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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.

In ten patients with coronary heart disease molsidomine achieved a clear-cut decrease in pre- and after-load of the heart at rest. Due to decreased venous return at rest there was a fall in stroke volume resulting in a fall of systolic and diastolic aortic pressure. But at the same level of standardised exercise, systolic and diastolic arterial pressure and cardiac output were similar with or without molsidomine. Without changing after-load, there was a fall in pulmonary artery mean pressure (P less than 0.005), probably due to an increase in left-ventricular compliance and (or) a fall in pulmonary vascular resistance. A rise in venous capacity or a decrease in venous return during exercise was excluded as a possible mechanism of molsidomine action.

In a total of 16 individuals, 4 females and 12 male patients ranging from 36 to 54 years, with proven coronary heart disease, hemodynamic parameters and coronary blood flow (argon method) were measured at rest and after administration of dipyridamole, 0.5 mg/kg body weight, and theophylline, 0.24 g i.v. Simultaneously, blood samples were taken from the arterial and coronary venous blood for determinations of oxygen content and concentrations of cyclic 3,5-adenosine monophosphate (cAMP) and lactate. Thus, myocardial oxygen consumption and uptake or release of cAMP and lactate could be calculated according to the Fick principle. After administration of dipyridamole, heart rate and cardiac index slightly increased together with a decrease in arterial pressure. Myocardial blood flow significantly increased, whereas myocardial oxygen consumption remained unchanged during the dipyridamole period. In nine patients myocardial release of cAMP and lactate could be observed during the dipyridamole action, whereas in the remaining seven patients there were only insignificant changes of release or uptake of cAMP and lactate in the dipyridamole and theophylline periods. Six of nine patients in the first group revealed specific anginal complaints corresponding to the release of cAMP and lactate, whereas only two patients in the non-cAMP-releasing individuals had characteristic angina pectoris. These data suggest that dipyridamole may induce myocardial ischemia with anginal complaints and that, under certain circumstances, myocardial release of cAMP as well as lactate might serve as biochemical correlates of these ischemic conditions.

Low density lipoprotein (LDL) is considered to be the major risk factor for the development of atherosclerosis and thus cardiovascular diseases. Familial hypercholesterolemia is an inherited, autosomal, dominant disease with massively elevated LDL levels due to an LDL receptor defect. 0.2% of the total population suffers from this disease, characterized from early atherosclerosis, mainly of the coronary arteries. The majority of these patients is heterozygous with total cholesterol levels ranging from 300- 500mg/dl. They die from myocardial infarction mainly between their 40-55th year of life. Homozygous patients are rare with a frequency of 1:1 000 000, with total cholesterol levels beyond 500 mg/dl and myocardial infarction occurring generally not later than at an age of 25-30 years, often much earlier. Both groups of patients suffer much earlier from coronary heart disease for many years.

In a 53-year-old female with a St. Jude Medical prosthesis in the aortic position, detachment of the prosthesis could be non-invasively diagnosed by means of echocardiography and confirmed during reoperation. The prosthesis was dissected from the aortic wall to 1/5 of its circumference and tilted within the left ventricle. Thus, by means of simultaneously registered echocardiogram and phonocardiogram, dysfunctions of St. Jude Medical prostheses can be detected noninvasively.

Es ist heute allgemein anerkannt, das die antianginose Wirkung von Nitraten unter Ruhebedingungen auf eine Reduzierung von Pre- und Afterload des linken Ventrikels zuruckzufuhren ist [2, 10]. Parker et al. [12] beobachteten nach Nitroglycerin (NTG) keinerlei Veranderungen der Koronardurchblutung (CBF) in Ruhe und unter Belastung. Im Gegensatz dazu fanden Lichtlen et al. [10] eine Reduzierung der Koronardurchblutung unter Belastung nach Gabe von Isosorbiddinitrat im Vergleich zu Kontrollwerten vor der Medikamenteneinnahme. Durch Vorhofstimulation induzierte Zeichen einer Myokardischamie, insbesondere eine myokardiale Laktat-Ausschuttung (LA), konnen durch NTG vermindert werden [9]. Bei Koronargesunden wurde wahrend korperlicher Aktivitat ein Ruckgang des myokardialen Verbrauchs an freien Fettsauren (FFS) und Glucose (G) zugleich mit einer erhohten myokardialen Laktatutilisation gegenuber den Ruhewerten gefunden [6]. Es gibt allerdings nur wenige Studien uber die Auswirkung einer Ergometerbelastung auf den Myokardstoffwechsel und den Einflus von Nitraten bei Patienten mit nachgewiesener koronarer Herzkrankheit (KHK). Diese Studie hatte daher zum Ziel, den myokardialen Stoffwechsel der Substrate FFS, LA und G wie auch von zyklischem 3,5-AMP und zyklischem 3,5-GMP bei Patienten mit koronarer Herzkrankheit in Ruhe und unter Belastung vor und nach Nitroglycerin-Gabe zu untersuchen.

