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Biomedical subjects

H Volkmann

Publications and source records attributed to H Volkmann.

At least 37 records · Page 2Linked to original sources
PubMed1992

Investigations into a new antiarrhythmic substance Z-2-amino-5-chlor-benzophenon-amidin-hydralazin in humans.

Z-2-amino-5-chlor-benzophenon-amidin-hydralazin is a new chemical potential antiarrhythmic substance. The blood levels were investigated after different dosages and forms of administration in patients and volunteers. The determination of the substance can be performed by high-pressure liquid chromatography. In addition the pharmacokinetic parameters were calculated. The pharmacokinetic profile is similar in humans and animals.

Administration, Oral↗
PubMed1991

[Electrophysiological anti-arrhythmia effects of tiracizine in ventricular tachycardia].

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.

Administration, Oral↗
PubMed1991

[Therapeutic value of trans-esophageal electrostimulation in tachycardic 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, 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.

Adult↗
PubMed1990

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.

Adult↗
PubMed1990

Diagnostic value of carotid sinus hypersensitivity.

In order to evaluate the diagnostic value of carotid sinus hypersensitivity (CSH) we have investigated 163 asymptomatic patients (88 male, 75 female, mean age 57.9 +/- 22.7 years) and 210 symptomatic patients (108 males, 102 females, mean age 61.1 +/- 28.1 years) with syncopes or dizziness. Thirty two of the 163 asymptomatic patients (20%) and 87 of the 210 symptomatic patients (41%) showed CSH (asystole greater than or equal to 3 sec during carotid sinus pressure). Male patients had a higher number of CSH than female (28% vs 10% in the asymptomatic group, 48% vs 34% in the symptomatic group). Electrophysiological investigations were performed in all 210 symptomatic patients. Normal electrophysiological results had 94 of the 210 patients. Thirty seven of these 94 patients showed CSH (39%). Prolonged sinus node recovery time (SNRT) and/or prolonged sinoatrial conduction time (SACT) were evaluated in 38 patients. Seventeen of the 38 patients had CSH (45%). Disorders of atrioventricular (AV) conduction were evaluated in 43 patients. Seventeen of the 43 patients showed CSH (40%). Thirty-five patients had both AV conduction disorders and prolonged SNRT or SACT. Sixteen of these 35 patients showed CSH (46%). In conclusion, no significant difference was found between patients with and without pathological electrophysiological results. The CSH is without value for predicting sinus node dysfunction and AV conduction disorder.

Age Factors↗
PubMed1990

[Terminating ventricular tachycardias by mechanical heart stimulation with precordial thumps].

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.

Adult↗
PubMed1989

[The anti-arrhythmia effect and hemodynamic effects of Bonnecor in intravenous administration].

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.

Adult↗
PubMed1989

[Ventricular late potentials in patients with cardiomyopathies in relation to electrophysiologic and myocardial biopsy findings].

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.

Adult↗
PubMed1989

[Complications of temporary transvenous endocardial pacemaker therapy].

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.

Adams-Stokes Syndrome↗
PubMed1989

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.

Bundle of His↗
PubMed1988

[Electrophysiologic findings in so-called latent cardiomyopathies].

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.

Adult↗
PubMed1988

[Transluminal electric catheter ablation in the treatment of drug-refractory focal ventricular tachycardias].

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.

Cardiac Catheterization↗
PubMed1988

[Mechanical emergency stimulation in asystole and extreme bradycardia].

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.

Adolescent↗
PubMed1987

[Differential modifiability of a usual and unusual type of atrial flutter by high frequency atrial stimulation].

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.

Atrial Flutter↗