Transthoracic Stimulation Research Articles

Sudden Cardiac Arrest and Death Following Application of Shocks From a TASER Electronic Control Device

The safety of electronic control devices (ECDs) has been questioned. The goal of this study was to analyze in detail cases of loss of consciousness associated with ECD deployment. Eight cases of TASER X26 ECD-induced loss of consciousness were studied. In each instance, when available, police, medical, and emergency response records, ECD dataport interrogation, automated external defibrillator information, ECG strips, depositions, and autopsy results were analyzed. First recorded rhythms were ventricular tachycardia/fibrillation in 6 cases and asystole (after ≈ 30 minutes of nonresponsiveness) in 1 case. An external defibrillator reported a shockable rhythm in 1 case, but no recording was made. This report offers evidence detailing the mechanism by which an ECD can produce transthoracic stimulation resulting in cardiac electrical capture and ventricular arrhythmias leading to cardiac arrest. ECD stimulation can cause cardiac electrical capture and provoke cardiac arrest resulting from ventricular tachycardia/ventricular fibrillation. After prolonged ventricular tachycardia/ventricular fibrillation without resuscitation, asystole develops.

P144 Transthoracic stimulation: Three years of hospital experience

P144 Transthoracic stimulation: Three years of hospital experience

Magnetic stimulation of biceps after intercostal cross-innervation for brachial plexus palsy. A study of motor evoked potentials in 25 patients

We studied the motor evoked potentials (MEP) in the biceps of 25 patients with traumatic brachial plexus palsy from root avulsion after cross-innervation by intercostal nerves. We used transcranial, transcervical and transthoracic magnetic stimulation at 8 to 235 months (mean 51) after transfer of intercostal nerves to the musculocutaneous nerve. Biceps strength recovered to MRC grade 2 in eight patients, grade 3 in three and grade 4 in 14. The mean latency of the MEP in the normal biceps on transcranial stimulation was 12.5 +/- 1.3 ms and on transcervical stimulation 6.3 +/- 1.1 ms. After intercostal reinnervation the mean latency on transcranial stimulation was 21.7 +/- 4.5 ms and on transthoracic stimulation 11.6 +/- 3.8 ms. The latency of the biceps MEP after reinnervation by intercostal nerves on transcranial and transthoracic magnetic stimulation correlated well with the duration of follow-up and the latency of the MEP on transthoracic magnetic stimulation correlated significantly with muscle power.

Transthoracic stimulation: Three years of hospital experience

Transthoracic stimulation: Three years of hospital experience

A volume conductor model of the thorax for the study of defibrillation fields.

The authors develop a physiologically realistic volume conductor model for calculating epicardial potentials during transthoracic stimulation. The objective of the study is to measure cardiac potentials during a transthoracic stimulus and compare the measurements to calculated epicardial potentials obtained from the model. The results for all four stimulus configurations (anterior-posterior, neck-waist, precordial, and right-left) on the torso consistently yield correlation coefficients of about 0.90 and RMS errors of 47% between calculated and measured epicardial potentials for a homogeneous torso. Incorporating the effects of the skeletal muscle layer improves the agreement, i.e., correlation coefficients increase to about 0.914 and RMS errors decrease to about 42%. At the same time, the lungs and heart have little influence on the agreement between measured and calculated epicardial potentials. The results of the study demonstrate the importance of the skeletal muscle layer in physiologically realistic volume conductor models. >