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Haddad F, Hunt SA, Rosenthal DN, Murphy DJ. Right ventricular function in cardiovascular disease, part I: Anatomy, physiology, aging, and functional assessment of the right ventricle. Circulation 2008; 117:1436-48. [PMID: 18347220 DOI: 10.1161/circulationaha.107.653576] [Citation(s) in RCA: 960] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- François Haddad
- Division of Cardiovascular Medicine, Stanford University, 770 Welch Rd, Suite 400, Palo Alto, CA 94304-5715, USA.
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Mori S, Nakatani S, Kanzaki H, Yamagata K, Take Y, Matsuura Y, Kyotani S, Nakanishi N, Kitakaze M. Patterns of the Interventricular Septal Motion Can Predict Conditions of Patients with Pulmonary Hypertension. J Am Soc Echocardiogr 2008; 21:386-93. [PMID: 17681728 DOI: 10.1016/j.echo.2007.05.037] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2007] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We sought to investigate the clinical and hemodynamic implications of interventricular septal motion in patients with pulmonary hypertension. BACKGROUND In patients with pulmonary hypertension, we have noticed two types of peculiar motions of the interventricular septum by M-mode echocardiography: marked early systolic anterior motion (type A) and marked early diastolic posterior motion (type B). METHODS We performed echocardiography on 32 patients (age 42 +/- 13 years) with pulmonary hypertension within 1 week of cardiac catheterization. Type A was found in 14 patients (group A) and type B was found in 18 patients (group B). RESULTS There was no difference between two groups in left ventricular eccentricity index at early diastole (2.4 +/- 0.6 vs 2.1 +/- 0.7) and mean pulmonary arterial pressure (54 +/- 10 vs 53 +/- 13 mm Hg). However, New York Heart Association functional class (2.7 +/- 0.4 vs 2.2 +/- 0.3) and serum levels of brain natriuretic peptide (271 +/- 155 vs 74 +/- 55 pg/mL) were significantly higher and cardiac index (1.7 +/- 0.3 vs 2.3 +/- 0.4 L/min/m(2)) was significantly lower in group A (P < .001). Simultaneous recordings of both ventricular pressures showed that right ventricular pressure was higher than left ventricular pressure during whole diastole in group A, but in group B, during only early diastole. By multiple linear regression analysis, type A motion independently predicted low cardiac index. CONCLUSIONS Interventricular septal motion could predict patients' conditions. Patients with type A motion were more morbid clinically and hemodynamically than patients with type B motion.
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Affiliation(s)
- Shumpei Mori
- Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Osaka, Japan
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Leeuwenburgh BPJ, Helbing WA, Wenink ACG, Steendijk P, de Jong R, Dreef EJ, Gittenberger-de Groot AC, Baan J, van der Laarse A. Chronic right ventricular pressure overload results in a hyperplastic rather than a hypertrophic myocardial response. J Anat 2008; 212:286-94. [PMID: 18248360 DOI: 10.1111/j.1469-7580.2008.00853.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Myocardial hyperplasia is generally considered to occur only during fetal development. However, recent evidence suggests that this type of response may also be triggered by cardiac overload after birth. In congenital heart disease, loading conditions are frequently abnormal, thereby affecting ventricular function. We hypothesized that chronic right ventricular pressure overload imposed on neonatal hearts initiates a hyperplastic response in the right ventricular myocardium. To test this, young lambs (aged 2-3 weeks) underwent adjustable pulmonary artery banding to obtain peak right ventricular pressures equal to left ventricular pressures for 8 weeks. Transmural cardiac tissue samples from the right and left ventricles of five banded and five age-matched control animals were studied. We found that chronic right ventricular pressure overload resulted in a twofold increase in right-to-left ventricle wall thickness ratio. Morphometric right ventricular myocardial tissue analysis revealed no changes in tissue composition between the two groups; nor were right ventricular myocyte dimensions, relative number of binucleated myocytes, or myocardial DNA concentration significantly different from control values. In chronic pressure overloaded right ventricular myocardium, significantly (P < 0.01) more myocyte nuclei were positive for the proliferation marker proliferating cellular nuclear antigen than in control right ventricular myocardium. Chronic right ventricular pressure overload applied in neonatal sheep hearts results in a significant increase in right ventricular free wall thickness which is primarily the result of a hyperplastic myocardial response.
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Acharya G, Räsänen J, Mäkikallio K, Erkinaro T, Kavasmaa T, Haapsamo M, Mertens L, Huhta JC. Metabolic acidosis decreases fetal myocardial isovolumic velocities in a chronic sheep model of increased placental vascular resistance. Am J Physiol Heart Circ Physiol 2008; 294:H498-504. [DOI: 10.1152/ajpheart.00492.2007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We hypothesized that acute fetal metabolic acidosis decreases fetal myocardial motion in a chronic sheep model of increased placental vascular resistance ( Rua). Eleven ewes and fetuses were instrumented at 118–122 days of gestation. After 5 days of recovery and 24 h of placental embolization to increase Rua, longitudinal myocardial velocities of the right and left ventricles and interventricular septum (IVS) were assessed at the level of the atrioventricular valve annuli via tissue Doppler imaging (TDI). Ventricular inflow (E and A waves) and outflow velocities were obtained, and cardiac outputs were calculated. All measurements were performed at baseline and during fetal acidosis caused by epidural anesthesia-induced maternal hypotension, which decreased uterine artery volume blood flow, fetal oxygenation, arterial pH, and base excess and increased lactate. Compared with baseline, the peak isovolumic myocardial contraction and relaxation velocities of the ventricles and IVS, early relaxation velocity (E′) of the ventricles, and systolic velocity of the IVS decreased during metabolic acidosis. The proportion of isovolumic contraction time of the cardiac cycle increased but the isovolumic relaxation and ejection time proportions and the TDI Tei index did not change. The E-to-E′ ratio for both ventricles was higher during metabolic acidosis than at baseline. During metabolic acidosis, right and left ventricular cardiac outputs remained unchanged compared with baseline. In sheep fetuses with increased Rua and acute metabolic acidosis, global cardiac function was preserved. However, acute metabolic acidosis impaired myocardial contractility during the isovolumic phase and relaxation during the isovolumic and early filling phases of the cardiac cycle.
