Long-term symptom improvement and patient satisfaction after AV-node ablation vs. pulmonary vein isolation for symptomatic atrial fibrillation: results from the German Ablation Registry.

BACKGROUND: We aimed to compare patient characteristics and outcome of patients who had either undergone pulmonary vein isolation (PVI) or AV-node ablation (AVN) to control AF-related symptoms. METHODS: From the German Ablation Registry, we analyzed data of 4444 patients (95%) who had undergone PVI and 234 patients (5%) with AVN. RESULTS: AVN patients were on average 10 years older than PVI patients (71 ± 10 vs. 61 ± 10 years, p < 0.001) with 33% aged > 75 years. AVN patients had significantly more cardiovascular comorbidities (diabetes 21% vs. 8%, renal insufficiency 24% vs. 3%, underlying heart disease 80% vs. 36%, severely reduced left ventricular function 28% vs. 1%, all p < 0.001). Significantly more PVI patients had paroxysmal AF (63% vs. 18%, p < 0.001), and more AVN patients had long-standing persistent AF (44% vs. 7%, p < 0.001). At 1-year follow-up, mortality in the AVN group was much higher (Kaplan-Meier estimates 9.8% vs. 0.5%). 20% of PVI patients had undergone another ablation vs. 3% AVN patients (p < 0.001). Symptomatic improvement was equally achieved in about 80%. Re-hospitalization for cardiovascular reasons occurred significantly more often in PVI vs. AVN patients (31% vs. 18%, p < 0.001). CONCLUSION: In the large German Ablation Registry, AVN ablation was performed much less frequently than PVI for symptomatic treatment of AF and typically in older patients with more comorbidity. Symptomatic improvement was similar in both groups. Hospitalizations for cardiovascular reasons were lower in AVN patients despite older age and more cardiovascular comorbidities. 20% of PVI patients had undergone at least one re-ablation.

The atrial defibrillator: a stand-alone device or part of a combined dual-chamber system?

Atrial fibrillation (AF) is an extremely common arrhythmia seen in clinical practice. Because of the limited efficacy of traditional therapeutic strategies to restore and maintain normal sinus rhythm, several nonpharmacologic options have evolved. The promising results achieved with internal atrial defibrillation have facilitated the development of an implantable atrial defibrilator. Preliminary results obtained from an initial study on a small number of highly selected patients with refractory AF suggest that atrial defibrillation can be performed effectively and safely with adequate patient tolerance by using a stand-alone device. The extension of this therapy will depend on the results of well-designed prospective studies comparing this new therapeutic option with traditional methods. Several acute studies have shown that internal conversion of AF is feasible at low energies with current endocardial transvenous lead configurations primarily designed for ventricular defibrillation, but long-term efficacy has, to date, only been demonstrated with atrial implantable defibrillator lead systems. As AF is a frequent arrhythmia in implantable cardioverter defibrillator (ICD) recipients, it would seem desirable to incorporate the capability for atrial defibrillation into an ICD. Clinical studies have shown that an atrial defibrillator, as part of a combined dual-chamber ICD system, may not require a potentially complicated switching network for establishing different electrode configurations for atrial and ventricular tachyarrhythmia. The efficacy in atrial cardioversion of such a combined, less complex device seems to be as high as reported for a pure atrial defibrillator, but generally at somewhat higher energy requirements. The results of further investigations will show whether a dual-chamber cardioverter defibrillator would be of clinical relevance in patients with ventricular and supraventricular tachyarrhythmia.

Tolerability of internal low-energy shock strengths currently needed for endocardial atrial cardioversion.

There seems to be no relation between shock strength and patient's tolerability using energy levels currently needed for low-energy internal atrial cardioversion. Every patient felt that the second delivered shock, independent of the amount of energy, was more uncomfortable than the first one, which indicates that psychological conditioning may also play an important role in determining discomfort.

Atrial defibrillation: can modifications in current implantable cardioverter-defibrillators achieve this?

