[Complications of selective coronary angiography and the choice of contrast media]. / Komplikationen der selektiven Koronarangiographie in Abhängigkeit von verwendeten Kontrastmitteln

The incidence of side effects of two contrast media containing different amounts of sodium (Urografin 76 and Conray 70) is compared in two groups of patients (totalling 133) under-going diagnostic examination by means of a cardiac catheter and selective angiocardiography. The following results were obtained: 1. Transient ischaemic reactions were observed in 4 patients of the Urografin group. Cerebral circulation was temporarily restricted in 2 patients, but there were no sequelae. One patient with a history of repeated cardiac infarction in whom the examination was the last hope with a view to coronary surgery died immediately after the angiocardiography. 2. In the Conray 70 group, ventricular fibrillation occurred 32 times in 22 patients after a total of 155 injections. Protracted asystole was observed in 2 patients. The explanation offered for the divergent findings from the use of the two contrast media is not the different anions--the iodine hosts--, but rather the difference in the amount of sodium contained in the preparations. It is concluded from the studies that contrast media which deviate to any great extent in their sodium content from the physiological range of the blood sodium concentration are unsuitable for angiocardiography.

[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.

[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.

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.

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.

A survey of contrast media used in coronary angiography.

In recent years, various contrast media have been developed for use in coronary angiography. These contrast media may be divided into ionic contrast media of high osmolality, those of low osmolality, and nonionic contrast materials. We conducted our own clinical studies with 40 patients. In random succession a standard contrast medium (ionic, of high osmolality) and a new-generation contrast medium (either nonionic or ionic with low osmolality) were injected into the right and left coronary arteries. After each injection we measured the systolic and diastolic blood pressure using a liquid-filled coronary catheter. In addition, the change in the length of the cardiac cycle was registered in terms of the R-R interval (in ms) and at the same time, leads I, II, and III of the ECG were recorded. We studied the influence of the various contrast media on the activity of ATPase in in vitro experiments, using Lasser and Lang's [30]. When ionic contrast media of low osmolality and nonionic contrast media were utilized the heart rate showed no change. Disturbances of rhythm such as ventricular tachycardia or fibrillation were not observed. All of the contrast media used produced the same ECG changes. These changes can be ascribed to the inhibition of ATPase. The arterial blood pressure was lowered significantly only by ionic contrast media of high osmolality only.

[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.

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.

[Autosomal dominant hereditary atrial septal defect with heart conduction defects and mitral valve insufficiency]. / Autosomal dominant vererbter Vorhofseptumdefekt mit Reizleitungsstörungen und Mitralinsuffizienz

An autosomal dominant inherited ASD with conduction defects in one family is described. 6 members of 4 generations were fallen ill. In 4 patients the diagnosis was made clinically, in 2 sisters the diagnosis was confirmed by operation. Moreover, the last 2 patients had a mitral insufficiency--probably congenital. The ecg-findings of 4 patients additionally showed conduction defects in form of AV-and bundle branch blocks.

[Coronary angiographic findings in dextrocardia (author's transl)]. / Koronarangio-graphische Befunde bei Dextrokardie

This paper reports on four different types of dextrocardia in situs solitus and situs inversus. The topography of the atrial and ventricular cavities, of the great vessels and of the coronary arteries is described in detail. The value of the selective coronary arteriography in differentiation between the types of dextrocardia is discussed.

[Examinations of the pulmonary function of untrained and physically trained old men (author's transl)]. / Untersuchungen zur Lungenfunktion an untrainierten und körperlich trainierten alten Männern.

In tests there were determined the vital capacity and absolute and relative seconds capacity of 180 physical-trained sportsmen aged 55 to 89 and of 175 untrained, but clinically healthy test persons. The results of the different age-intervals are compared statistically. It was noticed, that vital capacity and absolute seconds-capacity of both groups decrease statistically significant with the age. Vital capacity and seconds capacity are in all age-intervals on a higher level with the trained sportsmen than the control group. The relative seconds-capacity showed no significant difference between the two groups. There is a clear statistic connexion between the vital capacity and the time obtained in a 5 000 meters run. One can suppose that in contrast to juvenile sportsmen a good pulmonary function is a contributory determinant of the performance of old sportsmen.

[D-transposition in situs inversus, atrial septal defect, open foramen ovale and tricuspid valve insufficiency]. / D-Transposition bei Situs inversus, VSD, offenem Foramen ovale und Trikuspidalinsuffizienz

This paper reports on a rare case of a so-called corrected d-transposition of the great vessels of a 62-year old woman with situs inversus. In addition the patient had a VSD, a patent foramen ovale, and a tricuspid-valve insufficiency. The topography of the ventricular cavities, the great vessels and the coronary arteries is described in detail. There is pointed to the surgical treatment of additional abnormalities to improve the prognosis.

Enzyme changes after coronary angiography.

The enzymatic response to contrast media after coronary angiography was observed in 24 patients. The enzymes studied were glutamic oxaloacetic transaminase (SGOT), glutamic pyruvic transaminase (SGPT), lactic dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), gamma-glutamyl transferase (gamma-GT), creatine phosphokinase (CPK), and the myocardial-specific isoenzyme of CPK (CK-MB). Angiography produced no significant elevations in SGOT, SGPT, alpha-HBDH, LDH, or CK-MB activities; gamma-GT increased up to the twelfth hour. High levels of CPK and CK-MB observed in one patient were found to be products of a thymus carcinoma. In vitro examinations also showed that concentrations of contrast media used in coronary angiography do not inhibit gamma-GT, LDH, and CPK activities.

Hemodynamic effects of single-dose administration of AR-L 115 BS in patients with coronary artery disease.

2-[(2-Methoxy-4-methylsulfinyl)phenyl]-1H-imidazo[4,5-b]pyridine (AR-L 115 BS) was investigated in 14 patients with coronary artery disease (CAD) and an elevated left ventricular enddiastolic pressure at rest (LVEDP). There was a significant decrease in the systolic (AOPS) and diastolic aortic pressures (AOPD) of 9% and 6%, respectively, (p less than 0.001, p less than 0.01). The LVEDP decreased by 29% (p less than 0.001), and the maximum rate of pressure rise (dp/dt max) increased by 19% (p less 0.001). The systolic (PAPS) and diastolic pulmonary artery pressures (PAPD) fell by 17% and 16%, respectively (p less than 0.05). The cardiac index (CI) increased by 12% (p less than 0.05), and the peripheral resistance (SVR) fell by 17% (p less than 0.001). Heart rate increased slightly by 5% (p less than 0.1) but this was of no clinical relevance. The right atrial pressure (RAP) and the tension time index (TTI) remained unchanged. AR-L 15 BS was observed to have vasodilating and positive inotropic effects without increasing oxygen consumption. It can therefore be recommended for use in patients with CAD and an elevated LVEDP. Side-effects have not been reported.