Evolution of the Study of Left Ventricular Function
2002; Lippincott Williams & Wilkins; Volume: 105; Issue: 23 Linguagem: Inglês
10.1161/01.cir.0000021240.86593.9d
ISSN1524-4539
Autores Tópico(s)Cardiomyopathy and Myosin Studies
ResumoHomeCirculationVol. 105, No. 23Evolution of the Study of Left Ventricular Function Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBEvolution of the Study of Left Ventricular FunctionEverything Old Is New Again Blase A. Carabello, MD Blase A. CarabelloBlase A. Carabello From the Department of Medicine, Baylor College of Medicine, and Houston Veterans Affairs Medical Center, Houston, Tex. Originally published11 Jun 2002https://doi.org/10.1161/01.CIR.0000021240.86593.9DCirculation. 2002;105:2701–2703The science of cardiology has evolved parallel to most medical sciences, first emphasizing anatomy, then physiology, and now molecular biology. In the 1960s, when it had become obvious that effective medical and surgical therapies were available for cardiac diseases, there developed a heightened interest in measuring cardiac function as a way of evaluating the heart's response to those therapies. Because the heart is a muscle, it was logical that measurements of muscle function would be prognostic indicators of the success or failure of a given therapy.See Circulation. 2002;105:1602–1608The cardiac muscle translates force into motion, generating cardiac output that is the product of heart rate and stroke volume. Stroke volume is dependent upon contractility (the innate ability of the muscle to generate force), preload, and afterload. Because contractility is the fundamental ability of the heart muscle to do its job, this property generated the greatest focus for measurement. The ideal measure of contractility would have the characteristics listed in Table 1. Unfortunately, despite literally hundreds of investigations, this ideal measure was never developed. Each index of function went through a typical evolution of discovery, enthusiasm, concern for imperfections, and eventual abandonment. The strengths and weaknesses of many of the indexes are listed in Table 2.1–20 The result has been that ejection fraction was chosen by the cardiology community at large and remains the index overwhelmingly used to assess cardiac function in both clinical and experimental studies. The success and persistence of ejection fraction as the premiere indicator of function stems in part from its ease of application and ability to be understood. One of the key aspects of the heart that has attracted attention is the fact that it is one of the few internal organs that moves under its own force. This movement is easy to observe and quantify; there is the general assumption that the more the heart empties, the stronger it is, and ejection fraction quantitates this extent of emptying. Further, application of ejection fraction has usually led to correct interpretation of the pathophysiology present. Although ejection fraction is highly dependent upon preload and afterload1–4 in addition to contractility, in the most common causes of cardiac dysfunction (coronary disease and dilated cardiomyopathy), loading conditions are usually "normal," and ejection fraction reliably reports at least gross abnormalities in contractility. In some specific instances, however, ejection fraction causes a significant misinterpretation of the actual pathophysiology. In aortic stenosis, excess afterload may cause the ejection fraction to be reduced in the face of relatively normal contractility.21 In such cases, the ejection fraction would mislead the clinician into thinking that severe muscle dysfunction was present when it was not. In