Bei koronarkranken Patienten kommt es nach Gabe von Isosorbiddinitrat (ISDN) zu einer Senkung des Pulmonalarteriendruckes, des linksventrikularen Fullungsdruckes und des myokardialen Sauerstoffverbrauchs. Die Patienten erfahren hierdurch eine Verminderung der Haufigkeit und Schwere pectanginoser Anfalle; ihre Belastbarkeit nimmt zu. Diese Akutwirkungen von ISDN-Einzeldosen sind durch zahlreiche Untersuchungen bewiesen (2, 3, 4, 12, 13, 18, 23, 25, 26, 27, 28).

In twelve patients with coronary heart disease and hemodynamically significant coronary artery stenoses (LAD: 11, LAD plus RCA: 1) the effect of intracoronary nifedipine, 0.2 mg, on PTCA-related myocardial ischemia was evaluated. The severity of angina pectoris during balloon inflation was not significantly reduced by nifedipine, whereas the sum of ST segment alterations in Einthoven and Goldberger leads on inflation was significantly decreased by the drug. Before inflation intracoronary nifedipine lowered the systolic arterial blood pressure significantly, whereas diastolic and mean aortic pressure and heart rate remained unchanged. At the end of the inflation period heart rates were significantly faster after nifedipine, and the heart rate-blood pressure product higher with nifedipine. No significant correlations could be calculated between the extent of ST segment alterations and any of the hemodynamic parameters. From our results we conclude that, besides the possibility of ventricular afterload reduction, the beneficial cardioprotective effect of intracoronary nifedipine may mainly be attained by the local "cardioplegic" action of this substance.

Die Zugehorigkeit eines hypersensitiven Karotissinussyndroms zum Sinusknotensyn-drom (SSS) und die diagnostische Wertigkeit einer Karotissinusmassage bei dieser Er-krankung ist umstritten. Ferrer schliest in der 1968 und 1973 erschienenen Zusammen-fassung des Sinusknotensyndroms die vagale Suppression des Sinusknotens als zusatzli-ches Kriterium eines SSS aus [2,3]. Andere Autoren findenin unterschiedlichem Prozent-satz (bis zu 30%) eine Kombination eines hypersensitiven Karotissinussyndroms mit einem Sinusknotensyndrom [9].

We have developed a new high resolution ECG equipment for recording cardiac microvolt potentials from the body surface. Noise reduction has been achieved by specially designed suction electrodes, by spatial averaging of the electrocardiograms from four electrode pairs, using extremely low noise amplifiers, by performing registrations within a Faraday cage, and by teaching the patient to relax during endexpiratory breath holding. Fourteen young males (controls) and 30 patients with various cardiac diseases (27 with CHD) were studied. In normals ventricular late potentials were not seen, but in 1230 patients clearcut diastolic potentials were found. In 712 patients with positive findings, late potentials appeared beat-by-beat, in 512 patients those signals occurred intermittently, in 1130 patients questionably, and in the remaining 530 patients no late potentials were recorded. One patient with the Romano-Ward syndrome revealed phases with stable beat-by-beat and intermittently occurring ventricular late potentials. These results demonstrate the feasibility of continuous non-invasive recording of ventricular late potentials, whose clinical and prognostic significance remains to be established.

Following the administration of isosorbide dinitrate (ISDN) to patients with coronary heart disease, pulmonary artery pressure, left-ventricular filling pressure, and myocardial oxygen consumption decline. As a result, patients experience a reduction in the frequency and severity of anginal attacks and their exercise tolerance increases. These acute effects of single doses of ISDN have been confirmed in numerous studies (2–4, 12, 13, 18, 23, 25–28).