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Wu DK, Hsiao SH, Lin SK, Lee CY, Yang SH, Chang SM, Chiou KR. Main Pulmonary Arterial Distensibility Different Presentation Between Chronic Pulmonary Hypertension and Acute Pulmonary Embolism. Circ J 2008; 72:1454-9. [DOI: 10.1253/circj.cj-08-0223] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Den-Ko Wu
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
| | - Shih-Hung Hsiao
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
- School of Medicine, National Yang-Ming University
| | - Shih-Kai Lin
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
| | - Chiu-Yen Lee
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
| | - Shu-Hsin Yang
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
| | - Shu-Mei Chang
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
| | - Kuan-Rau Chiou
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital
- School of Medicine, National Yang-Ming University
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Stekelenburg-de Vos S, Steendijk P, Ursem NTC, Wladimiroff JW, Poelmann RE. Systolic and diastolic ventricular function in the normal and extra-embryonic venous clipped chicken embryo of stage 24: a pressure-volume loop assessment. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 30:325-31. [PMID: 17721868 DOI: 10.1002/uog.5137] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVES Fluid mechanical forces affect cardiac development. In the chicken embryo, permanent obstruction of the right lateral vitelline vein by clipping reduces the mechanical load on the embryonic myocardium, which has been shown to induce a spectrum of outflow tract anomalies. Insight into the effects of this intervention on the mechanical function of the developing myocardium could contribute to a better understanding of the relationship between hemodynamics and cardiac morphogenesis. We aimed to explore the effects of clipping on intrinsic systolic and diastolic ventricular function at stage 24 in the chicken embryo METHODS Cardiac pressure-volume relationships enable load-independent quantification of intrinsic ventricular systolic and diastolic properties. We determined ventricular function by pressure-volume loop analysis of in-ovo stage-24 chicken embryos (n = 15) 2 days after venous obstruction at 2.5 days of incubation (stage 17, venous clipped embryos). Control embryos (n = 15) were used for comparison. RESULTS End-systolic volume was significantly higher in clipped embryos (0.36 +/- 0.02 microL vs. 0.29 +/- 0.02 microL, P = 0.002). End-systolic and end-diastolic pressure were also increased compared with control animals (2.93 +/- 0.07 mmHg vs. 2.70 +/- 0.08 mmHg, P = 0.036 and 1.15 +/- 0.06 mmHg vs. 0.82 +/- 0.05 mmHg, P < 0.001, respectively). No significant differences were demonstrated for other baseline hemodynamic parameters. Analysis of pressure-volume relationships showed a significantly lower end-systolic elastance in the clipped embryos (slope of end-systolic pressure-volume relationship: 2.91 +/- 0.24 mmHg/microL vs. 7.53 +/- 0.66 mmHg/microL, P < 0.005) indicating reduced contractility. Diastolic stiffness was significantly increased in the clipped embryos (slope of end-diastolic pressure-volume relationship: 1.54 +/- 0.21 vs. 0.60 +/- 0.08, P < 0.005), indicating reduced compliance. CONCLUSION Venous obstruction apparently interferes with normal myocardial development, resulting in impaired intrinsic systolic and diastolic ventricular function. These changes in ventricular function may precede morphological derangements observed in later developmental stages.
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Affiliation(s)
- S Stekelenburg-de Vos
- Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
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Rex S, Missant C, Segers P, Rossaint R, Wouters PF. Epoprostenol treatment of acute pulmonary hypertension is associated with a paradoxical decrease in right ventricular contractility. Intensive Care Med 2007; 34:179-89. [PMID: 17710383 DOI: 10.1007/s00134-007-0831-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 07/19/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Prostacyclins have been suggested to exert positive inotropic effects which would render them particularly suitable for the treatment of right ventricular (RV) dysfunction due to acute pulmonary hypertension (PHT). Data on this subject are controversial, however, and vary with the experimental conditions. We studied the inotropic effects of epoprostenol at clinically recommended doses in an experimental model of acute PHT. DESIGN AND SETTING Prospective laboratory investigation in a university hospital laboratory. SUBJECTS Six pigs (36 +/- 7kg). INTERVENTIONS Pigs were instrumented with biventricular conductance catheters, a pulmonary artery (PA) flow probe, and a high-fidelity pulmonary pressure catheter. Incremental doses of epoprostenol (10, 15, 20, 30, 40ng kg(-1) min(-1)) were administered in undiseased animals and after induction of acute hypoxia-induced PHT. MEASUREMENTS AND RESULTS In acute PHT epoprostenol markedly reduced RV afterload (slopes of pressure-flow relationship in the PA from 7.0 +/- 0.6 to 4.2 +/- 0.7mmHg minl(-1)). This was associated with a paradoxical and dose-dependent decrease in RV contractility (slope of preload-recruitable stroke-work relationship from 3.0 +/- 0.4 to 1.6 +/- 0.2 mW s ml(-1); slope of endsystolic pressure-volume relationship from 1.5 +/- 0.3 to 0.7 +/- 0.3mmHg ml(-1)). Left ventricular contractility was reduced only at the highest dose. In undiseased animals epoprostenol did not affect vascular tone and produced a mild biventricular decrease in contractility. CONCLUSIONS Epoprostenol has no positive inotropic effects in vivo. In contrast, epoprostenol-induced pulmonary vasodilation in animals with acute PHT was associated with a paradoxical decrease in RV contractility. This effect is probably caused indirectly by the close coupling of RV contractility to RV afterload. However, data from normal animals suggest that mechanisms unrelated to vasodilation are also involved in the observed negative inotropic response to epoprostenol.
