Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Rationale, design and methodology for Intraventricular Pressure Gradients Study: a novel approach for ventricular filling assessment in normal and falling hearts. | Guerra et al. Journal of Cardiothoracic Surgery 2011 6 67 http content 6 1 67 JCTS JOURNAL OF CARDIOTHORACIC SURGERY STUDY PROTOCOL Open Access Rationale design and methodology for Intraventricular Pressure Gradients Study a novel approach for ventricular filling assessment in normal and falling hearts Ỷ 3Ỷ 2 2 13 Miguel Guerra 1 Mário J Amorim João C Mota Luis Vouga and Adelino Leite-Moreira 1 Abstract Background Intraventricular pressure gradients have been described between the base and the apex of the left ventricle during early diastolic ventricular filling as well as their increase after systolic and diastolic function improvement. Although systolic gradients have also been observed data are lacking on their magnitude and modulation during cardiac dysfunction. Furthermore we know that segmental dysfunction interferes with the normal sequence of regional contraction and might be expected to alter the physiological intraventricular pressure gradients. The study hypothesis is that systolic and diastolic gradients a marker of normal left ventricular function may be related to physiological asynchrony between basal and apical myocardial segments and they can be attenuated lost entirely or even reversed when ventricular filling emptying is impaired by regional acute ischemia or severe aortic stenosis. Methods Design Animal Studies Six rabbits will be completely instrumented to measuring apex to outflow-tract pressure gradient and apical and basal myocardial segments lengthening changes at basal afterloaded and ischemic conditions. Afterload increase will be performed by abruptly narrowing or occluding the ascending aorta during the diastole and myocardial ischemia will be induced by left coronary artery ligation after the first diagonal branch. Patient Studies Patients between 65-80 years old n 12 both genders with severe aortic stenosis referred for aortic valve replacement will be selected as eligible subjects. A high-fidelity .
