Search

A 44-year-old German fell ill in Libya, where he had been living for 10 years, with high fever, rigor and a nonitching centrifugally spreading macular rash, which had spared the head, hands and soles. In addition, a systolic cardiac murmur was heard. The Weil-Felix reaction had a titre rising within 3 days from 1:160 to 1:640, confirming the diagnosis of rickettsial disease, the total clinical picture indicating typhus. On treatment with chloramphenicol (1 g three times daily i.v.) the fever subsided within 5 days. On the ninth day treatment was changed to oral doxycyclin, 200 mg daily for 3 weeks. Echocardiography surprisingly revealed a floating thrombus, about 4 x 8 cm, attached to the hypo- and even akinetic apex of the left ventricle. In addition there was single-vessel coronary disease. Since the segmental contraction abnormality persisted after the typhus had been cured, a causal connection with the rickettsial disease is unlikely. The thrombus was removed at the time of a aortocoronary bypass operation: his course has been unremarkable since then.

The technical success of percutaneous coronary angioscopy using different guiding techniques was evaluated in 17 patients before (n = 17) and after (n = 8) coronary angioplasty. Steering the angioscope along or over a guidewire was successful in both groups; failures were predominantly due to insufficient alignment of the angioscope using along-the-wire guiding. Although over-the-wire angioscopy promises superior guiding and alignment capabilities, several technical problems remain unsolved.

ZusammenfassungBei 20 Patienten mit angiographisch dokumentierten Koronarstenosen von ≥70% und unauffälliger LV-Ruhefunktion wurde eine Kernspintomographie (KST) vor und nach Gabe von Dipyridamol (0,75 mg/kg KG) durchgeführt. Bei allen Patienten wurde zusätzlich eine MIBI-SPECT in Ruhe und nach symptomlimitierter Ergometerbelastung vorgenommen. 18 Patienten wiesen eine Belastungsischämie im MIBI-SPECT und 18 eine Dipyridamol-induzierte Wandbewegungsstörung im KST auf. In den Segmenten, die den Versorgungsgebieten der 29 stenosierten Gefäße zugeordnet wurden, konnte eine Ischämie durch MIBI-SPECT in 24 Fällen (Sensitivität 83%, Spezifität 90%) und eine Wandbewegungsstörung durch KST in 23 Fällen (Sensitivität 79%, Spezifität 90%) erkannt werden. Die Dipyridamol-KST ist der Belastungs-MIBI-SPECT zur Erkennung ischämischer Areale nicht überlegen.

Artificial valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abscesses. Anatomical structures adjacent to the artificial valve were clearly visible and the metal components of the valves showed no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from pathological paravalvular or transvalvular regurgitation. These results demonstrate that patients with artificial valve prostheses can be imaged by MR without risk and that prosthesis-induced artifacts do no interfere with image interpretation.

To assess the ability of magnetic resonance imaging (MRI) to identify the anatomic and functional abnormalities associated with completely scarred myocardium, 20 patients with chronic transmural myocardial infarction confirmed by electrocardiography and cineventriculography were examined by gradient echo MRI. Myocardial perfusion at rest was assessed in corresponding transverse sections using 99mTc-methoxyisobutyl-isonitrile single-photon emission computed tomography (MIBI-SPECT). MRI scar was defined as diastolic wall thickness (DWT) 2.5 SD below corresponding normal values or systolic wall thickening (delta WT) less than or equal to 1 mm. For MIBI-SPECT images, scar was defined as a MIBI uptake less than 2.5 SD below normal values. By MIBI-SPECT, 152 segments contained normal tissue and 88 contained scarred myocardium. In 226 of 240 (94%) segments, MRI gradings by DWT and MIBI-SPECT gradings were identical. DWT by MRI was higher in normal than in scarred MIBI-SPECT segments (10 +/- 1 versus 4 +/- 2 mm, p less than 0.001). In 230 of 240 (96%) segments, MRI gradings by delta WT and MIBI-SPECT gradings were identical. Segments graded normal by MIBI-SPECT showed higher delta WT by MRI than scar segments (5 +/- 1 versus 0.3 +/- 1 mm, p less than 0.001). MIBI-SPECT perfusion defect size and regions with reduced DWT on MRI tomograms correlated well (r = 0.85). This study indicates that myocardial regions fulfilling electrocardiographic and ventriculographic criteria for transmural myocardial scar are clearly depicted by regional diastolic wall thinning and delta WT less than or equal to 1 mm on gradient echo MR images.(ABSTRACT TRUNCATED AT 250 WORDS)