mitral regurgitation, augmented preload increases ejection fraction and may cause an overestimation of contractility, falsely leading the clinician to believe that because ejection fraction is "normal," contractility is also normal, which would ultimately lead to an untimely delay in correction of the lesion.22,23 Perhaps the most common misuse and misunderstanding of ejection fraction, however, occurs in the case of concentric left ventricular hypertrophy. Here, a normal ejection fraction may be maintained by the subnormal function of sarcomeres laid down in parallel.5 Subnormal shortening of extra parallel sarcomeres leads to the same thickening and to the same displacement of blood as would normal shortening of fewer sarcomeres. Thus, in the many cases of concentric left ventricular hypertrophy, an ejection fraction of 0.55 indicates substantial muscle dysfunction.24 This dysfunction can be detected by the use of afterload-corrected mid wall-mechanics, but unfortunately difficulty of application has led only a few investigators to use this concept productively. Properties of an Ideal Index of Contractility(1) Sensitive to changes in inotrophy(2) Independent of load(3) Independent of heart size and mass(4) Easy and safe to apply(5) Proven to be useful in the clinical settingCharacteristic of Selected Indexes of Ventricular FunctionIndexSensitive to Inotrophic ChangesDependence on PreloadDependence on AfterloadDependence on Heart Volume or MassEasy to ApplyReferenceESPVR indicates slope of the end systolic pressure volume relationship; VCF, mean velocity of circumferential fiber shortening.Ejection fraction; fractional shortening+++++++++++++1–5End systolic volume or dimension+0+++++++++6, 7VCF+++0++++++++5, 8Afterload-corrected VCF+++000+9, 10ESPVR++++00++++11–15End systolic stiffness++++000+15Preload recruitable stroke work+++00+++16dP/dt++++++++++++17–20In a previous issue of Circulation, Derumeaux and colleagues25 report use of tissue Doppler imaging (tDi) to differentiate physiological from pathological pressure overload hypertrophy in rats. Tissue Doppler imaging is able to quantitate the velocity of the myocardium as it moves. In addition, a velocity gradient between the endocardium and epicardium may help to account for changes in performance due to concentric hypertrophy and helps to remove apparent changes due to motion artifact. In the study by Derumeaux et al,25 tDi was normal in exercising rats that were expected to have physiological hypertrophy and normal contractility. Contractility, however, was abnormal in pressure overload hypertrophy created by banding when "conventional" parameters of left ventricular function "failed" to detect functional abnormalities. It seems logical that tDi would be sensitive in detecting abnormalities in cardiac function similar to mid-wall mean velocity of contractile shortening (VcF). One could predict from previous studies that tDi would be relatively insensitive to changes in preload but would be sensitive to changes in afterload, as is suggested by the current study. When afterload was reduced by debanding it for 2 months, tDi returned to normal, suggesting that it had been primarily an afterload mismatch that reduced tDi.Although I agree with the authors that their tDi techniques were sensitive in detecting both systolic and diastolic abnormalities in function, I do not agree with their statement that "conventional techniques" failed to detect these abnormalities. Rather, it was the interpretation of the data that failed to detect contractile abnormalities. Concentric hypertrophy increases dP/dt.20 In the exercising versus sedentary rats, the radius to thickness (r/h) ratio