Atrial fibrillation (AF), the most common arrhythmia resulting in hospital admission, is a major health problem. The limited efficacy of antiarrhythmic drugs to control this rhythm disorder and their potential proarrhythmic risk led to the development of new techniques to ameliorate the treatment of AF. Transvenous atrial defibrillation using endocardial electrodes has been shown to be effective at low energy levels. An implantable atrial defibrillator could be a potentially valuable treatment option for patients with paroxysmal AF that is medically refractory. Research is currently under way to investigate several critical issues concerning this new therapeutic concept: long-term efficacy, safety, patient's tolerance, and an acceptable cost/benefit ratio. It is well known that AF often complicates the use of the implantable cardioverter-defibrillator (ICD) for ventricular tachyarrhythmias. Therefore, it would seem desirable to implement the capability for atrial defibrillation into current ICD systems. It has been shown that atrial defibrillation, using endocardial lead configurations specifically designed for ventricular defibrillation, is feasible at energies well within the capabilities of current ICD technology. Further research is needed to evaluate if some enhancement of the lead configuration in combination with possible advanced technology could reduce the atrial defibrillation threshold to a well tolerated level as a prerequisite for automated atrial defibrillation, in ICD recipients with concomitant paroxysmal AF.

Comparison of mortality from acute myocardial infarction in patients receiving anistreplase with those not receiving thrombolysis.

Within 1 year, 434 patients were admitted to 14 hospitals with suspected acute myocardial infarction (AMI) < or = 4 hours after the onset of symptoms. Group A consisted of 171 patients (39%) treated with thrombolysis, and group B consisted of 263 patients (61%) with contraindications. Patients in group A more likely had a "definite AMI" (92%; group A1) than patients in group B (67%; group B1). Group B1 had 277 contraindications (1.6/per patient) with increased risk for life-threatening bleeding being the most frequently recorded at admission. The in-hospital mortality in group A1 was 7% (11 of 158) and in group B1, 27% (47 of 177) (p < 0.0001). Age and type of therapy (thrombolysis or no thrombolysis) were identified as independent predictors of increased mortality (p < 0.0001 and < 0.05, respectively). Thus, although most patients with an AMI are excluded from thrombolytic therapy because of contraindications, our data suggest that their in-hospital mortality is unexpectedly high. Further evaluation of this group of patients is warranted to define the impact of contraindications as an independent factor of mortality.

Circannual variation of malignant ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators and either coronary artery disease or idiopathic dilated cardiomyopathy.

We studied the possible relation between the frequency of ventricular tachyarrhythmic events and thermal stress in patients with an implantable cardioverter-defibrillator (ICD) living in a locally limited area under homogeneous climatic conditions. The frequency of tachyarrhythmic events was correlated with the thermal stress level according to the "Klima Michel Model," a complete thermophysiologic model that calculates "felt-temperature" values on the basis of the outdoor temperature and further meteorologic data. During a mean follow-up time of 40 +/- 17 months (range 4 to 72), 761 ventricular tachyarrhythmic events occurred in 50 of 138 consecutive ICD recipients. Analysis of the monthly felt-temperature levels and the mean circannual variation of the registered ventricular arrhythmias suggested that very cold and very hot conditions may be associated with an increased frequency of ventricular tachyarrhythmias. This finding was confirmed by calculation of the sum of tachyarrhythmias on all 2,039 days of the follow-up period divided into 5-degree-step felt-temperature classes. Thus, thermal stress may be 1 factor triggering the occurrence of ventricular tachyarrhythmias in patients with cardiac disease and suppressed cardiac function. Part of the increase in cardiac mortality under above-average hot and cold atmospheric conditions may be attributed to ventricular arrhythmic events.

Antitachycardia pacing in patients with implantable cardioverter-defibrillators: inverse circadian variation of therapy success and acceleration.

