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H O Gloor

Publications and source records attributed to H O Gloor.

At least 19 recordsLinked to original sources
PubMed1996

[Drug therapy of atrial fibrillation].

Atrial fibrillation can, clinically, be differentiated into several subgroups. Paroxysmal atrial fibrillation lasts less than 24 hours and is often caused by an autonomic dysregulation. Chronic atrial fibrillation occurs in a reversible and an irreversible form. Atrial fibrillation is frequently observed transiently after cardiac surgery. The therapeutic goal must be clearly defined before treatment is initiated. In patients with a reversible form of chronic atrial fibrillation, sinus rhythm can be restored with class Ia, Ic and III antiarrhythmic drugs. These patients with sinus rhythm benefit from higher cardiac output, fewer thromboembolic complications and fewer symptoms (no palpitations). In patients suffering from an irreversible form of chronic atrial fibrillation the therapeutic aim is control of ventricular rate. Digoxin, beta-blockers (class II) and calcium antagonists (class IV) are successfully used to slow atrioventricular conduction. Patients aged over 65 years should be anticoagulated, since numerous studies have shown a marked decrease in thromboembolic complications with warfarin.

Aged↗
PubMed1996

Are there stereoselective electrophysiologic effects of intravenously administered (S)- or (R)-propafenone hydrochloride in patients with supraventricular tachycardia?

OBJECTIVE: The electrophysiological effects of intravenously administered pure (S)- and (R)-propafenone hydrochloride has been determined for the first time in humans-12 patients with supraventricular tachycardia. METHODS: Measurements were performed before and during drug therapy. RESULTS: (S)- and (R)-propafenone prolonged the AH interval from 82 to 107 ms and 75 to 84 ms, respectively, and significantly increased the V nodal Wenckebach cycle length by 58 ms and 37 ms, respectively. The AV nodal effective refractory period in both groups was increased significantly to the same extent (45 vs 42 ms). Sinus node recovery times were not significantly influenced by either enantiomers. Both (S)- and (R)-propafenone significantly prolonged the HV interval to the same extent (from 41 to 51 ms, and 42 to 53 ms). Changes in the electrophysiological characteristics of the myocardium were more pronounced in the atria than in the ventricles. Only (S)-propafenone significantly increased the atrial effective refractory period from 204 to 230 ms, and the ventricular effective refractory period from 225 to 241 ms compared to (R)-propafenone (from 221 to 239 ms, and from 219 to 222 ms, respectively). There was a more pronounced electrophysiological effect on AV nodal conduction of (S)- than (R)-propafenone, probably as a result of its beta-blocking activity. CONCLUSION: The electrophysiological effects of (S)-compared to (R)-propafenone were not very pronounced, so it still remains questionable whether one of the enantiomers might be clinically superior to the other, or to the racemic mixture.

Adult↗
PubMed1995

[Radiofrequency ablation in the therapy of supraventricular and ventricular arrhythmias].

We summarize our experience with RF-ablation in 70 patients with symptomatic tachycardia (38 females and 32 males, age 25-73 years). 19 patients with AV reentry tachycardia in WPW-syndrome, 28 patients with node reentry tachycardia (AVNRT), 10 patients with ventricular tachycardia, 9 patients with atrial fibrillation and 4 patients with atrial flutter were treated. The primary success rate in the whole patient group is 87% and the longterm success rate (up to 1 year) 81%. RF-ablation of tachycardia is a highly effective therapy. The patients are free of symptoms and need no further medication. In patients with AVNRT in WPW-syndrome and ventricular tachycardia (structurally normal heart), RF-ablation is the therapy of choice. 32/70 patients were treated on an outpatient basis.

Adult↗
PubMed1993

[Surgery for arrhythmia in patients with therapy-resistant ventricular tachycardia].