fell from approximately 1.7 to 1.5, indicating an increase in concentricity of 12%. Concordantly, dP/dt rose by 12%, as was expected. Conversely, in the 2-month banded rats, the r/h ratio fell to 1.2, or a 30% increase in concentricity. Although dP/dt should have increased in similar fashion, there was virtually no increase in dP/dt. In fact, this lack of dP/dt increase in the 2-month banded rats despite the presence of concentric hypertrophy indicates that there was substantial left ventricular dysfunction indicated by this "conventional" parameter. If the authors had employed d-stress/dt, they almost certainly would have seen a decrease in contractility.26 Likewise, the presence of concentric hypertrophy should have an increased shortening fraction, but this parameter was unchanged at 2 months, indicating a functional defect. Had mid-wall mechanics been employed, they too almost certainly would have demonstrated decreased function at 2 months.24 Nonetheless, tDi provides a more straightforward indicator of function without having to go through the mental gymnastics exercised above. As such, it is likely to be a useful tool. Future studies using tDi to compare the effects of changes in tDi with changes in preload, afterload, contractility, left ventricular thickness, and left ventricular dimension to define the effects of each on myocardial velocities will be necessary to place tDi in the proper perspective of its uses and limitations in examining cardiac function. I would predict that tDi will be a successful advance once it is used within the context of its known limitations. It has the advantages of being easily employed and understandable, provides some advances over ejection fraction, and should help to advance our studies of cardiac physiology. However, tDi cannot fulfill the criteria listed in Table 1 because it almost certainly will be afterload-dependent.FootnotesCorrespondence to Blase A. Carabello, MD, 2002 Holcombe Blvd (111 MCL), Houston, Texas 77030. E-mail [email protected] References 1 Mahler F, Ross J Jr, O'Rourke RA, et al. Effects of changes in preload, afterload and inotropic state of ejection and isovolumic phase measures of contractility in the conscious dog. Am J Cardiol. 1975; 35: 625–634.Google Scholar2 Ross J Jr. Afterload mismatch and preload reserve: a conceptual framework for the analysis of ventricular function. Prog Cardiovasc Dis. 1976; 18: 255–264.CrossrefMedlineGoogle Scholar3 Borrow KM, Neumann A, Marcus RH, et al. Effects of simultaneous alterations in preload and afterload on measurements of left ventricular contractility in patients with dilated cardiomyopathy: comparisons of ejection phase, isovolumetric and end-systolic force-velocity indexes. J Am Coll Cardiol. 1992; 20: 787–795.CrossrefMedlineGoogle Scholar4 Kreulen TH, Bove AA, McDonough MT, et al. The evaluation of left ventricular function in man: a comparison of methods. Circulation. 1975; 51: 677–688.CrossrefMedlineGoogle Scholar5 Shimizu G, Zile MR, Blaustein AS, et al. Left ventricular chamber filling and mid-wall fiber lengthening in patients with left ventricular hypertrophy: overestimation of fiber velocities by conventional midwall measurements. Circulation. 1985; 71: 266–272.CrossrefMedlineGoogle Scholar6 Henry WL, Bonow RO, Borer JS, et al. Observations on the optimum time for operative intervention for aortic regurgitation: I. Evaluation of the results of aortic valve replacement in symptomatic patients. Circulation. 1980; 61: 471–483.CrossrefMedlineGoogle Scholar7 Carabello BA, Williams H, Gash AK, et al. Hemodynamic predictors of outcome in patients undergoing valve replacement. Circulation. 