We analyzed spontaneous ventricular tachycardias treated by antitachycardia pacing during long-term follow-up in 138 recipients of an implantable cardioverter-defibrillator. An inverse circadian variation of the antitachycardia pacing termination and acceleration rates with the worst antitachycardia pacing success during the time period with the highest episode frequency (morning hours) was demonstrated.

Assessment of heart rate variability by using different commercially available systems.

The results of heart rate variability analysis of the same Holter tape by using 4 different commercially available systems are statistically incomparable. This might have important implications when projecting and evaluating clinical trials.

Safety and efficacy of implantable defibrillator therapy with programmed shock energy at twice the augmented step-down defibrillation threshold: results of the prospective, randomized, multicenter Low-Energy Endotak Trial.

Whether the safety and efficacy of implantable cardioverter defibrillator (ICD) therapy can be assured with lower output devices is an important question. The purpose of this study was to evaluate whether programming the device output at twice the augmented defibrillation threshold was as safe and effective as using the maximum energy. Patients indicated for ICD therapy, but without slow monomorphic ventricular tachycardia (MVT), who achieved an augmented defibrillation threshold (DFT plus) < or = 15 joules (J) with a single endocardial lead system and a biphasic defibrillator were included in the study. Prior to ICD implantation, patients were randomized into 2 groups. The shock energies in test group patient were set as follows: first shock at twice DFT plus, the second to fifth shocks at maximum output (34 J). In control group patients, all shocks were programmed at 34 J. The study population consisted of 166 consecutive patients (mean age 57.4 +/- 12.1 years, mean left ventricular ejection fraction 36.8 +/- 13.8%). Mean DFT plus was 9.6 +/- 3.2 J in test group patients and 10.1 +/- 3.5 J in control group patients (p = 0.36). During a mean follow-up of 24.2 +/- 9.6 months, 736 arrhythmia episodes were analyzed. The first shock efficacy was 98.3% in the test group patients versus 97.4% in the control group (p = 0.45). Total mortality was 6%, equally distributed in both study groups. The results of this study prove that the method of doubling the defibrillation energy at the DFT plus level provides an adequate safety margin in defibrillator therapy.

Comparison of dihydropyridine and phenylalkylamine calcium antagonists in patients with coronary heart disease.

To evaluate possible differences between dihydropyridine and phenylalkylamine calcium antagonists in the setting of chronic stable angina, 2 placebo-controlled, double-blind, crossover trials were conducted comparing the effects of gallopamil and nifedipine on exercise tolerance and ischaemic ST depression, using standard as well as slow release formulations. In the first study, 30 patients received standard formulations of gallopamil (50mg 3 times daily) and nifedipine (20mg 3 times daily). This trial was stopped after 9 patients had been enrolled, because of severe exacerbation of angina in 3 nifedipine recipients. 21 patients then entered a second protocol in which the nifedipine dose was reduced to 10mg 3 times daily. Compared with the preceding placebo periods, time to angina onset and total exercise time were statistically significantly (p less than 0.01) prolonged by gallopamil (by 30 and 18%, respectively), and nonsignificantly prolonged by nifedipine (by 20 and 13%, respectively), after 4 weeks' treatment. Increases in heart rate and rate-pressure product at maximal comparable workloads were less with gallopamil than with nifedipine (p less than 0.01). In contrast to nifedipine, gallopamil was associated with very few side effects. The second trial comprised 24 patients who received slow release formulations of gallopamil (100mg twice daily) and nifedipine (20mg twice daily) over 2 weeks. Again, both drugs exhibited significant anti-ischaemic efficacy, as evidenced by reductions in ST depression at maximal comparable workloads and increases in exercise time compared with placebo, but the differences between the treatments were not statistically significant. Side effects were more frequent with nifedipine, but less severe than with the standard formulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of reperfusion after thrombolysis for myocardial infarction on the signal-averaged electrocardiogram.