We reviewed the data of 42 consecutive patients (mean age 55 +/- 12 years) who underwent surgery for control of recurrent drug-refractory ventricular arrhythmia. A history of myocardial infarction was present in 38 patients, 4 patients had congenital heart disease (2 aneurysms, 1 right ventricular dysplasia, 1 hamartoma). The mean LV ejection fraction was 40 +/- 14%. At preoperative electrophysiologic study, ventricular tachycardia was inducible in 32 of 33 patients. The mean heart rate was 188/min. A mean of 3.3 +/- 2.1 antiarrhythmic drug trials were ineffective. The most frequently performed surgical procedure (n = 36) was visually guided subendocardial resection, alone or in combination with cryothermal ablation. In 30 patients additional aneurysmectomy was performed. A mean of 1.9 +/- 1.4 coronary arteries in 32 patients were bypassed. The overall in-hospital mortality (30 days) was 9.5% (1 arrhythmic death, 1 pump failure, 1 sepsis, 1 hemorrhagic shock). We found 2 significant (p < 0.05) predictors of perioperative mortality: recent myocardial infarction and patient's age. During a mean follow-up of 33 months (range 1 to 90), there were 3 sudden cardiac deaths and 6 nonfatal recurrences of ventricular tachycardia which were subsequently prevented with antiarrhythmic drug therapy. Thus, the overall success in control of arrhythmia was 92%, in 59% by surgery alone. Survival was 79% at 2 years after surgery and 63% at 5 years. We conclude that patients who have successful subendocardial resection and aneurysmectomy for control of ventricular arrhythmia have an excellent chance of arrhythmia-free survival and a relatively good prognosis.

Adolescent↗
PubMed1993

[Clinical late results following surgical ablation of an accessory atrioventricular connection in Wolff-Parkinson White syndrome].

All patients operated because of WPW-syndrome between 1980 and 1990 at the University clinics of Zürich were followed up by clinical examination and by electrocardiography. Relief from symptoms (tachycardia, vertigo and/or syncopes) was defined as "symptomatic" success, lack of preexcitation in the ECG at rest as "surgical" success. Overall 56 patients (40 men, 16 women) aged from 13 to 66 years had been operated in the stated time period. Before operation 52 of these patients had pre-excitations in the ECG, 54 had tachycardia and 23 had syncopes. None of the patients died from the operation. In order to localize the AAVVs epicardial cartography was performed in all patients during operation before the AAVVs were cut through an endocardial access. The follow-up was possible after an average interval of 5.5 years (1-120 months) in 50 of the 56 patients. One patient died 10 years after operation from heart failure. 6 patients were reported to be out of the country. The follow-up revealed symptomatic success of the intervention, defined as absence of tachycardia, in 88% (44 out of 50). In 84% (42 out of 50) also a surgical success of the operation was found. In these patients the accessory atrio-ventricular bundle had been successfully ablated, and they were free of tachycardia and of preexcitation in the ECG. Two patients with persisting preexcitation remained free of clinical symptoms. Insofar the rate of symptomatic success was higher than the rate of surgical success. Summarizing the results surgical transsection (ablation) of an accessory atrioventricular bundle in patients with WPW-syndrome is a good therapeutic option with favorable long term success. It has today still its place--in selected cases--as alternative to the now available radio-frequency ablation.

Adolescent↗
PubMed1992

[Drugs in atrial fibrillation].

The initial therapy of atrial fibrillation is guided by the clinical symptomatology of the patient. Acute atrial fibrillation at a rapid ventricular rate is an emergency situation. Pharmacological therapy is aimed to delay atrioventricular conduction and thereby slow the ventricular rate. A new and interesting therapeutical option to induce conversion to sinus rhythm is the intravenous administration of class-Ic drugs. The conversion rate of patients with nonvalvular atrial fibrillation of recent onset is high and accounts up to 90%. Patients with atrial fibrillation have an increased incidence of ischemic stroke. Anticoagulation, i.e. administration of aspirin in patients under 70 years of age, can reduce the occurrence of cerebral ischemic event.

Anti-Arrhythmia Agents↗
PubMed1991

[What is the latest in anti-arrhythmia therapy?].