1986; 74: 1309–1316.CrossrefMedlineGoogle Scholar8 Nixon JV, Murray RG, Leonard PD, et al. Effect of large variations in preload on left ventricular performance characteristics in normal subjects. Circulation. 1982; 65: 698–703.CrossrefMedlineGoogle Scholar9 Colan SD, Borow KM, Neumann A. Left ventricular end-systolic wall stress-velocity of fiber shortening relations: a load-independent index of myocardial contractility. J Am Coll Cardiol. 1984; 4: 715–724.CrossrefMedlineGoogle Scholar10 Carabello BA, Usher BW, Hendrix GH, et al. Predictors of outcome in patients with aortic regurgitation and left ventricular dysfunction: a change in the measuring stick. J Am Coll Cardiol. 1987; 10: 991–997.CrossrefMedlineGoogle Scholar11 Suga H, Sagawa K, Shoukas AA. Load independence of the instantaneous pressure-volume ratio of the canine left ventricular and effects of epinephrine and heart rate on the ratio. Circ Res. 1973; 32: 314–322.CrossrefMedlineGoogle Scholar12 Kass DA, Maughan WL. From "Emax" to pressure-volume relations: a broader view. Circulation. 1988; 77: 1203–1212.CrossrefMedlineGoogle Scholar13 Belchar P, Boerboom LE, Olinger GN, Standardization of end-systolic pressure-volume relation in the dog. Am J Physiol. 1985; 249: H547–H553.MedlineGoogle Scholar14 Little WC, Cheng CP, Peterson T, et al. Response of the left ventricular end-systolic pressure-volume relation in conscious dogs to a wide range of contractile states. Circulation. 1988; 78: 736–745.CrossrefMedlineGoogle Scholar15 Nakano K, Sugawara M, Ishihara K, et al. Myocardial stiffness derived from end-systolic wall stress and the logarithm of the reciprocal of wall thickness: a contractility index independent of ventricular size. Circulation. 1990; 82: 1352–1361.CrossrefMedlineGoogle Scholar16 Glower D, Spratt J, Snow N, et al. Linearity of the Frank-Starling relationship in the intact heart: the concept of preload recruitable stroke work. Circulation. 1985; 71: 994–1009.CrossrefMedlineGoogle Scholar17 Grossman W, Haynes F, Paraskos J, et al. Alterations in preload and myocardial mechanics. Circ Res. 1972; 31: 83–94.CrossrefMedlineGoogle Scholar18 Wallace AG, Skinner NS, Mitchell JH. Hemodynamic determinants of the maximal rate of rise of left ventricular pressure. Am J Physiol. 1963; 205: 30–36.CrossrefMedlineGoogle Scholar19 Broughton A, Korner PI. Steady-state effects of preload and afterload on isovolumic indices of contractility in autonomically blocked dogs. Cardiovasc Res. 1980; 14: 245–253.CrossrefMedlineGoogle Scholar20 Gleason WL, Braunwald E. Studies on the first derivative of the ventricular pressure pulse in man. J Clin Invest. 1962; 41: 80–85.CrossrefMedlineGoogle Scholar21 Gunther S, Grossman W. Determinants of ventricular function in pressure-overload hypertrophy in man. Circulation. 1979; 59: 679–688.CrossrefMedlineGoogle Scholar22 Zile MR, Gaasch WH, Carroll JD, et al. Chronic mitral regurgitation: predictive value of preoperative echocardiographic indexes of left ventricular function and wall stress. J Am Coll Cardiol. 1984; 3: 235–242.CrossrefMedlineGoogle Scholar23 Carabello BA, Nolan SP, McGuire LB. Assessment of preoperative left ventricular function in patients with mitral regurgitation: value of the end-systolic wall stress-end-systolic volume ration. Circulation. 1981; 64: 1212–1217.CrossrefMedlineGoogle Scholar24 deSimone G, Devereux RB, Celentano A, et al. Left ventricular chamber and wall mechanics in the presence of concentric geometry. J Hypertens. 1999; 17: 1001–1006.CrossrefMedlineGoogle Scholar25 Derumeaux G, Mulder P, Vincent R, et al. Tissue Doppler imaging differentiates physiological from pathological pressure-overload left ventricular hypertrophy in rats. Circulation. 