Patients with early reperfusion after thrombolysis for acute myocardial infarction revealed a significantly reduced incidence of ventricular late potentials in the signal-averaged electrocardiogram obtained in the chronic post-infarction period in comparison to patients who did not meet the criteria for early successful thrombolysis (14 vs. 39%; P < 0.05). This data demonstrates that early reperfusion might prevent the development of an abnormal electrophysiological milieu after myocardial infarction.

Influence of beta-blockers on the frequency of arrhythmia recurrences in patients with implantable cardioverter-defibrillator: an intraindividual comparison.

We studied retrospectively 60 consecutive recipients of an implantable cardioverter-defibrillator and identified 16 patients who were temporarily on and off beta-blockers (further medication unchanged). An intraindividual analysis revealed that 56% of the patients experienced more arrhythmic episodes during follow-up off beta-blockers compared to 44% while being on beta-blockers. Also, the mean episode frequency during follow-up time on and off beta-blockers was comparable (0.4+/-0.6 vs. 0.5+/-0.5, ns).

Electrophysiological effects of nicainoprol in patients with paroxysmal supraventricular tachycardias.

The electrophysiological effects of nicainoprol, a new class I antiarrhythmic drug, were evaluated in 29 patients with supraventricular reentrant tachycardias, due to accessory pathways in 15 and dual atrioventricular nodal pathways in 14 patients. Nicainoprol was administered intravenously as a bolus followed by continuous infusion of 1.5 mg/kg in two and of 2 mg/kg in 27 patients over one hour. Nicainoprol was given as a bolus of 1.5-2 mg/kg during sinus rhythm in 11 patients or during induced supraventricular tachycardia in 18. The drug successfully terminated the tachycardia in 17 patients due to block in the retrograde tachycardia limb in 15 and the antegrade limb in 2 patients. Prolongation of the cycle length preceded the termination in each case. In one case, the termination could not be achieved despite the administration of 3 mg/kg. The sinus cycle length, heart rate corrected QT interval as well as right atrial and right ventricular effective refractory periods remained unchanged. In contrast, the intranodal and infranodal conduction times, as well as QRS duration, were prolonged significantly. In patients with dual atrioventricular nodal pathways, there was a significant (P less than 0.05) increase of the effective refractory periods of the anterograde slow pathways. The changes of the anterograde fast pathways, however, did not reach significance level. More pronounced effects were found on effective refractory periods of the retrograde pathways, which were blocked in 4 patients and significantly (P less than 0.05) prolonged in the remainder. Similarly, in patients with accessory pathways the effect on the retrograde conduction was more marked with complete block in 5 patients and significant prolongation of effective refractory periods and shortest paced cycle lengths in the remainder.(ABSTRACT TRUNCATED AT 250 WORDS)

Antianginal efficacy of gallopamil in comparison to nifedipine.

In a randomized double-blind crossover trial 30 patients with chronic stable angina were studied to compare the antianginal actions of gallopamil (150 mg/day) and nifedipine. With the initial nifedipine dose of 60 mg/day, the trial had to be stopped because of severe exacerbation of angina in 3 patients of the nifedipine group. Twenty-one patients were entered into a second protocol with the nifedipine dose reduced to 30 mg/day. Compared to the preceding placebo period, the exercise time to onset of angina (+ 30%, P less than 0.01) and the total exercise time (+ 18%, P less than 0.01) were prolonged by gallopamil but not by nifedipine (+ 20 and 13%, respectively, not significant) with no significant difference between the test drugs. Four patients became free of angina during exercise testing with gallopamil therapy and one patient with nifedipine. Both agents significantly reduced ST depression at maximal comparable workload by 77% (gallopamil) and 52% (nifedipine) compared with placebo; the difference between the drugs reached borderline significance (P = 0.055). The increase in heart rate and the rate-pressure product at maximal comparable workload was less with gallopamil than with nifedipine (P less than 0.01). In contrast to nifedipine, very few side effects were reported with gallopamil. Thus, gallopamil is an effective antianginal agent whose therapeutic to toxic ratio appears to be superior to that of nifedipine.

Incidence and clinical significance of short-term recurrent ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillator.

