[Electrode-myocardium distance in transesophageal atrial stimulation]. / Untersuchungen zum Elektroden-Myokard-Abstand bei der transösophagealen Vorhofstimulation.

In 9 voluntary test persons with a sound heart comparative examinations were carried out to discover the optimum depth of insertion by unipolar and bipolar determination of the absolute threshold and transoesophageal derivation as well as the correlation of the optimum depth of insertion with external measurements of the body. The methods mentioned to ascertain the optimum depth of insertion are equivalent concerning the bipolar arrangement of the electrodes in the oesophagus. The average effective depth of insertion can simplified be defined. A correlation of the average effective depth of insertion concerning external measurements of the body could not be found, so that the conscientious discovering of the optimum depth of insertion is a necessity for every patient. The average value found could attain an orientating importance with the primary placing of the probe concerning the average effective depth of insertion of 37 cm.

[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.

[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.

[Mechanical emergency stimulation in asystole and extreme bradycardia]. / Mechanische Notfallstimulation bei Asystolie und extremer Bradykardie.

Repetitive precordial thumping is the simplest method of temporary cardiac pacing. In 90 patients out of 100 with witnessed cardiac arrest because of asystole or marked bradycardia the critical situation could be effectively bridged over by this until a sufficient spontaneous rhythm returned or electrostimulation was ready to function. 69 patients were conscious during the stimulation. During the mechanical pacing only in 2 patients there occurred ventricular flutter or fibrillation, which was stopped by electric defibrillation. The existence of the myocardial contractility is the presupposition for effective mechanical and electrical pacing.

[Differential modifiability of a usual and unusual type of atrial flutter by high frequency atrial stimulation]. / Unterschiedliche Beeinflussbarkeit des gewöhnlichen und ungewöhnlichen Typs von Vorhofflattern durch hochfrequente Vorhofstimulation.

By means of highly frequent transoesophageal (left-atrial) atrial stimulation 69 patients with atrial flutter of type I (negative flutter waves in the leads II, III and aVF) and 35 patients with atrial flutter type II (positive flutter waves in the corresponding leads from the extremities) were treated and the results were compared with the results of right-atrial highly frequent stimulation (15 patients with type I atrial flutter, 6 patients with type II atrial flutter). In these cases the atrial flutter of type I nearly without any exception could be influenced by transoesophageal as well as by right-atrial stimulation (transfer into sinus rhythm, atrial fibrillation or atrial flutter of type II). The rate of success of the right-atrial as well as of the transoesophageal (left-atrial) stimulation was clearly lower in the atrial flutter of type II than in the atrial flutter of type I, in which cases are to be discussed as causes the slightly higher frequency of atrial flutter in type II, a smaller reentry circle, a higher rate of mechanisms of focal tachycardia and - in one part of the patients - an origin of tachycardia in the left atrium.

[Therapeutic electrical procedures in recurring, drug refractory tachycardias. I. Antitachycardiac implantable pacemaker systems]. / Elektrische Therapieverfahren bei rezidivierenden, medikamentös refraktären Tachykardien. I. Antitachykarde implantierbare Schrittmachersysteme.

In 9 Patients with medicamentously therapy-refractory tachycardias (twice paroxysmal AV-node-reentry tachycardia, four times paroxysmal orthrodromic reentry tachycardia in the WPW-syndrome, once paroxysmal atrial reentry tachycardia, twice recurrent ventricular tachycardia) after adequate electrophysiological testings antitachycardiac pacemakers able to activate the patients were implanted. In these cases the implantable tachyblocker TUR-RFP-01 was used in 4 cases for the highly frequent volley atrial stimulation, in 2 cases for the more highly frequent volley ventricular stimulation. In 3 patients the interruption of the tachycardia was performed by ventricular underdrive stimulation by means of putting the magnet on a conventional R-wave-inhibited ventricular pacemaker. In all cases the recurrent tachycardias could reliably be terminated by the patients themselves by activation of the antitachycardiac systems (duration of the follow-up period 3-14 months, on an average 10.7 +/- 3.4 months); only in one case in the further course a change of the stimulation parameters was necessary which were carefully tested at the beginning. On account of the danger of the acceleration of the tachycardia and of the evocation of ventricular fibrillation, respectively, should, however, be performed highly frequent ventricular stimulations for the termination of ventricular tachycardias only in readiness for defibrillation.

