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Biomedical subjects

G Breithardt

Publications and source records attributed to G Breithardt.

At least 109 records · Page 6Linked to original sources
PubMed2000

Infarct related artery patency: relation to serial electropharmacological studies and outcome in patients with previous myocardial infarction and ventricular tachyarrhythmias.

Evidence suggests that infarct related artery (IRA) patency may improve survival after acute myocardial infarction, which is thought to be partially due to a lower incidence of malignant ventricular tachyarrhythmias. However, little is known about the effect of IRA patency on antiarrhythmic drug response and long-term outcome in patients with previous infarction who already experienced sustained ventricular tachyarrhythmias. A total of 152 patients with remote myocardial infarction and documented ventricular tachycardia (VT) or ventricular fibrillation (VF) underwent coronary angiography and programmed ventricular stimulation before and after oral administration of d,l-sotalol (240-640 mg/day). D,l-sotalol suppressed inducibility of VT/VF in 37 (25.2%) patients. The IRA was patent in 38.1% of all patients. There was no significant difference in the frequency of drug response between patients with patent or occluded IRAs (26.8% vs 24.2%, P = 0.87). In patients with a patent IRA, d,l-sotalol tended to be more effective in the absence of a left ventricular aneurysm, although this difference did not reach statistical significance (P = 0.38). Ejection fraction and collateral blood flow had no effect on drug response in the presence or absence of IRA patency. During follow-up (13.0 +/- 19.9 months) of 29 patients discharged on oral d,l-sotalol, 3 patients experienced symptomatic VT and 4 sudden death. Arrhythmia recurrence and death of all cause (n = 6) and cardiac death (n = 4) were independent of IRA patency status. IRA patency had no effect on short-term drug response to d,l-sotalol in patients with remote myocardial infarction and documented VT/VF. Long-term outcome of patients with sustained ventricular tachyarrhythmias is independent of IRA patency status. In contrast to a previous report, outcome of electropharmacological testing was not predicted by the patency of the IRA.

Aged↗
PubMed2000

A patient with "atrial torsades de pointes".

A patient with long QT syndrome and a history of palpitations underwent electrophysiologic study. Runs of polymorphic self-terminating atrial tachyarrhythmias were easily induced and occurred spontaneously several times. Atrial monophasic action potential (MAP) durations were prolonged at short pacing cycle lengths. Premature high right atrial extrastimuli prolonged MAP durations in the low right atrium, resulting in an inverse electrical restitution curve, and increased dispersion of repolarization. MAP morphology showed gradually increasing early afterdepolarizations. When the arrhythmia was initiated, a new action potential reproducibly emerged from these afterdepolarizations. To the knowledge of the authors, this is the first reported case of "atrial torsades de pointes" in a patient.

Action Potentials↗
PubMed2000

Arrhythmias in heart failure: current concepts of mechanisms and therapy.

About one half of deaths in patients with heart failure are sudden, mostly due to ventricular tachycardia (VT) degenerating to ventricular fibrillation or immediate ventricular fibrillation. In severe heart failure, sudden cardiac death also may occur due to bradyarrhythmias. Other dysrhythmias complicating heart failure include atrial and ventricular extrasystoles, atrial fibrillation (AF), and sustained and nonsustained ventricular tachyarrhythmias. The exact mechanism of the increased vulnerability to arrhythmias is not known. Depending on the etiology of heart failure, different preconditions, including ischemia or structural alterations such as fibrosis or myocardial scarring, may be prominent. Reentrant mechanisms around scar tissue, afterdepolarizations, and triggered activity due to changes in calcium metabolism significantly contribute to arrhythmogenesis. Furthermore, alterations in potassium currents leading to action potential prolongation and an increase in dispersion of repolarization play a significant role. Treatment of arrhythmias is necessary either because patients are symptomatic or to reduce the risk for sudden cardiac death. The individual history, left ventricular function, electrophysiologic testing, and the signal-averaged ECG give useful information for identifying patients at risk for sudden cardiac death. The implantable cardioverter defibrillator (ICD) has evolved as a promising therapy for life-threatening arrhythmias. A potential role may exist for antiarrhythmic drugs, mainly amiodarone. There is growing evidence that patients with sustained VT or a history of resuscitation have the best outcome with ICD therapy regardless of the degree of heart failure. Many of these patients require additional antiarrhythmic therapy because of AF or nonsustained VTs that may activate the device. Catheter ablation or map-guided endocardial resection are additional options in selected patients but seldom represent the only therapeutic strategy.

