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In a total of 40 patients, 10 females and 30 males, aged 42 to 65 years (mean: 53 ± 6 years) the diagnostic accuracy of three methods that might indicate left ventricular vulnerability, has been tested. These methods comprise the spontaneous occurrence of complex ventricular arrhythmias (Lown’s classes IVa and b and ventricular tachycardias), the recovery of ventricular late potentials within the signal averaged surface ECG, and the induction of repetitive ventricular response during programmed right ventricular stimulation. The “gold standard” was the out-of-hospital documented spontaneous occurrence of ventricular tachycardias and/or fibrillation in each of these 40 patients, 21 of whom had to be resuscitated by DC shock.

Patients suffering from long QT syndrome are threatened by torsade de pointes tachycardias and sudden arrhythmic cardiac death. An inhomogenic sympathetic innervation of the heart with dominance of the left cervicothoracic sympathetic nerves has been considered to be a major cause of life threatening cardiac arrhythmias. This study presents the electrocardiographic and electrophysiologic results of 7 patients with long QT syndrome. In agreement with data published earlier our results of Holter monitoring, exercise testing and programmed electrical right ventricular stimulation were of no diagnostic or prognostic significance in predicting syncopal attacks or sudden arrhythmic cardiac death. Thus, the high resolution ECG methods played an important role in this study. During noninvasive recordings of signal averaged ECGs and high resolution surface ECGs with beat to beat registration, diastolic microvolt potentials could be detected in 6/7 patients within the ST segment and in 5/7 patients after the T wave. Our results evidently show that the signal averaged ECG and the high resolution surface ECG could be of diagnostic significance in patients with long QT syndrome.

In patients with chronic recurrent attacks of supraventricular, and in rare cases of ventricular tachycardia, chronic antitachycardia pacing using implantable pacemakers with different termination modes may be an attractive alternative to chronic drug therapy, particularly in patients with drug refractoriness or serious side effects. Before implantation of an antitachycardia pacemaker various clinical and technical conditions have to be considered and tested, such as reproducibility of tachycardia termination, effective and safe termination mode, optimal lead position, conditioning of the tachycardia by antiarrhythmic drugs for safe electrical termination, and the possible deterioration of the tachycardia by the antitachycardia pacing mode itself.

Long-term treatment of patients with recurrent attacks of ventricular tachycardia (VT) and an increased risk of sudden death may be crucial, since in some patients antiarrhythmic drugs may be ineffective or may induce serious side effects. Thus, endo-epicardial cardioversion-defibrillation seems an attractive alternative for short-term, and probably also long-term treatment of recurrent VT and ventricular fibrillation (VF).

An automatic, implantable cardioverter-defibrillator (AICD) which generates a high-energy current impulse is now available for the management of treatment-resistant malignant ventricular arrhythmias. Such a device (manufactured by Intec/CPI) was implanted into eight patients with coronary heart disease or dilated cardiomyopathy, and in four after surgery for postinfarction ventricular arrhythmias. All patients had had life-threatening episodes of ventricular fibrillation or tachycardia: the arrhythmias were refractory to multiple drug therapy (mean of 6.8 antiarrhythmia drugs per patient). The threshold energy for converting ventricular fibrillation was 9.6 Joules +/- 5.7. Except for one bacterial infection of the electrodes, there were no serious complications. During a mean observation period of 13.6 months 21 electrophysiologically induced and 105 spontaneous tachyarrhythmias were successfully terminated by the AICD. No malfunctions occurred and there was no death due to an arrhythmia.

Haemodynamic effects of 5-isosorbide mononitrate (5-ISMN) were studied at rest and on exercise in 31 patients with angiographically confirmed coronary heart disease. A decrease in arterial blood pressure and mean pulmonary artery pressure without significant change in heart rate, cardiac output and stroke volume occurred both at rest and on exercise after 20 mg of 5-ISMN to 12 patients. Administration of 50 mg 5-ISMN to 19 patients achieved greater decrease in mean pulmonary artery pressure; cardiac output and stroke volume were highly significantly reduced at rest, while on exercise both cardiac output and stroke volume remained unchanged. Ten patients, in whom after a single dose of 50 mg 5-ISMN the mean pulmonary artery pressure at rest and on exercise had decreased 28% and 45%, respectively, with a definite rise in exercise tolerance, repeat acute administration of a single dose of 50 kmg 5-ISMN produced a fall in mean pulmonary artery pressure at rest by 20% after 50 mg three times daily for four weeks. On exercise the fall was only 14% below the control levels before treatment. In addition, exercise tolerance was reduced. These results indicate that acute administration of 5-ISMN at rest and on exercise decreases cardiac work load. But on chronic administration of high doses, tolerance to the drug may develop.

