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Biomedical subjects

U Gerckens

Publications and source records attributed to U Gerckens.

15 recordsLinked to original sources
PubMed1990

[Cardiomyopathy in progressive muscular dystrophy].

A dilated cardiomyopathy with clear signs of left-ventricular functional abnormalities occurred in a 21-year-old man with known Duchenne's progressive muscular dystrophy. Echocardiography and magnetic resonance imaging delineated the regional disorder of ventricular wall motion and defined its segmental extent. With neither method was it possible to analyse texture with demonstration of differential regional involvement. As a noninvasive method echocardiography is suitable for diagnosing Duchenne's cardiomyopathy and monitoring its progression.

Adult↗
PubMed1989

Pharmacokinetic and pharmacodynamic properties of ramipril in patients with congestive heart failure (NYHA III-IV).

To investigate the pharmacokinetics and pharmacodynamics of a new angiotensin converting enzyme (ACE) inhibitor, ramipril (HOE 498), in patients with cardiac insufficiency (NYHA III-IV), we performed an open trial with a follow-up of 10 days. Twenty-seven patients (18 females, 9 males), mean aged 62 years (46-83) with severe heart failure, were included. After a single oral dose of 5 mg ramipril, the plasma and urine levels of ramipril, ramiprilat, ACE plasma activity, standard laboratory values, blood pressure and pulse rate were evaluated. The maximal plasma level of ramipril was 57.0 +/- 26.8 ng/ml after 1.4 h; t1/2 was 2.4 +/- 1.2 h. The peak level of ramiprilat was 27.9 +/- 24 ng/ml after 4.6 h; t1/2 for the active compound was 6 +/- 4.2 h. The total recovery of ramipril and metabolites in urine was on average 39 +/- 17.5% within 96 h. Ninety-five percent inhibition of ACE activity was observed in all patients and 80% inhibition lasted 24 h. Systolic and diastolic blood pressure decreased without changes in heart rate. Five patients had mild side effects: hypotension, diarrhea, and dizziness. In conclusion, in patients with severe heart failure, plasma levels of drug and active metabolite were higher and remained measurable longer, with more sustained inhibition of ACE activity than reported in healthy volunteers. This indicates that titration should start with lower doses (1.25-2.5 mg) and that doses above 5 mg may rarely be necessary.

Administration, Oral↗
PubMed1988

[Supraventricular tachycardia: therapy with a variable antitachycardia stimulation program].

Modern, microprocessor-controlled antitachycardia pacemakers are available with extended detection and termination programs for the treatment of supraventricular tachycardias. Using the "InterTach 262-12" we examined a universal antitachycardia pacing mode in the chronic state. Based on the individual electrophysiologic parameters, a defined burst stimulation mode was used for the first intervention and, consecutively, a determined scanning mode. The InterTach device was implanted in 17 patients with a mean age of 50 +/- 15 years: 10 with AV-nodal reentrant tachycardia, 6 with Wolff-Parkinson-White syndrome, 1 with reentrant tachycardia with Mahaim fibers. The mean tachycardia rate was 178 +/- 23/min and the follow-up 10 +/- 4 months. Every 3 months the efficacy of the termination mode was tested by programmed stimulation in supine and upright body position or during physical activity. In these tests, a rate of 95-100% successful terminations was observed. In the chronic state, 26 persistent tachycardias in 11 patients were noted; 21 episodes could be referred to an insufficient tachycardia detection. Only four persistent tachycardias were due to ineffective antitachycardia pacing. The introduction of extended variable termination programs, including consecutive, flexible pacing modes, can be considered as a marked advancement in the antitachycardia pacemaker therapy for supraventricular tachycardias.

Adult↗
PubMed1987

[Cyanotic patient with right ventricular dilatation and ventricular arrhythmias].

Uhl's disease is a very rare congenital anomaly of the heart. Extreme dilatation of the right ventricle is accompanied by virtual absence of the right ventricular myocardium. We report on a 30-year-old woman with ventricular arrhythmias and atrial-septal defect where the diagnosis was made by echocardiography and confirmed by angiocardiography. Diagnostic and therapeutic possibilities are discussed.

Adult↗
PubMed1987

[Automatic implantable cardioverter-defibrillator (AICD) and antitachycardia pacemaker (Tachylog 651) in the treatment of ventricular tachyarrhythmias].

For the electrotherapy of refractory ventricular tachycardia the automatic implantable cardioverter-defibrillator (AICD) and antitachycardia pacemaker are available. The long-term use of antitachycardia pacing is still limited by the potential risk of acceleration to ventricular fibrillation. To combine the advantages of antitachycardia pacing with back-up defibrillation, we evaluated the use of an antitachycardia pacemaker with the automatic defibrillator. The AICD was implanted in 13 patients with a mean age of 62 years (from 46 to 75 years); six of them with recurrent ventricular tachycardia (170 +/- 16 per minute) which could reliably be terminated by overdrive pacing, received also an antitachycardia pacemaker (Tachylog 651). The underlying cardiac disease was coronary heart disease in 11 patients and cardiomyopathy in 2 cases. All patients had survived 1 to 6 cardiac arrests and had not responded to 6 +/- 1.5 antiarrhythmic drugs. For antitachycardia pacing we used burst stimulation with 4 to 6 stimuli and coupling intervals from 260 to 300 ms. During the follow-up period of 12 +/- 2 months, 83% of 744 tachycardias could be terminated by burst stimulation, according to the diagnostic data of the pulse generator. If the pacemaker failed to terminate or in case of acceleration (three patients), the automatic countershock of the AICD (5-42 per patient) restored sinus rhythm. In seven patients with high rate tachycardia, 2 to 69 AICD discharges occurred. No patient died suddenly, but three died due to underlying disease and one because of a pneumonia postoperatively. Future antitachycardia devices should be flexible with regard to detection and termination modes, combining antitachycardia pacing with back-up defibrillation.

Electric Countershock↗
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↗