Inappropriate shocks delivered by implantable cardiac defibrillators during oversensing of activity of diaphagmatic muscle.
Two cases are reported (both men, one 72 and one 54 years old) of inappropriate shocks delivered by an implantable cardiac defibrillator (ICD) device, which oversensed the myopotentials induced by deep breathing and Valsalva manoeuvre. No damage to leads was associated with the oversensing of myopotentials. The mechanism of the inappropriate shocks was determined using real time electrograms. Modification of the duration of ventricular detection and decrease in sensitivity made it possible to avoid the oversensing of myopotentials and to deliver ICD treatment. (+info)
Transient quadriparesis after electric shock.
A case of acute transient flaccid quadriparesis after a low voltage electric shock is reported. The patient recovered completely with in three days. (+info)
Radiofrequency electrocution (196 MHz).
Radiofrequency (RF) electrocutions are uncommon. A case of electrocution at 196 MHz is presented partly because there are no previous reports with frequencies as high as this, and partly to assist in safety standard setting. A 53-year-old technician received two brief exposures to both hands of 2A current at 196 MHz. He did not experience shock or burn. Progressively over the next days and months he developed joint pains in the hands, wrists and elbows, altered temperature and touch sensation and parasthesiae. Extensive investigation found no frank neurological abnormality, but there were changes in temperature perception in the palms and a difference in temperature between hands. His symptoms were partly alleviated with ultra-sound therapy, phenoxybenzamine and glyceryl trinitrate patches locally applied, but after several months he continues to have some symptoms. The biophysics and clinical aspects are discussed. It is postulated that there was mainly surface flow of current and the micro-vasculature was effected. Differences to 50 Hz electrocution are noted. Electrocution at 196 MHz, even in the absence of burns may cause long-term morbidity to which physicians should be alerted. Safety standards should consider protection from electrocution at these frequencies. (+info)
Alpha(2)-antiplasmin gene deficiency in mice does not affect neointima formation after vascular injury.
The hypothesis that alpha(2)-antiplasmin (alpha(2)-AP), the main physiological plasmin inhibitor, plays a role in neointima formation was tested with use of a vascular injury model in wild-type (alpha(2)-AP(+/+)) and alpha(2)-AP-deficient (alpha(2)-AP(-/-)) mice. The neointimal and medial areas were similar 1 to 3 weeks after electric injury of the femoral artery in alpha(2)-AP(+/+) and alpha(2)-AP(-/-) mice, resulting in comparable intima/media ratios (eg, 0.43+/-0.12 and 0.42+/-0.11 2 weeks after injury). Nuclear cell counts in cross-sectional areas of the intima of the injured region were also comparable in arteries from alpha(2)-AP(+/+) and alpha(2)-AP(-/-) mice (78+/-19 and 69+/-8). Fibrin deposition was not significantly different in arteries of both genotypes 1 day after injury, and no mural thrombosis was detected 1 week after injury. Fibrinolytic activity in femoral arterial sections, as monitored by fibrin zymography, was higher in alpha(2)-AP(-/-) mice 1 week after injury (P<0.001) but was comparable in both genotypes 2 and 3 weeks after injury. Staining for elastin did not reveal significant degradation of the internal elastica lamina in either genotype. Immunocytochemical analysis revealed a comparable distribution pattern of alpha-actin-positive smooth muscle cells in both genotypes. These findings indicate that the endogenous fibrinolytic system of alpha(2)-AP(+/+) mice is capable of preventing fibrin deposition after vascular injury and suggest that alpha(2)-AP does not play a major role in smooth muscle cell migration and neointima formation in vivo. (+info)
Neuropsychiatric profile of a case of post traumatic stress disorder following an electric shock.
Exposure to extraordinary stressors or life-threatening events has been shown to result in negative cognitive, behavioural and emotional outcomes including the cluster of symptoms constituting Post Traumatic Stress Disorder (PTSD). This disorder has most often been studied in military veterans and victims of abuse who also show high rates of comorbid conditions. We report a case of PTSD following an electrical injury in a patient with no past psychiatric history. Implications for a full range of examinations including comprehensive neuropsychiatric testing are discussed. Results suggest that such approach addresses the complexity of a differential diagnosis between organic and psychiatric dysfunctions. (+info)
Leakage of energy to the body surface during defibrillation shock by an implantable cardioverter-defibrillator (ICD) system--experimental evaluation during defibrillation shocks through the right ventricular lead and the subcutaneous active-can in canines.
