Biomedical subjects

W Scheibelhofer

Publications and source records attributed to W Scheibelhofer.

10 recordsLinked to original sources

PubMed1988

Survival rate and causes of death in patients with pacemakers: dependence on symptoms leading to pacemaker implantation.

The survival rate of 2256 patients with pacemakers was analyzed. Patients paced for Adams-Stokes equivalents (e.g. dizziness) showed a significantly better survival rate than did patients with pacemakers implanted for Adam-Stokes attacks or heart failure (P less than 0.0001). The estimated survival of the latter two groups did not differ significantly. Of the deceased patients who had received a pacemaker for the treatment of heart failure, 54% died due to this condition despite pacemaker implantation. The relative percentage of cases of sudden death after pacemaker implantation was high in the groups with Adams-Stokes attacks (12%) and Adams-Stokes equivalents (13%). In patients paced for Adams-Stokes attacks, sudden death occurred more frequently in the first year after pacemaker implantation (P less than 0.015) than during the following years. Therefore, increased efforts should be made to monitor patients carefully after pacemaker implantation to enable prompt detection of malignant tachyarrhythmias, probably the cause of sudden death in a substantial number of patients with pacemakers.

Adams-Stokes Syndrome↗

PubMed1987

Exercise testing after surgical repair of coarctation of the aorta.

After repair of coarctation, exercise testing was performed in 20 patients with an isolated coarctation (group I) and in 26 with additional congenital cardiac malformations (group II). Ages at time of operation were significantly different in both groups (7.9 +/- 6.0 years in group I; 4.6 +/- 3.8 years in group II; p less than or equal to 0.01). Simultaneous blood pressures were obtained from upper and lower limbs at rest and after exercise. There was no significant difference regarding the systolic blood pressures at rest (122.5 +/- 15.6 mmHg in group I versus 119 +/- 15.8 mmHg in group II). Seven (14%) of the patients were hypertensive; five of them had blood pressure gradients between arms and legs of 15-45 mmHg. But the gradients at rest were found to be significantly different in both groups (9.0 +/- 10.5 mmHg in group I; 18.5 +/- 16.1 mmHg in group II; p less than or equal to 0.05). Six patients, all in group II, had gradients greater than or equal to 30 mmHg at rest. After exercise there were no significant differences in systolic blood pressure and gradients in both groups. Values for blood pressures and gradients at rest and after exercise showed a positive correlation (blood pressure r = 0.76, p less than or equal to 0.001; gradient r = 0.44, p less than or equal to 0.01). Thus exercise testing can provide valuable information about blood pressure and gradient changes during physical activity, but angiography is required to reveal restenosis or residual stenosis.

Adolescent↗

PubMed1986

[A new method for the treatment of supraventricular rhythm disorders].

Initial experience of His-bundle ablation is presented in 12 patients with intractable supraventricular arrhythmias which were not amenable to treatment with conventional drugs. In 8 patients His-bundle ablation resulted in total AV-block and in 2 patients significant improvement without total AV-block was achieved. During long-term follow-up (mean 5.3 months) tachycardia recurred in 1 patient with total AV-block resulting in an overall success rate of 75%. A permanent pacemaker was implanted in 10 patients. 1 patient developed deep leg vein thrombosis as a direct result of this procedure and in 2 patients there were complications due to pacemaker implantation. His-bundle ablation appears to be a promising tool in the management of intractable supraventricular tachycardia.

Aged↗

PubMed1984

[Antiarrhythmic effect and side effects of amiodarone].

UNLABELLED: Amiodarone (AM) is one of the most potent antiarrhythmic drugs, the value of which is limited by reversible and irreversible side-effects (SE). 59 patients, 50 male, 9 female (age 33 to 81 years) entered the study with ventricular tachycardia (VT, 68%), WPW-tachycardia (12%), non-sustained VT (12%) or untreatable paroxysmal atrial fibrillation or supraventricular tachycardia (8%). Prior to AM the patients had received 1 to 8 different antiarrhythmic drugs (m 3.5) and maximal 9 different combinations of antiarrhythmics. The drug regimen started with a loading dose of 1200 mg/d for 1 to 2 weeks and was continued with a maintenance dose of 200 to 600 mg/d. The patients were followed up 1 to 41 months (m 14 m). The drug effect was evaluated using clinical criteria (recurrence of arrhythmias, death), computer-assisted analysis of several 24 hr long-term ECGs and programmed electrophysiological stimulation. Three- to six-monthly the patients were seen in our outpatient department for check up and blood-sample analysis (liver, thyroid gland etc.). Also in the majority of the patients frequent ophthalmological and dermatological investigations, as well as lung functions tests were carried out. RESULTS: under AM therapy the initial arrhythmias were no longer detectable in 41% of the patients. In 37% a significant amelioration of the formerly life-threatening arrhythmias was found. 7 patients (12%), predominantly with reduced left ventricular function, died during follow up. No pulmonary, hepatotoxic or neurological SE were found. All patients developed reversible AM keratopathy. In 27% ETR and T4 were elevated, but only one patient developed hyperthyroidism with an increase in TT3. Another patient showed signs of hypothyroidism with an elevated TSH prior to TRH stimulation. Increased phototoxicity was found in 31%, whereas in two patients typical AM hyperpigmentation occurred, especially on the face. In conclusion, AM is a highly effective antiarrhythmic agent, despite a negatively selected collective, but it should only be used in patients with refractory arrhythmia in view of the SE.