[Does halothane, in subnarcotic dosage, have a detectable broncholytic effect?]. / Hat Halothan in subnarkotischer Dosierung einen nachweisbaren broncholytischen Effekt?

The reaction of halothane in subnarcotic dosage (0.25-0.5 Vol.-%) e.g. with the cooperative patient, was tested at 32 patients with chronic obstructive pulmonary affection (from them 26 patients with pathological increased resistance of the respiratory system) concerning bronchial obstruction. The significant decrease of the respiratory rate and of the resistance of the respiratory system as well as the significant increase of the volume of the breath inspiration unambiguously prove, beside the influence on the subjective health and on the auscultatory findings, a bronchial-enlarging effect of halothane. At 10 patients with serious acute bronchial obstruction, which could not be cured by means of conventional medicamentous therapy, halothane was employed in subnarcotic dosage. In spite of the difficulties in the assessment of the halothane effect by pretreatment we relate the impressive, subjective and objective improvement in these patients to its bronchospasmolytic effect because of the immediate temporal association with the halothane inhalation. In case that there are missing contraindications and an insufficient effect of the conventional medicamentous therapy the use of halothane in subnarcotic dosage with acute serious bronchial obstruction is indicated.

[Long-term results in the treatment of atrial tachycardial arrhythmias using temporary electric stimulation procedures]. / Langzeitergebnisse bei der Behandlung tachykarder Vorhofarrhythmien mittels temporärer elektrischer Stimulationsverfahren.

In 12 of 23 patients with atrial flutter, who were cardioversed by means of electric stimulation techniques and underwent a regular after-examination, a sinus rhythm was still existing 24 months after regularization. When these long-term results which in comparison to the late results are more favourable after electroshock cardioversion are interpreted apart from the different selection of patients must be taken into consideration that the rate of immediate success of about 50% was distinctly lower than in the DC-shock cardioversion. It is to be supposed that a stimulation therapy only in those patients leads to regularization, the atrial vulnerability and recidivity of whom is less distinct, whereas in the other cases only the transgression into an atrial fibrillation is successful.

[Preliminary diagnosis of heart rhythm disorders using transesophageal electrostimulation]. / Vorfelddiagnostik von Herzrhythmusstörungen mittels transösophagealer Elektrostimulation.

The transoesophageal electrostimulation of the heart offers as a non-invasive method in the preliminary diagnostics of disturbances of the cardiac rhythm, in which cases it shall not substitute the intracardiac electrography, but supplement its diagnostic possibilities. Particularly by the demonstration of the disturbed sinus node function or by initiation of tachycardias by means of transoesophageal stimulation methods the little extensive non-invasive examination method may lead to directing findings in patients with unclear arrhythmias and/or unclarified syncopes.

[Sinus node function test--diagnostic value and methodologic limits]. / Funktionsprüfung des Sinusknotens--Diagnostische Aussagen und methodische Grenzen.

By means of atrial stimulation methods for the establishment of the sinus node recovery time and for the indirect calculation of the so-called sinuatrial conduction time under certain methodical conditions disturbances of the sinus node automatism and of the sinuatrial conduction may be differentiated and moreover latent dysfunctions of the sinus node may be unmasked. Methodical problems in the recognition of the sinus node recovery time by higher-frequent atrial stimulation and the calculation of the sinuatrial conduction time by programmed atrial single or double manifold stimulation result above all on that account, since the various factors which determine the reaction of the sinus node in atrial stimulation are not to be surveyed in the individual case. Since there are no obligatory and reliable criteria for the judgment of the function of the sinus node a statement on sensitivity and specificity of the diagnostic stimulation methods is scarcely possible. With regard to a therapeutic decision aid a higher-frequent stimulation for the determination of the sinus node recovery time is of greater importance than the calculation of the sinuatrial conduction time. For the identification of a disturbed function of the sinus node the two parameters make a diagnostic contribution of approximately the same value.

