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Biomedical subjects

U Gerckens

Publications and source records attributed to U Gerckens.

27 records · Page 2Linked to original sources
PubMed1986

Combination of antitachycardia pacemaker and automatic implantable cardioverter/defibrillator for ventricular tachycardia.

Antitachycardia pacing for ventricular tachycardia (VT) is associated with the possibility of fibrillating the heart; on the other hand, the frequency of VT and patient discomfort can limit treatment with the automatic implantable cardioverter/defibrillator (AICD). To contribute to the further development of a universal pacemaker, we evaluated the combined use of the antitachycardia pacemaker ("tachylog") and the AICD in five patients with recurrent VT. In the automatic mode, the "tachylog" worked as a bipolar VVI pacemaker. For antitachycardia pacing, a burst of rapid ventricular pacing was delivered at about 80% of the cycle length. During a follow-up period of 5 +/- 2 months (range, 3 to 8) two to 291 successful interventions of antitachycardia pacing were counted from diagnostic data which had been collected by the pulse generator during the course of treatment. When the antitachycardia pacemaker failed to terminate VT, the AICD was activated. In the individual case, between 0 and 41 discharges of the AICD were delivered. The high pulse energy of the AICD did not damage the antitachycardia pacemaker; no interference of the two devices was observed. Future antitachycardia systems should be more flexible with regard to detection and termination modes, combining antitachycardia pacing with back-up defibrillation.

Aged↗
PubMed1986

Automatic implantable cardioverter/defibrillator (AICD) and antitachycardia pacemaker (Tachylog): combined use in ventricular tachyarrhythmias.

UNLABELLED: Antitachycardia pacing in ventricular tachyarrhythmias (VT) is associated with potential acceleration of VT; frequency of VT and discomfort of the patient (pt) can limit treatment with the AICD. We therefore evaluated the combined use of antitachycardia pacing and AICD in 6 of 14 patients (age 50-70, mean 60 years) with AICD implantation because of VT, which could be terminated by temporary overdrive pacing. With the interactive mode of the Tachylog, termination of VT by the pacemaker as well as by the AICD was assessed after implantation. In the automatic mode, the Tachylog functioned as a bipolar VVI device with antitachycardia burst stimulation: 2-5 stimuli, interval 260-300 ms, 1-2 interventions. During follow-up of 12 +/- 5 months, the Tachylog terminated VT reliably 20 to 327 times per patient. In three patients, burst stimulation accelerated VT, which was terminated then by the AICD discharge. CONCLUSION: Drug resistant ventricular tachyarrhythmias can be terminated by the Tachylog pacemaker avoiding patients' discomfort. In case of acceleration, ventricular tachyarrhythmias can be controlled by the automatic implantable cardioverter/defibrillator. A universal pacemaker should combine antitachycardia pacing with back-up defibrillation mode.

Aged↗
PubMed1986

[A rare pacemaker complication of a perforation by a ventricular screw electrode causing hemothorax].

The myocardial perforation of a pacemaker electrode is an extremely rare complication associated with the danger of cardiac tamponade. We report on a perforation of a ventricular screw-in electrode with migration through the pericardium and bleeding in the left thoracic cavity. Two-dimensional echocardiography in combination with clinical, electrocardiographic and X-ray examination permits a reliable non-invasive diagnosis.

Aged↗
PubMed1986

[Antitachycardia pacing therapy in supraventricular tachycardia using the microcomputer-guided Tachylog 651 pacemaker].

