Immediate and late effects of coronary angiography on soluble endothelial cell markers and P-selectin in patients with and without coronary artery disease.

Endothelial cell injury and platelet activation are considered primary events in the pathogenesis of coronary artery disease (CAD) and are marked by plasma concentrations of von Willebrand factor (vWF) and soluble thrombomodulin, and by soluble P-selectin, respectively. Because both endothelial cells and platelets interact with contrast media, we aimed to detect immediate and 24-h changes in these markers following coronary angiography in patients with and without CAD. Sixteen patients with angiographically proven CAD and 14 patients without significant coronary stenosis were investigated. Blood samples were obtained from an antecubital vein before and 24 h after cardiac catheterization, and from the coronary sinus before and immediately after angiography. Concentrations of the markers were determined using enzyme-linked immunosorbent assays. In the coronary sinus samples, the only significant finding was an increase in levels of soluble P-selectin in the patients with CAD (P < 0.038). In the post-catheterization peripheral blood samples, concentrations of soluble P-selectin (P = 0.004), vWF (P = 0.0007) and soluble thrombomodulin (P = 0.0013) were all increased in patients with CAD. In contrast, patients without CAD demonstrated increased levels of vWF only (P = 0.0015) in peripheral blood samples obtained 24 h after angiography. We conclude that both immediate and 24-h changes take place in endothelial cells and platelet markers in response to cardiac catheterization, and that these changes are different in patients with angiographically proven CAD and in patients free of disease. These differences may reflect alterations in endothelial cell or platelet reactivity in patients with CAD.

Heart rate variability and ischaemia in patients with coronary heart disease and stable angina pectoris; influence of drug therapy and prognostic value. TIBBS Investigators Group. Total Ischemic Burden Bisoprolol Study.

AIMS: Determination of the influence of therapy with bisoprolol and nifedipine on the heart rate variability of patients from the Total Ischemic Burden Bisoprolol Study and examination of the prognostic value. METHODS AND RESULTS: Four hundred and twenty-two patients with stable angina were included. The heart rate variability was determined over a period of 24 h. Parameters determined: standard deviation of the mean of all corrected RR intervals, standard deviation of all 5 min mean cycle lengths, square root of the mean of the squared differences of successive corrected RR intervals. Nifedipine reduced the mean values of all heart rate variability parameters tested. Square root of the mean of the square differences of successive corrected RR intervals increased under bisoprolol. Standard deviation of the mean of all corrected RR intervals and standard deviation of all 5 min mean cycle lengths increased from low baseline values and declined from higher baseline values. The increase in heart rate variability under therapy was accompanied by a tendency towards a better prognosis. Patients with an increase in heart rate variability and simultaneous complete suppression of ischaemia under therapy displayed no serious events in the course of one year. CONCLUSIONS: The increase in the heart rate variability, which can be regarded as prognostically favourable, was predominantly observed under bisoprolol. The parameter constellation of an increase in heart rate variability and complete ischaemia suppression on the 48-h Holter ECG was associated with the greatest benefit.

Quality Determining Parameters of Balloon Angioplasty Catheters.

The investigations carried out on balloon angioplasty catheters using a parameter test unit allow an objective comparison and a qualitative assessment of catheter brands with respect to their stenosis passability. The design of the test unit allows the measure of other parameters important for clinical practice, such as pushability and trackability. Altogether 8 over-the-wire and 10 monorail-catheters from 7 different manufacturers were investigated by our study. Between modern over-the-wire and monorail systems there exists no fundamental difference in passage capability. In some brands of catheter the stenosis model shows no increase in the amount of thrust required, even after repeated inflation; this is accountable to the good folding properties of the balloon. Angioplasty balloons made of less overstretchable or thinner material yielded the best results. The fact that changes in balloon quality may result from pre-inflation should carry weight in discussions concerning the reuse of catheters. The measurement results are useful for the correct selection of a catheter appropriate to the therapy task at hand.

[Imprints of coronary plaque particles in the PTCA balloon surface during the dilatation processing]. / Impression koronarer Plaquepartikel in die PTCA-Ballonoberfläche durch den Dilatationsprozess.

