| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Medicine, University of Melbourne, Melbourne, Vic, Australia; Department of Epidemiology & Preventive Medicine and Department of Medicine, Monash University, Melbourne, Vic, Australia
2 Medicine, University of Melbourne, Melbourne, Vic, Australia
3 Cardiac Mechanics Research Laboratory, Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
4 Cardiac Investigation Unit, St Vincent's Hospital, Melbourne, Vic, Australia
* To whom correspondence should be addressed. E-mail: connelly{at}medstv.unimelb.edu.au.
Transgenic animal models have provided a vital insight into the pathogenesis of cardiovascular disease, but functional cardiac assessment is often limited by high heart rates and small heart size. We hypothesized that in the presence of concentric left ventricular hypertrophy (LVH), load sensitive measures of contractility may be misinterpreted as overestimating global cardiac function, because normal function of excess sarcomeres may displace a greater volume of blood during contraction. Conductance catheter technology was used to evaluate pressure-volume (PV) relationships as a load insensitive method of assessing cardiac function in-vivo in eighteen week heterozygous (mRen-2)27 transgenic rats (a model of LVH), compared with aged matched Sprague Dawley (SD) controls. Load sensitive measures of systolic function including fractional area change, fractional shortening, ejection fraction and dP/dt max were greater in the Ren-2 than control animals (p<0.05). Load insensitive measures of systolic function, including the preload recruitable stroke work relationship and the end systolic pressure volume relationship, were not different between Ren-2 and SD rats. Regional wall motion assessed by circumferential shortening velocity suggested enhanced circumferential fiber contractility in the Ren-2 rats (p=0.02), but tissue Doppler imaging, used to assess longitudinal function, was not different between groups. Although conventional measures suggested enhanced systolic function in the Ren-2 rat, load insensitive measures of contractility were not different between Ren-2 and SD animals. These findings suggest that the normal range of values for load sensitive indices of contractility needs to be altered according to the degree of LVH. To accurately identify changes in systolic function, we suggest that a combination of echocardiography with assessment of load insensitive measures be used routinely.
This article has been cited by other articles:
|
|
 |
|
  K. A. Connelly, D. J. Kelly, Y. Zhang, D. L. Prior, A. Advani, A. J. Cox, K. Thai, H. Krum, and R. E. Gilbert Inhibition of Protein Kinase C-{beta} by Ruboxistaurin Preserves Cardiac Function and Reduces Extracellular Matrix Production in Diabetic Cardiomyopathy Circ Heart Fail, March 1, 2009; 2(2): 129 - 137. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Phrommintikul, L. Tran, A. Kompa, B. Wang, A. Adrahtas, D. Cantwell, D. J. Kelly, and H. Krum Effects of a Rho kinase inhibitor on pressure overload induced cardiac hypertrophy and associated diastolic dysfunction Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1804 - H1814. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Ganame, L. Mertens, B. W. Eidem, P. Claus, J. D'hooge, L. M. Havemann, C. J. McMahon, M. A. A. Elayda, W. K. Vaughn, J. A. Towbin, et al. Regional myocardial deformation in children with hypertrophic cardiomyopathy: morphological and clinical correlations Eur. Heart J., December 1, 2007; 28(23): 2886 - 2894. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Kelly, Y. Zhang, K. Connelly, A. J. Cox, J. Martin, H. Krum, and R. E. Gilbert Tranilast attenuates diastolic dysfunction and structural injury in experimental diabetic cardiomyopathy Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H2860 - H2869. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K.A. Connelly, D.J. Kelly, Y. Zhang, D.L. Prior, J. Martin, A.J. Cox, K. Thai, M.P. Feneley, J. Tsoporis, K.E. White, et al. Functional, structural and molecular aspects of diastolic heart failure in the diabetic (mRen-2)27 rat Cardiovasc Res, November 1, 2007; 76(2): 280 - 291. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Ballo, A. Bocelli, and S. Mondillo Adaptive and Maladaptive Cardiac Hypertrophy: What Is the Effective Role of Heat Shock Transcription Factor 1? Circ. Res., February 16, 2007; 100(3): e45 - e46. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