The noninvasive determination of hemodynamic parameters at rest and during physical stress is increasingly gaining importance, since invasive measurements for the observation of large patient collectives, particularly follow-ups, are very expensive technically and furthermore not ethically justifiable. Various existing clinically utilized methods, such as e.g. echocardiography, have methodological limits. Thoracic beat-to-beat electrical impedance cardiography (IG) is an indirect, noninvasive method for the determination of stroke volume and cardiac output. The examination is quickly and easily performed, without danger to the patient, and is repeatable as often as desired; it requires only the passive participation of the patient. The ICG is based upon the measurement of thoracic electrical resistance change synchronous with the cardiac rhythm. Using the derived base impedance and the resistance changes resulting from intrathoracic volume shifts during systole and diastole, one can calculate the stroke volume of the left ventricle. The impedance fluctuations are derived simply by means of attached ECG electrodes (Ag/AgC1).

Pulmonary complications are a major cause of morbidity and mortality in patients with acquired immunodeficiency syndrome (AIDS). Full-blown pneumocystis carinii pneumonia (PCP) with fever, cough, dyspnea, interstitial infiltrates in the x-ray, and low oxygen tension in the arterial blood gas analysis is easy to diagnose. In contrast, early diagnosis of PCP is difficult, because x-ray of the chest and arterial oxygen tension are often normal and respiratory symptoms are unspecific. Early treatment of pulmonary complications improves prognosis of the HIV-infected patients, therefore functional screening tests for early recognition are needed. Exercise blood gas analysis (Ex.-BGA) has been proven to be a highly sensitive marker of approaching interstitial pneumonia [1]. Cardiopulmonary exercise testing (CPX) measures pulmonary gas exchange and is a modern computerized version of spiroergometry, used to test cardiopulmonary limitations to exercise. Little is known about CPX in the diagnosis of HIV-associated pulmonary complications. It was therefore the aim of our study to investigate the diagnostic value of CPX for early diagnosis of pulmonary complications in HIV-infected patients.

The O2-uptake at the anaerobic threshold ( \(\dot V\) O2 AT), as detected by gas exchange measurements during an incremental exercise test on a semi-supine bicycle, is an objective parameter for the estimation of cardiopulmonary exercise capacity. It was used to assess the severity of cardiopulmonary and cardiovasculary diseases in patients with coronary heart disease (CAD, N = 22, mean age 54.05 ± 7.88 years) and chronic heart failure (CHF, n = 15, mean age 57.73 ± 12.61 years). According to \(\dot V\) O2 AT, we found a high distinction between the subjective and the objective evaluation of exercise capacity, using the Weber- and the NYHA-classes. The NYHA-classes provide insufficient criteria for exercise capacity (i.e. 14 CAD-patients NYHA II were individually assigned to very different Weber-classes: 2/14 Weber A, 2/14 Weber B, 4/14 Weber C, 5/14 Weber D, 1/14 Weber E). Our investigations showed that the O2-uptake of every pedaled watt (Δ \(\dot V\) O2/ΔWR) should be a parameter to estimate the exercise capacity, but seems to be very insufficient in patients with severe heart failure and low values of maximum work rate (WR). Oscillations of the respiratory variables during rest, exercise, and recovery were reported in 4/22 CAD-patients (18.2%) and in 9/15 CHF-patients (60%). A constant value for O2-pulse, the O2-uptake of every heart beat ( \(\dot V\) O2/HR), was reached in 10/ 22 CAD-patients (45.5%) and in 8/15 CHF-patients (53.3%). The computerized ergospirometry is a feasible, secure, accurate, and well-tolerated method to objectively evaluate the functional disability of patients with CAD of CHF. The present study offers new insights in the evaluation of critically ill patients using non-invasive procedures.

In addition to improvement of the very serious mortality prognosis of patients with severe heart failure in New York Heart Association (NYHA) classes III and IV, a priority goal of therapy is to raise the exercise tolerance increasingly restricted by progressive heart failure, as well as to relieve the agonizing dyspnea in the daily life of these patients. Every treatment concept for long-term therapy of chronic heart failure must consider these two important parameters. Nitrates and diuretics offer immediate relief of the clinical symptoms of patients with severe heart failure. The beneficial influence of ACE inhibitors on the mortality prognosis and clinical symptoms in 60–80% of patients has now been established [1–3]. Yet the prognosis remains very serious once the clinical condition of patients has reached NYHA classes III and IV [4, 5]. Even an optimal therapeutic concept including digitalis, diuretics, nitrates, and ACE inhibitors can often hardly improve the significantly reduced exercise tolerance, nor can it measurably relieve the dyspnea of these patients in the advanced stage of their chronic heart failure.

