Unexpanded, irretrievable stent in the proximal right coronary artery: successful management with stent graft implantation.

Stent loss and failure of retrieval are rare; nevertheless, complications have to be taken into account during percutaneous coronary intervention. Here we report a case of an unexpanded, irretrievable Palmaz-Schatz stent in the proximal right coronary artery near to the ostium and the successful management by implanting a synthetic stent graft.

[Hemodynamic effects and adverse effects of the anti-arrhythmic substance AWD-G256 in man]. / Hämodynamische Effekte und Verträglichkeit der antiarrhythmischen Substanz AWD-G256 beim Menschen.

In 19 patients with different supraventricular tachycardias the antiarrhythmic drug AWD-G256 was studied to investigate the effects on hemodynamic parameters. Over all, stroke volume, pulmonary pressure and systemic blood pressure were not significantly altered. The only main adverse effect was a transient rise of serum transaminases in two patients. We conclude that AWD-G256 is usually hemodynamically tolerated, but the antiarrhythmically effective dosage is not reached yet.

[Clinical-electrophysiologic studies on the actions of the anti-arrhythmic substance AWD-G256 in man]. / Klinisch-elektrophysiologische Untersuchungzen zur Wirkung der antiarrhythmischen Substanz AWD-G256 beim Menschen.

The effects of the new antiarrhythmic drug AWD-G256 (1) were investigated by clinical electrophysiology (His bundle electrography, programmed electrical stimulation) in 19 patients with supraventricular tachycardias but without structural heart disease. In a maximal dosage of 0.45 mg/kg body mass 1 only minimally affects electrophysiological parameters of the impulse formation and conduction. At this time the therapeutic value of 1 is not clear.

Termination of tachycardias by transesophageal electrical pacing.

To evaluate the therapeutic significance of noninvasive transesophageal pacing for termination of tachycardias the method of rapid atrial or ventricular transesophageal pacing was used in 233 patients with different tachycardiac arrhythmias. We were able to terminate atrial flutter in 136 of 162 patients by transesophageal rapid atrial stimulation (conversion to sinus rhythm in 75 cases, induction of atrial fibrillation in 61 cases). Atrial tachycardias were interrupted in 17 of 23 patients (sinus rhythm in 11 cases, atrial fibrillation in six cases). AV reciprocating/AV nodal supraventricular reentry tachycardias were terminated in 62 of 63 patients (sinus rhythm in 58 cases, atrial fibrillation in four cases). By transesophageal rapid ventricular pacing ventricular tachycardias could be terminated in ten of 15 patients. The success rate of transesophageal pacing was influenced by the pacing rate, by the type of tachycardiac arrhythmia inclusive by the type of atrial flutter and by the tachycardia's cycle length. Because the success rates are comparable with invasive technique and the procedure is simpler, the noninvasive transesophageal antitachycardiac pacing should be respected as the method of the first choice in patients with supraventricular tachycardias.

[Electrophysiological anti-arrhythmia effects of tiracizine in ventricular tachycardia]. / Elektrophysiologische und antiarrhythmische Effekte von Tiracizin bei ventrikulären Tachykardien.

The electrophysiologic effects and antiarrhythmic efficacy of tiracizine, a new class I antiarrhythmic drug, were studied in 16 patients with documented sustained ventricular tachycardia (VT) after intravenous drug application and in 6 patients after oral drug administration by means of programmed ventricular stimulation (PVS). After intravenous tiracizine (0.3 mg/kg) the VT was no longer inducible by PVS in 3 of 16 patients and became nonsustained in another patient. In 11 of 13 patients with further inducible VT the cycle duration of VT increased after tiracizine (mean 29 ms). After oral tiracizine (150-225 mg/day) the VT induction was suppressed in one patient. In a second patient the VT became nonsustained. Cycle length of VT in 4 patients with persistent induction of VT was longer after therapy (mean 88 ms). Antiarrhythmic efficacy of intravenous or oral tiracizine can be expected in at least one third of patients with VT.

[Therapeutic value of trans-esophageal electrostimulation in tachycardic arrhythmias]. / Therapeutische Wertigkeit von transösophagealer Elektrostimulation bei tachykarden Rhythmusstörungen.

We were able to terminate atrial flutter in 136 of 162 patients by transesophageal rapid atrial stimulation (conversion to sinus rhythm in 75 cases, induction of atrial fibrillation in 61 cases). Atrial tachycardias were interrupted in 17 of 23 patients (sinus rhythm in 11, atrial fibrillation in 6 cases), AV reciprocating resp. AV nodal supraventricular tachycardias were terminated in 32 of 33 patients (sinus rhythm in 28 cases, atrial fibrillation in 4 cases). By transesophageal rapid ventricular and/or atrial pacing, ventricular tachycardias could be terminated in 10 of 15 patients. The success rate of transesophageal pacing is influenced by the type of tachyarrhythmia, by the type of atrial flutter and by the stimulation rate. It is not influenced by the tachycardia's cycle length. Because the success rates are comparable with invasive technique and the procedure is simpler, the non-invasive transesophageal antitachycardia pacing represents a useful method for termination of tachycardic arrhythmias.

