anterior infarction. CT-1 measured soon after AMI is indicative of LV dysfunction, and this cytokine may have a role in the development of ventricular remodelling and heart failure after AMI.

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Effects of a myofilament calcium sensitizer on left ventricular systolic and diastolic function in rats with volume overload heart failure

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00423.2014 ◽

2014 ◽

Vol 307 (11) ◽

pp. H1605-H1617 ◽

Cited By ~ 11

Author(s):

Kristin Wilson ◽

Anuradha Guggilam ◽

T. Aaron West ◽

Xiaojin Zhang ◽

Aaron J. Trask ◽

...

Keyword(s):

Heart Failure ◽

Troponin I ◽

Regulatory Protein ◽

Volume Overload ◽

Left Ventricular ◽

Lv Function ◽

Stroke Work ◽

Sprague Dawley ◽

Diastolic Relaxation ◽

Systolic And Diastolic Function

Aortocaval fistula (ACF)-induced volume overload (VO) heart failure (HF) results in progressive left ventricular (LV) dysfunction. Hemodynamic load reversal during pre-HF (4 wk post-ACF; REV) results in rapid structural but delayed functional recovery. This study investigated myocyte and myofilament function in ACF and REV and tested the hypothesis that a myofilament Ca2+ sensitizer would improve VO-induced myofilament dysfunction in ACF and REV. Following the initial sham or ACF surgery in male Sprague-Dawley rats (200–240 g) at week 0, REV surgery and experiments were performed at weeks 4 and 8, respectively. In ACF, decreased LV function is accompanied by impaired sarcomeric shortening and force generation and decreased Ca2+ sensitivity, whereas, in REV, impaired LV function is accompanied by decreased Ca2+ sensitivity. Intravenous levosimendan (Levo) elicited the best inotropic and lusitropic responses and was selected for chronic oral studies. Subsets of ACF and REV rats were given vehicle (water) or Levo (1 mg/kg) in drinking water from weeks 4–8. Levo improved systolic (% fractional shortening, end-systolic elastance, and preload-recruitable stroke work) and diastolic (τ, dP/d tmin) function in ACF and REV. Levo improved Ca2+ sensitivity without altering the amplitude and kinetics of the intracellular Ca2+ transient. In ACF-Levo, increased cMyBP-C Ser-273 and Ser-302 and cardiac troponin I Ser-23/24 phosphorylation correlated with improved diastolic relaxation, whereas, in REV-Levo, increased cMyBP-C Ser-273 phosphorylation and increased α-to-β-myosin heavy chain correlated with improved diastolic relaxation. We concluded that Levo improves LV function, and myofilament composition and regulatory protein phosphorylation likely play a key role in improving function.

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Peripartum Cardiomyopathy Presenting with Predominant Left Ventricular Diastolic Dysfunction: Efficacy of Bromocriptine

Case Reports in Medicine ◽

10.1155/2012/476903 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Piercarlo Ballo ◽

Irene Betti ◽

Giuseppe Mangialavori ◽

Leandro Chiodi ◽

Gherardo Rapisardi ◽

...

Keyword(s):