The extent and degree of coronary atherosclerosis may be assessed by indirect parameters and by direct angiographic measurements. Determinations of the hemodynamic significance and properties of coronary stenoses by classical fluid dynamics, and semi-quantitative evaluation of regional hypoperfusion or abnormalities of metabolism and of regional contractile performance are indirect parameters, that do not provide precise information on progression or regression of coronary atherosclerosis. To obtain reliable and reproducible angiographic measurements of coronary stenoses, angiographic pitfalls (film exposure and processing as well as distance of the patient to x-ray tube and image intensifier must be constant, pincushion distortion must be compensated for, standard reference must be used), physiological variables (respiratory and cardiac cycle and coronary vascular tone must be identical on repeat films, slitlike stenoses must be visualized in different projections), and problems with the measurement procedure itself (reproducibility is important, inter- and intra-observer variability must be minimized, stenosis dynamics and plaque volume can only be quantitated by a computer system) have to be overcome or be compensated for. Using a standardized angiographic protocol, we were able to follow progression and regression in a cohort of 10 patients with familial hypercholesterolemia IIa, who were successfully treated with long-term specific LDL-cholesterol immunoabsorption (LDL-apheresis), that favorably influenced the long-term atherosclerotic activity in the coronary arteries of these patients.

Seventy-nine patients with angiographically documented coronary artery disease were studied with exercise ECG and Holter ECG for ischaemic ST segment changes. Fifty-four patients (68.3%) had ischaemia on exercise, 48 patients (62.0%) had ischaemic ST segment depression during Holter monitoring. Twenty-four (30%) of the patients with a positive exercise test and 30 (61%) with a positive Holter ECG were asymptomatic during the test, 83.7% of the total count of 456 episodes of spontaneous ischemia during Holter monitoring were silent. Forty-four patients (55.7%) had ischaemic ECG changes during exercise and Holter ECG, 20 patients (25.3%) were negative on both tests. Ten (12.7%) had only a positive exercise test and five (6.3%) only a positive Holter ECG. The sensitivity of Holter monitoring for the detection of ischaemia in patients with coronary artery disease is comparable to the sensitivity of the exercise ECG.

Modern programmable pacemakers often incorporate features that allow one to perform a series of diagnostic maneuvers to aid in postimplantation surveillance. These features often include noninvasive measurements of thresholds, lead impedance, and intracardiac electrogram recognition via telemetry circuits. Interindividual differences in these measurements are so great that one must utilize individual comparisons for longitudinal studies of reliability. While these devices allow "fine tuning" of individual units, they require major time-consuming efforts and add to the total device costs.

This study describes the relationship between the antiarrhythmic efficacy of β- blockade with atenolol and the increased sympathetic tone during submaximal ergometric exercise in 18 patients with various inducible supraventricular tachycardias. At rest, atenolol prevented or controlled (i.e. normalisation of ventricular rate) pacing- induced supraventricular tachycardias in 13/19 arrhythmias. In the remaining patients the tachycardia or echo zones were both prolonged or shortened. Ergometric exercise after β- blockade changed the tachycardia or echo zones in 5/8 arrhythmias (prolongation or shortening), compared with the resting conditions of β- blockade. In 1 patient with Wolff- Parkinson- White syndrome, the tachycardia could be reinitiated during physical activity, and in another patient atrial flutter was no longer inducible under the increased sympathetic tone. In general, the tachycardia or echo zones are not uniformly changed by both β- blockade and ergometric exercise, particularly in situations where they are combined. It is concluded that increasing the sympathetic tone by ergometric exercise may considerably change the electrophysiological and antiarrhythmic properties of β- blocking agents. These effects of physical activity on the electrophysiological behaviour of the specialised cardiac- conduction system should be taken into account when the arrhythmia- suppressing potency of any antiarrhythmic drug is evaluated.

Coronary angioscopy (CA) was performed in 30 patients (pts) during cardiac catheterization (Group 1) and in 11 pts during coronary bypass surgery (Group 2) using ultrathin fiberoptic angioscopes (phi 1.2-1.8 mm). For percutaneous CA (Group 1) the angioscope was introduced through a 9F guiding catheter from the femoral artery. The viewing field was cleared by flushing Ringer's solution and short-time occlusion of the coronary ostium by the guiding catheter. In Group 2 CA was performed retrogradely from the distal arteriotomy and through the bypass vein during flushing with cardioplegic solution. In Group 1 in 17/30 pts the coronary artery could be successfully examined by CA. In 13 pts the obstruction was eccentric and irregular shaped. In 2/5 pts, in whom CA was performed successfully pre and post balloon dilatation, CA after PTCA revealed an intimal rupture without clinical or angiographical signs of the intimal dissection. In Group 2 in 9/11 pts good visualization of stenoses could be achieved. At the obstruction site CA revealed thrombi in 3 pts and ulcer in 1 pts. In contrast to angiography, which estimates the lumen diameter of a segmental lesion, CA gives information about the luminal shape and the underlying substance of the obstruction (e.g. atheroma, thrombus, ulceration). The main problems in percutaneous CA are the insufficient intraluminal guidance, the insufficient depth of view of the angioscopes, and the limited examination time.