Since it’s introduction into clinical cardiology PTCA proved to be an effective method for reduction of coronary stenoses, thus leading to relief of angina pectoris and an increase of exercise tolerance in CHD patients. The success rates of PTCA depend on the type of lesion, catheter material, experience of the angiographer, and on the inflation pressure and inflation time used. With longer inflation times possible hazards of PTCA-induced ischemia may arise like LV pump failure or the occurrence of dangerous ventricular arrhythmias. Myocardial protection during PTCA may be achieved by means of intracoronary (ic.) administration of Nitro glycerine and/or Nifedipine (or other calciumantagonists as well) prior to inflation, or by simultaneous perfusion of the dependent myocardial area with arterial blood during the whole inflation period. Several studies using ic.-Nitroglycerine and/or Nifedipine have shown that sometimes symptoms and particularly signs of myocardial ischemia on PTCA may be delayed by these drugs and the occurence of ventricular arrhythmias decreased, thus allowing potentially longer inflation periods. On the other hand, using quantitative LV angiography we could demonstrate that the impairment of global and regional LV contraction due to PTCA-induced ischemia was considerably and significantly less pronounced when using simultaneous perfusion with arterial blood during inflation. Administration of Nitroglycerine and/or Nifedipine by ic.-route seems to be a simple, rapid and safe method of myocardial protection from PTCA-related ischemia, but it may not preserve LV global and regional performance to such a degree as could be achieved using perfusion with arterial blood. The perfusion method may, therefore, provide the opportunity to also attempt PTCA in patients with multiple vessel disease and severely impaired left ventricular perfomance, as well as in individuals with left main stenoses.

100 healthy medical students were studied with 24-h Holter monitoring for ST-segment evaluation. Six recordings (1.8% of males and 11.6% of females) contained at least one episode of horizontal or downsloping ST-segment depression of at least 0.1 mV or more and 1 min duration in the V-5-like lead. Since ST-segment elevations (in 73% of the recordings in the V-5-like lead, and in 40% in the V-2-like lead) and discordant (negative) T-waves associated with ST-segment depressions (in 31% of the recordings in the V-2-like lead) were commonly seen, these ECG findings have to be considered as nonspecific. During exercise tests using a protocol of maximal work load, not one of these healthy individuals displayed typical ST-segment depressions indicative of myocardial ischemia. Therefore, typical documented ST-segment alterations in Holter-ECG recordings should be used with caution when observed in individuals with suspected coronary heart disease, particularly when they are female.

Rifampicin (RMP) induziert nach mehrtagiger Gabe die mischfunktionellen Oxygenasen in der Leber, so das auch sein eigener Metabolismus beschleunigt wird (Eigeninduktion, Acocella 1978a). Wie wir beobachteten, nahmen die RMP-Plasmaspiegel unter oraler Dauertherapie starker ab als bei intravenoser Applikation (Musch et al. 1982; Loos et al. 1983). Klinisch zeigten 30 initial mit RMP intravenos behandelte Patienten mit offener Lungentuberkulose eine schnellere Sputumnegativierung und Rontgenbefundbesserung im Vergleich zu 48 oral therapierten Patienten (Kombinationstherapie: RMP-Isoniazid-Ethambutol). So war z. B. die Sputumkulturkonversion nach dem 1. Behandlungsmonat bei intravenoser RMP-Gabe doppelt so hoch (63%) wie bei oral behandelten Patienten (27%). Der Azetyliererstatus wie auch die tagliche Gabe von 5 oder 10 mg Isoniazid/kg Korpergewicht oder die Verabreichung von Streptomycin anstatt von Ethambutol hat dagegen keinen wesentlichen Einflus auf den Behandlungserfolg im 1. Monat. Entscheidend war vielmehr, das unter intravenoser RMP-Gabe hoher Plasmaspiegel, auch Spitzenkonzentrationen, uber die ersten Behandlungswochen erreicht wurden als bei oraler RMP-Applikation. Als Erklarung fur diesen unterschiedlichen Therapieerfolg und Plasmaspiegel-verlauf erscheint eine Induktion des RMP-Metabolismus in der Darmschleimhaut moglich (Musch et al. 1982).