UNLABELLED: Seventy-six PTCA-balloons after coronary angioplasty were studied for superficial changes using scanning electron microscopy (SEM) after fixing in glutardialdehyde. Coronary plaque particles were identified on the balloon surface in 52 cases (68%). Twelve new and unused balloons were subjected to the same chemical treatment and SEM showed no imprints. The average length of the longest imprinted plaques was 128 +/- 201 microns and the average number of plaque particles per balloon was 4.9 +/- 2.7. The maximal dilatation pressure and the number of dilatations showed no influence on the impregnation of plaque particles. However, longer plaque imprints tended to occur under low dilatation pressure. Imprints of plaque particles were significantly higher in patients with low cholesterol (p = 0.0001) and low triglycerides (p = 0.0016). No correlation was seen between imprint length and lipid levels. Similarly, the different balloon materials (polyethylene, polyolefincopolymer) showed no significant differences with regard to plaque occurrence. The PTCA-balloons, plaque particles and six coronary plaques obtained after endatherectomy were subjected to energy dispersive x-ray analysis (EDX) under SEM as EDX reveals qualitative and quantitative information about the structural elements. Highly significant differences in calcium, sodium, phosphorus and silicon contents (p = 0.0000) between plaque particles and balloon surface were observed, owing to the absence of these in balloon material. Thus EDX offers additional advantages over SEM in that it clearly differentiates deformed balloon surface, plaque particle, and retained contrast medium. CONCLUSION: Plaque particles can be recovered from balloon surfaces after PTCA. Depending upon their size, they could lead to coronary spasm or microembolic phenomenon.

[The incidence of silent myocardial ischemia]. / Ein Beitrag zur Hüfigkeit stummer Myokardischämien.

Retrospectively evaluated was the patient population of the years 1982 to 1988 which underwent ergometric investigations concerning the appearance of silent myocardial ischaemias. In 256 reactions of exercise ischaemia of patients with definitive coronary disease in 47 cases angina pectoris appeared (18.4%). Reactions of ischaemia in a large area of the breast wall showed, compared with a small area of ischaemia, a significantly higher proportion of symptomatic episodes (34.3% vs 13.0%, P less than 0.05). Ergometric exercises lying below the norm of age were more frequently accompanied by symptomatic ischaemias than ischaemic reactions, which only appeared in a good area of performance (26.0% vs 11.4%, P less than 0.05). In addition to this more anginose complaints were found in patients, whose ischaemic reaction was accompanied by an insufficient frequency response (28.1% vs 9.8%, P less than 0.05).

[Ventricle-vessels relationship in aspects of hypertension]. / Ventrikel-Gefäss-Beziehungen unter dem Aspekt der Hypertonie.

The diagnostics of the ventricle-vessel relations in arterial hypertension is significant in particular for advanced stages. Under the aspect to regard the cardiac contraction in form of a model as temporarily varying elastance of the volume invasively (P-measurement, V-measurement, preload alteration via balloon in the inferior vena cava) relations of the ventricular pressure volume (ESPVR, EDPVR) and system-arterial ones in form of the effective arterial elastance can be established. Additionally calculated functional curves give separated information concerning the influence of preload, afterload and contractility on the stroke work. Thus a comprehensive statement concerning the cardiovascular function and a basis for valuable therapeutic effects is worked out. Several references result for advanced stages of the arterial hypertension with hypertrophied heart. The systolic function remains normal for a long time. Diastolically the increasingly disturbed relaxation with pathological preload is found. The relation stroke work-afterload is no more in the optimum region and can further be deteriorated by vasodilation. Whether or not, however, this relation has the same relevance for all clinical questions, remains open. Is the stroke work really that parameter which shall be optimized therapeutically?

[Effects of diltiazem in acute and long-term administration]. / Diltiazemeffekte im Akut- und Langzeiteinsatz.

In 16 patients with unstable angina pectoris haemodynamic and clinical effects of diltiazem were investigated. In a second group patients (n = 11) with unstable or therapy-refractory course the long-term effect was tested. The acute intervention with injected and infused diltiazem via an improved oxygen balance due to decreased minute work and reduced product of cardiac frequency and pressure stabilized the clinical picture from the haemodynamic aspect. The decreases of the ST segment were significantly lower. In the long-term use a significant influence on the frequency of angina pectoris with increase of the range of efficacy by one NYHA-state was the result. Diltiazem can be regarded as alternative medicament in unstable phases and in therapy-refractory courses of the chronic coronary heart disease.

[A measuring procedure for experimental determination of tensile strength of catheters and flexible probes]. / Messverfahren zur experimentellen Bestimmung der Biegesteifigkeit von Kathetern und flexiblen Sonden.

