Showing papers by "Helge Skulstad published in 2009"
TL;DR: The accelerometer had the ability to distinguish ischaemia from interventions altering global myocardial function, and can be detected with epicardial three-axis accelerometers.
Abstract: Background We describe a novel technique for continuous real-time assessment of myocardial ischaemia using a three-axis accelerometer. Methods In 14 anaesthetized open-chest pigs, two accelerometers were sutured on the left ventricle (LV) surface in the perfusion areas of the left anterior descending (LAD) and circumflex (CX) arteries. Acceleration was measured in the longitudinal, circumferential, and radial directions, and the corresponding epicardial velocities were calculated. Regional LV dysfunction was induced by LAD occlusion for 60 s. Global LV function was altered by nitroprusside, epinephrine, esmolol, and fluid loading. Epicardial velocities were compared with strain by echocardiography during LAD occlusion and with aortic flow and LV dP/dtmax during interventions on global LV function. Results LAD occlusion induced ischaemia, shown by lengthening in systolic strain in the LV apical anterior region (P Conclusions Myocardial ischaemia can be detected with epicardial three-axis accelerometers. The accelerometer had the ability to distinguish ischaemia from interventions altering global myocardial function. This novel technique may be used for continuous real-time monitoring of myocardial ischaemia during and after cardiac surgery.
34 citations
TL;DR: Intracoronary shunt prevents ischemia during grafting of the left anterior descending coronary artery and provides satisfactory immediate- and short-term graft patency.
27 citations
TL;DR: A mathematical method to separate translational and gravitational acceleration components based on a priori assumptions of myocardial motion was developed, giving very good agreement with the reference methods.
Abstract: In this study we have investigated the accuracy of an accelerometer sensor designed for the measurement of cardiac motion and automatic detection of motion abnormalities caused by myocardial ischaemia. The accelerometer, attached to the left ventricular wall, changed its orientation relative to the direction of gravity during the cardiac cycle. This caused a varying gravity component in the measured acceleration signal that introduced an error in the calculation of myocardial motion. Circumferential displacement, velocity and rotation of the left ventricular apical region were calculated from the measured acceleration signal. We developed a mathematical method to separate translational and gravitational acceleration components based on a priori assumptions of myocardial motion. The accuracy of the measured motion was investigated by comparison with known motion of a robot arm programmed to move like the heart wall. The accuracy was also investigated in an animal study. The sensor measurements were compared with simultaneously recorded motion from a robot arm attached next to the sensor on the heart and with measured motion by echocardiography and a video camera. The developed compensation method for the varying gravity component improved the accuracy of the calculated velocity and displacement traces, giving very good agreement with the reference methods.
13 citations
TL;DR: This combined experimental and clinical study using an epicardial accelerometer aimed to test two methods for real-time automated detection of myocardial ischemia.
Abstract: Epicardial accelerometers have proved to detect myocardial ischemia with high sensitivity [1]. In this combined experimental and clinical study using an epicardial accelerometer, we aimed to test two methods for real-time automated detection of myocardial ischemia.
9 citations