Aufgrund tierexperimenteller und klinischer Erfahrungen kann man erwarten, das die Erfolgsrate einer Ballondilatation von der Lage und der Anatomie der Stenose, der Lange der Inflationsdauer und der Hohe des Inflationsdrucks abhangen [5, 13]. So konnen nach eigenen Erfahrungen in der Regel bei Inflationsdauern von 45–60 s und einem hohen Inflationsdruck von 6-8-12 atm relativ gunstige hamodynamische Erfolge der Stenosereduktion erzielt werden. Auf der anderen Seite wachst mit zunehmender Inflationsdauer auch die Gefahr der zunehmend starkeren Beeintrachtigung der linksventrikularen Funktion, wodurch potentiell Blutdruckabfalle und besonders bedrohliche ventrikulare Arrhythmien induziert werden konnen. Aus diesem Grunde hat man sich in den letzten Jahren bemuht, mit Hilfe physiologischer Methoden, z. B. der Perfusion der betroffenen Herzkranzarterie mit arteriellem Blut [7, 11] oder mit pharmakologischen Masnahmen wie der intrakoronaren Applikation von Nitroglyzerin [4] eine gewisse Myokardprotektion zu ermoglichen. Wir haben in einer Pilotstudie die Wirkung von intrakoronar verabreichtem Nifedipin auf die Ischamietoleranz des menschlichen Herzens wahrend therapeutisch notwendiger perkutaner transluminaler Koronarangioplastien uberpruft.

In four different groups coronary endoscopy and endoscopy of peripheral vessels was carried out, using two ultrathin fibre endoscopes with a working length of 120 cm and a diameter of 1.4 or 1.8 mm. In a first series of seven cadaver hearts, normal vessels were found in three, one had high-grade stenosis and in the remaining three there were flat whitish atheromatous changes, rather scar-like in appearance. In a second series of 16 patients, the vascular wall in the iliac region was easily visualised in ten, while six showed diffuse atherosclerotic changes of the wall. In a third group of eight patients, coronary endoscopy was carried out at the time of balloon-catheter dilatation; endoscopy was successful in five patients. In two of them, the stenosis or occlusion to be dilated by balloon was visualised. In a fourth series, good visualisation of the vessels was obtained intraoperatively in seven out of nine patients, and in addition the course of the vessel distal to the stenosis as well as the site of anastomosis with the venous bypass graft could be seen. No serious side-effects of the procedure have yet been observed. Coronary endoscopy opens up a new dimension in the morphological assessment of coronary vascular changes. The method must, however, still be regarded as experimental.

Die Koronardurchblutung (Vcor, Argon-Methode) wurde in Ruhe und nach i.v. Gabe von 0.5 mg/kg Dipyridamol bei 27 Patienten gemessen, die die folgenden Kriterien erfullten: Angina pectoris (obligat), Besserung durch antianginose Pharmaka (obligat), pathologisches (Belastungs-) Ekg (bei 80%), kein gesicherter Infarkt, normales Koronarogramm (Gruppe „SVD“). Die Vcor-Werte wurden verglichen mit denen einer Gruppe Koronargesunder (n = 16) sowie eines Kollektivs mit angiographisch gesicherter koronarer Herzkrankheit (Gruppe KHK, n = 90).

The effect of endocardial cardioversion was investigated in 17 patients (aged 26-76 years), ten of them with ventricular tachycardia, either spontaneous or initiated by programmable stimulation. During a total of 14 days of observation there were 33 episodes of spontaneous or induced ventricular tachycardia. A special cardioverter catheter had been placed into the right ventricle and endocardial microshocks were given ranging from 0.05-2.0 J. All patients could feel the shock, but in most instances it was mild to moderate, in only one painful. The tachycardia was slowed in 20% of all microshocks, moderate acceleration occurred in 6%, while in 71% the tachycardia rate remained unchanged. In 7 out of 65 microshocks sinus rhythm occurred spontaneously, after an interval in which the tachycardia slowed. Atrial fibrillation was induced in 6% of cases, but there was no instance of ventricular fibrillation. Reversion directly to sinus rhythm after endocardial cardioversion occurred in 26 of 33 episodes of ventricular tachycardia, while in 7 episodes the tachycardia rate slowed. In no case was it necessary to use external DC cardioversion to terminate a ventricular tachycardia. Threshold values for successful cardioversion of ventricular tachycardia averaged 0.77 (+/- 0.63) J. In one patient, atrial flutter with a relatively high A-V conduction rate was converted into atrial fibrillation by an intra-atrial microshock of 5.0 J. Thus endocardial cardioversion proved effective and safe in terminating ventricular tachycardia, even in patients in whom anti-tachycardic ventricular pacemaker stimulation had failed. The method is apparently not suitable for the conversion of supraventricular tachy-arrhythmias to sinus rhythm.