Microprocessor-controlled antitachycardia pacemaker expand the automatic detection of the tachycardia and incorporate multiple, different termination modes. We report our results in the long-term therapy of paroxysmal supraventricular tachycardia with the antitachycardia pacemaker "Tachylog 651". The system was implanted in 10 patients with a mean age of 48 years (from 20 to 68 years): Wolff-Parkinson-White syndrome 4 patients, paroxysmal AV nodal reentrant tachycardia 6 cases. The rate of the reentrant tachycardia was 162 +/- 23/min. The system reliably differentiated between paroxysmal supraventricular tachycardia and sinus tachycardia, including 4 patients with a tachycardia rate of less than 150/min. Burst overdrive pacing was effective in 6 patients and the "self-search system" in 3 patients. During follow-up of 9 +/- 4 months 104 +/- 93 successful interventions per patient were observed; change of the termination mode became necessary in 4 patients and of the detection mode in 3 patients. The incorporation of programmable detection and multiple termination modes in the microprocessor-controlled antitachycardia systems allows the effective long-term antitachycardia pacing. The multiprogrammable "Tachylog 651" pacemaker is an advancement in the electrotherapeutic treatment of paroxysmal supraventricular tachycardias, including the automatic treatment of tachycardias with low rates.

Adult↗
PubMed1986

[Electrophysiologic effects of diprafenone in supraventricular and ventricular tachycardia].

The electrophysiologic effects of diprafenone were evaluated in 31 patients (9 X AV nodal reentrant tachycardia, 9 X Wolff-Parkinson-White syndrome, 4 X paroxysmal atrial fibrillation, 10 X recurrent ventricular tachycardia). Electrophysiologic studies were performed before and after intravenous infusion of 1.5 mg/kg body weight diprafenone in a period of 10 minutes. Diprafenone prolonged the mean RR interval during sinus rhythm from 690 +/- 109 ms to 789 +/- 93 ms and the maximal sinus node recovery time from 1081 +/- 216 ms to 1300 +/- 398 ms (p less than 0.001). The effective refractory period of the right atrium increased from 195 +/- 22 ms to 210 +/- 28 ms (p less than 0.01) and of the right ventricle from 220 +/- 20 ms to 235 +/- 20 ms (p less than 0.001). Diprafenone produced a prolongation of the antegrade effective refractory period of the AV node from 260 +/- 35 ms to 294 +/- 39 ms (p less than 0.01) and of the retrograde effective refractory period from 265 +/- 76 ms to 400 +/- 130 ms (p less than 0.001). The effective refractory periods of the Kent bundle increased: antegrade from 299 +/- 45 ms to 413 +/- 133 ms, retrograde from 252 +/- 33 ms to 286 +/- 169 ms (p less than 0.05). Suppression of inducibility was observed in 12 of 17 patients with supraventricular reentrant tachycardia, in 5 of 8 patients with atrial fibrillation and in 7 of 10 patients with recurrent ventricular tachycardia. The rate of supraventricular tachycardias decreased under the influence of the substance.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Arrhythmia Agents↗
PubMed1985

[Functional disorders of chamber demand (VVI) and sequential AV (DDD) pacemakers caused by muscle potentials].

Muscle potentials as a cause of pacemaker malfunction are often unrecognized, because control examinations are usually performed without physical exercise. Two observations are cited to illustrate how malfunctioning of different modes of stimulation can be caused by interference from muscle potentials. In addition to the known suppression of impulse production, fixed-rate stimulation may occur. These observations indicate that pacemaker function should be tested also during physical activity. Any malfunction can almost always be stopped by re-programming amplifier sensitivity.

Action Potentials↗
PubMed1985

[Supraventricular tachycardia: the results of bundle of His ablation].

Transvenous electrical ablation of AV conduction was performed in 15 patients with drug-resistant supraventricular tachycardia. Eight patients had paroxysmal AV nodal reentry tachycardia, one had permanent junctional reentry tachycardia, five had recurrent atrial flutter and one paroxysmal atrial tachycardia. The intracardiac ablation was done with 150-350 J, on average twice per patient. Permanent 3 degrees AV block was achieved in ten patients, in none of whom there was a recurrence of the tachycardia. In four patients with re-established AV conduction the clinical symptoms had nonetheless improved; despite repeated use of His-bundle ablation, permanent junctional reentry tachycardia could not be controlled satisfactorily and required surgical section of the accessory pathway. Apart from septic fever in one patient there were no serious complications. Implantation of a pacemaker, however, was required in all those patients in whom a permanent 3 degrees AV block had been produced. For this reason alone, His-bundle ablation should only be used in drug-refractory supraventricular tachycardias. But in these this method presents an important advance in treatment.

Adolescent↗