The feasibility and safety of coronary endoscopy was evaluated in three sets of investigations: in 7 cadaver hearts, in 11 patients undergoing coronary bypass surgery, and in 30 patients during routine cardiac catheterization prior to coronary balloon angioplasty (PTCA). In three of the seven cadaver hearts the lumen of the arteries appeared normal. In three diffuse atherosclerotic lesions, and in one, a high-grade, tight stenosis were observed. In nine of eleven patients in the operation room, the lesions of interest could be visualized, and high-grade stenoses were found in all. In addition, in three patients with unstable angina pectoris, fresh thrombi were seen at the site of stenosis. In six of the nine patients, the periphery of the native coronary vessel was found to have no further stenotic regions. During cardiac catheterization in 17/30 patients, the lesion of interest could be examined angioscopically, and in 13 instances the stenosis appeared excentric and irregularly shaped. In three instances, multiple ulcerations were seen in the stenotic area. In two of the five patients, intimal ruptures were found following PTCA, which could not be documented angiographically. Coronary endoscopy provides valuable additional information on the nature and appearance of atherosclerotic lesions. It can be performed clinically without great harm to the patients. Despite some limitations, it will probably become a routine diagnostic tool in patients undergoing routine coronary angiography, balloon angioplasty or high-frequency angioplasty, and coronary bypass grafting.

To test the clinically supposed development of tolerance during chronic molsidomine therapy we studied a total of 11 patients with angiographically-proven coronary heart disease at rest and during ergometric exercise (supine position; submaximal, i.e. 50 W for 3 min, and maximal exercise). Pulmonary arterial pressure (PAPmean, floating catheter), arterial blood pressure (RR, cuff method), work capacity (W x min) and duration of exercise loading (sec) were measured at rest and on exercise before and during chronic (4 weeks) oral therapy with 3 x 4 mg day-1 of molsidomine. Acute administration of 4 mg molsidomine reduced the mean arterial resting pressure by 12% and under submaximal exercise loading by 8%. After molsidomine, the PAPmean was reduced by 35% at rest; following a period of treatment of 4 weeks no significant decrease in efficacy could be discerned (PAPmean reduction by 31%). Under submaximal and maximal exercise the PAPmean dropped by 44% and 37%, respectively (35.5 +/- 6.7 cf. 19.9 +/- 4.5 mmHg; 39.2 +/- 6.5 cf. 24.8 +/- 7.0 mmHg), whilst simultaneously the work capacity increased by 93% (281 +/- 108 cf. 545 +/- 254 W x min). After 4 weeks treatment with 12 mg day-1 of molsidomine, the PAPmean of 22.4 +/- 6.6 mmHg and 30.1 +/- 9.9 mmHg under identical exercise loading conditions, remained significantly below the exercise load value prior to the onset of medication. The molsidomine-induced increase in the exercise tolerance was maintained throughout the long-term medication (537 +/- 268 W x min). With a four-week treatment with daily doses of molsidomine there was a persistent effect on the pulmonary arterial pressure and the work capacity. Thus development of tolerance during high dose, long-term molsidomine therapy is not to be expected.

On the occasion of a routine medical check-up 256 out of 1100 individuals with an accumulation of coronary risk factors were screened for silent myocardial ischaemia by exercise testing and Holter monitoring. Of these individuals 5.5% had a pathological exercise test, 7.4% had ischaemia-like events on the Holter ECG, 11.3% had at least one pathological test, but only 1.6% had ischaemic signs in both ECG tests. The outcome of the ECG tests appears to be independent of the type and the total number of risk factors. To date, 13 of the 29 individuals with a positive test have undergone thallium myocardial imaging: only three individuals had signs of ischaemia. Holter monitoring and exercise ECG show comparable results in this population. The pathological ECG findings were only partly confirmed by the thallium test. The follow-up will show the prognostic significance of the ECG changes.