[The transesophageal approach to the heart in electrotherapy of trachycardiac arrhythmias. I. Transesophageal electrostimulation procedure]. / Der transöphageale Zugangsweg zum Herzen zur Elektrotherapie tachykarder Rhythmusstörungen. I. Transösophageale Elektrostimulationsverfahren.

Transoesophageal electrostimulation techniques were used in 124 cases of different tachycardiac disturbances of rhythm. By means of highly frequent transoesophageal atrial stimulation we succeeded in transformating into sinus rhythm in 46% of the patients with atrial flutter, in 29% of the cases with atrial tachycardias and in 75% of the patients with av-junctional tachycardias. At least atrial fibrillation (with decrease of the ventricular frequency) could be induced in 48% in pre-existing auricular flutter, in 38% in auricular tachycardias and in 15% in av-junctional atrial (partial success of therapy). Sinus tachycardias, atrial fibrillation and ventricular tachycardias could practically not be influenced by highly frequent transoesophageal atrial stimulation. Moreover, for the first time the techniques of the doubled or coupled atrial stimulation, in 2 cases also ventricular stimulations with higher frequency were tested on transoesophageal way and were introduced into the treatment of tachycardiac disturbances of rhythm. The therapeutic results of transoesophageal electrostimulation techniques seem to be comparable entirely with those of intracardiac stimulations, in which cases the non-invasive and uncomplicated techniques are accessible also to institutions without possibilities of heart catheterization.

[The transesophageal approach to the heart in electrotherapy of tachycardia. II. Transesophageal cardioversion by means of direct current shock]. / Der transösophageale Zugangsweg zum Herzen zur Elektrotherapie tachykarder Rhythmusstörungen. II. Transösophageale Kardioversion mittels Gleichstromschock.

Electric experiments of cardioversion by means of direct current shock using special oesophagus electrodes were performed in 153 cases of various tachycardiac disturbances of rhythm. Here we succeeded in the conversion to the sinus rhythm in 86% of the patients with auricular flutter, in 84% of the cases with auricular fibrillation, in 3 of 4 patients with auricular tachycardias, in 10 patients with AV-junctional tachycardias without exception and in 5 of the 6 cases of ventricular tachycardias. Thus, the rate of an immediate success approximately corresponds to the conventional extrathoracic position of the electrodes. Here the smaller expenditure of energy with the possibility of an electrocardioversion also without anaesthesia as well as the readiness to the immediate electrostimulation in the case of an asystolia after cardioversion represent the essential advantages of the transoesophageal way. Despite the smaller rate of success on account of the smaller possibilities of complication, however, primarily transoesophageal stimulation techniques should be used (with the exception in auricular fibrillation), in which cases the use special oesophagus as in their failure following cardioversions by means of direct current shock transoesophageally through the same non-invasive approach. Moreover, the analysis of the oesophageally derivable ECG-potentials may facilitate the differentiation of the preexisting tachycardia.

[Comparison of different stimulation procedures of the calculation of so-called sinoatrial conduction time]. / Vergleich verschiedener Stimulationsverfahren zur Kalkulation der sog. sinuatrialen Leitungszeit.

The results of the premature individual atrial stimulation for calculating the so-called sinuatrial conduction times (SACT) were compared with those in double-manifold atrial stimulation (n = 160), frequent atrial stimulation (n = 50) and ventricular individual and double-manifold stimulation (n = 14), respectively. Premature atrial individual stimulation and atrial double-manifold stimulation in these cases gave corresponding, closely correlating results for the SACT-calculation. In frequent atrial stimulation were calculated considerably longer as well as (more infrequently) clearly shorter conduction times. Calculation errors are on the one hand thinkable due to lacking, on the other hand due to repeated sinus node depolarisation with the possibility of overdrive suppression and overdrive excitation (sinus node depression and sinus node acceleration) since the method does not allow a control of the sinus node depolarisation performed. Also in modified calculation of the SACT with consideration of the duration of spontaneous periods after stimulation the correlation to the results of the individual stimulation was relatively loose. After ventricular stimulation (and following ventriculo-atrial stimulus conduction) essentially shorter sinuatrial conduction times could be calculated than in the atrial place of stimulation. As a rule, the poststimulatory spontaneous interval showed an abbreviation compared with the duration of periods before the stimulation, in which cases the haemodynamic relations changed due to ventricular stimulation might explain the increase of frequency.

