[Crataegus Special Extract WS 1442. Assessment of objective effectiveness in patients with heart failure (NYHA II)]. / Crataegus-Spezialextrakt WS 1442. Objektiver Wirksamkeitsnachweis bei Patienten mit Herzinsuffizienz (NYHA II).

METHOD: In a multicenter, placebo-controlled double-blind study, the efficacy of the Crataegus-Specialextrakt WS 1442 in patients with NYHA stage II cardiac insufficiency was investigated. A total of 136 patients with this diagnosis were admitted to the study and, following a 2-week run-in phase, treated with Crataegus-Specialextract or placebo over a period of 8 weeks. The primary target parameter was the change in the difference of the pressure, heart rate product (systolic blood pressure x heart rate/100) (PHRP 50 W load vs. rest) measured at the beginning and end of treatment. RESULTS: On the basis of this variable, a clear improvement in the performance of the heart was shown in the group receiving the test substance, while the condition of the placebo group progressively worsened. The therapeutic difference between the groups was statistically significant. The positive result for the objective efficacy parameter was confirmed by a statistically obvious superiority of Crataegus in the patient's own assessment of improvement in the main symptoms (reduced performance, shortness of breath, ankle edema etc.). In addition, active treatment led, in comparison with placebo, to a considerably better quality of life for the patient, in particular with respect to mental well-being. The tolerability of the active substance proved to be very good-as shown by comprehensive laboratory investigations and the recording of undesirable events. CONCLUSION: All in all, the results of the present clinical investigation confirm those of previous studies showing that Crataegus-Specialextrakt WS 1442 is an effective and low-risk phytotherapeutic form of treatment in patients with NYHA II cardiac insufficiency.

Congenital myocardial sympathetic dysinnervation (CMSD)--a structural defect of idiopathic long QT syndrome.

Concerning the pathogenetic mechanism of idiopathic long QT syndrome (LQTS), the hypothesis of a specific sympathetic imbalance has gained general acceptance, but its validity has never been proven. To test this hypothesis I-123-MIBG, an analogue of norepinephrine and guanethidine, was used to provide scintigraphic display of the efferent cardiac sympathetic innervation. Twelve members of four LQTS families (mean age 38.2 +/- 17.2 years, eight males) and eight healthy volunteers (mean age 48.2 +/- 13.3 years, five males) were studied by means of I-123-MIBG single photon emission computed tomography (SPECT). A quantitative analysis of all scans was performed. All scans of the healthy volunteers show a uniform tracer uptake with sometimes slightly decreased activity in the apex. (1) All patients with QTc greater than 440 msec (n = 5); (2) all, who had suffered from at least one episode of torsade de pointes, ventricular fibrillation (VF) or syncope (n = 5); and (3) all symptomatic patients with QTc prolongation (n = 4) have reduced or abolished (P less than 0.02) MIBG uptakes in the inferior and inferior septal parts of the left ventricle (congenital myocardial sympathetic dysinnervation [CMSD]). Additionally, one female without symptoms or QTc prolongation (LQT) shows an abnormal MIBG SPECT similar to the one of her daughter, who has LQT and symptoms. One male without LQT, who had suffered from VF shows CMSD similar to his father, who has LQT, but no symptoms. All members of the families with normal MIBG SPECTs have neither LQT nor symptoms. In all families CMSD fulfills the criteria of autosomal-dominant inheritance. Normal QTc-interval predicted only in 57% normal cardiac sympathetic innervation in the present LQTS families. Therefore, quantitative I-123-MIBG SPECT enables to identify myocardial sympathetic dysinnervation as structural defect in LQTS. CMSD is associated with and without LQT and presents a pattern of autosomal-dominant inheritance. LQT at rest or during exercise was specific (100%), but less sensitive (63%) in the assessment of CMSD than I-123-MIBG SPECT.

[Magnetocardiography. Biomagnetic localization of impulse development and transmission of the heart]. / Magnetokardiographie. Biomagnetische Lokalisation von Reizbildung und Erregungsleitung am Herzen.