Ventricular late potentials are regarded as an expression of delayed impulse conduction in an area of myocardial ischemia and, accordingly, indicative of a preformed reentry circuit. Late potentials can be detected in chronic, stable coronary artery disease and their presence correlates closely with impairment of ventricular function and with the probability of future occurrence of tachyarrhythmic events or sudden cardiac death. While repetitive ventricular arrhythmias in the chronic stage of coronary artery disease result almost invariably from circling intraventricular wavefronts, tachyarrhythmias associated with acute myocardial infarction appear attributable to differing pathomechanisms. According to experimental studies, in acute myocardial infarction, three phases of arrhythmogenesis can be differentiated: phase 1 encompasses the first hours after vessel occlusion which generally corresponds with the prehospital phase. Due to the difference in potential of up to 25 mV between ischemic and nonischemic cardiac muscle areas, an injury current is called into existence which leads to depolarization of normal cardiac muscle tissue. The ectopic impulses so precipitated, the conduction of which is supported by the functional inhomogeneity of the infarcted region, are capable of initiating reentry tachycardia. During phase 2, a few hours to days after the ischemic event, only the subendocardial Purkinje fibers in the infarcted region exhibit focal arrhythmogenicity. In contrast to the working myocardial cells, the latter survive due to their immediate proximity to the cardiac chamber and show, ischemia-induced, a propensity to high-frequency impulse formation in terms of abnormal automaticity. Similar to the experimental findings, the cause of the frequently-observed ventricular arrhythmias in the early hospital phase appears predominantly attributable to a focal arrhythmia mechanism. During phase 3, several days to weeks after the acute myocardial ischemic event, reentry mechanisms again are in the foreground in which the electrophysiologic changes in the Purkinje fibers, in terms of increasing desynchronization, together with conduction barriers arising through the infarct scar, pave the way for reentry phenomenon. After abrupt restoration of patency of a previously occluded vessel the very frequent "reperfusion arrhythmias" are also attributable primarily to reentry mechanisms due to inhomogeneous improvement of the conduction properties in the region of the reperfused myocardium. Ventricular late potentials can be registered both invasively by means of epi- or endocardial leads as well as noninvasively from the body surface.(ABSTRACT TRUNCATED AT 400 WORDS)

The long-term effect of specific LDL plasma immunabsorption on the course of coronary arteriosclerosis was tested in ten patients with familial hypercholesteremia type IIa (seven females, three males; age range 15-57 years). Available were ECG, bicycle ergometry, hemodynamic and angiographic data. These tests were repeated seriatim in the course of the LDL immunabsorption. It was found that exercise tolerance markedly increased, ischemic ST-changes became less marked and the initial hemodynamic parameters remained unchanged. The morphology of the coronary arteries was influenced lastingly: among 22 stenoses only one progressed, there was no further progression in 11 stenoses and regression in ten. When there was generalized arteriosclerosis, progression occurred in two of 79 coronary artery segments, progression was arrested in 56 and regression was noted in 21 of 79 segments. These results demonstrate that specific LDL plasma immunabsorption for the elimination of LDL cholesterol favorably influences the course of coronary arteriosclerosis in patients with familial hypercholeremia type IIa. The findings support the lipid theory of atherosclerosis and coronary arteriosclerosis, at least in this special group of patients.

Cor triatriatum dextrum is a rare malformation of the right atrium usually without typical signs or symptoms. Today the intra vitam diagnosis of C.t.d. is done by echocardiography, MR and angiocardiography. Once the diagnosis is established, surgical correction of this anomaly is possible in symptomatic patients.