Heart Failure ◽

Diastolic Dysfunction ◽

Diastolic Function ◽

Systolic Function ◽

Systolic Dysfunction ◽

Left Ventricular ◽

Peripartum Cardiomyopathy ◽

Lv Function ◽

Lv Diastolic Dysfunction ◽

Lv Diastolic Function

Management of patients with peripartum cardiomyopathy (PPCM) is still a major clinical problem, as only half of them or slightly more show complete recovery of left ventricular (LV) function despite conventional evidence-based treatment for heart failure. Recent observations suggested that bromocriptine might favor recovery of LV systolic function in patients with PPCM. However, no evidence exists regarding its effect on LV diastolic dysfunction, which is commonly observed in these patients. Tissue Doppler (TD) is an echocardiographic technique that provides unique information on LV diastolic performance. We report the case of a 37-year-old white woman with heart failure (NYHA class II), moderate LV systolic dysfunction (ejection fraction 35%), and severe LV diastolic dysfunction secondary to PPCM, who showed no improvement after 2 weeks of treatment with ramipril, bisoprolol, and furosemide. At 6-week followup after addition of bromocriptine, despite persistence of LV systolic dysfunction, normalization of LV diastolic function was shown by TD, together with improvement in functional status (NYHA I). At 18-month followup, the improvement in LV diastolic function was maintained, and normalization of systolic function was observed. This paper might support the clinical utility of bromocriptine in patients with PPCM by suggesting a potential benefit on LV diastolic dysfunction.

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Temporal pattern of left ventricular structural and functional remodeling following reversal of volume overload heart failure

Journal of Applied Physiology ◽

10.1152/japplphysiol.00691.2011 ◽

2011 ◽

Vol 111 (6) ◽

pp. 1778-1788 ◽

Cited By ~ 36

Author(s):

Kirk R. Hutchinson ◽

Anuradha Guggilam ◽

Mary J. Cismowski ◽

Maarten L. Galantowicz ◽

Thomas A. West ◽

...

Keyword(s):

Heart Failure ◽

Systolic Dysfunction ◽

Volume Overload ◽

Left Ventricular ◽

Lv Function ◽

Stroke Work ◽

Important Indicator ◽

Ecm Remodeling ◽

Functional Changes ◽

Custom Made

Current surgical management of volume overload-induced heart failure (HF) leads to variable recovery of left ventricular (LV) function despite a return of LV geometry. The mechanisms that prevent restoration of function are unknown but may be related to the timing of intervention and the degree of LV contractile impairment. This study determined whether reduction of aortocaval fistula (ACF)-induced LV volume overload during the compensatory stage of HF results in beneficial LV structural remodeling and restoration of pump function. Rats were subjected to ACF for 4 wk; a subset then received a load-reversal procedure by closing the shunt using a custom-made stent graft approach. Echocardiography or in vivo pressure-volume analysis was used to assess LV morphology and function in sham rats; rats subjected to 4-, 8-, or 15-wk ACF; and rats subjected to 4-wk ACF followed by 4- or 11-wk reversal. Structural and functional changes were correlated to LV collagen content, extracellular matrix (ECM) proteins, and hypertrophic markers. ACF-induced volume overload led to progressive LV chamber dilation and contractile dysfunction. Rats subjected to short-term reversal (4-wk ACF + 4-wk reversal) exhibited improved chamber dimensions (LV diastolic dimension) and LV compliance that were associated with ECM remodeling and normalization of atrial and brain natriuretic peptides. Load-independent parameters indicated LV systolic (preload recruitable stroke work, Ees) and diastolic dysfunction (tau, arterial elastance). These changes were associated with an altered α/β-myosin heavy chain ratio. However, these changes were normalized to sham levels in long-term reversal rats (4-wk ACF + 11-wk reversal). Acute hemodynamic changes following ACF reversal improve LV geometry, but LV dysfunction persists. Gradual restoration of function was related to normalization of eccentric hypertrophy, LV wall stress, and ECM remodeling. These results suggest that mild to moderate LV systolic dysfunction may be an important indicator of the ability of the myocardium to remodel following the reversal of hemodynamic overload.

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Complete dexrazoxane cardioprotection for cardiac function but incomplete female cardioprotection for cardiac structure in doxorubicin-treated osteosarcoma survivors: Hearts too small for the body.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.10519 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. 10519-10519

Author(s):

Lisa M. Kopp ◽

Mark L. Bernstein ◽

Cindy L. Schwartz ◽

David Ebb ◽

Vivian L Franco ◽

...

