Comparison of measured and calculated epicardial potential during transthoracic stimulation

The authors develop a physiologically realistic volume conductor model for calculating epicardial potentials during transthoracic stimulation to measure cardiac potentials during a transthoracic stimulus, and compare the measurements to calculated epicardial potentials obtained from the model. Potential measurements during a stimulus are recorded for three closed chest dogs. Four different torso electrode combinations (anterior-posterior, neck-waist, precordial and right-left lateral) are used to deliver the stimulus. A boundary integral model is developed which utilizes electrode, heart, and torso geometry, the surface geometry from lung and skeletal muscle interfaces, and internal inhomogeneity conductivities to compute epicardial potentials from a knowledge of stimulus strength and location.<>