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

Cor triatriatum dextrum is a rare malformation of the right atrium usually without typical signs or symptoms. Today the intra vitam diagnosis of C.t.d. is done by echocardiography and angiocardiography. Once the diagnosis is established, surgical correction of this anomaly is possible in symptomatic patients. When the presence of an abnormal membrane in the right atrium is not recognized before operation, the outcome may be unsatisfactory.

In 17 of the 28 patients a surface potential of the bundle of His could be differentiated. Pharmacological tests with verapamil and ajmaline raised the number of positive body surface recordings of the bundle of His to 22 out of 30 (=73%). In 11 of the 30 subjects (=37%) depolarizations of the Tawara bundle branches were recorded in addition. Two possible applications of this method are discussed: follow-up of patients with AV-block and supervision of negative dromotropic cardiac medication.

Das Syndrom des verlangerten QT-Intervalls (LQTS) nimmt unter den haufig mit tachykarden Herzrhythmusstorungen einhergehenden Erkrankungen eine Sonderstellung ein. Diese Einschatzung resultiert nicht nur aus der Seltenheit der Erkrankung und der Tatsache, das vorwiegend Kinder befallen werden, sondern auch aus den charakteristischen pathophysiologischen Veranderungen und der Notwendigkeit spezieller diagnostischer und therapeutischer Masnahmen.

Der gunstige antianginose Effekt der Nitrokorper wird hauptsachlich durch seine das Herz entlastende periphere Wirkung — im Sinne einer Senkung des Preload und des Afterload beider Ventrikel — erklart. Dies geht mit einer Herabsetzung des Herzzeitvolumens, der Herzarbeit und des myokardialen Sauerstoffverbrauchs einher. Die Ergebnisse bezuglich der Veranderungen der Myokarddurchblutung nach Gabe von Nitraten sind widerspruchlich. Wahrend Behrenbeck [1], Gorlin [5], Stauer [11] und Tauchert [13] eine Abnahme der Koronardurchblutung feststellten, berichteten Cowan [3], Carson [2] und Horwitz [6] uber einen Anstieg. Es gibt nur wenige Berichte uber die Wirkungen von Nitraten auf den myokardialen Sauerstoffverbrauch und die Koronardurchblutung unter korperlicher Belastung [7,10].

The antianginal effect of nitrates is mainly due to a reduction of left ventricular wall stress by lowering the ventricular pre- and afterload. This is accompanied by a decrease of the cardiac output, of cardiac performance, and of the myocardial oxygen consumption. Results concerning changes of myocardial blood flow after administration of nitrates are contradictory. While Behrenbeck [1], Gorlin [5], Strauer[11], and Tauchert[13] observed a decrease of coronary blood flow, Cowan [3], Carson [2], and Horwitz [6] reported an increase. There are only a few communications on the effects of nitrates on the myocardial oxygen consumption and on the coronary blood flow under physical stress [7, 10].

Complications following percutaneous transluminal coronary angioplasty (PTCA), such as coronary artery occlusion, spasm, or dissection, frequently require urgent surgical intervention. Out of 26 patients from our hospital, 12 who underwent emergency coronary bypass grafting because of balloon catheter complications with a total ischemic time of 100-255 min, were restudied in the late postoperative period by clinical examination and by coronary and left ventricular angiography. Left ventricular angiograms were evaluated quantitatively for global and regional function using the AVD system (Siemens Elema, Erlangen). Electronmicroscopic results from myocardial biopsy samples, taken intraoperatively from the presumed center of the ischemic zone, were compared with the clinical results. An improvement of left ventricular function parameters could be seen in patients with reperfusion intervals within 130 min. In the case of intermittent perfusion of the occluded vessel (catheter perfusion with arterial blood, intermittent spasm) operative revascularization proved to salvage jeopardized myocardium. There was a close correlation between the degree of left ventricular dysfunction and histological results, coronary morphology and clinical staging. In conclusion, the efficacy of myocardial protection by emergency bypass surgery depends mainly on coronary morphology and above all on reperfusion intervals.