Es wird uber spezielle kardiologische Untersuchungsbefunde bei Pericarditis constrictiva, sog. idiopathischer Myokardhypertrophie sowie Endokardfibrose (Fibroelastosis endocardica bzw. Endocarditis parietalis fibroplastica) berichtet. Dabei werden insbesondere die bei der Katheterisierung des linken und rechten Herzens erhaltenen Druckkurven und die angiokardiographischen Befunde berucksichtigt, speziell die selektive Laevokardiographie. An Hand der Befunde wird die Differentialdiagnostik der besprochenen Erkrankungen untereinander und gegenuber der Mitralstenose, den Aortenstenosen und verschiedenen Myokarderkrankungen abgehandelt sowie die hamodynamische Auswirkung der Erkrankungen diskutiert.-Bei den Patienten mit Pericarditis constrictiva werden die praoperativen kardiologischen Untersuchungsergebnisse mit den Operationsbefunden daraufhin verglichen, inwieweit sie Auskunft geben uber Lokalisation und funktionelle bedeutung der Perikardverschwielung bzw. evtl. Myokardschadigungen. Erhebliche, eine Perikardektomie kontraindizierende Myokardschadigungen sind mit Hilfe der Kardiographie und der intrakardialen Druckmessung zu erfassen.-Endokardfibrosen und die sog. idiopathische Myokardhypertrophie konnen durch kombinierte Katheterisierung des rechten und linken Ventrikels und deren Kontrastmitteldarstellung klinisch mit hoher Wahrscheinlichkeit diagnostiziert werden.-Die Druckmessung im linken Ventrikel verhindert die Fehldiagnose einer Mitralstenose bei den genannten Erkrankungen bzw. einer Aortenstenose bei der sog. idiopathischen Myokardhypertrophie.-Es wird gezeigt, das die Perikarditis constrictiva ebenso wie die Endokardfibrose sowohl die systolische Verkleinerung als auch die diastolische Erweiterung der Ventrikel behindert, wahrend bei der sog. idiopathischen Myokardhypertrophie im Stadium der Kreislaufkompensation nur die diastolische Erweiterung beeintrachtigt zu sein scheint.

Die selektive Laevokardiographie erlaubt eine exakte anatomische Lokalisierung des Ventrikelseptumdefektes mit Links-Rechts-Shunt. Das gilt selbst fur kleinere, durch die O2-Analyse nicht fasbare Defekte. Der Shuntstrom vom linken in den rechten Ventrikel zeigt bei subvalvularen Defekten fasbare Unterschiede, was an Beispielen demonstriert wird. Der Canalis atrio-ventricularis communis ist im selektiven Laevogramm durch die direkte Kontrastfullung des erweiterten rechten Vorhofes vom linken Ventrikel zu diagnostizieren; auserdem sind im Laevogramm Aussagen uber ein offenes oder geschlossenes Ventrikelseptum bei Canalis atrioventricularis communis moglich. Selective laevocardiography permits accurate anatomical localisation of ventricular septal defects with left to right shunt. This is true even for small defects which cannot be recognised by oxygen analysis. A left to right shunt through a subvalvular defect shows characteristic appearances which are demonstrated by examples. A common atrio-ventricular canal can be diagnosed by a selective laevocardiogram by means of direct opacification of an enlarged right atrium from the left ventricle. In addition it is possible to differentiate cases with open or closed ventricular septa in the presence of a common atrio-ventricular canal. La cardiographie selective gauche permet une localisation anatomique exacte d'une communication interventriculaire avec shunt gauchedroite. Elle en demontre l'existence meme pour de tres petites communications que l'analyse par l'oxygene ne permet pas de deceler. Le courant du shunt entre le ventricule gauche et le ventricule droit presente des differences prononcees quand la communication se trouve en-dessous de la valvule. Le diagnostic de l'existence d'un canal atrio-ventriculaire commun peut etre pose a la cardiographie gauche par le remplissage direct de l'oreillette droite dilatee a partir du ventricule gauche; la cardiographie gauche permet en outre de se prononcer sur les possibilites de l'existence d'une communication inter ventriculaire en presence d'un canal atrio-ventriculaire commun. La levocardiografia selectiva permite una localizacion anatomica exacta del defecto del tabique ventricular con shunt izquierdo-derecho. Esto vale aun para las comunicaciones pequenas que no se traducen en el analisis del O2. El shunt de ventriculo izquierdo al derecho muestra, en los casos de defectos sub valvulares, diferencias objetivas, lo que se demuestra con ejemplos. El canal atrioventricular comun es posible de diagnosticar en el levograma selectiva por medio de la opacificacion directa de la auricula derecha dilatada desde el ventriculo izquierdo; ademas, en el levograma puede recogerse ilustracion acerca de una comunicacion interventricular abierta o cerrada en caso de canal atrio-ventricular comun.

Simultaneous cine-angiographic examination of the coronary arteries in two planes is now possible, due to technical advances, without losing any of the information that may be obtained by a single-plane technique. This method shortens the examination, reduces the radiation dose when compared with a large film technique and significantly reduces the risk to the patient. Our experience in 67 examinations is recorded.