In a prospective study of 23 patients the clinical effects of rate-adapted activity-sensed (by mechanical resonance oscillations) pacing (Activitrax system) were tested over a mean period of 8.1 +/- 3.8 months. This form of pacemaker treatment was used when, after exercise and on long-term ECG monitoring, the spontaneous heart rate had not exceeded 85 beats per min and there had been symptoms of decreased exercise tolerance. Lasting improvement in physical exercise tolerance was achieved in 11 of 17 patients after changing from fixed-rate to rate-adapted pacing. Treadmill ergometry, randomised in the fixed-rate or rate-adapted mode, brought about a significant rise in exercise tolerance (P greater than 0.01). Contrary to results after external influences, insufficient rate increases in five patients in the course of static stress was of clinical significance and thus narrow the indications for this type of 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)

Several investigators have judged the burst overdrive pacing mode to be effective in tachycardia termination during right ventricular programmed stimulation. The aim of the study was to investigate the long-term results of burst overdrive pacing by means of an implanted, programmable burst pacemaker (Intermedics Cybertach 60) in the treatment of drug-refractory supraventricular (n = 3) and ventricular (n = 3) tachycardias. Therefore 6 patients were repeatedly controlled during a follow-up period of up to 3 years. In 4/6 patients the parameters of the burst stimulation had to be changed within the first 6 months after the implantation. All 6 patients needed an additional antiarrhythmic drug treatment for the tachycardia conditioning. Due to a significant reduction of the tachycardias and hospitalisations all patients could normalize their lives. In a 20 year old man the battieries ran out after a 2 year period of excellent antitachycardia function. The patient was hospitalised due to continuous burst pacing, even during sinus rhythm or premature ventricular beats.

In all, 47 patients aged 28–63 years (mean age 50.4 ± 7.0 years) who had angiographically confirmed coronary disease were investigated. The purpose of the study had been explained to all the patients and they had given consent in writing. All drugs acting on the coronary system were withdrawn 72 h before the investigation. Short-acting nitrates for aborting attacks were permitted up to 6 h before the investigation. Patients with heart defects, arrhythmias, marked arterial hypertension, lung diseases, severe angina pectoris symptoms, and radiological or clinical evidence of heart failure were not admitted to the investigation. All investigations were carried out in the early morning to avoid diurnal variations [19].

In 500 patients suffering from angina pectoris (454 males, 46 females) in whom coronary angiography had been performed a dipyridamole test was carried out. The test was positive in 319 of 396 patients with stenosing coronary heart disease (sensitivity 80%); ECG changes typical of ischaemia were demonstrated in 51%. The exercise ECG test was positive in only 68% of 229 patients with coronary heart disease. Among 104 patients without stenosing coronary heart disease the dipyridamole test was false-positive in 47, giving a specificity of 55%, while in 17 (16%) there were false-positive ECG-changes. The exercise test was falsely positive in 20 of 38 patients without stenosing coronary heart disease (specificity of 47%). Coronary blood flow was measured with the argon technique in 19 of 47 with a false-positive dipyridamole test and three with a false-positive exercise ECG. Maximal pharmacologically induced coronary blood flow was significantly reduced in all so that the diagnosis of "atypical coronary heart disease" or "small vessel disease" was made. The dipyridamole test or the exercise ECG test were falsely positive in these patients only with regard to the coronary arteriogram, correctly positive, however, in relation to angiographically non-demonstrable coronary blood flow abnormalities. The dipyridamole test is complementary to the exercise ECG test and has comparable accuracy. The same precautions must be observed for both tests.