Anti-Arrhythmia Agents↗
PubMed2000

Insulin-like growth factor-binding protein-3 is associated with the presence and extent of coronary arteriosclerosis

Aging is associated with the progression of arteriosclerosis and the decline of several endocrine functions. We therefore investigated the association of coronary arteriosclerosis with hormones, the serum concentrations of which change during aging. Coronary angiograms of 189 men <70 years old were evaluated by 3 semiquantitative score systems to estimate the extent of focal and diffuse vessel wall alterations. Fasting sera were analyzed for levels of glucose, lipids, thyroid-stimulating hormone, insulin, insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3), dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone-binding globulin (SHBG). After adjustment for age, body mass index, and waist-to-hip ratio, 92 patients with >/=1 stenoses >70% differed from 97 patients without such focal lesions by higher serum levels of glucose, total and LDL cholesterol, and apolipoprotein (apo) B, as well as by lower serum levels of IGFBP-3. Multivariate analyses revealed significant and independent correlations of all 3 coronary scores with LDL cholesterol (or apoB) and IGFBP-3; of 2 coronary scores with age, glucose, and insulin; and of 1 score with IGF-I. No significant correlations existed for waist-to-hip ratio (or body mass index) and DHEAS (or testosterone or SHBG). IGFBP-3 explained 9% to 14% and 3.5% to 10% of the variances of focal and diffuse lesions, respectively. In conclusion, IGFBP-3 and, with much less strength and consistency, insulin and IGF-I, but not markers of hypothyroidism, adrenopause, and andropause, have statistically significant and independent associations with coronary arteriosclerosis in men.

Journal Article↗
PubMed2000

Insulin-like growth factor-binding protein-3 is associated with the presence and extent of coronary arteriosclerosis

Aging is associated with the progression of arteriosclerosis and the decline of several endocrine functions. We therefore investigated the association of coronary arteriosclerosis with hormones, the serum concentrations of which change during aging. Coronary angiograms of 189 men <70 years old were evaluated by 3 semiquantitative score systems to estimate the extent of focal and diffuse vessel wall alterations. Fasting sera were analyzed for levels of glucose, lipids, thyroid-stimulating hormone, insulin, insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3), dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone-binding globulin (SHBG). After adjustment for age, body mass index, and waist-to-hip ratio, 92 patients with >/=1 stenoses >70% differed from 97 patients without such focal lesions by higher serum levels of glucose, total and LDL cholesterol, and apolipoprotein (apo) B, as well as by lower serum levels of IGFBP-3. Multivariate analyses revealed significant and independent correlations of all 3 coronary scores with LDL cholesterol (or apoB) and IGFBP-3; of 2 coronary scores with age, glucose, and insulin; and of 1 score with IGF-I. No significant correlations existed for waist-to-hip ratio (or body mass index) and DHEAS (or testosterone or SHBG). IGFBP-3 explained 9% to 14% and 3.5% to 10% of the variances of focal and diffuse lesions, respectively. In conclusion, IGFBP-3 and, with much less strength and consistency, insulin and IGF-I, but not markers of hypothyroidism, adrenopause, and andropause, have statistically significant and independent associations with coronary arteriosclerosis in men.

Journal Article↗
PubMed2000

Maintenance of sinus rhythm as a therapy goal.

