Effects of Strong Electrical Shock on Cardiac Muscle Tissuea

A computer modeling tool for comparing novel ICD electrode orientations in children and adults

“…Such a finding necessitates that a portion of the heart to be subjected to high voltage gradients in order to raise the rest of myocardium above the voltage gradient threshold. Such gradients have been shown experimentally to have the potential to cause electroporation and potential arrythmogenesis 27,28 . The actual clinical morbidity associated with these effects is unknown, and perhaps represent a competing risk of certain defibrillation strategies.…”

“…We also calculated the percentage of myocardium with voltage gradient above 30V/cm at defibrillation threshold, to predict possible areas of myocardial damage. 27,28 SCIRun was utilized to visualize all these parameters interactively (see Figures for examples). In addition, the percentage of myocardium above the defibrillation threshold was calculated and visualized by projecting a color scale onto the myocardial elements.…”

How the Subcutaneous Implantable Cardioverter Defibrillator Works

“…17 These high voltage gradients have been shown to damage myocytes in animal models, an effect known as electroporation, and clinically manifest by transient decreases in contractility and troponin release, and at voltage gradients greater than 50 V per cm electrical stunning and postshock ventricular arrhythmias. [18][19][20][21][22] In contrast, the S-ICD more closely approximates an ideal model of defibrillation. By placing electrodes farther from the heart, myocardial voltage gradients are expected to be more spatially uniform.…”

Complex Structure and Dynamics of the Heart

“…Afterwards, the low-frequency impulses of the sinoatrial node (see section 1.2) can excite the heart and restore normal sinus rhythm. There is contradictory evidence whether the shock energies used in today's defibrillators can cause considerable injury of the cardiac muscle [69,70] and possibly increase the risk of future arrhythmias by introducing additional structural heterogeneity. A second important problem is that ICD therapy is also associated with severe psychological implications such as anxiety and reduced quality of life [71], mainly due to defibrillating shocks delivered during consciousness.…”

“…In addition, the p j are correspond directly to the integrals of equations (3.63) via the relations 69) provided that E i andR i are related by equation (3.59) or equation (3.60)…”