Keyword(s):

Heart Failure ◽

Wall Thickness ◽

Systolic Function ◽

Posterior Wall ◽

Left Ventricular ◽

The Body ◽

Lv Function ◽

Lv Systolic Function ◽

Trastuzumab Cardiotoxicity

10519 Background: Dexrazoxane is protective for lower-dose doxorubicin ( < 300 mg/m2) cardiotoxicity in childhood cancer, but the effect of dexrazoxane (DXRZ) administered with higher-dose (HD) doxorubicin (DOXO) is unknown. Methods: We evaluated patients from Children’s Oncology Group trials for localized (P9754) and metastatic (AOST0121) osteosarcoma (OS) who received HD DOXO (375-600 mg/m2) preceded by DXRZ (10:1 ratio), methotrexate, and cisplatin; some also received ifosfamide alone or ifosfamide/etoposide ± trastuzumab. Cardiotoxicity was identified by echocardiography and by serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations. Results: 81 DXRZ -treated OS patients ( age at enrollment = 13.7 years; range 3.8 - 23.7 years) had normal left ventricular (LV) systolic function as measured by LV fractional shortening and no heart failure. Female sex and longer follow-up since DOXO were associated with a significantly smaller LV dimension z-score normalized to BSA (μ = -1.20, 95%CI [-1.70, -0.70]). Similarly, in the one-third of patients treated > 81 days after minimal expected treatment (groups equally partitioned by time), significantly thinner LV posterior wall thickness for BSA (μ = -0.57, [-1.05, -0.09]) was found. Interventricular septal wall thickness (μ = -0.84, [-1.2, -0.48]) and LV mass (μ = -0.73, [-1.06, -0.40]) were significantly smaller for BSA than normal for both sexes. For females, these became significantly more abnormal with increasing length of follow-up. Females also showed progressive increases in NT-proBNP. Conclusions: DXRZ is cardioprotective for HD DOXO in terms of LV function and heart failure. Females had progressive abnormalities of LV structure, leading to smaller hearts for body size. This was associated with increasing cardiac stress, as measured by NT-proBNP. DXRZ protection was incomplete for HD DOXO effects on LV structure, resulting in higher LV stress and risk for late LV dysfunction. DXRZ should continue to be used in this population, including for females who exhibit more cardiotoxicity than males at specific cumulative DOXO doses.

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Abstract 17904: Deficiency of Yes-associated Protein Promotes Cardiac Dysfunction in Response to Pressure Overload in the Mouse Heart

Circulation ◽

10.1161/circ.132.suppl_3.17904 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Jaemin Byun ◽

Dominic P Del Re ◽

Peiyong Zhai ◽

Akihiro Shirakabe ◽

Junichi Sadoshima

Keyword(s):

Cardiac Hypertrophy ◽

Mammalian Cells ◽

Diastolic Pressure ◽

Systolic Function ◽

Pressure Overload ◽

Wall Stress ◽

Left Ventricular ◽

Lv Function ◽

Mouse Heart ◽

And Control

Yes-Associated Protein (YAP), a downstream effector of the Hippo pathway, plays an important role in regulating cell proliferation and survival in mammalian cells. We have shown that cardiac-specific loss of YAP leads to increased cardiomyocyte (CM) apoptosis and impaired hypertrophy during chronic myocardial infarction in the mouse heart. However, it remains unclear whether YAP mediates hypertrophy of individual CMs under stress conditions in vivo. We hypothesized that endogenous YAP plays an essential role in mediating hypertrophy and survival of CMs in response to pressure overload (PO). Three-month-old YAP+/fl;α-MHC-Cre (YAP-cKO) and YAP+/fl (control) mice were subjected to transverse aortic constriction (TAC). Two weeks later, YAP-cKO and control mice developed similar levels of cardiac hypertrophy (left ventricular (LV) weight/tibia length: 7.27±0.38, 6.93±0.29) compared to sham (5.08±0.14, 4.07±0.33). LV CM cross sectional area was similarly increased by TAC in YAP-cKO and control mice compared to their respective shams. Induction of fetal-type genes, such as Anf and Myh7, was also similar in YAP-cKO and control mice. YAP-cKO and control mice exhibited similar baseline LV systolic function (ejection fraction (EF): 75, 76%). YAP-cKO mice had significantly decreased LV function after TAC compared to Sham-control mice (EF: 51%, 76%, p<0.05) and TAC-control mice (75%, p<0.05). LV end diastolic pressure (LVEDP, mmHg) was significantly increased (19.3 ±3.2, 9.8±1.6, p<0.05), and LV +dP/dt (mmHg/s, 7250±588, 9500±453, p<0.01) and -dP/dt (mmHg/s, 6000±433, 7781± 314, p<0.05) were significantly decreased in YAP-cKO compared to in control mice after TAC. LV end diastolic diameter (mm) was significantly greater in YAP-cKO than in control mice after TAC (3.95±0.11, 3.35±0.15, p<0.05), whereas LV pressure was similar, suggesting that LV wall stress was elevated in YAP-cKO compared to in control mice. Since cardiac hypertrophy in YAP-cKO mice is similar to that in control mice despite elevated wall stress, the lack of YAP appears to limit the extent of cardiac hypertrophy in response to increased wall stress. These data suggest that endogenous YAP plays an important role in mediating adaptive hypertrophy and protecting the heart against PO.