Magnetocardiography is a non-invasive biomagnetic technique for measuring magnetic fields produced at the surface of the body when the heart is stimulated to beat. The measurement is contact-free and is independent of tissue resistance. For the first time, magnetocardiography employing multi-channel systems permits the accurate, non-invasive localization of accessory conduction pathways and ectopic ventricular activity.

Biomagnetic localization of ventricular arrhythmias.

The magnetic fields caused by electrical activity of the human heart can be coherently measured with a highly sensitive, multichannel, superconducting quantum interference-device system and can enable noninvasive localization of the underlying electrical activity. The magnetocardiograms (MCGs) of 10 patients with spontaneous premature ventricular complexes (PVCs), three patients with ventricular tachycardia (VT), and four healthy subjects with induced paced beats were recorded for 2-15 minutes. After correction for superimposed repolarization activity, the site of origin of the arrhythmias was localized from the magnetic field distribution at the onset of the ectopic beats. The localization results of paced beats showed an error of a few millimeters in relation to the position of the catheter tip. The results of spontaneous PVC and VT were confirmed with endocardial mapping or associated with ischemic lesions. The authors conclude that multichannel magnetocardiographic studies enable the completely noninvasive localization of ventricular arrhythmias.

[Anatomic variants in the peripheral conduction system of the heart. Are there electrocardiography correlates?]. / Anatomische Varianten im peripheren Reizleitungssystem des Herzens. Gibt es elektrokardiographische Korrelate?

Anatomical variations of the peripheral conduction system are a very common finding. One of these variations are the so-called aberrant tendons, which are found in about 67% of the hearts. In this paper the possible correlation between these anatomical variations and disturbances of conduction in the electrocardiogram is discussed.

[In-vitro-study and patient examinations with MRT: the significance of metal implants]. / In-vitro- und Patientenuntersuchungen mittels MRT: Bedeutung metallischer Implantate.

This study presents the results of in-vitro and clinical experiences with metallic implants during MRT investigations. In-vitro temperature measurements of various implants showed little temperature rise depending on the shape and the orientation in the static magnetic field (max. 0.3 degrees C). Ferromagnetic forces could not be detected with these implants. In contrast, severe temperature increase (9.4 degrees C) was observed with an intratracheal spiral tube. Tubes of this type should not be used in MR imaging to avoid the risk of burning. 105 MR examinations were performed in patients with metallic implants (CNS shunts, aortocoronary bypass grafts, aortic-, mitral-prosthesis, orthopedic implants, skin staples, shrapnels). Patients with vascular clips were accepted for MR imaging when the clips were non-ferromagnetic only. No adverse effects were observed in these patients.

[Localized 31 phosphorus NMR spectroscopy of the human heart--development of a measuring method and initial clinical application]. / Lokalisierte 31Phosphor-NMR-Spektroskopie des menschlichen Herzens--Entwicklung einer Messmethode und erste klinische Applikation.

In this work, the technique of 31P-NMR-spectroscopy is applied for the first time to diagnose coronary heart disease in patients, using a suitable measuring technique. In 13 healthy volunteers we applied a method comfortable and tolerable for patients, which enabled us to examine the myocardium inside the reception area of a surface coil. Concerning myocardium-specific selectivity and sensitivity the localization techniques FROGS (Fast-ROtating-Gradient-Spectroscopy), 1-D-ISIS (1-Dimensional-Image-Selected-In-vivo-Spectroscopy) and 3-D-ISIS were compared. By a combination of the 3-D-ISIS-technique with magnetic resonance imaging, we obtained a monitored position of the volume of interest (VOI) within the myocardium, thus gaining a selective measurement. The cube-shaped VOI with a lateral length of 50 mm was placed into the apical-septal area of the myocardium. On the basis of the obtained results, we examined seven patients suffering from coronary heart disease, which was symptomatic and verified by coronary angiography. The 31P-NMR-spectra of the two examined groups were computed into numbers representing the relative content of the myocardial high-energy-phosphates. In addition, the quotients PCr/ATP and Pi/ATP were calculated and compared. With this small number of cases the evaluation of the PCr/ATP-ratios already showed a significant difference of 0.34 (p less than 0.01) between patients with coronary heart disease (0.49 +/- 0.19) and healthy volunteers (0.83 +/- 0.27). The findings suggest the conclusion that 31P-NMR-spectroscopy is able to be instrumental in the diagnostic detection assessment of the metabolic state in coronary heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical magnetocardiography: experience with a biomagnetic multichannel system.