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Affiliation(s)
- Steffen Rex
- Section Centre for Experimental Anesthesiology, Emergency and Intensive Care Medicine, Department of Acute Medical Sciences, Katholieke Universiteit Leuven, Minderbroederstraat 19 - bus 7003, 3000 Leuven, Belgium
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Gan CTJ, Holverda S, Marcus JT, Paulus WJ, Marques KM, Bronzwaer JGF, Twisk JW, Boonstra A, Postmus PE, Vonk-Noordegraaf A. Right Ventricular Diastolic Dysfunction and the Acute Effects of Sildenafil in Pulmonary Hypertension Patients. Chest 2007; 132:11-7. [PMID: 17625080 DOI: 10.1378/chest.06-1263] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
AIMS This study investigated whether right ventricular (RV) diastolic function is impaired in pulmonary hypertension (PH) patients, and whether it is related to RV mass and afterload. In addition, the effects of an acute reduction of RV afterload by the oral intake of sildenafil were studied. Finally, we assessed whether diastolic function is related to cardiac parameters of disease severity. METHODS AND RESULTS Twenty-five PH patients and 11 control subjects were studied. Right-heart catheterization and N-terminal pro-brain natriuretic peptide (NT-proBNP) sampling were performed in patients. MRI measured RV ejection fraction, mass, and diastolic function. Isovolumic relaxation time (IVRT), normalized early peak filling rate (E), atrium-induced peak filling rate (A), and E/A ratio described diastolic function. Compared to control subjects, patients had prolonged mean (+/- SD) IVRT (133.5 +/- 53.2 vs 29.3 +/- 20.8 ms, respectively; p < 0.001), decreased E (3.0 +/- 1.6 vs 6.4 +/- 2.5 s(-1), respectively; p < 0.001) and E/A ratio (1.1 +/- 0.7 vs 5.3 +/- 4.9, respectively; p < 0.001), and increased A (3.0 +/- 1.4 vs 1.5 +/- 0.9 s(-1), respectively; p = 0.001). IVRT was related to RV mass (r(25) = 0.56; p = 0.005) and pulmonary vascular resistance (r(25) = 0.74; p < 0.0001). Sildenafil therapy reduced RV afterload and improved RV diastolic and systolic function. IVRT was correlated with NT-proBNP level (r = 0.70; p < 0.001), and was inversely related to cardiac index (r = -0.70; p < 0.001) and RV ejection fraction (r = -0.69; p < 0.001). CONCLUSION In PH patients, RV diastolic dysfunction is related to RV mass and afterload. RV diastolic function improves by reducing afterload. The correlations between diastolic function and prognostic parameters showed that diastolic function is most impaired in patients with severe disease.
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Affiliation(s)
- C Tji-Joong Gan
- VU University Medical Center, De Boelelaan 1117 PO Box 7057, 1007 MB Amsterdam, the Netherlands
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Teshima K, Asano K, Iwanaga K, Koie H, Uechi M, Kato Y, Kutara K, Edamura K, Hasegawa A, Tanaka S. Evaluation of right ventricular Tei index (index of myocardial performance) in healthy dogs and dogs with tricuspid regurgitation. J Vet Med Sci 2007; 68:1307-13. [PMID: 17213699 DOI: 10.1292/jvms.68.1307] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Right ventricular (RV) Tei index (index of myocardial performance) has been demonstrated to be clinically useful in estimating RV function in various human cardiac diseases. The purposes of this study were to validate the correlation between RV Tei index and RV function obtained by cardiac catheterization in healthy dogs, and to evaluate the RV Tei index in dogs with tricuspid regurgitation (TR). In healthy dogs, the RV Tei index significantly correlated with the RV peak +dP/dt (r=-0.80, p<0.0001) and -dP/dt (r=0.69, p=0.0001). In normal dogs, the RV Tei index was not significantly correlated with heart rate, body weight, and age. The RV Tei index significantly increased in dogs with moderate to severe TR (0.39 +/- 0.35, p=0.0015), filariasis (0.46 +/- 0.16, p=0.0131), and trivial to mild TR and severe mitral regurgitation (MR; 0.61 +/- 0.14, p=0.0017) when compared with the normal dogs (0.17 +/- 0.10). In addition, the RV Tei index in dogs with TR significantly increased in association with pulmonary hypertension [PH(-), 0.19 +/- 0.09; PH(+), 0.65 +/- 0.14; respectively p<0.0001]. Our study has demonstrated that RV Tei index is a feasible approach to estimate RV function in dogs and is not influenced by heart rate, body weight, and aging. Further investigations are required to clarify the clinical significance of RV Tei index in dogs with right-sided cardiac diseases.