Adult↗

PubMed1984

[Causes of death in patients with pacemakers - with respect to the indication for implantation].

We compared the life expectancy of 1559 patients with an implanted pacemaker (PM) with a normal age-matched population and found a significantly reduced survival rate in paced patients. Patients paced for heart failure have the lowest survival rate, whilst those paced for Adams-Stokes attacks do slightly better. Patients with Adams-Stokes equivalents do not differ significantly from our normal population. 54% of patients with PM implanted for heart failure died due to heart failure despite PM implantation. The relative percentage of sudden death after PM implantation is high in groups with Adams-Stokes attacks (16%) and Adams-Stokes equivalents (20%). In both of these groups sudden death occurred especially during the first two years after PM implantation. The high risk of sudden death after PM implantation should increase our efforts to monitor patients carefully after PM implantation for the occurrence of malignant tachyarrhythmias.

Adams-Stokes Syndrome↗

PubMed1984

Reversible end-of-life indicator leading to erroneous pacemaker replacement-pitfalls of telemetry.

In several modern pacemakers, end-of-life (EOL) is indicated by a single-step rate drop, which is initiated by a voltage-sensitive electronic switch. This switch may also be activated by other causes, such as very short voltage drops, low temperatures, and electrocautery. We report a case in which a Cordis 233 F Sequicor II pulse generator was operating at 51.6 bpm in VOO mode at the time of implantation. As telemetry seemed to indicate that back-up pacing (the EOL indicator in this model) was "off," it was erroneously assumed that the pacemaker was not working properly. The unit was replaced by another impulse generator. At laboratory testing, the pacemaker was within specifications, when back-up pacing was separately programmed off. In conclusion, physicians should be aware of the new phenomenon of reversible EOL indicators, and that they may not rely on telemetry in this respect. Future pacemakers should incorporate a telemetry message which prevents similar misunderstandings.

Equipment Design↗

PubMed1983

Reversible EOL-indicator: a new cause for low pacemaker rate.

A case is presented in which a new cause for decrease in pacemaker rate was encountered: six months after implantation of a Medtronic 5967 pacemaker, the first routine check-up revealed a rate of 62.5 ppm instead of 70 ppm. After application of a magnet, all measurements returned to normal. The cause for this phenomenon, which could not be attributed to battery depletion or oversensing, was probably a change of state of the flip-flop which is responsible for the sudden rate drop of 10% which serves as the end-of-life (EOL)-indicator in this pacemaker. This change of state may result from a very short decrease of power supply voltage during shipment or at the time of implant, and is fully and permanently reversible by performance of the magnet test. In order to prevent unnecessary pacemaker explants, future pacemaker circuits should be redesigned to eliminate the effect of very short voltage changes. Meanwhile, a routine magnet test should be performed immediately after implantation.

Electric Power Supplies↗

PubMed1982

Induction of ventricular tachycardia by pacemaker programming.

The induction of ventricular tachycardia or ventricular fibrillation by competitive pacing, especially in the setting of acute myocardial ischemia, is well known. A case of ventricular tachycardia induced by a multiprogrammable unipolar cathodal ventricular pacemaker is reported. The arrhythmia was caused by reprogramming, which necessitates a short switch to fixed rate pacing in this model (Spectrax 5985 SX). This potential hazard is not well established in patients with unipolar pacemakers. The use of the magnet as one of the preconditions for reprogramming should be avoided in future pacemakers.

Bradycardia↗

PubMed1982

[Diagnosis and therapy of carotid sinus syndrome (author's transl)].

We investigated 76 patients with carotid sinus syndrome followed over a time period of 12-40 months (mean 24 months). In 27 patients long-term ECG were recorded over 24 hours continuously. Carotid Doppler sonography was performed in all patients. 14 patients were studied electrophysiologically. The long-term ECG examinations in patients with carotid sinus syndrome showed a significant tendency to nocturnal bradycardia, and normal heart frequency during the day. In 41% of patients extracranial obstruction of internal carotid arteries could be demonstrated. During carotid sinus massage was a significant increase of the AH time, but there was no significant changes of the HV time. 12 out of 14 patients (86%) developed an AV-block during carotid sinus massage and atrial pacing. In 31 patients pacemakers were implanted. The indication for pacemaker implantation was the clinical symptom of syncope. These patients were observed over a period of 15-40 months (mean 24 months). 15 patients were free of symptoms after the pacemaker implantation, whereas 8 patients complained of dizziness and 4 patients experienced TIA's. 45 patients without pacemaker implantation were observed over a time period of 12-24 months. 30 patients were followed over 12 months. 16 patients were free of symptoms, 14 complained of dizziness. There was no syncopy in this group and no patients died during the observation period. In patients with cardio inhibitory carotid sinus syndrome and syncopy, pacemaker implantation is the therapy of choice. In asymptomatic patients or patients with occasional dizziness pacemaker is not indicated.

Aged↗

PubMed1982

[The ECG in physiologic pacing (author's transl)].

Hemodynamic advantages led to an increasing number of implantations of so called "physiologic pacemakers", which preserve the natural sequence of atria and ventricles. The growing complexity of these systems renders ECG evaluation increasingly difficult. 85 patients had physiologic pacemakers implanted during the last 4 years and were controlled in our pacemaker outpatient clinic. Typical problems in ECG evaluation of the different pacemaking modes are discussed.

Arrhythmias, Cardiac↗