Electrophysiological evaluation of tachycardias using transesophageal pacing and recording.

Programmed electrical stimulation of the heart to initiate and terminate tachycardia has been useful in the evaluation of supraventricular and ventricular tachyarrhythmias. A wide use of these procedures, however, failed because of the expense of the invasive approach as well as the lack of physician experience in smaller hospitals. These disadvantages of the invasive proceeding can be abolished by transesophageal pacing. In our study, supraventricular tachycardias were initiated by programmed transesophageal atrial stimulation in 251 patients (AV node reentry in 75 patients, orthodromic AV reciprocating tachycardia using accessory pathway in 97 patients, antidromic AV reciprocating tachycardia in 11 patients, and atrial reentry in 39 patients). The stimulation protocol included one and two extrastimuli during sinus rhythm and after a pacing drive at different cycle lengths. The electrophysiological mechanism of tachycardias was determined by surface ECG, VA interval (esophageal lead), initiation mode at programmed transesophageal stimulation and by behavior of AV conduction and refractoriness. In 29 patients the mechanism of tachycardia was not clear. Invasive electrophysiological study was done in 219 of these 251 patients. In only nine patients, the supposed mechanism of tachycardia was not confirmed by invasive investigation. In 11 patients, the electrophysiological mechanism remained uncertain. In conclusion, the noninvasive transesophageal pacing is an appropriate method for evaluation of supraventricular tachycardia. It allows serial drug testing in a simple manner for finding an effective antiarrhythmic treatment.

[Terminating ventricular tachycardias by mechanical heart stimulation with precordial thumps]. / Terminierung von Kammertachykardien durch mechanische Herzstimulation mit Präkordialschlägen.

To determine value and limitations of mechanical cardiac stimulation by precordial thumps for termination of ventricular arrhythmias, we systematically treated 47 consecutive cases of ventricular tachycardias (resp. ventricular flutter or fibrillation) by this method. In 20 of 37 cases of ventricular tachycardias the arrhythmia was terminated by manual stimulation. The mean tachycardia rate amounted to 145/min (range from 102 to 222/min) in successfully treated patients. Bursts of rapid precordial thumps were more effective than single precordial thumps. In 17 of the 37 cases of ventricular tachycardia. The mean tachycardia rate was significantly higher (176/min, range from 120 to 250/min) than in successfully treated cases. Altogether, ventricular tachycardias with heart rate less than or equal to 160/min were terminated by mechanical stimulation in 17 of 22 cases, and ventricular tachycardias with heart rate greater than 160/min only in 3 of 15 cases. Ventricular fibrillation (n = 3) or ventricular flutter (n = 7) was not interrupted in any case by precordial thumps. In patients with ventricular tachycardia, mechanical stimulation extends the therapeutic possibilities. The rate of success is higher, the lower the tachycardia rate. The tachycardia rate is the only predictive parameter for therapeutic success.

[The anti-arrhythmia effect and hemodynamic effects of Bonnecor in intravenous administration]. / Antiarrhythmische Wirksamkeit und hämodynamische Effekte von Bonnecor bei intravenöser Applikation.

For testing the efficiency of Bonnecor in intravenous administration (0.3 mg/kg) 36 patients were examined electrophysiologically (31 with paroxysmal supraventricular tachycardias, 5 with ventricular tachycardias). In other 6 patients haemodynamic investigations were performed by means of right-heart catheterization and thermodilution. The supraventricular tachycardias induced by programmed electrostimulation could be interrupted by administration of Bonnecor in 45% of the cases. After the administration of Bonnecor the inducibility of supraventricular tachycardias was suppressed in 11 of the 31 patients. In 2 of the 5 patients with ventricular tachycardia an evocation of ventricular tachycardias was no more possible after an intravenous application of Bonnecor; a medicamentous termination of the ventricular tachycardias had been tried only in one case. Clinically relevant negatively inotropic effects could not be proved. Apart from insignificant malaises in few cases, no side-effects occurred.

[Ventricular late potentials in patients with cardiomyopathies in relation to electrophysiologic and myocardial biopsy findings]. / Ventrikuläre Spätpotentiale bei Patienten mit Kardiomyopathien in Abhängigkeit von elektrophysiologischen und myokardbioptischen Befunden.

With the noninvasive registration of late ventricular potentials there is the possibility to obtain statements about a regionally delayed excitation of ventricular parts which may refer to an increased inclination to ventricular tachyarrhythmias. Late ventricular potentials in patients with suspicion of primary diseases of the myocardium more frequently appeared both in the case of inducible non-sustained or sustained ventricular tachycardias and in the presence of simultaneous fibrous hypertrophy of the myocardium and interstitial fibrosis in the bioptate of the myocardium than in noninducibility of ventricular tachycardias and in the absence of histological changes of the myocardium. Thus in patients with cardiomyopathies a certain predicting significance seems to be ascribed to the evidence of late potentials in the highly increased signal-averaged ECG both for the ability to evoke ventricular tachycardias by programmed ventricular stimulation and for the presence of more distinct histological changes of the myocardium.