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Abstract 87: Alterations to Cardiac Mechanics Do Not Preserve Normal Cardiac Function in a Novel Ossabaw Swine Model of Heart Failure with Preserved Ejection Fraction

Circulation Research ◽

10.1161/res.121.suppl_1.87 ◽

2017 ◽

Vol 121 (suppl_1) ◽

Author(s):

Jenna C Edwards ◽

Madeleine Dionne ◽

T. D Olver ◽

Jan R Ivey ◽

Pamela K Thorne ◽

...

Keyword(s):

Heart Failure ◽

Ejection Fraction ◽

Cardiac Function ◽

Strain Rate ◽

Pressure Overload ◽

Left Ventricular ◽

Volume Index ◽

Lv Function ◽

Swine Model ◽

Preserved Ejection Fraction

Introduction: Heart failure with preserved ejection fraction (HFpEF) is clinically characterized by an increased incidence in females and many comorbidities including type 2 diabetes (T2D) and obesity. Animal models accurately representing clinical HFpEF are lacking; thus, the purpose of this study was to examine left ventricular (LV) mechanics in a novel Ossabaw swine model of chronic pressure-overload (aortic-banding; AB) and T2D (Western diet; WD) using two dimensional speckle tracking echocardiography (2D-STE). We hypothesized that global LV strain would be decreased primarily in the longitudinal direction in WD-AB animals. Methods: Female Ossabaws were randomly divided into 2 groups: CON (n=5) and WD-AB (n=5). LV function and strain were measured at 1 year of age after 6 mo. of AB and 9 mo. of WD via pressure-volume relations and 2D-STE. Significance was set at P < 0.05 using t-test vs. CON. Results: In the WD-AB group, ejection fraction (EF%) and end diastolic volume were normal (>50%), and observed in parallel with increased LV weight, lung weight, and LV diastolic wall thickness (i.e. concentric hypertrophy). WD-AB group had increased HOMA-IR and body surface area, two common features in T2D. In WD-AB animals, although global longitudinal systolic strain rate and end systolic displacement were increased, stroke volume index was decreased. Early diastolic rotation rate was decreased, while global longitudinal late diastolic strain rate was increased in the WD-AB group. These changes, considered in parallel with an increased end diastolic pressure-volume relationship in WD-AB animals, are consistent with diastolic dysfunction. In contrast, longitudinal, radial, and circumferential early diastolic strain rates increased in the WD-AB group. Conclusion: Contrary to our hypothesis, LV longitudinal strain was increased during both systole and diastole, and observed in parallel with decreased early diastolic untwisting in WD-AB animals. Our results suggest alterations to LV mechanics do not preserve normal systolic and diastolic cardiac function, despite normal resting EF%, in this novel translational model of pressure-overload HF with potential relevance to human HFpEF including associated clinical comorbidities (sex, obesity, and T2D).

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