Ventricular premature beats are an independent risk factor for sudden cardiac death. Class Ic antiarrhythmic drugs suppress these premature contractions. The Cardiac Arrhythmia Suppression Trial (CAST-Trial) tested the hypothesis that the suppression of ventricular premature beats after myocardial infarction reduces the incidence of cardiac death. The results of treatment in this low risk group were, however, disappointing. Cardiac mortality (mortality related to arrhythmia and myocardial infarction) was higher in the group treated with flecainide or encainide than in the placebo group. After a treatment period of 10 months, 89 of 1498 patients had died, 63 (8.3%) of them in the flecainide/encainide and only 26 (3.5%) in the placebo-treated group. Drugs that increase the refractory period of a myocardial substrate are obviously more effective in suppressing cardiac death than drugs that delay conduction. In the Basel Antiarrhythmic Study of Infarct Survival (BASIS study) patients with complex ventricular arrhythmias after infarction were treated with low dose amiodarone (200 mg/day). After a follow-up period of 12 months, mortality was lower in the amiodarone treated group (5/98 patients, 5%) than in the group that received no antiarrhythmic treatment (15/114 patients, 13%). Amiodarone was also more beneficial than individual antiarrhythmic therapy (mortality 10/100 patients, 10%). In the past few years no new antiarrhythmic drugs have been registered in Switzerland. Our pathophysiological and clinical knowledge has, however, increased and we know that the asymptomatic patient with low grade ventricular ectopies after myocardial infarction need not be treated. However, if we decide to use antiarrhythmic drugs, strict quality control of the effects of the treatment is mandatory.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone↗
PubMed1991

[Clinical experience with a second-generation cardioverter-defibrillator].

Implantable cardioverter defibrillators (ICD's) are effective for reducing mortality in refractory malignant ventricular arrhythmias (MVA). Second generation ICD's (Telectronics Guardian 4202/4203) were implanted in 7 patients (all male, mean age 58.1 years) with ventricular fibrillation (VF) in 2, ventricular tachycardia (VT) in 1, and both VF and VT in 4. Underlying heart disease was coronary artery disease in 4 patients, and valvular heart disease, dilated cardiomyopathy and no obvious cause (documented primary VF, reproducible at electrophysiologic study) in 1 patient each. Mean ejection fraction was 40 +/- 14%. Mean defibrillation threshold of the two epicardial patches at implantation by means of median sternotomy was 18 +/- 9 joule, and patch impedance 35 +/- 7 ohms. Post defibrillation bradypacing via epicardial electrode was programmed in 5 patients (70%). Mean follow-up was 10.1 months (1-25 months). Successful defibrillation of 28 spontaneous VT/VF episodes was noted in 2 patients, while the other 5 have had no further episodes of MVA so far. One device was explanted following tissue necrosis at the battery site after a MVA-recurrence-free interval of 15 months. The reconfirmation algorithm prevented false shock delivery in 2 patients.

Cardiac Pacing, Artificial↗
PubMed1991

Activity-sensing rate responsive versus conventional fixed-rate pacing: a comparison of rate behavior and patient well-being during routine daily exercise.

Rate responsive single chamber pacing (VVIR) may be the pacemaker of choice in patients who are not suitable candidates for a dual chamber system. Several studies, most of them performed in an exercise laboratory, have shown a significantly higher exercise capacity demonstrating an improvement in cardiac output and anaerobic threshold compared to conventional fixed rate pacing (VVI). Expressing our idea that stress testing in an "artificial environment" on a bicycle or motor driven treadmill has its limitations and may be difficult to extend into patient's daily life, we designed an outdoor study imitating patient's daily activity. Twenty-one patients with an activity-sensing rate responsive pacemaker performed in a double blind fashion in VVI and VVIR mode the following test circuit: walking 170 meters on flat ground, 210 meters incline, climbing a flight of stairs, and the same circuit in reverse order, and therefore "downhill". Heart rate behavior was recorded by Holter monitoring and patients subjective feelings of well-being, i.e. fatigue and dyspnea were also evaluated. VVIR pacing responded promptly to exercise, i.e., walking on a flat ground, but no further significant increase in pacing rate was observed in relationship to the strength of physical activity while walking inclined or climbing stairs. While patients became exhausted, a nonphysiological decrease in heart rate sometimes occurred. Despite these limitations 6 of 12 patients who had a paced-only rhythm while exercising in both VVI and VVIR mode reported feeling significantly better in the VVIR mode, expressing less dyspnea and fatigue. In contrast, two of nine patients having only intermittently paced rhythm preferred the VVIR mode. Patients with lower ejection fraction (EF) were more likely to show subjectively a benefit while exercising in VVIR mode, compared to those with less reduced or normal EF. Despite the technical limitations of using a piezo crystal for rate adaptation, VVIR pacing is an important option in paced-only patients, but it seems less beneficial in patients with only intermittent paced rhythm.

