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Jeanette Strametz-Juranek

Publications and source records attributed to Jeanette Strametz-Juranek.

3 recordsLinked to original sources
PubMed2006

Interference of programmed electromagnetic stimulation with pacemakers and automatic implantable cardioverter defibrillators.

A commercially available magnetic therapy system, designed for clinical application as well as for private use without medical supervision, was examined with respect to its potential for causing electromagnetic interference with implantable pacemakers (PMs) and automatic implantable cardioverter defibrillators (AICDs). A sample of 15 PMs and 5 AICDs were experimentally investigated. Each of the implants was realistically positioned in a homogeneous, electrically passive torso phantom and exposed to the magnetic fields of the system's applicators (whole body mat, cushion, and bar applicator). The detection thresholds of the implants were programmed to maximum sensitivity and both unipolar as well as bipolar electrode configurations were considered. The evaluation of possible interferences was derived from the internal event storages and pacing statistics recorded by the implants during exposure. Any "heart activity" recorded by the implants during exposure was interpreted as a potential interference, because the implant obviously misinterpreted the external interference signal as a physiological signal. Only cases without any recorded "heart activity" and with nominal pacing rates (as expected from the program parameter settings) of the implants were rated as "interference-free." Exposure to the whole body mat (peak magnetic induction up to 265 microT) did not show an influence on PMs and AICD in any case. The cushion applicator at the highest field intensity (peak magnetic induction up to 360 microT) led to atrial sensing defects in four PM models with unipolar electrode configuration. Under bipolar electrode configuration no disturbances occurred. The bar applicator led to sensing problems and consecutively reduced pacing rates in all tested PM models under unipolar electrode configuration and maximum field intensity (peak magnetic induction up to 980 microT). Bipolar electrode configuration resolved the problem. The investigated AICDs did not show malfunctions under any investigated condition. In conclusion, the examined PEMF therapy system did not interfere with the investigated implantable cardiac devices with bipolar electrode configuration. However, unipolar electrode configuration in pacemakers seems to be potentially hazardous during application of the examined PEMF therapy system.

Defibrillators, Implantable↗
PubMed2003

Sequential big endothelin plasma levels in heart transplant recipients during bridging therapy and after successful heart transplantation.

BACKGROUND: The purpose of this study was to investigate the impact of successful heart transplantation in patients with refractory heart failure receiving bridging therapy on sequential plasma levels of big endothelin, norepinephrine, atrial natriuretic peptide and aldosterone. METHODS: Fourteen patients (2 women, 12 men) accepted for heart transplantation were studied. All had severe chronic heart failure refractory to optimized oral therapy with angiotensin-converting enzyme inhibitors and furosemide, were in New York Heart Association functional Class IV, and had a left ventricular ejection fraction of <15%, Right heart catheterization was performed in all patients (cardiac index 1.9 +/- 0.1 liters/min. m(2), pulmonary capillary wedge pressure 30 +/- 2 mmHg, systemic vascular resistance index 2,827 +/- 253 dyn. s/cm(5). m(2)). As bridging therapy, patients received either prostaglandin E(1), prostaglandin E(1) and dobutamine or dobutamine alone as a continuous infusion. Neurohumoral variables were measured prior to bridging therapy and 3.5 months before and 7 and 10 months after successful heart transplantation. RESULTS: Big endothelin, norepinephrine and atrial natriuretic peptide plasma levels decreased from 7.4 +/- 2.9 fmol/ml, 1112 +/- 686 pg/ml and 366 +/- 312 pg/ml to 6.0 +/- 4.5 fmol/ml, 720 +/- 503 pg/ml and 198 +/- 160 pg/ml, respectively, after bridging therapy, and further to 2.1 +/- 0.9 fmol/ml (p < 0.00001 vs baseline), 527 +/- 31 pg/ml (p < 0.02 vs baseline) and 115 +/- 70 pg/ml (p < 0.03 vs baseline), respectively, after cardiac transplantation. Aldosterone plasma levels decreased from 242 +/- 220 pg/ml to 183 +/- 142 pg/ml during bridging therapy and increased after heart transplantation to 252 +/- 189 pg/ml. Plasma creatinine levels increased from 1.2 +/- 0.4 mg/dl at baseline to 1.4 +/- 0.2 mg/dl after transplantation (NS). CONCLUSIONS: The study suggests that excessive overproduction of big endothelin, atrial natriuretic peptide and norepinephrine is predominantly related to pump failure and, after cardiac transplantation, a moderate spillover of big endothelin persists. Its specific origin, however, remains to be elucidated. Furthermore, our data suggest a protective effect of prostaglandin E(1) on kidney function after heart transplantation.

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