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Affiliation(s)
- Kenji Teshima
- Laboratory of Veterinary Surgery, College of Bioresource Sciences, Nihon University, Fujisawa, Japan
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Missant C, Rex S, Segers P, Wouters PF. Levosimendan improves right ventriculovascular coupling in a porcine model of right ventricular dysfunction*. Crit Care Med 2007; 35:707-15. [PMID: 17255859 DOI: 10.1097/01.ccm.0000257326.96342.57] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Experimental data suggest that levosimendan has pulmonary vasodilatory properties which, in combination with its positive inotropic effects, would render it particularly attractive for the treatment of right ventricular dysfunction. To test this hypothesis, we developed an experimental model of right ventricular failure and analyzed the effects of levosimendan on ventriculovascular coupling between the right ventricle and pulmonary artery (PA). DESIGN Prospective, randomized, placebo-controlled animal study. SETTING University hospital laboratory. SUBJECTS Fourteen pigs (mean weight 36 +/- 1 kg). INTERVENTIONS Pigs were instrumented with biventricular conductance catheters, a PA and right coronary artery flow probe, and a high-fidelity pulmonary pressure catheter. Right ventricular dysfunction was induced by repetitive episodes of ischemia/reperfusion in the presence of temporary PA constriction. Pigs were randomly assigned to receive levosimendan (120 mg/kg/hr [corrected] for 10 mins followed by continuous infusion of 60 mg/kg/hr [corrected] for 45 mins) or the placebo (control). MEASUREMENTS AND MAIN RESULTS Induction of right ventricular dysfunction resulted in a 42% decrease in contractility (reduction in slope of preload recruitable stroke work [Mw] from 2.5 +/- 0.4 to 1.8 +/- 0.5 mW x sec x mL(-1); p = .02) and a 60% increase in right ventricular afterload (effective pulmonary arterial elastance [PA-Ea] from 0.6 +/- 0.1 to 1.0 +/- 0.3 mm Hg x mL(-1); p < .01). Right ventriculovascular coupling, as assessed by the quotient of right ventricular end-systolic elastance (E(max)) over PA-Ea, decreased from 1.23 +/- 0.38 to 0.64 +/- 0.21 (p = .03). Treatment with levosimendan improved right ventricular contractility (Mw from 1.9 +/- 0.4 to 2.9 +/- 0.5 mW x sec x mL(-1); p < .01), lowered right ventricular afterload (PA-Ea from 1.1 +/- 0.3 to 0.8 +/- 0.3 mm Hg x mL(-1); p = .02), and restored right ventriculovascular coupling to normal values (E(max)/PA-Ea = 1.54 +/- 0.51). Levosimendan also significantly increased coronary blood flow and left ventricular contractility (Mw from 7.2 +/- 3.3 to 9.5 +/- 2.9 mW x sec x mL(-1); p = .01) but did not affect biventricular diastolic function. CONCLUSIONS In an experimental model of acute right ventricular dysfunction, levosimendan improved global hemodynamics and optimized right ventriculovascular coupling via a moderate increase in right ventricular contractility and a mild reduction of right ventricular afterload.
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Affiliation(s)
- Carlo Missant
- Center for Experimental Anesthesiology, Emergency and Intensive Care Medicine, Department of Acute Medical Sciences, Katholieke Universiteit Leuven, Belgium
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Rex S, Missant C, Segers P, Wouters PF. Thoracic epidural anesthesia impairs the hemodynamic response to acute pulmonary hypertension by deteriorating right ventricular-pulmonary arterial coupling. Crit Care Med 2007; 35:222-9. [PMID: 17095942 DOI: 10.1097/01.ccm.0000250357.35250.a2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Thoracic epidural anesthesia is increasingly used in critically ill patients. This analgesic technique was shown to decrease left ventricular contractility, but effects on right ventricular function have not been reported. A deterioration of right ventricular performance may be clinically relevant for patients with acute pulmonary hypertension, in which right ventricular function is an important determinant of outcome. In the present study, we tested the hypothesis that thoracic epidural anesthesia decreases right ventricular contractility and limits its capacity to tolerate pulmonary hypertension. DESIGN Prospective, placebo-controlled study using an established model of acute pulmonary hypertension. SETTING University hospital laboratory. SUBJECTS A total of 14 pigs (mean weight, 35 +/- 2 kg). INTERVENTIONS After instrumentation with an epidural catheter, biventricular conductance catheters, a pulmonary flow probe, and a high-fidelity pulmonary pressure catheter, seven pigs received thoracic epidural anesthesia and seven pigs served as control. Hemodynamic measurements were performed in baseline conditions and after induction of pulmonary hypertension via hypoxic pulmonary vasoconstriction (Fio2 of 0.15). MEASUREMENTS AND MAIN RESULTS Ventricular contractility was assessed using load- and heart rate-independent variables. Right ventricular afterload was characterized with instantaneous pressure-flow measurements. In baseline conditions, thoracic epidural anesthesia decreased left but not right ventricular contractility. In untreated animals, pulmonary hypertension was associated with an increase in right ventricular contractility and cardiac output. Pretreatment with thoracic epidural anesthesia completely abolished the positive inotropic response to acute pulmonary hypertension. As a result, ventriculo-vascular coupling between the right ventricle and pulmonary-arterial system deteriorated, and cardiac output was significantly lower in animals with thoracic epidural anesthesia than in untreated controls during hypoxia-induced pulmonary hypertension. CONCLUSIONS Thoracic epidural anesthesia inhibits the native positive inotropic response of the right ventricle to increased afterload and deteriorates the hemodynamic effects of acute pulmonary hypertension.