The magnetic fields caused by the human heart's electrical activity were coherently recorded with a biomagnetic multichannel system (KRENIKON) during 1 to 10 minutes in 49 patients. 31 to 37 magnetic channels were recorded simultaneously with the ECG and respiration. Comparison of a magnetic index and the Sokolow-Lyon index to echocardiographic findings in the quantification of left ventricular hypertrophy demonstrated the superiority of the magnetocardiogram (MCG) as compared to the ECG. The magnetocardiographic investigation of patients with WPW-Syndrome, ventricular extrasystoles, ventricular tachycardia, and paced ventricular beats demonstrated that multichannel magnetocardiography permits the non-invasive three dimensional localization of arrhythmogenic tissue with high spatial accuracy.

Sputter-deposited TiN electrode coatings for superior sensing and pacing performance.

The sensing and pacing performance of pacemaker electrodes is characterized by the electrochemical properties of the electrode/tissue interface affecting tissue reactions and the kinetics of the ionic exchange. The usually smooth metallic electrode surface results in a high pass filter characteristic. To better match the electrode's filter characteristic to the spectral content of the depolarization signal, various combinations of electrode shape, material and surface structure have been researched. The electrode with sputter-deposited TiN coating presented in this report has been designed to meet the demand for low acute as well as chronic thresholds and superior sensing performance not only with respect to spontaneous activity but also regarding the detection of the evoked response. The clinical results obtained with this electrode prove the excellent pacing and sensing properties resulting from minimized polarization losses and optimized filtering of the signal to be detected, respectively. The acute and chronic clinical advantages over previous concepts are attributed mainly to the biocompatibility of the material used and the microcrystalline surface structure achieved by the coating process. The design concept of the new electrode is presented together with the clinical results obtained. While the advancements in microelectronics and battery technology have certainly formed the basis for the development of pulse generators featuring an ever increasing versatility of functions at the same or even smaller pacemaker dimensions, from a point of view of pacing system performance the development of improved electrode concepts as the one presented must be regarded as equally indispensable.

Multichannel biomagnetic system for study of electrical activity in the brain and heart.

The authors designed a multichannel system for noninvasive measurement of the extremely weak magnetic fields generated by the brain and the heart. It uses a flat array of 37 superconducting magnetic field-sensing coils connected to sophisticated superconducting quantum interference devices. To prevent interference from external electromagnetic fields, the system is operated inside a shielded room. Complete sets of coherent data, even from spontaneous events, can be recorded. System performance was evaluated with phantom measurements and evoked-response studies. A spatial resolution of a few millimeters and a temporal resolution of a millisecond were obtained. First results in patients with partial epilepsy and investigations of the cardiac conductive pathway indicate that biomagnetism is now ready for a systematic clinical evaluation. Interpretation of measurements was facilitated by highlighting biomagnetically localized electrical activity in three-dimensional digital magnetic resonance images.

A non-magnetic, MR-compatible pacing catheter for clinical application in magnetocardiography.

A special bipolar pacing catheter for use in magnetocardiographic investigations has been developed. Several investigations have shown that it is fully compatible to both biomagnetic and MR imaging and thus serves as an ideal reference point for intracardial stimulation in magnetocardiography.

Elimination of electronic offset and physiological background activity in magnetocardiographic localization.