Despite recent advances in our understanding of the mechanisms and consequences of atrial fibrillation, appropriate management of this common condition presents something of a dilemma. Control of ventricular rate alone is a common strategy, considered by many physicians to be the safest treatment option and a relatively simple approach to preserving left ventricular function. Rhythm control using antiarrhythmic agents, however, offers a number of important advantages, with the potential to correct abnormal physiology, increase exercise tolerance, reduce thromboembolic risk, prevent atrial remodelling and eliminate the risk of tachycardia-induced cardiomyopathy. Selection of an appropriate antiarrhythmic agent for such long-term prophylaxis is however problematic. Class I agents are associated with an unacceptable proarrhythmic risk especially in patients with structural heart disease and long-term therapy with the class III agent amiodarone can result in serious non-cardiac adverse effects. It is apparent, therefore, that there is little consensus on appropriate management strategies for atrial fibrillation and less still on the antiarrhythmic agent to be used. A number of studies are, however, ongoing which attempt to determine the benefits of rhythm versus rate control. These include the PIAF (Pharmacological Intervention in Atrial Fibrillation), AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) and RACE (Rate Control versus Electrical Cardioversion) studies, which should provide valuable answers which will help to guide physicians in their therapy choices.

Atrial Fibrillation↗
PubMed1999

Fetoscopic transesophageal electrocardiography and stimulation in fetal sheep: a minimally invasive approach aimed at diagnosis and termination of therapy-refractory supraventricular tachycardias in human fetuses.

BACKGROUND: Therapy-refractory supraventricular tachycardia commonly results in hydrops and death in human fetuses. The purpose of this study in fetal sheep was to assess the feasibility of a minimally invasive fetoscopic approach for fetal transesophageal electrocardiography and stimulation aimed at diagnosis and termination of these tachycardias. METHODS AND RESULTS: We studied a total of 10 fetal sheep (87 to 103 days of gestation; term=145 days). We entered the amniotic cavity using a percutaneous fetoscopic approach and placed various electrophysiology catheters into the fetal esophagus. We recorded the number of animals in which fetoscopic transesophageal electrocardiography and stimulation were successful and assessed pacing success and thresholds for different catheters. In addition, we monitored for potential adverse effects from stimulation and for other complications of the operation. Recording of transesophageal electrocardiograms was successful in all fetal sheep. Capture during stimulation was successfully documented by additional fetal bipolar surface electrocardiograms in 7 fetuses. In fetuses in which fetal surface electrocardiograms were not recorded, pacing stimulus artifacts interfered with documentation of capture. Although stimulation thresholds were high, the maternal rhythm was not affected by fetal stimulation. CONCLUSIONS: Fetoscopic fetal transesophageal electrocardiography and stimulation are feasible in fetal sheep. This minimally invasive approach might have the potential to improve diagnosis and management of therapy-refractory supraventricular tachycardias in human fetuses.

Animals↗
PubMed1999

A new algorithm to determine complete isthmus conduction block after radiofrequency catheter ablation for typical atrial flutter.

The induction of a complete conduction block of the isthmus between inferior vena cava and tricuspid annulus is considered the best predictor for lack of arrhythmia recurrence if radiofrequency catheter ablation for typical atrial flutter is performed. We evaluated a simplified algorithm to determine complete isthmus block that, in our series, had a predictive accuracy of 100% when compared with the gold standard.

Algorithms↗
PubMed1999

Combining nonpharmacologic therapies for advanced heart failure: the Münster experience with the assist device-defibrillator combination.

Implantable cardioverter defibrillators (ICDs) and ventricular assist devices (VADs) have been used as a bridge to cardiac transplantation. In selected patients, the combined implantation may be required. This study was motivated by a case of a 33-year-old female patient with giant cell myocarditis who died of ventricular tachyarrhythmias after having been placed on a VAD with which she had been treated on an out-of-hospital basis for a prolonged period of time. A subsequent retrospective analysis of our data showed that, of 73 patients who had to be bridged mechanically (54 Novacor, 12 TCI Heartmate, 4 Thoratec, 3 Medos) in our institution between 1993 and 1998, 10 patients had undergone defibrillator implantation either before (n = 8) or after (n = 2) implantation of a VAD. The cases are presented, and the feasibility of the combination therapy discussed.