In order to investigate the possibility of providing a myocardial protective effect by intracoronary perfusion through the dilatation catheter during the phase of balloon inflation for PTCA, in vitro studies were performed to determine the relationship between proximal perfusion pressure and flow through the catheter. In addition, blood samples obtained proximal and distal to the catheter system were examined to establish whether a change in blood composition across the catheter occurs.

During PTCA, inflation of the catheter balloon to dilate the coronary stenosis produces complete coronary occlusion and results in myocardial ischaemia, thus limiting the duration of inflation. It was the aim of this study to determine if a protective effect can be obtained by blood perfusion through the dilatation catheter during the phase of balloon inflation, which might permit an increase in the duration of inflation. Such a protective effect would reduce the problems of repeated localisation of the catheter if the primary dilatation was unsuccessful, and if PTCA induced a critical phase for the patient requiring surgical intervention, this interval could be bridged by this new method of perfusion.

Gated magnetic resonance imaging of the heart displays cardiac structures with excellent resolution. This ability should be useful for assessment of cardiac physiology where acquisition of systolic and diastolic images is required. In this study, left ventricular ejection fraction was determined in 50 patients from oblique long axis views of the left ventricle using the area length formula. Angulated views were obtained by electronic gradient angulation. For comparison, all patients had monoplane angiocardiography in the RAO position. Forty-five patients were also studied by radionuclide ventriculography. Ejection fractions determined by MRI and angiocardiography were closely correlated (r = 0.90). Correlation between MRI and radionuclide ventriculography was also acceptable (r = 0.79). In addition to global left ventricular function, MR images provide information about regional wall motion. In order to acquire a three-dimensional set of images at various phases of the cardiac cycle, shorter imaging times are mandatory. A new imaging technique with potential for functional studies uses low flip angles, short repetition times and gradient refocused echoes. Up to 40 images can be obtained within one cardiac cycle. When displayed in a looped fashion, visual assessment of cardiac motion, intracardiac blood flow, and systolic wall thickening is possible. Potential advantages of functional studies by MRI are the concomitant acquisition of anatomical information and the three dimensional frame of reference.

The functional significance of “small vessel disease” of the heart receives very different treatment in clinical and pathologic investigations.

In a series of 44 patients, 5 females and 39 males, the incidence and dynamic behavior of ventricular late potentials was studied. Using a home-built high resolution electrocardiogram equipment ventricular late potentials were found within the ST segment in 27/44 patients, and in 11 patients were the late potentials observed intermittently. In 21/44 patients late potentials were also present after the T wave, in 5 individuals intermittently.

Summary: Since 1963 the signal averaging technique has been applied to improve the signal to noise ratio in highly amplified EKG registrations. Based on the experiences from the literature and the authors own laboratory, the applications of the signal averaging technique in clinical cardiology are reviewed: extraction and analysis of the fetal EKG and P-wave variations, His bundle electro-grams from the body surface (recovery rate 33–100% of cases), ventricular delayed depolarizations within the ST segment of the surface EKG (recovery rate, 40–90% of cases, depending on patient groups investigated), preatrial activity (sinus nodal potentials) from intra-cardiac (recovery rate, 80–90% of individuals), or surface EKGs (recovery rate, 60% of patients), analysis of frequency components of surface EKG-QRS complexes in patients with previous myocardial infarctions, and detection of low amplitude diastolic signals from surface phonocardiogram (recovery rate, 80% of cases). At present, advantages and limitations of the signal averaging technique may be appraised as follows: (1) sinus nodal potentials: S-A conduction times may be more reliable than those obtained by the extra-stimulus technique, since with averaging they are recorded during undisturbed sinus rhythm; direct recordings of changing S-A blocks may be impossible due to the summation process; validation of sinus nodal potentials in man necessary, (2) A-V nodal potentials: demonstration of true A-V nodal rhythm rather than His bundle rhythm; possibly direct identification of abnormal pathways in A-V nodal tachycardias; direct recordings of single A-V nodal blocks impossible due to summation process; (3) surface His bundle potentials: follow-up or screening of patients with A-V nodal and particularly His-Pur-kinje-system blocks; monitoring of antiarrhythmic drug therapy; atrial overlap in one-third of cases; direct identification of higher degree A-V nodal blocks impossible due to summation process (future developments may overcome this problem); (4) ventricular delayed depolarizations: possible identification of patients at high risk of sudden cardiac death; follow-up of therapeutic measures like antiarrhythmic drug therapy or cardiac surgery (bypass grafting, aneurysmectomy); validation of delayed depolarizations from body surface by direct intracardiac and/or epicardial mapping necessary.

