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Biomedical subjects

S H Hohnloser

Publications and source records attributed to S H Hohnloser.

At least 37 records · Page 2Linked to original sources
PubMed2001

Predictors of medical events and of their competitive interactions in the Cardiac Insufficiency Bisoprolol Study 2 (CIBIS-2).

AIMS: Predictive factors for medical events and interactions between events were not reported in the Cardiac Insufficiency Bisoprolol Study 2 (CIBIS-2). We examined the interactions among death, permanent treatment withdrawals, nonlethal cardiovascular hospitalizations and their own occurrence in a given patient, the treatment received, and baseline variables during CIBIS-2. METHODS AND RESULTS: A Cox model for censored data was used to analyze the relations among baseline variables, medical events, and their interactions with treatment. We used competitive risk analysis to examine the interactions between successive events in a given patient during follow-up. No baseline variable predicted the reduction of mortality with bisoprolol. Withdrawal from bisoprolol therapy was more frequent in patients whose baseline heart rate was in the lower tertile of the distribution (P =.0002) but otherwise was not different between patients randomized to bisoprolol and to placebo. Event history analysis revealed that bisoprolol reduced mortality (P =.0006) and hospitalizations for nonlethal cardiovascular events (P =.003) in patients in whom treatment was not permanently withdrawn. Analysis of survival curves in patients who permanently discontinued treatment showed that bisoprolol did not reduce mortality compared with placebo in this population (relative risk 1.03, 95% CI 0.67-1.59; P =.88). Recurrent nonlethal events were reduced by bisoprolol. CONCLUSION: In CIBIS-2, medical events were significantly influenced by treatment withdrawal. Patients who derive benefit from bisoprolol therapy are those in whom treatment is not permanently withdrawn.

Adrenergic beta-Antagonists↗
PubMed2001

Torsade de pointes tachycardia as a rare manifestation of acute enteroviral myocarditis.

A patient with cardiac arrest and documented torsade de pointes ventricular tachycardia is presented in whom acute coxsackievirus B2 myocarditis was identified as the most likely underlying cardiac condition. This case shows that torsade de pointes may occur as a rare manifestation of viral myocarditis. Serial serological tests and endomyocardial biopsies may be helpful in establishing a diagnosis in such patients.

Acute Disease↗
PubMed2001

Severe intracranial bleeding mimicking acute inferior myocardial infarction with right ventricular involvement.

Electrocardiographic (ECG) changes and wall motion abnormalities of the left ventricle have been observed in patients with severe intracranial hemorrhage. However, ECG evidence of an acute myocardial infarction in this setting is extremely rare but may have important therapeutic consequences. We report the case of a 45-year-old female who became unconscious with respiratory insufficiency after an endoscopic retrograde cholangiopancreaticoscopy with ECG changes consistent of an inferior myocardial infarction with right ventricular involvement. Immediate coronary angiography revealed normal coronaries; however, left ventricular angiography showed extensive wall motion abnormalities predominantly in the anteroseptal region. Immediate cranial computer tomography demonstrated massive intracranial bleeding. Intracranial hemorrhage can be associated in the initial phase with ECG evidence of an acute myocardial infarction. This has to be taken into consideration in the setting of unexplained loss of consciousness or nonresponsiveness of a patient. A rapid diagnostic evaluation has to be initiated to rule out a myocardial infarction and to diagnose intracranial hemorrhage before the use of thrombolytic or anticoagulant therapy.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed2000

Rhythm or rate control in atrial fibrillation--Pharmacological Intervention in Atrial Fibrillation (PIAF): a randomised trial.

BACKGROUND: Atrial fibrillation is the most commonly encountered sustained cardiac arrhythmia. Restoration and maintenance of sinus rhythm is believed by many physicians to be superior to rate control only. However, there are no prospective data that compare both therapeutic strategies. METHODS: The Pharmacological Intervention in Atrial Fibrillation (PIAF) trial was a randomised trial in 252 patients with atrial fibrillation of between 7 days and 360 days duration, which compared rate (group A, 125 patients) with rhythm control (group B, 127 patients). In group A, diltiazem was used as first-line therapy and amiodarone was used in group B. The primary study endpoint was improvement in symptoms related to atrial fibrillation. FINDINGS: Over the entire observation period of 1 year, a similar proportion of patients reported improvement in symptoms in both groups (76 responders at 12 months in group A vs 70 responders in group B, p=0.317). Amiodarone administration resulted in pharmacological restoration of sinus rhythm in 23% of patients. Walking distance in a 6 min walk test was better in group B compared with group A, but assessment of quality of life showed no differences between groups. The incidence of hospital admission was higher in group B (87 [69%] out of 127 vs 30 [24%] out of 125 in group A, p=0.001). Adverse drug effects more frequently led to a change in therapy in group B (31 [25%] patients compared with 17 [14%] in group A, p=0.036). INTERPRETATION: With respect to symptomatic improvement in patients with atrial fibrillation, the therapeutic strategies of rate versus rhythm control yielded similar clinical results overall. However, exercise tolerance is better with rhythm control, although hospital admission is more frequent. These data may serve as a basis to select therapy in individual patients.