Adult↗
PubMed1999

The implantable cardioverter defibrillator and primary prevention of sudden death: the Multicenter Automatic Defibrillator Implantation Trial and the Coronary Artery Bypass Graft (CABG)-Patch Trial.

The Multicenter Automatic Defibrillator Implantation Trial (MADIT) and the Coronary Artery Bypass Graft (CABG)-Patch study were the first 2 randomized trials investigating the usefulness of the implanted cardioverter defibrillator (ICD) for primary prevention of sudden death. Patients enrolled in MADIT and CABG-Patch had never experienced a sustained ventricular tachycardia (VT) but were thought to be at high risk of sudden death. All patients had coronary artery disease and severely suppressed left ventricular ejection fraction. CABG-Patch patients received their ICD during CABG surgery. Most MADIT patients already had received CABG or percutaneous transluminal coronary angiography and had no indication for revascularization procedures at study entry. MADIT patients had nonsustained spontaneous VT and inducible, nonsuppressible VT; CABG-Patch patients had only an abnormal signal-averaged electrocardiogram as an indicator of their arrhythmic risk. CABG-Patch patients did not benefit from ICD implantation, presumably due to the influence of revascularization on ischemia and left ventricular function. In contrast, MADIT patients showed an improved survival by the ICD. MADIT patients had no need for revascularization and, presumably, their risk indicator for arrhythmic events was stronger than the one used in CABG-Patch. MADIT criteria have become a class I indication for ICD implantation and, in the absence of testing for suppressibility of induced VTs, a class IIb criterion for ICD implantation. Screening for MADIT patients is expensive, as only relatively few patients after myocardial infarction fulfill the criteria. Nevertheless, in comparison with amiodarone, treatment of MADIT patients with ICDs seems to be cost-effective, especially if ICDs are implanted transvenously and have the improved battery longevity of the current devices.

Aged↗
PubMed1999

Antiarrhythmic drugs or implantable cardioverter defibrillators in heart failure: the "poor heart".

Ventricular tachycardia and ventricular fibrillation account for a substantial proportion of all deaths in patients with heart failure. Of currently available therapies, amiodarone and the implantable cardioverter defibrillator (ICD) appear to have the greatest potential to decrease sudden death in heart failure. In this article, the presently available information on the relative role of antiarrhythmic drugs, with a focus on amiodarone and ICDs in heart failure, is reviewed.

Amiodarone↗
PubMed1999

[Cardiology].

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Adult↗
PubMed1999

Impact of local donor and regionalization on a German transplantation center. UNI NRW. Universities of North Rhine Westfalia.

Optimal allocation of donor organs is an ongoing matter of debate. We report on the impact of the foundation of UNI NRW, a close transplant collaboration of seven university centers with the intention of improving donor organ allocation, on the heart transplant program in Münster. All donor organs retrieved were offered first to the patients within this region before going into the Eurotransplant (ET) Foundation pool. The heart transplant program data were prospectively (for 1997) and retrospectively (for 1996) analyzed with regard to donor organ availability and allocation. There was a slight decrease in the number of donor hearts offered and accepted within the UNI NRW region in 1997 as compared to in 1996. However, due to the significantly lower organ export rate, the number of heart transplantations performed in UNI NRW rose from 47 to 72 procedures. In Münster, only six donor organs (16%) were procured from outside UNI NRW in 1997, and these were, in part, due to special urgency requests. In conclusion, the institutionalization of UNI NRW within the framework of ET offers more flexibility, decreases total ischemic time, and may help to lower costs.

Europe↗