The leakage of electrical current to the body surface during defibrillation shock delivery by an implantable cardioverter-defibrillator (ICD) device (the Medtronic Jewel Plus PCD system) was evaluated in 5 dogs. The defibrillation shocks were delivered between the active-can implanted in the left subclavicular region and the endocardial lead placed in the right ventricle at the energy levels of 1, 2, 8, 12, 24 and 34 J. During each delivery, the electrical current leakage from the body surface was measured by electrodes connected to a circuit at 4 recording positions: (A) parallel-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the left shoulder and the right lower chest, and the direction of the electrode vector was parallel to the direction of the defibrillation energy flow); (B) cross-subcutaneous (the electrodes were fixed in the subcutaneous tissue of the right shoulder and the left lower chest, and the vector of the electrodes was roughly perpendicular to the direction of the energy flow); (C) parallel-surface (the electrodes were fixed with ECG paste on the shaved skin surface at the left shoulder and the right lower chest); and (D) surface grounded (the electrodes were fixed on the shaved skin surface at the left shoulder and the left foot, which was grounded). The circuit resistance was set at a variable level (100-5,000 ohms) in accordance with the resistance measured through each canine body. Leakage energies were measured in 750 defibrillation shocks with each circuit resistance in 5 dogs. The leakage energy increased in accordance with the increase of the delivered energy and the decrease of the circuit resistance in all 4 recording positions. When the circuit resistance was set at 1,000 ohms, the leakage energy during shock delivery at 34 J was 32+/-17 mJ at position A, 5+/-9 mJ at B, 10+/-9 mJ at C, and 4+/-3 mJ at D (p=0.042). The peak current was highest at position A and was 87+/-22 mA with a circuit resistance of 1,000 ohms. The power of the leakage energy depended on the delivered energy and the impedance between the electrodes. The angle between the alignment of the recording electrodes and the direction of the energy flow was another important factor in determining the leakage energy. Although the peak current of the leakage energy reached the level of macro shock, the highest leakage energy from the body surface was considerably less because of the short duration of the shock delivery. (+info)
Inappropriate discharges from an intravenous implantable cardioverter defibrillator due to T-wave oversensing.
This report describes the clinical management of 2 patients with ventricular fibrillation (VF) who received inappropriate shocks from an implantable cardioverter defibrillator (ICD) due to T-wave oversensing. Cardiac sarcoidosis was confirmed as the underlying heart disease in 1 patient and idiopathic dilated cardiomyopathy in the other. Within 2 months after ICD implantation, both patients received several inappropriate shocks during sinus rhythm. Stored electrograms showed decreased R-wave amplitudes and increased T-wave amplitudes. The ICD sensed both R- and T-waves as ventricular activation, which met the rate criteria for VF treatment. Reprogramming the sensing threshold in association with administration of a drug to slow the heart rate decreased the incidence of the inappropriate shocks in both patients, but these palliative measures did not completely suppress the inappropriate shocks. To avoid T-wave oversensing, the repositioning or adding of a sensing lead is required. The potential risk of T-wave oversensing in ICD patients who have small R-wave amplitudes should be recognized. (+info)
Correlation between serum IL-6 levels and death: usefulness in diagnosis of "traumatic shock"?
Interleukin-6 (IL-6) has been considered as an important mediator of inflammation. Clinically it is a well-known marker of the severity of injury following major trauma. In this study, the levels of IL-6 in body serum were applied to a traumatic death index. Of ninety victims 55 were men and 35 women, with a mean age of 53.4+/- 19 (S.D.) years. The cases were classified as traumatic deaths (38 cases), non-traumatic deaths other than natural causes of deaths (36 cases), and deaths due to natural causes (16 cases). All samples were collected within 2 days after death. The mean values of IL-6 levels of the traumatic, non-traumatic and disease groups were 8608.97, 2205.65, and 3266.64 pg/ml, respectively. Some cases in non-traumatic and disease cases were beyond 10 000 pg/ml, however, the mean value of the traumatic group was statistically higher than that of the other two groups. Even though several cases had high levels of IL-6 in spite of instantaneous death, the results showed that IL-6 levels are helpful in the diagnosis of traumatic shock. (+info)