Adult↗
PubMed2000

Current status of dual-sensor pacemaker systems for correction of chronotropic incompetence.

Rate-adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. However, all sensors used to adapt the pacing rate to meet metabolic demands show typical limitations. To overcome these, concepts using 2 sensors for rate adaptation have been developed, combining an unspecific but fast-reacting sensor with a specific but slower-reacting one. Clinical performance of these dual-sensor pacemaker systems is related to 3 factors: (1) choice of sensors, (2) mode of sensor integration, and (3) algorithms for automatic optimization of the integrated sensor response. Clinical studies using dual-sensor rate-adaptive pacing systems have demonstrated their ability to mimic normal sinus rate during different forms of exercise, avoiding inadequate or delayed rate response. However, to avoid combining the disadvantages of both single sensors, dual-sensor rate-adaptive systems need effective automatic algorithms. Sensor cross-check should be quick and combine fast reactivity and high specificity, particularly so as to prevent overpacing. Programmable rate response-related parameters should continuously be optimized. The pacemaker should provide diagnostic facilities during exercise to simulate short-term sensor performance at different settings and memory functions to evaluate long-term sensor performance. Assessment and eventually deactivation of all automatic functions should be possible. Finally, even with automatic algorithms for sensor optimization, maximal benefit from a dual-sensor system can only be achieved if the physician is able to identify and correct pitfalls of each system.

Algorithms↗
PubMed2000

Rate-dependence of QT dispersion and the QT interval: comparison of atrial pacing and exercise testing.

OBJECTIVES: The study was done to determine whether variables of QT dispersion from the 12-lead electrocardiogram (ECG) are dependent on heart rate. BACKGROUND: The dispersion of the QT interval is under evaluation as a risk marker in patients at risk for ventricular arrhythmias. Assuming that a similar rate correction is necessary as for the QT interval itself, investigators have frequently reported QTc-dispersion values utilizing the Bazett formula. It is not known whether there is a physiologic basis for such a rate correction in the human heart. METHODS: In 35 patients referred for evaluation of ventricular arrhythmias, digital 12-lead ECGs recorded at various heart rates during submaximal exercise testing and again during atrial pacing upon electrophysiologic testing were submitted to computerized interactive analysis of several ECG dispersion variables. RESULTS: Data from 11 patients were excluded due to incomplete high-quality analysis possible at all heart rates. From the remaining 24 patients, a total of 193 ECG recordings at various heart rates (ranging from 76 +/- 17 beats/min to 117 +/- 14 beats/min during atrial pacing and from 78 +/- 18 beats/min to 110 +/- 14 beats/min during exercise testing) were available. A highly significant linear relationship with heart rate was found for both the QT interval and the Q-to-T-peak interval. By contrast, standard QT interval dispersion (QTmax - QTmin), the T-peak-to-T-end interval, and the average area under the T wave did not change with increasing heart rates. CONCLUSIONS: Dispersion of the QT interval and other ECG variables of dispersion of ventricular repolarization are independent of heart rate. Therefore, it is not necessary to rate-correct these measurements.

Electrocardiography↗
PubMed2000

Analysis of 12-lead T-wave morphology for risk stratification after myocardial infarction.

BACKGROUND: The stratification of post-myocardial infarction (MI) patients at risk of sudden cardiac death remains important. The aim of the present study was to assess the prognostic value of novel T-wave morphology descriptors derived from resting 12-lead ECGs. METHODS AND RESULTS: In 280 consecutive post-MI patients, a 12-lead ECG was recorded before discharge, optically scanned, and digitized. For the present study, 5 T-wave morphology descriptors were automatically calculated after singular value decomposition of the ECG signal. The total cosine R-to-T (TCRT [describes the global angle between repolarization and depolarization wavefront]) and the T-wave loop dispersion were univariately associated (P:=0.0002 and P:<0.002, respectively, U: test) with 27 prospectively defined clinical events in 261 patients (mean follow-up 32+/-10 months). Kaplan-Meier event probability curves for strata above and below the median confirmed the strong risk discrimination by TCRT and T-wave loop dispersion (P:<0.003 and P:<0.001, respectively, log-rank test). On Cox regression analysis, with the entering of age, left ventricular ejection fraction, heart rate, QRS width, reperfusion therapy, beta-adrenergic-blocker treatment, and standard deviation of R-R intervals on 24-hour Holter monitoring, TCRT (P:<0.03) yielded independent predictive value, whereas T-wave loop dispersion was of borderline independence (P:=0.064). Heart rate (P:<0.02), left ventricular ejection fraction (P:<0.02), and reperfusion therapy (P:<0.02) also remained in the final model. CONCLUSIONS: Computerized T-wave morphology analysis of the 12-lead resting ECG permits independent assessment of post-MI risk and an improved risk stratification when combined with other risk markers.