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Affiliation(s)
- Steffen Rex
- Laboratory for Experimental Anesthesiology, Department of Acute Medical Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
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Amà R, Leather HA, Segers P, Vandermeersch E, Wouters PF. Acute pulmonary hypertension causes depression of left ventricular contractility and relaxation. Eur J Anaesthesiol 2007; 23:824-31. [PMID: 16953943 DOI: 10.1017/s0265021506000317] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2006] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE The haemodynamic effects of acute pulmonary hypertension can be largely attributed to ventricular interdependence during diastole. However, there is evidence that the two ventricles also interact during systole. The aim of the present study was to examine the effects of acute pulmonary hypertension on both components of left ventricular systole, i.e. contraction and relaxation, using load-independent indices. METHODS Ten pigs were instrumented with biventricular conductance catheters, a pulmonary artery flow probe and a high-fidelity pulmonary pressure catheter. Haemodynamic measurements were performed in baseline conditions and during stable pulmonary vasoconstriction induced by the thromboxane analogue U46619. Contractility was quantified using the end-systolic pressure-volume and preload recruitable stroke work relationships. The tau-end-systolic pressure relationship was used to assess load-dependency of relaxation. RESULTS Acute pulmonary hypertension caused a decrease in the slope of the left ventricular preload recruitable stroke work relationship (from 6.64 +/- 1.7 to 5.19 +/- 1.9, mean +/- SD; P < 0.05), a rightward shift of the end-systolic pressure-volume relationship (P < 0.05), and an increase in the slope of the tau-end-systolic pressure relationship (from -0.15 +/- 0.5 to 0.35 +/- 0.17; P < 0.05). The diastolic chamber stiffness constant of both ventricles increased during pulmonary hypertension (P < 0.05). CONCLUSIONS In the present model, acute pulmonary hypertension impairs left ventricular contractile function and relaxing properties. The present study provides additional evidence that, besides the well-known diastolic ventricular cross talk, systolic ventricular interaction may play a significant role in the haemodynamic consequences of acute pulmonary hypertension.
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Affiliation(s)
- R Amà
- Katholieke Universiteit Leuven, Center for Experimental Surgery and Anesthesiology, Department of Anesthesiology, Belgium
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63
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Tulner SAF, Steendijk P, Klautz RJM, Bax JJ, Schalij MJ, van der Wall EE, Dion RAE. Surgical ventricular restoration in patients with ischemic dilated cardiomyopathy: evaluation of systolic and diastolic ventricular function, wall stress, dyssynchrony, and mechanical efficiency by pressure-volume loops. J Thorac Cardiovasc Surg 2006; 132:610-20. [PMID: 16935117 DOI: 10.1016/j.jtcvs.2005.12.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 12/15/2005] [Accepted: 12/22/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Surgical ventricular restoration aims at improving cardiac function by normalization of left ventricular shape and size. Recent studies indicate that surgical ventricular restoration is highly effective with an excellent 5-year outcome in patients with ischemic dilated cardiomyopathy. We used pressure-volume analysis to investigate acute changes in systolic and diastolic left ventricular function, mechanical dyssynchrony and efficiency, and wall stress. METHODS In 3 patient groups (total, n = 33), pressure-volume loops were measured by conductance catheter before and after surgery. The main study group consisted of 10 patients with ischemic dilated cardiomyopathy (New York Heart Association class III/IV, left ventricular ejection fraction <30%) who had surgical ventricular restoration and coronary artery bypass grafting. In this group, 7 patients had additional restrictive mitral annuloplasty. To assess potential confounding effects of restrictive mitral annuloplasty and cardiopulmonary bypass, we included a group of 10 patients (New York Heart Association class III/IV, left ventricular ejection fraction <30%) who had isolated restrictive mitral annuloplasty and a group of 13 patients with preserved left ventricular function who had isolated coronary artery bypass grafting. RESULTS After surgical ventricular restoration, end-diastolic and end-systolic volumes were reduced from 211 +/- 54 to 169 +/- 34 mL (P = .03) and from 147 +/- 41 to 110 +/- 59 mL (P = .04), respectively. Left ventricular ejection fraction (from 27% +/- 7% to 37% +/- 13%, P = .04) and end-systolic elastance (from 1.12 +/- 0.71 to 1.57 +/- 0.63 mm Hg/mL, P = .03) improved. Peak wall stress (from 358 +/- 108 to 244 +/- 79 mm Hg, P < .01) and mechanical dyssynchrony (from 26% +/- 4% to 19% +/- 6%, P < .01) were reduced, whereas mechanical efficiency improved (from 0.34 +/- 13 to 0.49 +/- 0.14, P = .03). End-diastolic pressure increased (from 13 +/- 6 to 20 +/- 5 mm Hg, P < .01), whereas the diastolic chamber stiffness constant tended to be increased (from 0.021 +/- 0.009 to 0.037 +/- 0.021 mL(-1), NS). CONCLUSIONS Surgical ventricular restoration achieves normalization of left ventricular volumes and improves systolic function and mechanical efficiency by reducing left ventricular wall stress and mechanical dyssynchrony.
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Affiliation(s)
- Sven A F Tulner
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
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Ha RR, Wang D, Zwischenberger JB, Clark JW. Hemodynamic analysis and design of a paracorporeal artificial lung device. ACTA ACUST UNITED AC 2006; 6:10-29. [PMID: 16900418 DOI: 10.1007/s10558-006-9000-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We have extended our model of the ovine pulmonary circulation to include a model of a paracorporeal artificial lung (AL) and its attachments to the natural pulmonary circulation in two configurations: in series and in parallel. Our model of the natural lung (NL) circulation is first shown to be in agreement with hemodynamic and input impedance data from the open literature. We then study design efficacy of the AL in terms of its housing and attachments. A sensitivity analysis of the modified pulmonary circulation model reveals that there are three key parameters: inlet graft length (IGL) and the compliances of the inlet compliance chamber (CC) and housing of the artificial lung. Based on literature reports, we assume the right ventricle is well-matched to the impedance of the natural pulmonary circulation and adjust the parameters of the modeled AL circuit to achieve the best least-squares fit to natural pulmonary input impedance data. Best-fit parameters produce impedance curves that fit natural impedance well, particularly below 3 Hz, where both compliance and graft length have their largest effects. Of these parameters, the impedance profile is most sensitive to IGL. However, the compliances are important, as well, particularly at low frequencies.