A method has been developed to eliminate disturbing magnetic signals in the biomagnetic localization of arrhythmogenic sources in the heart. The procedure consists of two steps: Superimposed background activity of the heart is eliminated by subtraction of a template of pure background activity. Systematic and electronic offset is subsequently eliminated by baseline-correction during periods of zero activity. The method was applied to several kinds of arrhythmias. It was demonstrated that elimination of background activity is the prerequesite for exact localization and that the proposed procedure yields correct results.

[ECG changes caused by the effect of static magnetic fields of nuclear magnetic resonance tomography using magnets with a field power of 0.5 to 4.0 Telsa]. / EKG-Veränderungen durch Einwirkung von statischen Magnetfeldern bei der Kernspintomographie in Magneten der Feldstärke 0,5 bis 4,0 Tesla.

ECG-alterations under the influence of static magnetic fields were investigated in phantoms (1.5 Tesla), animals and volunteers (4.0 Tesla), as well as in 12 patients (0.5, 1.0, and 1.5 Tesla). Under the influence of static magnetic fields high- and low-frequency voltages are superimposed on the ECG. Motions of the electrical leads induce high-frequency waves, which can alter the ECG to the extent that only the QRS-complex can be recognized. Electrolytes moved by the blood stream in static magnetic fields also induce voltages (Hall-effect) which, according to the patient's position, result in ST-segment- and partial T-wave-elevations or depressions. All ECG-alterations are reversible after exposition to the static magnetic field. Rhythm disturbances do not occur. The results indicate that static magnetic fields up to 4.0 Tesla do not have permanent adverse effects on the human ECG.

[Titanium nitride cardiac pacemaker electrodes]. / Titannitrid-Herzschrittmacher-Elektroden.

The sensing and pacing performance of pacemaker electrodes is characterized by the electrochemical properties of the electrodes/tissue layer; the usually smooth metallic electrode surface results in a high pass filter characteristic. Consequently, the detected intracardiac signals, which control the implantable systems, are not optimally matched to the spectral contents of the depolarisation signal. To avoid interference caused by noise (EMI, muscle potentials, etc.) a shift of the frequency of the band pass towards the lower frequency spectrum is required. As previously reported, the electrochemical properties of sintered and surface-treated electrodes prove the predicted improvement of sensing performance if titanium-nitride coated electrodes are used. Our results demonstrate their superiority above all the other electrodes presently known. The advantages can be referred to the micro-crystalline surface structure achieved by sputter-deposited electrode coatings and the kinetics of the ionic exchange. Furthermore, the acute thresholds achieved with the TiN-systems were significantly better than those of the smooth metallic surface. These results were also confirmed for chronic implants and are attributable to the known biocompatibility of titanium and its alloys.

[Motion energy as a control variable for adapting stimulation frequency]. / Bewegungsenergie als Steuergrösse für die Anpassung der Stimulationsfrequenz.

An activity sensing rate-responsive pacing system is presented which adaptively controls heart rate to adjust cardiac output in response to increased metabolic demand, and more optimally restore homeostasis of the intact cardiovascular system. The current use of ventricular demand and DDD universal pacing systems, although rate and multi-parameter and multi-function programmable, are fixed at these programmed settings. These devices are adequate for patients at rest or during moderate exertion, but are suboptimal for physically active patients whose physiology requires increased oxygen supply to meet an increased cardiac demand. In the past, these patients may have experienced fatigue or dyspnea out of proportion to their cardiovascular disease. The Ergos rate-adaptive single- and dual-chamber pacing system is a second generation pulse generator which is rate responsive to a patient's increased physiologic demand by sensing a motion signal which reflects increased work load and the need for a compensating increase in heart rate. Ergos offers increased assistance to patients with sinus bradycardia who may require the rate-responsiveness with the additional advantage of AV synchrony. Clinical results show the effectiveness of the presented sensor control by motion energy for rate adaptive pacing therapy.