2002; 105: 1602–1608.LinkGoogle Scholar26 Fifer MA, Gunther S, Grossman W, et al. Myocardial contractile function in aortic stenosis as determined from the rate of stress development during isovolumic systole. Am J Cardiol. 1979; 44: 1318–1325.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Verbeke J, Calle S, Kamoen V, De Buyzere M and Timmermans F (2021) Prognostic value of myocardial work and global longitudinal strain in patients with heart failure and functional mitral regurgitation, The International Journal of Cardiovascular Imaging, 10.1007/s10554-021-02474-y, 38:4, (803-812), Online publication date: 1-Apr-2022. D'Andrea A, Ilardi F, D'Ascenzi F, Bandera F, Benfari G, Esposito R, Malagoli A, Mandoli G, Santoro C, Russo V, D'Alto M and Cameli M (2021) Impaired myocardial work efficiency in heart failure with preserved ejection fraction, European Heart Journal - Cardiovascular Imaging, 10.1093/ehjci/jeab153, 22:11, (1312-1320), Online publication date: 19-Oct-2021. McMahon C and Ganame J (2021) Hypertrophic Cardiomyopathy Echocardiography in Pediatric and Congenital Heart Disease, 10.1002/9781119612858.ch36, (772-793), Online publication date: 27-Dec-2022. Aissaoui N, Riant E, Lefèvre G, Delmas C, Bonello L, Henry P, Bonnefoy E, Schiele F, Ferrières J, Simon T, Danchin N and Puymirat E (2018) Long-term clinical outcomes in patients with cardiogenic shock according to left ventricular function: The French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) programme, Archives of Cardiovascular Diseases, 10.1016/j.acvd.2017.11.002, 111:11, (678-685), Online publication date: 1-Nov-2018. Lolli L, Batterham A and Atkinson G (2018) Ejection fraction as a statistical index of left ventricular systolic function: the first full allometric scrutiny of its appropriateness and accuracy, Clinical Physiology and Functional Imaging, 10.1111/cpf.12510, 38:6, (976-985), Online publication date: 1-Nov-2018. Gopal D (2018) OBSOLETE: Hemodynamics of the Right Heart in Health and Disease Reference Module in Biomedical Sciences, 10.1016/B978-0-12-801238-3.64156-9, . Gopal D and Alsamarah A (2018) Hemodynamics of the Right Heart in Health and Disease Encyclopedia of Cardiovascular Research and Medicine, 10.1016/B978-0-12-809657-4.64156-X, (497-507), . Krüger W (2017) Heart Failure with Normal Left Ventricular Ejection Fraction (HFNEF) Acute Heart Failure, 10.1007/978-3-319-54973-6_5, (273-339), . Patel V, Gupta D, Terry J, Kabagambe E, Wang T, Correa A, Griswold M, Taylor H and Carr J (2017) Left Ventricular Function Across the Spectrum of Body Mass Index in African Americans, JACC: Heart Failure, 10.1016/j.jchf.2016.12.020, 5:3, (182-190), Online publication date: 1-Mar-2017. Deeg K (2017) Echocardiography for the Neonatologist Doppler Echocardiography in Infancy and Childhood, 10.1007/978-3-319-42919-9_25, (351-412), . Schuster A, Hor K, Kowallick J, Beerbaum P and Kutty S (2016) Cardiovascular Magnetic Resonance Myocardial Feature Tracking, Circulation: Cardiovascular Imaging, 9:4, Online publication date: 1-Apr-2016. Spalla I, Locatelli C, Zanaboni A, Brambilla P and Bussadori C (2016) Echocardiographic Assessment of Cardiac Function by Conventional and Speckle‐Tracking Echocardiography in Dogs with Patent Ductus Arteriosus, Journal of Veterinary Internal Medicine, 10.1111/jvim.13938, 30:3, (706-713), Online publication date: 1-May-2016. McMahon C and Ganame J (2016) Hypertrophic Cardiomyopathy Echocardiography in Pediatric and Congenital Heart Disease, 10.1002/9781118742440.ch35, (677-693) Hsu S, Chao C, Chang C, Lin M and Cheng B (2016) Heat shock protein 72 may improve hypotension by increasing