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Affiliation(s)
- Roy R Ha
- Department of Electrical and Computer Engineering MS-366, Rice University, 6100 Main St, Houston, TX 77005-1892, USA
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Stoica SC, Satchithananda DK, White PA, Sharples L, Parameshwar J, Redington AN, Large SR. Brain death leads to abnormal contractile properties of the human donor right ventricle. J Thorac Cardiovasc Surg 2006; 132:116-23. [PMID: 16798311 DOI: 10.1016/j.jtcvs.2005.12.061] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2005] [Revised: 12/16/2005] [Accepted: 12/22/2005] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Experimental and clinical data suggest that brain death predominantly affects the right ventricle. We aimed to investigate right ventricle function after brain death and during clinical transplantation with load-independent methods. METHODS Patients with and without brain death were enrolled. A total of 33 consecutive heart donors (5 live, "domino" donors) and 10 patients undergoing coronary surgery (coronary artery bypass graft controls) were studied with pressure-volume loops in the right ventricle. Contractile reserve was measured with dopamine stimulation. RESULTS Brain-dead donors had a higher mean cardiac index than coronary artery bypass graft controls (3.3 vs 2.8 L/min/m2), but impaired load-independent indices. Despite increased right ventricle stroke volume, the ejection fraction and slope of the end-systolic pressure-volume relationship were significantly reduced in brain-dead donors compared with controls. Diastolic abnormalities were also manifest as increased end-diastolic volume index and prolonged Tau (P < .05). Dopamine improved cardiac output, but without influencing end-systolic pressure-volume relationship, or Tau, and at the expense of further increased right ventricle end-diastolic volume. Before explantation, a significantly higher diastolic volume was also seen in hearts that developed postoperative dysfunction compared with organs without this complication (114.4 vs 77.2 mL/m2, P = .02). CONCLUSIONS Brain death leads to right ventricle dysfunction, which may go undetected with conventional techniques. Right ventricle dilatation could represent an early marker of failure. Refinement of selection criteria to include load-independent indices of performance may be desirable to help expand the donor pool.
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Hsiao SH, Lee CY, Chang SM, Yang SH, Lin SK, Huang WC. Pulmonary Embolism and Right Heart Function: Insights from Myocardial Doppler Tissue Imaging. J Am Soc Echocardiogr 2006; 19:822-8. [PMID: 16762763 DOI: 10.1016/j.echo.2006.01.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND Acute pulmonary embolism (PE) has significant impact in right heart function. We assess the difference of Doppler tissue parameters among control subjects, patients with pulmonary hypertension, and patients with acute PE. After optimal treatment, the changes of Doppler tissue parameters in patients with PE were assessed. METHODS A total of 50 patients with acute PE, confirmed by multidetector-row chest computed tomography, were enrolled. Another 70 patients with pulmonary hypertension, but no evidence of PE found by computed tomography, were also enrolled. A total of 100 healthy people without signs of cardiopulmonary dysfunction served as a control group. We assessed left and right ventricular (RV) ejection fraction by Simpson's rule. Doppler tissue parameters were obtained from lateral sides of tricuspid and mitral annulus, and interventricular septum. Myocardial performance index (MPI) of RV was estimated from lateral tricuspid annulus by Doppler tissue imaging, MPI of left ventricle from lateral mitral annulus. RESULTS The left ventricular and RV ejection fractions in patients with pulmonary hypertension were lower than for the control group and patients with PE. But the RV-MPI in patients with PE was the lowest as a result of significant prolongation of isovolumic relaxation time (IVRT). One month after anticoagulant treatment, the IVRT and RV-MPI recovered in patients with PE. There was no significant correlation between IVRT and pulmonary artery systolic pressure. By bivariate correlation analysis, the most significant factor correlated to pulmonary artery systolic pressure was peak late diastolic velocity of tricuspid annulus with r 0.67, r(2) 0.45, and P less than .0001. CONCLUSIONS Acute PE has significant impact in systolic and diastolic function of RV. The higher RV-MPI implies that condition. However, optimal anticoagulant treatment corrects RV dysfunction in patients with PE. After a 1-month course of anticoagulant treatment, RV-MPI diminishes as the result of RV-IVRT reduction.
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Affiliation(s)
- Shih-Hung Hsiao
- Cardiovascular Center, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
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Hessel MHM, Steendijk P, den Adel B, Schutte CI, van der Laarse A. Characterization of right ventricular function after monocrotaline-induced pulmonary hypertension in the intact rat. Am J Physiol Heart Circ Physiol 2006; 291:H2424-30. [PMID: 16731643 DOI: 10.1152/ajpheart.00369.2006] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We characterized hemodynamics and systolic and diastolic right ventricular (RV) function in relation to structural changes in the rat model of monocrotaline (MCT)-induced pulmonary hypertension. Rats were treated with MCT at 30 mg/kg body wt (MCT30, n = 15) and 80 mg/kg body wt (MCT80, n = 16) to induce compensated RV hypertrophy and RV failure, respectively. Saline-treated rats served as control (Cont, n = 13). After 4 wk, a pressure-conductance catheter was introduced into the RV to assess pressure-volume relations. Subsequently, rats were killed, hearts and lungs were rapidly dissected, and RV, left ventricle (LV), and interventricular septum (IVS) were weighed and analyzed histochemically. RV-to-(LV + IVS) weight ratio was 0.29 +/- 0.05 in Cont, 0.35 +/- 0.05 in MCT30, and 0.49 +/- 0.10 in MCT80 (P < 0.001 vs. Cont and MCT30) rats, confirming MCT-induced RV hypertrophy. RV ejection fraction was 49 +/- 6% in Cont, 40 +/- 12% in MCT30 (P < 0.05 vs. Cont), and 26 +/- 6% in MCT80 (P < 0.05 vs. Cont and MCT30) rats. In MCT30 rats, cardiac output was maintained, but RV volumes and filling pressures were significantly increased compared with Cont (all P < 0.05), indicating RV remodeling. In MCT80 rats, RV systolic pressure, volumes, and peak wall stress were further increased, and cardiac output was significantly decreased (all P < 0.05). However, RV end-systolic and end-diastolic stiffness were unchanged, consistent with the absence of interstitial fibrosis. MCT-induced pressure overload was associated with a dose-dependent development of RV hypertrophy. The most pronounced response to MCT was an overload-dependent increase of RV end-systolic and end-diastolic volumes, even under nonfailing conditions.