Aims of the present study were (1) to investigate the clinical significance of short-term recurrent tachyarrhythmias (STRTs) in ICD recipient, (2) to identify basic characteristics of the subgroup of patients with STRTs and (3) to compare the frequency and circadian pattern of single arrhythmic events and STRTs. We reviewed data from 119 consecutive patients with late generation ICD. All registered spontaneous ventricular tachyarrhythmias were divided into STRTs (defined as two or more consecutive episodes separated by < or =1 h of sinus rhythm) and single events. During a mean follow up of 36+/-18 months (range 2-67 months) 1849 ventricular arrhythmic events were detected in 57 out of 119 ICD recipients (48%). 202 STRTs consisting of 1128 single detection (6+/-7/STRT, range 2-52) occurred in 34/57 patients (60%; 6+/-6 per patient, range 1-21). Recurrent ventricular tachycardias before device implantation and a high number of single arrhythmic events during follow-up distinguished patients with STRTs. Cardiac mortality was significantly higher in patients with STRTs (26 vs. 4%, P<0.05). The majority of both single episodes and STRTs were registered between 8 a.m. and noon and in the evening. This study reveals a high incidence of STRTs in ICD recipients with spontaneous tachyarrhythmias during follow-up and identifies STRTs as prognostic significant events. Comparable circadian variations suggest that similar triggering factors may be involved in the genesis of STRTs and single tachyarrhythmias.

Implantable cardioverter-defibrillator therapy: influence of left ventricular function on long-term results.

The degree of left ventricular impairment in an acknowledged important prognostic marker of long-term outcome for patients being evaluated for implantation of cardioverter-defibrillators. Just how left ventricular function impacts freedom from all-cause mortality, as well as from sudden death and cardiac death, is a subject of current major debate, and is analyzed hereunder from a large, recent multicenter ICD patient cohort. The multicenter database consists of data from 361 patients receiving implantable cardioverter-defibrillators for standard indications, that is, documented episodes of ventricular fibrillation or sustained ventricular tachycardias with poor hemodynamic toleration. Data were collected from 1988 to 1995 at three centers in Germany. Two-hundred and three patients (56%) had a left ventricular ejection fraction (LVEF) > 0.30 (group I), and 158 patients (44%) had a LVEF < or = 0.30 respectively (group II). The mean follow-up was 23.9 months (range 3-98 months). Overall survival at 5 years for group II patients was lower, as expected, at 74.1% versus 94.2%, respectively (P < 0.0001). Mortality was higher for each different cause of death in group II patients than in Group I: sudden arrhythmic deaths, 5 versus 1 (P < 0.048); nonsudden cardiac deaths, 16 versus 5 (P < 0.002); noncardiac deaths, 7 versus 2 (P < 0.03). Group II patients received a higher rate of at least one presumably appropriate shock at 86 (54.4%) versus 89 (43.8%) in group I (P < 0.05). However (and somewhat surprisingly), neither the time from ICD implantation to death, comparing only the patients who died, nor the event-free probability of appropriate shocks due to very rapid, sustained ventricular arrhythmias (> 230 beats/min), including a presumed risk of sudden arrhythmogenic death, differed between groups I and II. Sudden cardiac death was only marginally affected by LVEF (group I, 1.5% actuarial, 5-year survival 99.5%; group II, 3.1% and 95.8%, respectively). Therefore, the lower overall survival in ICD patients with LVEF < or = 0.30 resulted mainly from causes of death that cannot be directly influenced by cardioverter-defibrillator therapy. However, because group II patients had a far higher incidence of at least one ventricular tachyarrhythmia terminated by ICD shocks than group I patients, they also probably derived benefit from ICD therapy.

Factors influencing heart rate variability in patients with severe aortic valve disease.