cardiac mechanical efficiency and arterial elastance in heatstroke rats, International Journal of Cardiology, 10.1016/j.ijcard.2016.05.004, 219, (63-69), Online publication date: 1-Sep-2016. Tesak M, Kala P, Jarkovsky J, Poloczek M, Bocek O, Jerabek P, Kubková L, Manousek J, Spinar J, Mebazaa A, Parenica J and Cohen-Solal A (2016) The value of novel invasive hemodynamic parameters added to the TIMI risk score for short-term prognosis assessment in patients with ST segment elevation myocardial infarction, International Journal of Cardiology, 10.1016/j.ijcard.2016.03.073, 214, (235-240), Online publication date: 1-Jul-2016. (2016) Left Ventricular Systolic Function ASE's Comprehensive Echocardiography, 10.1016/B978-0-323-26011-4.09943-5, (113-138), . Buchanan L, Warner W, Arthur S, Gleason C, Lewen G, Levesque P and Gill M (2016) Evaluation of cardiac function in unrestrained dogs and monkeys using left ventricular dP/dt, Journal of Pharmacological and Toxicological Methods, 10.1016/j.vascn.2016.03.006, 80, (51-58), Online publication date: 1-Jul-2016. Dahle G, Stangeland L, Moen C, Salminen P, Haaverstad R, Matre K and Grong K (2016) The influence of acute unloading on left ventricular strain and strain rate by speckle tracking echocardiography in a porcine model, American Journal of Physiology-Heart and Circulatory Physiology, 10.1152/ajpheart.00947.2015, 310:10, (H1330-H1339), Online publication date: 15-May-2016. Nußbaum B, McCook O, Hartmann C, Matallo J, Wepler M, Antonucci E, Kalbitz M, Huber-Lang M, Georgieff M, Calzia E, Radermacher P and Hafner S (2016) Left ventricular function during porcine-resuscitated septic shock with pre-existing atherosclerosis, Intensive Care Medicine Experimental, 10.1186/s40635-016-0089-y, 4:1, Online publication date: 1-Dec-2016. Sandor G (2016) Echocardiographic Tests of Left Ventricular Function in Pediatric Cardiology: Are We Searching for the Holy Grail?, Canadian Journal of Cardiology, 10.1016/j.cjca.2015.10.031, 32:10, (1186-1192), Online publication date: 1-Oct-2016. Spalla I, Locatelli C, Zanaboni A, Brambilla P and Bussadori C (2016) Speckle-Tracking Echocardiography in Dogs With Patent Ductus Arteriosus: Effect of Percutaneous Closure on Cardiac Mechanics, Journal of Veterinary Internal Medicine, 10.1111/jvim.13919, 30:3, (714-721), Online publication date: 1-May-2016. Wang Q, Sun Q, Wu D, Yang M, Li R, Jiang B, Yang J, Li Z, Wang Y and Yang Y (2015) Early Detection of Regional and Global Left Ventricular Myocardial Function Using Strain and Strain-rate Imaging in Patients with Metabolic Syndrome, Chinese Medical Journal, 10.4103/0366-6999.149211, 128:2, (226-232), Online publication date: 20-Jan-2015. Nanayakkara S and Kaye D (2015) Management of Heart Failure With Preserved Ejection Fraction: A Review, Clinical Therapeutics, 10.1016/j.clinthera.2015.08.005, 37:10, (2186-2198), Online publication date: 1-Oct-2015. Rai A, Lima E, Munir F, Faisal Khan A, Waqas A, Bughio S, ul Haq E, Attique H and Rahman Z (2015) Speckle Tracking Echocardiography of the Right Atrium: The Neglected Chamber, Clinical Cardiology, 10.1002/clc.22438, 38:11, (692-697), Online publication date: 1-Nov-2015. Kraigher-Krainer E, Shah A, Gupta D, Santos A, Claggett B, Pieske B, Zile M, Voors A, Lefkowitz M, Packer M, McMurray J and Solomon S (2014) Impaired Systolic Function by Strain Imaging in Heart Failure With Preserved Ejection Fraction, Journal of the American College of Cardiology, 10.1016/j.jacc.2013.09.052, 63:5, (447-456), Online publication date: 1-Feb-2014. Wong J and Jugdutt B (2014) Aging and Right Ventricular Failure from Pulmonary Hypertension: Effect of Right Ventricular and Pulmonary