Analysis of Variance↗
PubMed2000

Predictive value of T-wave alternans for arrhythmic events in patients with congestive heart failure.

Measurement of microvolt level T-wave alternans in the surface electrocardiogram is a novel way to assess the risk of ventricular arrhythmias. Seven tests of arrhythmic risk, including T-wave alternans, were undertaken in 107 consecutive patients with congestive heart failure and no history of sustained ventricular arrhythmias; the patients were followed up for arrhythmic events during the next 18 months. Of the patients with events, 11 had positive and two indeterminate T-wave alternans results; there were no arrhythmic events among patients with negative T-wave alternans results. Of the seven tests, only T-wave alternans was a significant (p=0.0036) and independent predictor of arrhythmic events.

Arrhythmias, Cardiac↗
PubMed2000

Association between atrial fibrillation and appropriate implantable cardioverter defibrillator therapy: results from a prospective study.

INTRODUCTION: Atrial fibrillation (AF) is associated with significant morbidity and mortality that may be related to hemodynamic impairment, thromboembolic events, or enhanced electrical instability of the ventricular myocardium. There is, however, a lack of data concerning the association of AF and ventricular tachyarrhythmias. METHODS AND RESULTS: Consecutive patients with indication for an implantable cardioverter defibrillator (ICD) were classified for the presence or absence of persistent AF at the time of device implantation. Incidence of device therapy, stored electrograms, and clinical events during follow-up were evaluated prospectively. Two hundred fifty patients were included. During follow-up (20+/-14 months), patients in AF experienced appropriate device therapy for recurrent ventricular arrhythmias more frequently compared with patients in sinus rhythm (SR) (63% vs 38%, P = 0.01). On multivariate analysis, AF was an independent predictor of appropriate ICD therapy (relative risk 1.8; 95% confidence interval [CI] 1.2 to 2.9) and inappropriate device therapy (relative risk 2.3; 95% CI 1.2 to 4.5). Predefined clinical events (cluster endpoint: death, syncope, and hospitalizations) were observed more frequently in AF than in SR patients (55% vs 31%, P = 0.01). Analysis of device-stored electrograms revealed a higher incidence of short-long-short cycles preceding ventricular arrhythmias in AF compared with SR patients (50% vs 16%, P = 0.002). Baseline heart rate preceding ventricular arrhythmias did not differ between the two groups. CONCLUSION: AF is an independent predictor of recurrent ventricular arrhythmias in ICD recipients. The underlying electrophysiologic mechanism seems to be irregular rather than rapid ventricular activation, with a high incidence of short-long-short sequences preceding ventricular tachyarrhythmias in AF patients.

Aged↗
PubMed2000

The defibrillator in acute myocardial infarction trial (DINAMIT): study protocol.

BACKGROUND: The implantable cardioverter/defibrillator (ICD) has been shown to be superior to antiarrhythmic drug therapy for the secondary prevention of sudden cardiac death. Its role in the primary prevention of sudden death after myocardial infarction is unknown. Methods and Results The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT) is a randomized, open-label, parallel-group comparison of ICD therapy versus no ICD therapy in selected survivors of acute myocardial infarction. It will test the hypothesis that reduction of sudden arrhythmogenic death by means of the ICD will result in reduction of overall mortality rates in patients at high risk after acute myocardial infarction. Accordingly, this international multicenter study aims to enroll patients shortly after their infarction (day 6 to day 40) who have reduced left ventricular function (left ventricular ejection fraction </=0. 35) and impairment of cardiac autonomic function shown by depressed heart rate variability (standard deviation of normal-to-normal R-R intervals </=70 ms) or elevated average 24-hour heart rate (mean 24-hour R-R interval </=750 ms, assessed by Holter monitoring). Patients will be followed for approximately 3 years on average with subsequent data analysis based on the intent-to-treat principle. Primary outcome is all-cause death. The trial is expected to be completed in 2003. CONCLUSIONS: DINAMIT is the first prospective study to evaluate the benefit of ICD therapy for the primary prevention of sudden cardiac death in patients at high risk after acute myocardial infarction.