Nach groben Schatzungen werden in Deutschland an etwa 600 Kliniken im Jahr zwischen 15–20 000 Neuimplantationen von Herzschrittmachern durchgefuhrt, und etwa 200–300 000 Patienten durften potentielle Schrittmacherkandidaten sein. An unserer Klinik wurden in den Jahren 1977–80 insgesamt 751 Schrittmacherneuimplantationen vorgenommen (im Schnitt 188/Jahr). Die Indikation zur Implantation entfiel dabei zu jeweils einem Drittel der Falle auf Bradykardien infolge einer Storung der Sinusknotenfunktion, der AV-Uberleitung (AV-Blockierungen hoheren Grades) und infolge bradykarder, medikamentenpflichtiger absoluter Arrhythmien im Rahmen einer Herzinsuffizienztherapie. Die genannten Zahlen belegen die diagnostische und therapeutische Dimension der Schrittmachertherapie und die Notwendigkeit einer rationellen und zunachst moglichst nichtinvasiven Untersuchungstechnik zur Diagnosesicherung und Selektion der Patienten. Durch den technischen Fortschritt der letzten Jahre sind die Moglichkeiten der nichtinvasiven Diagnostik bradykarder Herzrhythmusstorungen bedeutend erweitert, vertieft und zuverlassiger geworden, wobei der Registrierung des Langzeit-EKGs, des signalgemittelten Oberflachen-EKGs und den pharmakologischen Tests zur Prufung der Sinusknotenfunktion und der AV-Uberleitung eine besondere Rolle zufallt. Im folgenden soll versucht werden, einen Uberblick uber die heute zur Verfugung stehenden, nichtinvasiven Methoden der Diagnostik bradykarder Herzrhythmusstorungen zu geben und Aussagekraft, Zuverlassigkeit, Praktikabilitat und klinische Wertigkeit dieser Methoden zu analysieren.

Overdrive pacing is a commonly used method for terminating tachycardias [2]. Furthermore, overdrive suppression of repetitive Purkinje fibre activity is a well known electrophysiological phenomenon. The so far discussed working mechanisms are shown in Table 1. Dynamic overdrive pacing (DO), which means an overdrive stimulation with varying rate, was incorporated in the DPG 1 (Vitatron) for tachycardia prevention. In order to investigate the reliability of this new pacing mode, we first induced complex ventricular extrasystoles (VES) and ventricular tachycardia by bipolar, epicardial direct current (DC) application in 5 pig hearts (20 to 30 kg) in situ during neuroleptanalgesia (method: 24). During ventricular DO pacing, DC-induced complex VES disappeared and tachycardoas needed significantly higher current strengths to be induced. I some cases, tachycardias could not intiated any more.

Aus zahlreichen tierexperimentellen Arbeiten geht hervor, das biochemische Untersuchungen am Herzmuskelgewebe direkt vorgenommen werden sollten, um genauere Einblicke in die Stoffwechselsituation einzelner Herzmuskelabschnitte zu erhalten [1]. Es ist klar, das solche Untersuchungen beim Menschen in vivo nicht durchgefuhrt werden konnen. Die Kenntnisse uber den menschlichen Herzstoffwechsel, so auch bei der koronaren Herzerkrankung, beruhen deshalb uberwiegend auf tierexperimentellen Befunden oder stutzen sich auf andere Indizien wie z. B. die arterio-koronar-venose Differenz von Substraten oder Enzymen. In dieser Arbeit soll gezeigt werden, das aus biochemischen Befunden, die am postmortal entnommenen Herzmuskelgewebe erhoben wurden, noch hilfreiche Hinweise auf bestimmte Stoffwechselprozesse in vivo gewonnen werden konnen. Der Hauptakzent liegt dabei auf Veranderungen der Aktivitat einiger Enzyme des Hexose-Mono-Phosphat-Shunts (HMPS) In vorausgegangenen Untersuchungen [2, 3] konnte bereits gezeigt werden, das sich die Aktivitat mancher Enzyme postmortal innerhalb gewisser Grenzen uberraschend wenig andert. Zu diesen Enzymen gehoren u. a. die Glukose-6-Phosphat-Dehydrogenase (G-6-PDH, E.E. 1.1.1.49) und die 6-Phospho-Glukonat-Dehydrogenase (6-P-GDH, E.C. 1.1.1.43). Beide Enzyme dienten deshalb in dieser Studie als Index fur den HMPS.

Overdrive pacing has been found to suppress repetitive arrhythmias or focal automaticity. Dynamic overdrive is a type of overdrive pacing in which the pacemaker continuously adjusts the overdrive stimulation rate to the underlying rhythm. Our own animal experiments revealed a significant reduction of direct current and ischemia-induced premature ventricular beats (VPB). Furthermore the threshold for the direct current induction of ventricular tachycardias was significantly increased during dynamic overdrive pacing.