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Affiliation(s)
- Marleen H M Hessel
- Dept. of Cardiology, C5-P, Leiden Univ. Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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Bleeker GB, Steendijk P, Holman ER, Yu CM, Breithardt OA, Kaandorp TAM, Schalij MJ, van der Wall EE, Nihoyannopoulos P, Bax JJ. Assessing right ventricular function: the role of echocardiography and complementary technologies. Heart 2006; 92 Suppl 1:i19-26. [PMID: 16543597 PMCID: PMC1860734 DOI: 10.1136/hrt.2005.082503] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- G B Bleeker
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
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Gaynor SL, Maniar HS, Bloch JB, Steendijk P, Moon MR. Right atrial and ventricular adaptation to chronic right ventricular pressure overload. Circulation 2006; 112:I212-8. [PMID: 16159819 DOI: 10.1161/circulationaha.104.517789] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Increased mortality in patients with chronic pulmonary hypertension has been associated with elevated right atrial (RA) pressure. However, little is known about the effects of chronic right ventricular (RV) pressure overload on RA and RV dynamics or the adaptive response of the right atrium to maintain RV filling. METHODS AND RESULTS In 7 dogs, RA and RV pressure and volume (conductance catheter) were recorded at baseline and after 3 months of progressive pulmonary artery banding. RA and RV elastance (contractility) and diastolic stiffness were calculated, and RA reservoir and conduit function were quantified as RA inflow with the tricuspid valve closed versus open, respectively. With chronic pulmonary artery banding, systolic RV pressure increased from 34+/-7 to 70+/-17 mm Hg (P<0.001), but cardiac output did not change (P>0.78). RV elastance and stiffness both increased (P<0.05), suggesting preserved systolic function but impaired diastolic function. In response, RA contractility improved (elastance increased from 0.28+/-0.12 to 0.44+/-0.13 mm Hg/mL; P<0.04), and the atrium became more distensible, as evidenced by increased reservoir function (49+/-14% versus 72+/-8%) and decreased conduit function (51+/-14% versus 28+/-8%; P<0.002). CONCLUSIONS With chronic RV pressure overload, RV systolic function was preserved, but diastolic function was impaired. To compensate, RA contractility increased, and the atrium became more distensible to maintain filling of the stiffened ventricle. This compensatory response of the right atrium likely plays an important role in preventing clinical failure in chronic pulmonary hypertension.
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Affiliation(s)
- Sydney L Gaynor
- Division of Cardiothoracic Surgery, Washington University School of Medicine, St Louis, MO 63110-1013, USA
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Bal MP, de Vries WB, van der Leij FR, van Oosterhout MFM, Baan J, van der Wall EE, van Bel F, Steendijk P. Left ventricular pressure-volume relationships during normal growth and development in the adult rat - studies in 8- and 50-week-old male Wistar rats. ACTA ACUST UNITED AC 2005; 185:181-91. [PMID: 16218923 DOI: 10.1111/j.1365-201x.2005.01484.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Left ventricular (LV) pressure-volume relations provide relatively load-independent indexes of systolic and diastolic LV function, but few data are available on pressure-volume relations during growth and development in the normal adult heart. Furthermore, to quantify intrinsic ventricular function the indexes should be normalized for heart weight. However, in many studies the indexes are reported in absolute terms, or body weight-correction is used as a surrogate for heart weight-correction. METHODS We determined pressure-volume relations in young (8-week-old, n = 13) and middle-aged (50-week-old, n = 19) male Wistar rats in relation to their heart and body weights. The animals were anaesthetized and a 2F pressure-conductance catheter was introduced into the LV to measure pressure-volume relations. RESULTS Heart and body weights were significantly higher in the 50-week-old rats, whereas the heart-to-body weight ratio was significantly lower (2.74 +/- 0.32 vs. 4.41 +/- 0.37 mg g(-1), P < 0.001). Intrinsic systolic function, quantified by the slopes of the end-systolic pressure-volume relation (E(ES)), the dP/dt(MAX) vs. end-diastolic volume relation (S-dP), and the preload recruitable stroke work relation (PRSW), normalized for heart weight, was slightly decreased in the 50-week-old rats (S-dP: -6%, P < 0.004; PRSW: -3%, P < 0.06). Heart weight-corrected diastolic indexes were not significant different. The absolute indexes qualitatively showed the same results, but body-weight corrected pressure-volume indexes showed improved systolic function and significantly depressed diastolic function. CONCLUSIONS Intrinsic systolic function slightly decreases from the juvenile to the middle-aged period in normal male Wistar rats. Furthermore, correction of pressure-volume indexes for body weight is not an adequate surrogate for heart weight-correction in these animals.