[Diagnostic transesophageal atrial stimulation as a sinus node function test. I. Normal values and comparison with right atrial stimulation]. / Diagnostiche transösophageale Vorhofstimulation zur Sinusknoten-Funktionsprüfung. I Normalwerte und Vergleich mit rechtsatrialer Stimulation.

For the non-invasive functional analysis of the sinus node diagnostic transoesophageal atrial stimulations were performed. By means of transoesophageal premature individual stimulation we succeeded in a calculation of the so-called sinuatrial conduction time in 112 of 118 normal persons (ESACT = 103 +/- 23.5 ms). In comparison to the results in right-atrial stimulation the transoesophageally established times were 20 to 30 ms longer. By means of transoesophageal atrial stimulation with higher frequency in 64 healthy test persons the recreation time of the sinus node was determined in 64 healthy test persons (ESNRT = 968 +/- 218 ms). Taking into consideration the double standard deviation in an upper limit of 1,400 ms was the result which corresponds to the limit in intraatrial stimulation. In the direct comparison of the transoesophageal and right-atrial stimulation technique in patients with and without syndrome of the sinus node for the sinuatrial conduction time (r = 0.81, n = 51) as well as for the recreation time of the sinus node (r = 0.90, n = 36) relatively good correspondences were found. In the transoesophageal stimulation, however, the larger distance of the place of stimulation from the marginal area of the sinus node, the conduction of the impulse over the left to the right atrium as well as a possible vagal irritation are to be taken into consideration.

[Diagnostic transesophageal atrial stimulation for sinus node function testing. II. Results in patients with and without sinus node syndrome]. / Diagnostische transösophageale Vorhofstimulation zur Sinusknoten-Funktionsprüfung. II. Ergebnisse bei Patienten mit und ohne Sinusknotensyndrom.

By means of transoesophageal atrial stimulation of higher frequency in patients with sinus node syndromes (n = 78) in about 60% of the cases a prolonged sinus node recovery time could be proved. After the end of the stimulation secondary stops appeared in about half of the patients, so that in 81% of the cases at least one pathological result was established. By means of premature individual transoesophageal stimulation (n = 99) in 2/3 of the patients with sinus node syndrome we contrived to perform a calculation of the sinuatrial conduction time. Half of all calculable values were above the normal. In 1/3 of the examined persons pathological stimulation patterns were found. Altogether 90% of the patients showed at least one pathological result, when apart from prolonged sinus node recovery times and sinuatrial conduction times at the same time secondary stops after serial stimulation with higher frequency and abnormal behaviour patterns of the post-extrasystolic stops after individual stimulation were taken into consideration. In patients with different cardiovascular diseases without clinical or electrocardiographic reference to a sinus node dysfunction in 25% of the cases at least one pathological result was found, in which case cannot be clarified, whether latent functional sinus node disturbances or falsely positive results are in question or not. Altogether the non-invasive transoesophageal stimulation technique leads to on principle diagnostic evidences of the same value as the up to now usual stimulation of the right atrium. Methodical problems which arise from the stimulation of the righ atrium in transoesophageal approach are to be taken into consideration in the interpretation of the results.

[Sinostrial node initial block after digoxin--unmasking by double and multiple stimulation]. / Sinusknoten-Eintrittsblock nach Digoxin--Demaskierung mittels atrialer Doppel- und Mehrfachstimulation.

After intravenous application of 1 mg digoxin in a 28-year-old patient with condition after myocarditis by means of premature atrial individual stimulation a SA-block I. type II was observed. Also in extremely premature stimuli the post-extrasystolic pauses remained compensating. After atrial double and multiple stimulation--a new method for the calculation of the sinuatrial conduction time--totally irregular poststimulation pauses appeared, which were regarded as an expression of a sinoauricular node initial block. Other possibilities of explanation are discussed.