NEW ASPECTS OF VENTRICULAR ASSIST DEVICES Edited by Guillermo Reyes New Aspects of Ventricular Assist Devices Edited by Guillermo Reyes Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Iva Lipovic Technical Editor Teodora Smiljanic Cover Designer Jan Hyrat Image Copyright Sebastian Kaulitzki, 2010. Used under license from Shutterstock.com First published August, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org New Aspects of Ventricular Assist Devices, Edited by Guillermo Reyes p. cm. ISBN 978-953-307-676-8 Contents Preface VII Part 1 Physiopathology of Ventricular Assist Devices 1 Chapter 1 Importance of Arterial Conduit Function Assessment in Chronic Congestive Heart Failure: Predictors of True Circulatory Decompensation for Optimal Timing of Mechanical Circulatory Support 3 Henryk Siniawski and Roland Hetzer Chapter 2 Left Ventricular Assist Devices: Engineering Design Considerations 21 Marwan A. Simaan, George Faragallah, Yu Wang and Eduardo Divo Chapter 3 Evaluation of Cardiac Function after VAD Implantation 43 John Terrovitis, Eleni Tseliou, Stavros Drakos and John Nanas Part 2 Clinical Aspects of Ventricular Assist Devices 65 Chapter 4 Ventricular Assist Device: Emerging Modality for Long Term Cardiac Support 67 Rachit Shah, Sharath Kommu, Rohit Bhuriya and Rohit Arora Chapter 5 Myocardial Recovery Following Left Ventricular Assist Device Therapy 83 M. Navaratnarajah, M. Ibrahim, M. Yacoub and C. Terracciano Chapter 6 Risk Factor Analysis and Management of Cerebrovascular Accidents in Japanese Patients Supported by Left Ventricular Assist Device 105 Tomoko S. Kato, Kazuo Komamura, Ikutaro Nakajima, Ayako Takahashi, Noboru Oda and Masafumi Kitakaze Chapter 7 Ventricular Assist Devices for Pediatric Heart Disease 115 Cenk Eray Yildiz Preface Ventricular assist devices are the future, but also the present. They are meant not only to increase the survival of patients, but also to improve their quality of life. The technology that involves these devices improves every year. It is essential not only to choose the right patient for a VAD implantation, but also to know when is the right time to do it. It is very important to be updated about the advances in VAD technology, the physiopathology of the assisted heart and the outcomes of patients who receive this therapy. Now VADs are available for short, intermediate and long term support. This means that a wide spectrum of patients may benefit from this therapy. The associated complications following the use of VAD will be reduced with the use of more modern devices, a better understanding of the physiopathology of the assisted heart and a better patient selection. Numerous international authors have participated in the creation of this book. We have compiled their experience and their concern about ventricle assist device therapy. In order to organize the book content two sections have been created. First part will focus on aspects concerning how the heart will behave when a VAD is implanted and some new aspects regarding VAD technology. Secondly, clinical outcomes and others aspects of patients are updated and commented in different ways. I would like to thank especially the authors of this book. They have shared their experience, knowledge and time with all of us. To care for patients and spread our knowledge may be sometimes the first step to achieve our goal. Dr. Guillermo Reyes Department of Cardiovascular Surgery La Princesa University Hospital, Madrid Spain Part 1 Physiopathology of Ventricular Assist Devices [...]... optimal time-point for the implantation of mechanical circulatory support Finding the optimal time also means that univentricular (usually left ventricular) support 4 New Aspects of Ventricular Assist Devices may be sufficient In such cases the outcome is better than with extracorporeal support of both ventricles The goal of assessment of the “circulatory reserve” of the individual patient suffering from... in the carotid artery it defines the cooperation of the heart with the arterial conduit (aorta and arterial system) as a whole and not exclusively the arterial system of the heart This is the law of “connected compartments” (vessels) Our results 16 New Aspects of Ventricular Assist Devices documented the true importance of WI assessment in defining lack of circulatory reserves, although for patients... first phase of systole (Fig 5A) The 2nd peak is high (approx 8800 mmHg*s³) and produced by sharply falling pressure and flow (even below the zero line) during the last phase of systole The diameter of the artery was significantly larger than 12 New Aspects of Ventricular Assist Devices during reduced Impella flow (6.93±1.39 vs 6.45±1.97 mm respectively, p = 0.003) Reduced systolic function of the diseased... beta value (β), diameter of the artery studied, minimal and maximal flow in the artery 10 New Aspects of Ventricular Assist Devices and dynamic changes in real time of several other parameters The T wave was not found to have prognostic importance in our studies The 2nd peak of WI (“expansion wave”) is calculated in the same way as the 1st peak, which means that it is the result of algebraically calculated... left ventricular dysfunction post myocardial infarction, but only in those with signs and symptoms of heart failure Circulation 2007; 116: II 579 [46] Van Vliet BN, Montaini JP Baroreflex stabilization of the double product Am J Physiol 1999;277:H1679-89 20 New Aspects of Ventricular Assist Devices [47] Niki K, Sugawara M, Chang D, Harada A, Okada T, Sakai R, Uchida K, Tanaka R, Mumford CE A new noninvasive... derivatives of pressure/flow (dU/ dt) • (dV / dt) is reduced to 50% of the previous strong beat The 2nd peak is preserved and both peaks are at the level of 1800 mmHg*s³ The high 2nd peak of WI is exemplified by a negative and sharp fall in the product of the derivatives pressure and flow recorded simultaneously An explanation of the reduction of the 1st and preservation of the 2nd Importance of Arterial... simultaneous analysis of pressure change and flow signals sampled during short constant intervals (5 ms) can be used for real-time non-invasive WI (NWI) analysis 8 New Aspects of Ventricular Assist Devices The waveform of carotid wall displacement (dU) closely corresponds to pressure change (dP) in a carotid artery measured invasively with high correlation quotient (goodness of fit r²=0.97) and can... wave” and is mathematically positive as a product of two positive values of first derivatives of pressure and flow waveform as demonstrated mathematically (Fig 1) The compression wave of the 1st peak of WI describes the state of myocardial contractility of the LV in relation to the afterload At the end of isovolumic contraction (which is the beginning of the 1st peak) the LV pressure becomes equal to... is 6 New Aspects of Ventricular Assist Devices hardly able to raise cardiac output by more than 10% The arterial tree can change the distribution of perfusion, depending on the acute need, to supply the more important organs and let other organs “hibernate.” The physiological process known as “preconditioning” is responsible for the smoothly functioning economy of the body with a constant lack of oxygen... elastance expression used in our model is modified New Aspects of Ventricular Assist Devices 24 according to E(t)=δEH(t) That is, the elastance E(t) is scaled version of EH(t) with a factor 0 . NEW ASPECTS OF VENTRICULAR ASSIST DEVICES Edited by Guillermo Reyes New Aspects of Ventricular Assist Devices Edited by Guillermo. univentricular (usually left ventricular) support New Aspects of Ventricular Assist Devices 4 may be sufficient. In such cases the outcome is better than with extracorporeal support of. of Cardiac Function after VAD Implantation 43 John Terrovitis, Eleni Tseliou, Stavros Drakos and John Nanas Part 2 Clinical Aspects of Ventricular Assist Devices 65 Chapter 4 Ventricular Assist