In order to obtain a more objective description of the properties usually subsumed under such terms as the "handling" of catheters, it is necessary to measure the significant parameter bending stiffness. A contact-free method of recording the oscillations of rod-shaped elements is presented. The stiffness EI can be calculated from the measured characteristic frequency. The logarithmic decrement can be derived from the damped natural oscillation and the damping properties of the catheter thus characterised. In addition, a consideration of imposed oscillations can be employed to calculate resonance frequency. A computer-driven measuring set-up employing a CCD line camera for the non-contact recording of oscillations of rodshaped elements, together with the software required is presented. The measuring principle and possible errors are discussed and a measurement described by way of an example.

[Definition and classification of heart failure]. / Definition und Klassifikation der Herzinsuffizienz.

The definition of the syndrome of heart failure is dependent upon clinical, pathophysiological and biochemical criteria. The interrelationship of the contributing factors in a given hemodynamic situation must be clarified by simple examination. "Heart failure" implies a condition with insufficient peripheral perfusion, despite a normal blood volume, a sufficient or increased filling pressure, and intact intrinsic and extrinsic compensatory mechanisms. The cardiac output varies with basic illness. The worsening vicious cycle between cardiac dysfunction and neuroendocrinal dysregulation in chronic heart failure has to be taken into consideration, especially while planning therapeutic strategy. The classification of the severity of the disease is based upon simple, clear history taking and clinical examination. The conclusions have to be supported by radiological and echocardiografic observations. It is difficult to categorize patients during early stages of the disease. Prognosis is based on preexisting hemodynamic, biochemical, neuroendocrinal, and clinical parameters, as well as therapeutic strategy. At the same time, prognosis is dependent on the efficacy of the therapeutic regimen in any given situation.

[Treatment indications of hypertensive blood pressure dysregulation (a 7-year follow-up)]. / Zur Frage der Behandlungspflichtigkeit bei hypertoner Blutdruckdysregulation (eine Verlaufsbeobachtung über 7 Jahre).

The results of the present course investigations by means of bicycle ergometry over seven years on patients with vitality-limiting load hypertension in normotensive and initial situation of the borderline blood pressure, respectively, render necessary from the point of view of the authors an increase of the former indications to treatment. Situative measurement of blood pressure only at rest are hereby not sufficient and demand a bicycle-ergometric objectivation of the possible hypertensive dysregulation of blood pressure in patients with anamnestically restricted range of physical efficacy. In patients with exclusively under load increased vitality-limiting blood pressure values the ergometry represents the diagnostic method of choice.

Relationship between design and control of artificial heart for protection of the right/left balance.

Right/left matching in the total artificial heart (TAH) is essential to prevent fatal volume displacement into the pulmonary circuit. Measurements were made with three different sized Rostock pneumatic artificial ventricles incorporated in the Donovan mock circulatory system together with the heart driver AKT 86. First for each ventricle we determined the dependence of the maximum effective stroke volume on the systolic driving pressure and the afterload. The right ventricle (RV) is about 10% more effective than the left ventricle (LV). Control of the TAH permits different or equal frequencies for the RV and LV. For control with equal frequencies and full-to-empty regimen of one ventricle (RV-Master or LV-Master) the ratio of designed stroke volumes between RV and LV is important. This follows from the smaller efficiency of the LV and the left-to-left shunt. Otherwise a control mode with different heart rates must be used.

[Current status of the use of the artificial heart and ventricular assist systems]. / Zum gegenwärtigen Stand der Anwendung des künstlichen Herzens und ventrikulärer Assistsysteme.

The state of the technical development of the mechanical assist systems and the artificial heart, respectively, guarantees a sufficient support of the circulatory system up to the improvement of the own heart function or to the possible heart transplantation. There is the necessity for the temporarily limited support of the heart, but also for the long-term one. Independent of the underlying etiology in acute conditions of cardiac failure in many cases the external supporting system may be sufficiently helpful. The antithrombotic therapy and the prophylaxis of infections demands particular carefulness. There is still no representable release for the long-term use of the hitherto available cardiovascular supporting systems. The question is controversial, whether then an experiment on patients or an already accepted therapeutic intervention is still taken into consideration. Essential prerequisites for the long-term use would be a full implantability of the systems in transcutaneous energy transmission, a further biologization of the blood-contacting materials, a clarification of the immune phenomena, a possibly automatic mode of action adapted to the need as well as a reliable strategy of antithrombotic therapy. The increased risk of infection should be taken into consideration.