Artery Remodeling Aging and Heart Failure, 10.1007/978-1-4939-0268-2_19, (291-304), . Liu A, Schreier D, Tian L, Eickhoff J, Wang Z, Hacker T and Chesler N (2014) Direct and indirect protection of right ventricular function by estrogen in an experimental model of pulmonary arterial hypertension, American Journal of Physiology-Heart and Circulatory Physiology, 10.1152/ajpheart.00758.2013, 307:3, (H273-H283), Online publication date: 1-Aug-2014. Guihaire J, Haddad F, Boulate D, Decante B, Denault A, Wu J, Herve P, Humbert M, Dartevelle P, Verhoye J, Mercier O and Fadel E (2013) Non-invasive indices of right ventricular function are markers of ventricular-arterial coupling rather than ventricular contractility: insights from a porcine model of chronic pressure overload, European Heart Journal - Cardiovascular Imaging, 10.1093/ehjci/jet092, 14:12, (1140-1149), Online publication date: 1-Dec-2013. Cho Y and Ma J (2013) Right ventricular failure in congenital heart disease, Korean Journal of Pediatrics, 10.3345/kjp.2013.56.3.101, 56:3, (101), . Giglioli C, Nesti M, Cecchi E, Landi D, Chiostri M, Gensini G, Spini V and Romano S (2013) Hemodynamic effects in patients with atrial fibrillation submitted to electrical cardioversion, International Journal of Cardiology, 10.1016/j.ijcard.2013.06.150, 168:4, (4447-4450), Online publication date: 1-Oct-2013. Kotani Y, Chetan D, Atlin C, Mertens L, Jegatheeswaran A, Caldarone C, Van Arsdell G and Honjo O (2012) Longevity and Durability of Atrioventricular Valve Repair in Single-Ventricle Patients, The Annals of Thoracic Surgery, 10.1016/j.athoracsur.2012.04.048, 94:6, (2061-2069), Online publication date: 1-Dec-2012. Sagiv M (2012) Left Ventricular Function Exercise Cardiopulmonary Function in Cardiac Patients, 10.1007/978-1-4471-2888-5_5, (109-133), . Guo X, Ding X, Lei M, Xie M, Zhong L and Xiao S (2012) Non-invasive monitoring and evaluating cardiac function of pregnant women based on a relative value method, Acta Physiologica Hungarica, 10.1556/APhysiol.99.2012.4.2, 99:4, (382-391), Online publication date: 1-Dec-2012. Claus P, Slavich M and Rademakers F (2012) Left-Ventricular Function Quantitative Parameters and Their Relationship to Acute Loading Variation: From Physiology to Clinical Practice, Current Cardiovascular Imaging Reports, 10.1007/s12410-012-9129-5, 5:2, (83-91), Online publication date: 1-Apr-2012. A'roch R, Gustafsson U, Johansson G, Poelaert J and Haney M (2012) Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model, Cardiovascular Ultrasound, 10.1186/1476-7120-10-22, 10:1, Online publication date: 1-Dec-2012. Giglioli C, Cecchi E, Landi D, Chiostri M, Spini V, Valente S, Gensini G and Romano S (2011) Levosimendan Produces an Additional Clinical and Hemodynamic Benefit in Patients With Decompensated Heart Failure Successfully Submitted to a Fluid Removal Treatment, Congestive Heart Failure, 10.1111/j.1751-7133.2011.00261.x, 18:1, (47-53), Online publication date: 1-Jan-2012. Bozkurt B, Bolos M, Deswal A, Ather S, Chan W, Mann D and Carabello B (2012) New Insights into Mechanisms of Action of Carvedilol Treatment in Chronic Heart Failure Patients—A Matter of Time for Contractility, Journal of Cardiac Failure, 10.1016/j.cardfail.2011.11.004, 18:3, (183-193), Online publication date: 1-Mar-2012. Elkilany G, Groef M and Kabbash I (2011) How to Identify Latent Systolic Dysfunction and Post Operative Risk in Patients with Mitral Incompetence and Normal Ejection Fraction?, World Journal of Cardiovascular Surgery, 10.4236/wjcs.2011.12003, 01:02, (11-17), . Haddad F, Skhiri M and Michelakis E (2011) Right Ventricular Dysfunction in Pulmonary Hypertension Textbook of