Recognition of patients at risk of sudden cardiac death and prevention of such lethal events represent important and, for the most part, unresolved problems in clinical cardiology. From pathologic-anatomical and clinical studies of instances of sudden death it is known that in more than 80% the lethal electrical events, that is ventricular fibrillation, are attributable to myocardial ischemia, usually due to coronary artery disease. Experience in experimental studies as well as in treatment of patients with myocardial infarction on coronary care units has shown that certain types of arrhythmias such as frequent, multiform, repetitive and early-occurring (R-on-T) ventricular premature beats, in particular, may be associated with sudden arrhythmic cardiac death. Accordingly, in 1971, Lown and Wolf proposed a system for grading of ventricular arrhythmias and their severity which assumed world-wide importance for clinical and prognostic studies. This system of classification contains quantitative and qualitative criteria and is ordered in part on exclusion and in part on hierarchy, in which it is implied that the hierarchy of ventricular premature beats corresponds with that of the risk of death. Since the system enables only semiquantitative delineation of ventricular arrhythmias whose absolute number, however, within a given observation period appears to be of prognostic relevance and, additionally, since the Lown system is encumbered by the fact that classification is based only on the most severe arrhythmia with subsequent loss of information regarding concurrent arrhythmias of lesser severity, Bigger and his associates, in 1978, suggested a modification to provide quantification of all ventricular premature beats. In addition to the problems inherent to grading ventricular premature beats, further problems are also incurred with respect to spontaneous variability of ventricular arrhythmias. Based on statistical considerations and clinical studies accordingly, adequate assessment of complex ventricular arrhythmias prerequisites continuous monitoring for a period of 24 to 48 hours. Furthermore, for the exact recognition and quantitative detection of ventricular arrhythmias, the reliability of the individual systems for continuous ECG monitoring plays an important role since, by no means, have they all been validated in arrhythmia-detection capabilities. Since 1971, a number of clinical studies have shown, in particular, that complex ventricular arrhythmias are of important prognostic relevance in characterization of patients at risk of sudden cardiac death. The results may be summarized as follows: Ventricular premature beats can be found frequently in

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.

In spite of the introduction of effective antimicrobial therapy, the incidence of bacterial endocarditis has not been diminished. To the contrary: the number of publications regarding this disease increased over the last years [1–5]. In our patients we also found an increasing incidence of infective endocarditis (Fig. 1).

Conventional Holter ECG devices have no separate track for the pacemaker spike recording. Thus, an exact differentiation of the underlying rhythm, pacemaker rhythm, background and pacemaker-related arrhythmias or pacemaker dysfunctions (failure to sense; failure to output; failure to capture) is not possible. This seems however to be important since several investigators found that up to 30% of pacemaker patients were symptomatic. The aim of the study was to investigate the clinical reliability of three different pacemaker Holter ECG devices (Del Mar Avionics: Trendsetter, Pa-cerecorder; Reynolds: Pathfinder; Ela Medical: Anatec). Therefore we performed 24-hour pacemaker Holter ECG recordings in 157 consecutive pacemaker patients (47 female; 83 male, age: 63 ± 12 years). The patients had 119 VVI, 5 AAI, 13 DDD, 5 DVI, 1 VAT and 14 rate adaptive pacemakers. In each patient a careful exploration of the anamnesis and symptoms was performed. A good signal quality can be achieved by careful electrode position and cable fixation, avoidance of high amplitude artefacts and electrostatic interference. An automatic analysis of the tapes is technically possible in VVI and AAI pacemakers. An additional visual control of the tapes should nevertheless be performed in each case. We found a high sensitivity combined with a high number of false-positive events. A differentiation of the rhythm, arrhythmias and pacemaker reactions was easily possible. Pacemaker dysfunctions could be separated according to type and incidence (I°: no dysfunctions; IP: 1 dysfunction per hour; III°: 1 to 30 dysfunctions per hour; IV°: 30 dysfunctions per hour). In some pacemaker Holter ECG devices, the differentiation of fusion beats from failure to sense is not always performed correctly. Failure to sense detected mainly in patients with premature ventricular beats, tachyarrhythmia and bundle branch blocks. Failure to output is often the consequence of false inhibition by noise. According to our data pacemaker patients at high risk are the following: patients with AV-block IIP and increased ventricular vulnerability (VES Lown III°, IV°) or ≥ 1 pacemaker dysfunctions per hour.