Activities of Daily Living↗
PubMed1990

[Pacemakers].

Explore the source record for details and available documents.

Cardiac Complexes, Premature↗
PubMed1985

[Transcutaneous application of nitroglycerin and isosorbide dinitrate versus placebo: effect in myocardial ischemia].

The effect of nitroglycerin ointment (30 mg) and isosorbide dinitrate ointment (100 mg) versus placebo on exercise capacity has been investigated in 12 patients. All had angina pectoris and coronary artery disease documented by coronary angiography. Nitroglycerin and isosorbide dinitrate ointment produced a significant increase in exercise capacity, without any significant difference in the beneficial effect of the two. Stress-induced changes of the ST-segment in the electrocardiogram decreased by 65% after nitroglycerin ointment and by 41% after isosorbide dinitrate ointment, compared to placebo. These results indicate that nitroglycerin and isosorbide dinitrate ointment reduce stress-induced myocardial ischemia at similar work loads.

Administration, Topical↗
PubMed1985

Evaluation of flecainide acetate in rapid atrial fibrillation complicating Wolff-Parkinson-White syndrome.

Flecainide is reported to be effective in patients with paroxysmal tachycardias, but its effect on rapid ventricular response over accessory atrioventricular pathway during atrial fibrillation is not known. The influence of flecainide on various electrophysiological properties of the accessory pathway with special emphasis on ventricular rate during atrial fibrillation was investigated in 9 patients with severe symptomatic Wolff-Parkinson-White syndrome. The shortest ventricular response during atrial fibrillation increased from 218 (190-270) to 320 (240-block) ms. In 4 patients sustained rapid atrial fibrillation converted to sinus rhythm. The rate of circus movement tachycardia decreased from 166/min to 130/min after flecainide, due to a lengthening of retrograde ventriculoatrial conduction time over the accessory pathway. Flecainide caused a significant prolongation of the effective refractory period of the accessory pathway in our subgroup with extremely fast AV conduction during atrial fibrillation and induced a depressant effect on retrograde accessory pathway conduction. This makes the drug very promising for the emergency treatment of dangerous rapid tachyarrhythias complicating this syndrome.

Adolescent↗
PubMed1983

Differential effect of verapamil isomers on sinus node and AV junctional region.

The l- and d-isomers of verapamil were selectively perfused into the sinus node artery and atrioventricular (AV) node artery of 48 dogs. Injection of l-verapamil into the sinus node artery during sinus rhythm and into the AV node artery during AV junctional rhythm depresses both sinus rhythm and AV junctional rhythm significantly more than does the d-isomer. l-Verapamil is three to four times more powerful than d-verapamil. Injection of the isomers into the AV node artery during sinus rhythm rapidly impairs AV conduction. Increments in conduction time are measured exclusively at the level of the A-H interval of the His bundle electrogram, and l-verapamil is six times more powerful than d-verapamil. Neither d- nor l-verapamil in concentrations that exert a profound negative chronotropic effect or cause AV block, has any significant effect on transatrial or His bundle conduction. Thus these concentrations of d-verapamil have little or no significant effect on the fast sodium channel, but both verapamil isomers affect the slow channel. The main difference in action between l- and d-verapamil appears to be only quantitative in nature. The sinus node is significantly more sensitive to the negative chronotropic action of verapamil than is the AV junctional pacemaker, and this differential responsiveness appears to be related to the different intrinsic rates of the two pacemakers. During sinus rhythm (either in the presence or absence of atropine) sinus node automaticity is less affected than AV conduction when verapamil is given parenterally. We propose that this greater negative dromotropic effect of verapamil is also in part due to a rate-dependent process, since during sinus rhythm AV junctional cells have to be depolarized at frequencies significantly higher than their intrinsic rates.