Pulmonary Vascular Disease, 10.1007/978-0-387-87429-6_94, (1313-1331), . Cingolani O, Pérez N, Ennis I, Álvarez M, Mosca S, Schinella G, Escudero E, Cónsole G and Cingolani H (2011) In vivo key role of reactive oxygen species and NHE-1 activation in determining excessive cardiac hypertrophy, Pflügers Archiv - European Journal of Physiology, 10.1007/s00424-011-1020-8, 462:5, (733-743), Online publication date: 1-Nov-2011. Giglioli C, Landi D, Cecchi E, Chiostri M, Gensini G, Valente S, Ciaccheri M, Castelli G and Romano S (2014) Effects of ULTRAfiltration vs. DIureticS on clinical, biohumoral and haemodynamic variables in patients with deCOmpensated heart failure: the ULTRADISCO study, European Journal of Heart Failure, 10.1093/eurjhf/hfq207, 13:3, (337-346), Online publication date: 1-Mar-2011. Tanaka K, Kodama M, Ito M, Hoyano M, Mitsuma W, Ramadan M, Kashimura T, Hirono S, Okura Y, Kato K, Hanawa H and Aizawa Y (2010) Force-frequency relationship as a predictor of long-term prognosis in patients with heart diseases, Heart and Vessels, 10.1007/s00380-010-0040-1, 26:2, (153-159), Online publication date: 1-Mar-2011. Melenovsky V, Benes J, Skaroupkova P, Sedmera D, Strnad H, Kolar M, Vlcek C, Petrak J, Benes J, Papousek F, Oliyarnyk O, Kazdova L and Cervenka L (2011) Metabolic characterization of volume overload heart failure due to aorto-caval fistula in rats, Molecular and Cellular Biochemistry, 10.1007/s11010-011-0808-3, 354:1-2, (83-96), Online publication date: 1-Aug-2011. Bogaard M, Houthuizen P, Bracke F, Doevendans P, Prinzen F, Meine M and van Gelder B (2014) Baseline left ventricular d P /d t max rather than the acute improvement in d P /d t max predicts clinical outcome in patients with cardiac resynchronization therapy , European Journal of Heart Failure, 10.1093/eurjhf/hfr094, 13:10, (1126-1132), Online publication date: 1-Oct-2011. Shudo Y, Matsumiya G, Takeda K, Matsue H, Taniguchi K and Sawa Y (2011) Novel software package for quantifying local circumferential myocardial stress, International Journal of Cardiology, 10.1016/j.ijcard.2009.05.026, 147:1, (134-136), Online publication date: 1-Feb-2011. Zile M and Baicu C (2011) Alterations in Ventricular Function Heart Failure: A Companion to Braunwald's Heart Disease, 10.1016/B978-1-4160-5895-3.10014-2, (213-231), . Connelly K, Royse C and Royse A (2011) Tissue Doppler Em and Instantaneous End-diastolic Stiffness: Validation Against Pressure–Volume Loops in Patients Undergoing Coronary Artery Bypass Surgery, Heart, Lung and Circulation, 10.1016/j.hlc.2011.01.003, 20:4, (223-230), Online publication date: 1-Apr-2011. Carabello B (2011) Assessment of the patient with valvular heart disease: An integrative approach, Aswan Heart Centre Science & Practice Series, 10.5339/ahcsps.2011.15, 2011:2, Online publication date: 30-Dec-2011. Donal E, Thebault C, O'Connor K, Veillard D, Rosca M, Pierard L and Lancellotti P (2011) Impact of aortic stenosis on longitudinal myocardial deformation during exercise, European Journal of Echocardiography, 10.1093/ejechocard/jeq187, 12:3, (235-241), Online publication date: 1-Mar-2011. Imai H, Kurokawa S, Taneoka M and Baba H (2011) Tissue Doppler imaging is useful for predicting the need for inotropic support after cardiac surgery, Journal of Anesthesia, 10.1007/s00540-011-1231-3, 25:6, (805-811), Online publication date: 1-Dec-2011. Kaditis A, Alexopoulos E, Dalapascha M, Papageorgiou K, Kostadima E, Kaditis D, Gourgoulianis K and Zakynthinos E (2010) Cardiac systolic function in Greek children with obstructive sleep-disordered breathing, Sleep Medicine, 10.1016/j.sleep.2009.05
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