Defibrillators, Implantable↗
PubMed2000

Atrial pacing in the prevention of paroxysmal atrial fibrillation: first results of a new combined algorithm.

UNLABELLED: Pacing algorithms for prevention of atrial tachyarrhythmia (AT) are under clinical evaluation. The present study prospectively evaluated the efficacy of three simultaneously active algorithms for AT prevention and aimed at identifying patients in whom atrial preventive pacing (APP) may be particularly successful. METHODS: In 31 patients with conventional pacing indications and paroxysmal AT, a DDDRP pacing system was implanted, which stores 35 AT episodes with atrial electrograms and marker annotations. Counters and stored AT episodes were retrieved 30 days after implant. APP algorithms (atrial preference pacing, atrial rate stabilization, postmode switching overdrive) were activated. Counters and stored AT episodes were again retrieved 60 days later. The number and duration of AT episodes was measured. Several clinical variables were examined with respect to their ability to identify candidates for APP. RESULTS: During APP, the mean number of AT episodes/patient/day decreased from 7.67 to 1.68 (P = 0.04). However, time in AT was not significantly reduced (9.45% versus 10.41%). APP decreased the number of episodes/day in 11 patients and increased it in 9 patients. No clinical parameters predicting APP success was identified. CONCLUSIONS: APP using three algorithms significantly reduced the mean number of AT episodes/patient/day. However, the time during which patients were in AT was not reduced. No clinical variable predicted the success or failure of APP.

Aged↗
PubMed2000

Efficacy and safety of transvenous atrial cardioversion in patients with mitral valve disease and long-standing atrial fibrillation.

BACKGROUND: Transvenous internal cardioversion (ICV) of atrial fibrillation (AF) may be successful after unsuccessful external CV. However, the safety and efficacy of ICV in patients with significant mitral valve disease and AF of long duration have not been evaluated prospectively. METHODS: This study included 22 consecutive patients (mean age = 59 +/- 14 years, 12 women) with mitral regurgitation grade = II (n = 14) or after mitral valve replacement (n = 8), who underwent ICV with 3/3 ms biphasic shocks delivered via two defibrillation catheters placed in the right atrium and the coronary sinus, respectively. The mean left atrial diameter was 53 +/- 7 mm (range 45-68), and AF had been diagnosed for a median of 24 months. All patients received oral amiodarone pretreatment followed by a maintenance dose of 200 mg/day. RESULTS: Sinus rhythm (SR) was restored by ICV in 15/20 patients (75%), and returned spontaneously in two patients during amiodarone pretreatment. The mean threshold for ICV was 6.2 +/- 3.5 J. Sinus node disease was present in one patient after ICV, and two patients developed amiodarone-induced hyperthyroidism. During a follow-up of 11 +/- 5 months, 8 patients had recurrent AF. The remaining 11 patients who were successfully cardioverted remained in stable SR. CONCLUSION: SR can be safely and successfully restored by ICV in patients with MVD and long-standing AF. During intermediate-term follow-up, a significant proportion of patients remained in SR with oral amiodarone therapy.

Administration, Oral↗
PubMed2000

Ablation of atypical atrial flutter guided by the use of concealed entrainment in patients without prior cardiac surgery.

INTRODUCTION: Mapping techniques have not been systematically evaluated with respect to atypical atrial flutter (AF) not involving the inferior vena cava isthmus. The purpose of this study was to assess prospectively the use of concealed entrainment (CE) in mapping of AF and to assess the clinical benefit of ablation of clinically relevant atypical AF. METHODS AND RESULTS: In seven consecutive patients without prior cardiac surgery presenting with atypical AF, mapping was performed in the right and, if necessary, left atrium. At sites with CE, radiofrequency energy was delivered. In a posthoc analysis, the endocardial activation time, stimulus-flutter wave (F) interval, presence of split potentials and diastolic potentials, and postpacing interval were assessed, and effective sites were compared to ineffective sites. A total of 22 forms of atypical AF either could be induced or were present at the time of the study. Eleven of the 13 targeted atypical AFs (85%) were successfully ablated. The positive predictive value of CE increased from 45% to 75% in the presence of matching electrogram-F and stimulus-F intervals or if flutter terminated during entrainment pacing, and to 88% in the presence of split atrial electrograms or diastolic potentials. During short-term clinical follow-up, none of the patients had recurrence of the ablated AF. However, the majority of patients required either medication for atrial fibrillation or repeated interventions for new forms of AF. CONCLUSION: Mapping and ablation of atypical AF is feasible if sites with CE can be identified. However, the clinical benefit of successful ablations in patients with atypical flutter appears to be limited.

Adult↗