Animals↗
PubMed1983

Acute effects of amiodarone upon the canine sinus node and atrioventricular junctional region.

Amiodarone was selectively perfused into the sinus node artery and atrioventricular node artery of 51 dogs. Amiodarone had an immediate negative chronotropic and dromotropic effect. Threshold concentration was 2.5 micrograms/ml. 25 and 50 micrograms/ml of amiodarone injected into the sinus node artery slowed the heart by 25.6 +/- 3.1 and 33.7 +/- 2.6 beats/min (mean +/- 1 SEM), respectively. Amiodarone 25 and 50 micrograms/ml injected into the AV node artery during AV junctional rhythm slowed the AV junctional pacemaker by 12.2 +/- 1.8 and 17.4 +/- 1.7 beats/min, respectively. Injections of amiodarone into the AV node artery during sinus rhythm regularly increased AV conduction time sometimes causing 2 degrees AV block at the highest concentration used. Impaired conduction was exclusively measured at the level of the A-H interval in the His electrogram. Neither atropine nor propranolol prevented the negative chronotropic effects of amiodarone. Amiodarone had no significant effect on sinus node response to either stellate stimulation or intranodal administration of norepinephrine. The negative chronotropic action of amiodarone was significantly enhanced when amiodarone was administered in a perfusate containing low (0.6 mM) instead of normal calcium. Taken collectively these observations indicate that amiodarone has immediate depressant electrophysiologic effects on both the sinus node and the AV junction and that these early effects might involve the blockade of the slow channel.

Amiodarone↗
PubMed1982

Hemodynamic effects of atrial synchronization in acute and long-term ventricular pacing.

The acute and long-term hemodynamic benefit from atrial synchronization in ventricular (VAT) pacing has been investigated at rest and during exercise in 10 patients undergoing pacemaker implantation for complete A-V block. The results were compared to conventional (VOO) ventricular stimulation at rates of 70 BPM and 96 BPM. Cardiac index (CI) in VAT-pacing increased at rest by 8% and during exercise by 15% more than with VOO pacing (p less than 0.01). No significant change between the two different rates of asynchronous pacing was observed. CI at rest and during exercise was unchanged after 10 weeks of VAT-pacing. CI is regulated by change of stroke volume in VOO-pacing and by heart rate only with VAT-pacing. In contrast to earlier results with asynchronous ventricular pacing, the hemodynamic benefit of pacing in an atrial synchronized mode is long-lasting. Physiologic mechanisms regulate hemodynamics during exercise and in heart failure.

Adult↗
PubMed1981

[Differentiated pacemaker therapy].

17 patients were treated by atrial (AAI) or atrial-triggered ventricular pacing (VAT). The atrial electrode was placed using a new endocardial screw-in technique. No complications occurred during a follow-up period of 3 months. Cardiac output at rest was measured in 12 patients before pacemaker implantation and was 3.571/min with VVI pacing at a heart rate (HR) of 70/min and 3.97 l/min (HR 75/min) with AAI or VAT pacing (p less than 0.001). Measurement of cardiac output was repeated in 7 patients with AV-block III degrees 10 weeks after pacemaker implant and the result was 4.40 l/min (HR 77/min) on VAT stimulation. During dynamic exercise in 5 patients, cardiac output under VAT pacing was 20% higher than with VVI pacing. This difference remained unchanged after 10 weeks. It is concluded that atrial electrodes can be placed reliably by the new technique. In contrast to VVI pacing, the hemodynamic benefits of atrial-triggered ventricular pacemakers appear to be long lasting.

Adult↗