To evaluate spontaneous variability of ST-segment changes within the Holter ECG, in 20 patients with documented coronary heart disease (CHD) long-term ambulatory ECG recordings were performed over 3 consecutive days, when the patients were only receiving short-acting nitrates. ST-segment alterations per day were measured as the area beneath the baseline (mV x min), and were compared day-to-day intraindividually. The intra-day variations of ST-segment area alterations were a factor of about 10, when compared with the baseline values. Following administrations of 120 mg ISDN ret. at the beginning of day 4, the number of anginal attacks was reduced, as was the acute medication with short-acting nitrates. There was also a trend to reduction of ischemic ST-segment changes, but these reductions could not be confirmed statistically. In studies on the course and therapeutic interventions of patients with CHD, the phenomenon of spontaneous variability of ST-segment alterations must be taken into account--as applies also to the arrhythmia analysis within the Holter ECG--and the recording period must probably be prolonged beyond the 24-h limit presently used.

In 13 patients in the age range of 34 to 70 years (mean: 53 +/- 10 years), during diagnostic His-bundle investigations, registrations from the sinus nodal area were analyzed with a signal-averaging computer. In 12 patients we were able to get reproducible per-P-potentials with a sino-atrial conduction interval between 56 and 227 ms. The normal sequence of the excitation process from the atrium to the AV node together with the bundle of His and to the ventricles in all patients, and the reproducibility of the signal-averaged pre-P-potentials, which were well outlined from the atrial potential with a reasonable conduction interval, suggest that these signal-averaged pre-P-potentials reflect the sinus nodal activity rather than an ectopic focus. In 5 of 11 comparable cases there was a good correlation between the signal-averaged sino-atrial conduction intervals and those calculated with the extrastimulus technique. In 2 patients this correlation was moderate. The signal-averaging process may be impaired by coarse random noise, frequent atrial or ventricular extrasystoles, and by fluctuations of the baseline of the sinus nodal lead. The fact that the registrations are performed during normal undisturbed sinus rhythm offers a considerable advantage over the extrastimulus technique.

1. After initial acute administration of 20 or 60 mg ISDN, 2 mg molsidomine and 20 mg nifedipine, a clear effect on the circulation and an increase in work tolerance is detectable. 2. Following 4 weeks' treatment with 3 X 20 mg ISDN, there is no essential loss of action in the venous branch or with respect to working capacity. 3. After 4 weeks' treatment with 3 X 60 mg ISDN, the improvement in working capacity is partially retained, but the action on the venous branch is significantly poorer. 4. During 4 weeks' treatment with 3 X 20 mg nifedipine, there is no essential loss of action in the arterial or venous branches, or with respect to working capacity. 5. Our results with continuous high doses of ISDN indicate that high doses should be used only in monitored exceptions.

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.

In ten patients with coronary heart disease molsidomine achieved a clear-cut decrease in pre- and after-load of the heart at rest. Due to decreased venous return at rest there was a fall in stroke volume resulting in a fall of systolic and diastolic aortic pressure. But at the same level of standardised exercise, systolic and diastolic arterial pressure and cardiac output were similar with or without molsidomine. Without changing after-load, there was a fall in pulmonary artery mean pressure (P less than 0.005), probably due to an increase in left-ventricular compliance and (or) a fall in pulmonary vascular resistance. A rise in venous capacity or a decrease in venous return during exercise was excluded as a possible mechanism of molsidomine action.

At present it is generally accepted that in resting conditions the antianginal effect of nitrates is due to a reduction of ventricular pre-and afterload [2, 10]. Parker et al. [12] did not observe any change in coronary blood flow (CBF) at rest and during exercise after administration of nitroglycerin (NTG). In contrast, Lichtlen et al. [10] found a reduction of exercise CBF due to the action of isosorbide dinitrate, when compared with the control values before drug administration. Atrial pacing induced signs of myocardial ischemia, particularly myocardial lactate (LA) release, may be alleviated by NTG [9]. In normal individuals without obvious coronary heart disease (CHD), during physical activity a reduction of myocardial utilization of free fatty acids (FFA) and glucose (G) was observed together with an enhanced myocardial utilization of lactate, when compared with the control values at rest [6]. However, studies on the effect of ergometric exercise on myocardial metabolism and the influence of nitrates on it in patients with proven CHD are sparse. Therefore, the intention of this study was to investigate the myocardial metabolism of the substrates FFA, LA, and G as well as of cyclic 3,5-AMP and cyclic 3,5-GMP in patients with coronary heart disease at rest and during exercise before and after administration of nitroglycerin.