Bundle branch reentrant tachycardia treated by transvenous catheter ablation of the right bundle branch.

Recurrent episodes of ventricular tachycardia not responding to medical treatment occurred in a 56-year-old man. Electrophysiological investigation showed ventricular tachycardia due to bundle branch reentry. Using a method similar to catheter ablation of the atrioventricular junction, ablation of the right bundle branch was performed by an electrical shock of 250 joules. While before the ablation ventricular tachycardia occurred several times a day and its induction by programmed ventricular stimulation was facilitated by the administration of antiarrhythmic drugs, no initiation of ventricular tachycardia was possible after ablation of the right bundle branch. Over a follow-up of 30 months the patient has not suffered from tachycardia and the right bundle branch block persists.

[Complications of temporary transvenous endocardial pacemaker therapy]. / Komplikationen der temporären transvenös-endokardialen Schrittmachertherapie.

The prospective analysis of the results of the temporary transvenous-endocardial pacemaker therapy in 591 cases of treatment resulted in a total rate of complications of 37.1%. Hereby the main part of complications were disturbances of the function of electrodes (28.3%). The greatest numbers of complications showed infiltrable electrode catheters which were applied at bedside with a dislocation rate of 17.2% and a rate of not achieved stable stimulation positions of 13.7%. The smallest numbers of complications were to be observed in semiflexible stimulation catheters, which were positioned under X-ray control (dislocations in 4.1%, no achievement of a stable stimulation position in 3.3%). For the practice of the temporary pacemaker therapy from this analysis result particularly consequences in the choice of a suitable stimulation catheter and the methodical approach in positioning of this catheter.

[Electrophysiologic findings in so-called latent cardiomyopathies]. / Elektrophysiologische Befunde bei sog. latenten Kardiomyopathien.

In the framework of a diagnostic cardiac catheterization for the confirmation or exclusion of an idiopathic myocardial disease 72 patients with latent cardiomyopathy (LCM) and 51 patients without pathological haemodynamic parameters (Non-CM) were examined electrophysiologically. Intraventricular and His-Purkinje conduction defects were essentially more frequently to be proved in patients with LCM than in the non-CM group, whereas an increased ventricular vulnerability in the two groups of patients was existing in about 20% of the cases. The disturbances of rhythm anamnestically frequently mentioned by patients with LCM might above all be traced back to atrial dysrhythmias, since in about one third of the examined patients an increased atrial vulnerability could be proved. Prospective studies of the course must explain, whether the pathological electrophysiological parameters are of prognostic importance in patients with LCM.

[Transluminal electric catheter ablation in the treatment of drug-refractory focal ventricular tachycardias]. / Transvasale elektrische Katheterablation zur Behandlung medikamentös refraktärer fokaler Kammertachykardien.

In a 46-year-old patient with dilatative cardiomyopathy and medicamentously therapy-resistant focal ventricular tachycardias after endocardial right- and left-ventricular catheter mapping a transvasal electric ablation of the focus of tachycardia was carried out. For this purpose at the left-ventricular-septally localized origin of tachycardia two electroshocks of 100 and 200 J via the electrode catheter positioned there was given. Immediately after ablation a stable sinus rhythm was to be registered; longer persisting recidivations of tachycardia did not appear again subsequently. In the further course the patient suddenly died after transitory haemodynamic improvement, in which case a new, acutely beginning arrhythmia is to be assumed as a prefinal event.

[Effect of body position on the ability to initiate paroxysmal supraventricular reentry tachycardias and on the conduction system properties of the reentry circuit]. / Der Einfluss der Körperlage auf die Initiierbarkeit paroxysmaler supraventrikulärer Reentry-Tachykardien und auf die Leitungsbahneigenschaften des Reentry-Kreises.

The obtainability as well as the maintenance and termination of paroxysmal supraventricular reentry tachycardias depend upon the interaction of the individual components of the reentry circle, in which cases the properties of the pathway are influenced by the changing preponderance of the sympathetic and parasympathetic tonus and thus also by the body position. In 29 investigations by means of highly frequent and programmed transoesophageal atrial stimulation the influence of the body position on the initiation possibility of the paroxysmal supraventricular tachycardia and on the pathway properties of the individual components of the reentry circle are analysed. The investigations were performed either in the standing position or in lying position, in 16 patients for the objectivation of anamnestically reported paroxysms of tachycardia and in 13 patients for the therapy control after medicamentous stabilisation. In 6 patients supraventricular reentry tachycardias could be initiated only in standing position, in lying position only a few echo systoles appeared. In 9 patients in whom we obtained a tachycardia both in standing position and in lying position in upright posture an in most cases clear increase of the frequency of tachycardia was found. The evocation mode of the tachycardia was partly alleviated in the standing position, but also rendered difficult in several cases. It seems to be indicated to repeat the investigation under orthostatic conditions, when an adequate anamnesis of the tachycardia is present and an initiation possibility in lying position is lacking, or when a great subjective impairment in a paroxysm of tachycardia is reported and there is a relatively low frequency of tachycardia in lying position.