In 70 patients (3 females and 67 males), aged 16-72 years (mean: 51 +/- 9 years), the low noise ECG was recorded from body surface by the signal averaging and the high resolution beat-to-beat techniques. We found 61 patients were suffering from coronary heart disease, 4 had atypical coronary heart disease (syndrome X), 4 had dilatative cardiomyopathy, and one had the long QT syndrome (Romano-Ward syndrome). We found the following recovery rates for ventricular late potentials within the ST segment with the averaging technique: clearcut in 13/53 patients, doubtful in 16/53 patients, and late potentials absent in 26/53 patients. With the beat-to-beat technique the following recovery rates were found: clearcut late potentials in 27/70 patients, doubtful in 23/70 patients, none in 20/70 patients, and intermittently occurring late potentials in 18/70 patients (categorized as doubtful late potentials). When comparing the detection of late potentials with both methods in individual patients, we found concordant results in 39/53 patients studied (positive with both methods in 24/53 patients, negative with both methods in 15/53 patients), and discordant results in 14/53 patients (positive with the beat-to-beat technique and negative with the averaging technique in 12 individuals, negative with the beat-to-beat technique and positive with the averaging technique in the remaining 2 patients). The correlation between the incidence of late potentials and the presence of exercise-induced myocardial ischemia (submaximal bicycle exercise) was higher when using the high resolution beat-to-beat technique, as holds also true for the correlation to complex ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon dilatation (PTCA) at present seems to be the standard procedure for nonsurgical coronary angioplasty in patients with clinically significant stenoses (3, 5). Despite relatively high initial success rates of up to 90% and more (1), there are many patients with stenotic lesions (e.g., eccentric, calicified or longsized) that seem to be unsuitable for balloon dilatation. Moreover, recurrency rates after initial successful PTCA are in the range of 20% –30%. This may in part be due to a traumatization of the vessel intima by the balloon inflation, which may cause the release of aggregatory and vasoconstrictor substances, as well as of proliferatory factors that result in growing of the atheroma at the site of foregoing PTCA. Lastly, with balloon angioplasty atheromatous material will not be removed or condensed as could be accomplished by atherectomy or thermal angioplasty. Therefore alternative methods of coronary angioplasty are being developed, among which radiofrequency angioplasty (4) and laser angioplasty (8) seem to be the most effective and attractive methods. Based on experimental results with radiofrequency thermal recanalization of thrombotically occluded arteries in domestic pigs (4), we have designed a new catheter system for radiofrequency coronary angioplasty in patients with hemodynamically relevant coronary artery stenoses.

Gewohnlich genugen ½ bis 2 Tabletten (1 Tabl. = 3 mg) Phenprocoumon (Marcumar = PPC) pro Tag, um den Quickwert konstant im optimalen therapeutischen Bereich von 15 bis 25% der Norm einzustellen. In dieser Arbeit berichten wir uber zwei Patienten (P-57, P-102), die durchschnittlich 4 Tabletten Marcumar pro Tag als Erhaltungsdosis benotigten.

Im Gegensatz zur rechtsseitigen venosen und selektiven Angiokardiographie und dem Herzkatheterismus erlaubt die selektive Laevokardiographie eine exakte Lokalisierung und eine weitgehende Grosenbestimmung des Ventrikelseptumdefektes mit Links-Rechts-Shunt. Auserdem sind multiple Defekte nachzuweisen oder auszuschliesen. Methodisch verwenden wir die percutane, retrograde Laevokardiographie.

Die Schwierigkeiten, eine Myokarditis zu diagnostizieren, sind bekannt. Hieruber existiert eine umfangreiche Literatur [1, 2, 4, 5, 6, 7, 8, 9, 10]. Wenn eine bioptische oder autoptische Objektivierung unmoglich ist, mus sich die Diagnose einer Myokarditis auf folgende Kriterien stutzen: 1. klinische Zeichen, 2. EKG- Veranderungen, 3. rontgenologische Zeichen. Die haufigsten der bekannten klinischen Zeichen sind Herzschmerzen, Herzstolpern, subjektive sowie objektive Zeichen der Herzinsuffizienz, eine Schocksymptomatik und gelegentlich auch ein plotzlicher Tod. Unter anderen hat Holzmann [4] darauf verwiesen, das zahlreiche EKG-Veranderungen zu beobachten sind, wie Rhythmusstorungen, Uberleitungsstorungen, Veranderungen der De- und Repolarisation. Besonders charak-teristisch sind wechselnde EKG-Veranderungen im Verlauf des Krankheitsbildes. Rontgenologisch wird die Diagnose durch passagere Veranderungen der Herzgrose und Konfiguration mit oder ohne pulmonale Stauungszeichen gestutzt.