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Affiliation(s)
- M P Bal
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
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Ha RR, Qian J, Ware DL, Zwischenberger JB, Bidani A, Clark JW. An Integrative Cardiovascular Model of the Standing and Reclining Sheep. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/s10558-005-5341-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Stekelenburg-de Vos S, Steendijk P, Ursem NTC, Wladimiroff JW, Delfos R, Poelmann RE. Systolic and diastolic ventricular function assessed by pressure-volume loops in the stage 21 venous clipped chick embryo. Pediatr Res 2005; 57:16-21. [PMID: 15531737 DOI: 10.1203/01.pdr.0000147734.53277.75] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cardiac pressure-volume relations enable quantification of intrinsic ventricular diastolic and systolic properties independent of loading conditions. The use of pressure-volume loop analysis in early stages of development could contribute to a better understanding of the relationship between hemodynamics and cardiac morphogenesis. The venous clip model is an intervention model for the chick embryo in which permanent obstruction of the right lateral vitelline vein temporarily reduces the mechanical load on the embryonic myocardium and induces a spectrum of outflow tract anomalies. We used pressure-volume loop analysis of the embryonic chick heart at stage 21 (3.5 d of incubation) to investigate whether the development of ventricular function is affected by venous clipping at stage 17, compared with normal control embryos. Steady state hemodynamic parameters demonstrated no significant differences between the venous clipped and control embryos. However, analysis of pressure-volume relations showed a significantly lower end-systolic elastance in the clipped embryos (slope of the end-systolic pressure-volume relation: 5.68 +/- 0.85 versus 11.76 +/- 2.70 mm Hg/microL, p < 0.05), indicating reduced contractility. Diastolic stiffness tended to be increased in the clipped embryos (slope of end-diastolic pressure-volume relation: 2.74 +/- 0.56 versus 1.67 +/- 0.21, p = 0.103), but the difference did not reach statistical significance. The results of the pressure-volume loop analysis show that 1 d after venous obstruction, development of ventricular function is affected, with reduced contractility. Pressure-volume analysis may be applied in the chick embryo and is a sensitive technique to detect subtle alterations in ventricular function.
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Lambermont B, Segers P, Ghuysen A, Tchana-Sato V, Morimont P, Dogne JM, Kolh P, Gerard P, D'Orio V. Comparison between single-beat and multiple-beat methods for estimation of right ventricular contractility. Crit Care Med 2004; 32:1886-90. [PMID: 15343017 DOI: 10.1097/01.ccm.0000139607.38497.8a] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE It was investigated whether pharmacologically induced changes in right ventricular contractility can be detected by a so-called "single-beat" method that does not require preload reduction. DESIGN Prospective animal research. SETTING Laboratory at a large university medical center. SUBJECTS Eight anesthetized pigs. INTERVENTIONS End-systolic elastance values obtained by a recently proposed single-beat method (Eessb) were compared with those obtained using the reference multiple-beat method (Eesmb). MEASUREMENTS AND MAIN RESULTS Administration of dobutamine increased Eesmb from 1.6 +/- 0.3 to 3.8 +/- 0.5 mm Hg/mL (p =.001), whereas there was only a trend toward an increase in Eessb from 1.5 +/- 0.2 to 1.7 +/- 0.4 mm Hg/mL. Esmolol decreased Eesmb from 1.7 +/- 0.3 to 1.1 +/- 0.2 mm Hg/mL (p =.006), whereas there was only a trend for a decrease in Eessb from 1.5 +/- 0.2 to 1.3 +/- 0.1. CONCLUSIONS The present method using single-beat estimation to assess right ventricular contractility does not work as expected, since it failed to detect either increases or decreases in right ventricular contractility induced by pharmacologic interventions.
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Reply to the editor. J Thorac Cardiovasc Surg 2003. [DOI: 10.1016/s0022-5223(03)00796-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Leeuwenburgh BPJ, Helbing WA, Steendijk P, Schoof PH, Baan J. Effects of acute left ventricular unloading on right ventricular function in normal and chronic right ventricular pressure-overloaded lambs. J Thorac Cardiovasc Surg 2003; 125:481-90. [PMID: 12658189 DOI: 10.1067/mtc.2003.28] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Right ventricular pressure overload occurs in several types of (congenital) heart disease, as well as in pulmonary disease. Clinical outcome in some of these patient groups might in part be related to left ventricular loading conditions. The effects of left ventricular unloading on the function of the hypertrophic right ventricle have not been studied. We aimed to study the effects of left ventricular unloading on right ventricular hemodynamics and contractility in an animal model of chronic right ventricular pressure overload. METHODS In lambs the pulmonary artery was chronically banded to increase right ventricular pressure to systemic levels. After 8 weeks, right ventricular contractility and hemodynamic function were assessed in these lambs, as well as in age-matched control animals, by using a combined pressure-conductance catheter in the right ventricle during baseline conditions and during complete bypass of the left ventricle. RESULTS In both groups acute left ventricular unloading significantly decreased left ventricular pressure to low levels while aortic pressure was maintained. In the right ventricle of the control group, both end-systolic and end-diastolic volumes increased with left ventricular unloading (P <.01) while end-systolic pressure was maintained. Cardiac output was unchanged despite decreased right ventricular contractility. In the banding group acute left ventricular unloading also decreased right ventricular contractility but increased cardiac output. During acute left ventricular unloading, diastolic stiffness was unchanged in the control group, whereas it was significantly decreased in the banding group. CONCLUSIONS Both in normal hearts and in hearts subject to chronic right ventricular pressure overload, acute left ventricular unloading decreases right ventricular contractility. Although no effects on cardiac output are encountered in normal hearts during left ventricular bypass, cardiac output is improved in right ventricular pressure-overloaded hearts, most likely related to improved right ventricular diastolic compliance.
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Affiliation(s)
- Boudewijn P J Leeuwenburgh
- Departments of Pediatric Cardiology, Cardiology, CardioThoracic Surgery, Leiden University Medical Center, The Netherlands
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