BACKGROUND AND HYPOTHESIS: Heart rate variability (HRV) is an accepted tool for the assessment of cardiovascular autonomic tone. There are no sufficient data concerning its application to patients with severe aortic valve disease (AVD) requiring cardiac surgery. METHODS: It was the aim of this study to examine HRV and its physiologic correlates in patients with severe aortic valve disease requiring cardiac surgery. The correlates of time domain indices of HRV obtained from 24-h Holter electrocardiographic recordings were analyzed in 36 consecutive patients (23 men and 13 women, mean age 62 +/- 11 years) with AVD prior to cardiac surgery (aortic stenosis: 17 patients, aortic valve regurgitation: 3 patients, combined aortic valve disease: 16 patients). RESULTS: Low values of HRV were found in the entire study group: SDNN 96.8 +/- 30.9 ms, SDNNI 39.3 +/- 14.4 ms, SDANN 86 +/- 28.9 ms, and RMSSD 30 +/- 18.1 ms. In a univariate analysis, there was no significant correlation between the time domain measures of HRV and age, gender, medication, left ventricular ejection fraction, peak aortic pressure gradient, fraction of aortic valve regurgitation, and left ventricular mass assessed by echocardiography. Patients in advanced functional classes of heart failure [New York Heart Association (NYHA) III or IV] had significantly lower values for SDNN (83.8 +/- 33.6 vs. 107.3 +/- 24.7 ms; p < 0.05) and SDANN (72.7 +/- 29.4 vs. 96.6 +/- 24.3 ms; p < 0.05) than patients in NYHA class I or II. Reassessment of HRV 1 week after aortic valve replacement was performed in 17 patients and showed a significant further decrease of SDNN (102.4 +/- 29.7 vs. 61.5 +/- 23.5 ms; p < 0.001), SDNNI (40.7 +/- 13.6 vs. 23.4 +/- 12.4 ms; p < 0.001) and SDANN (91.8 +/- 29.2 vs. 54.2 +/- 22.8 ms; p < 0.001). CONCLUSION: Patients with AVD requiring cardiac surgery reveal reduced time domain indices of HRV. This observation is pronounced in patients with a progressed clinical class of heart failure, whereas hemodynamic and echocardiographic parameters seem to have no significant influence on HRV parameters in this population. In addition, there is evidence of a further reduction of HRV time domain indices 1 week after uncomplicated aortic valve replacement.

[Anticoagulation in primary prevention of thromboembolism in advanced left ventricular dysfunction]. / Antikoagulation zur Primärprophylaxe thromboembolischer Ereignisse bei fortgeschrittener linksventrikulärer Funktionseinschränkung.

BACKGROUND: Patients with heart failure have an increased risk for thromboembolic events. In clinical practice the physician is often confronted with the decision to establish a prophylactic anticoagulation. DATA: The incidence for clinical embolization is 1.5 to 3.5% per year. It seems that patients with a lower peak oxygen uptake and with a lower ejection fraction are at higher risk for embolic events. There is no evidence for a correlation of such events with the clinical classification (NYHA) or with the genesis of heart failure. Concerning a prophylactic anticoagulation, the results of the published studies and meta-analyses are inhomogenous with a benefit in some, no difference in others and a significant disadvantage for the patients with anticoagulation in a part of them compared to a non-treated control group. None of these data is established by a prospective, randomized, controlled study with the primary endpoint thromboembolic event in patients with or without anticoagulation. The incidence for a hemorrhage under anticoagulation is 0.6-5.3% per year for life-threatening and 0.04-0.64% for fatal bleeding. CONCLUSION: Because of similar incidences for thromboembolic events and for the bleeding complication of anticoagulation, there is no evidence for a general indication for anticoagulation of patients with heart failure, persistent sinus rhythm and lack of risk factors. In patients with high-grade heart failure (e.g. VO2max < 14 ml/min/kg body weight or left ventricular ejection fraction < 20-30%), who belong to a high-risk population, anticoagulation should be considered and may be acceptable in individual cases.

Verbal aggression in computer-mediated decision making.

37 participants receiving verbally aggressive messages during a mediated interaction viewed their interactants as less socially attractive.