Ann Thorac Surg 2005;80:2255-2256
© 2005 The Society of Thoracic Surgeons
Original article: Cardiovascular
Invited commentary
Jerry Braun, MD
Department of Cardiothoracic Surgery, Leiden University Medical Center, Postbus 9600, Leiden, 2300 RC the Netherlands
(Email: j.braun{at}lumc.nl).
Surgeons are increasingly challenged by the sequelae of left ventricular remodeling secondary to ischemic heart disease. Current therapeutic options in ischemic end-stage heart failure surgery (ie, surgical ventricular restoration, restrictive mitral annuloplasty, and application of cardiac support devices) are empirically implemented and evaluated. Although steady progress is made, very little is known about the underlying pathophysiologic changes inducing and perpetuating LV remodeling, and even less knowledge exists as to which factors determine successful reverse remodeling.
With their ovine model, Jackson and colleagues [1] have already provided many valuable contributions toward understanding the remodeling changes that occur in the infarcted ventricle. In this study, they evaluate the ability of three-dimensional contrast enhanced echocardiography (3DCE) to assess geometric changes in the borderzone myocardium, the normally perfused but hypocontractile myocardium adjacent to the infarcted area. This novel approach combines evaluation of form (geometrical shape) and function (perfusional status and contractility). New observations made in this study are the myocardial thickening and inward curvature (ie, convex towards the LV lumen) of the borderzone myocardium in the long axis (ie, meridianal or zenithal direction). This paradoxical finding supports the hypothesis that infarction-induced LV geometry changes cannot only be explained by increased wall stress alone, but may reflect a complex interaction of intrinsic myocardial changes and wall stress.
Surgery for heart failure should be tailored, as we experience in our daily practice. Imaging techniques that currently aid us in decision making and evaluating our results (ie, dobutamine stress echocardiography, SPECT imaging, magnetic resonance imaging and LV pressure-volume loops measurements) each have their own limitations. Especially in surgical ventricular restoration, imaging modalities to assess the contractile reserve preoperatively and the ability of the remote myocardium to show reverse remodeling postoperatively are essential to achieve optimal results. Improving imaging techniques combined with basic research models of (reverse) remodeling will allow us to further refine our patient selection criteria and the surgical approach in this increasing group of patients. As yet, the clinical implementation of 3DCE will not take place in the near future, but the exciting findings in this study will make us look forward to future technical advancements with this technique and further lessons to be learnt from the ovine model.
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References
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- Jackson BM, Parish LM, Gorman III JH, et al. Borderzone geometry after acute myocardial infarctiona three-dimensional contrast enhanced echocardiographic study. Ann Thorac Surg 2005;80:2250-2256.[Abstract/Free Full Text]
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