Günter Lehmann

Patient characteristics and underlying heart disease as predictors of recurrent atrial fibrillation after internal and external cardioversion in patients treated with oral sotalol

The aim of this study was to identify predictors for recurrent atrial fibrillation after internal and external cardioversion in 157 patients. After cardioversion, patients were treated orally with sotalol (174 +/- 54 mg/day). Univariate predictors for recurrence included coronary artery disease (p < 0.05) and advanced age (p < 0.05). Multivariate adjusted risk for relapse increased with the presence of coronary artery disease (odds ratio [OR] 3.4, 95% confidence interval [CI] 1.6 to 8.0), presence of atrial fibrillation > 2 months before cardioversion (OR 2.3; 95% CI 1.4 to 4.5), left atrial diameter > 60 mm (OR 2.1; 95% CI 1.2 to 3.1), and age > 65 years (OR 1.6; 95% CI 1.3 to 3.3). In 26% of patients with lone atrial fibrillation, recurrence was observed compared with 51% of patients with underlying structural heart disease (p < 0.05). The mode of conversion, internal or external, had no impact on the recurrence rate. These findings might be useful for selection of the most appropriate therapy for the individual patient.

Do airport metal detectors interfere with implantable pacemakers or cardioverter-defibrillators?

OBJECTIVES The aim of this study was to determine whether airport metal detector gates (AMDGs) interfere with pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs). BACKGROUND It is currently unknown whether AMDGs interfere with implanted PMs or ICDs. METHODS A total of 348 consecutive patients (200 PM and 148 ICD recipients) have been tested for the occurrence of electromagnetic interference (EMI) within the electromagnetic field of a worldwide-used airport metal detector. RESULTS No interference, such as pacing or sensing abnormalities, was observed in any of the 200 PM and 148 ICD patients; also no reprogramming occurred. CONCLUSIONS In vivo testing of PM and ICD systems showed no EMI with a standard AMDG. Clinically relevant interactions with implanted PMs or ICDs seem unlikely.

Effect of Electrode Position on Outcome of Low-Energy Intracardiac Cardioversion of Atrial Fibrillation

The aim of this study was to evaluate the new method of low-energy, catheter-based intracardiac cardioversion in patients with chronic atrial fibrillation (AF) and to compare 2 different lead positions. Accordingly, we prospectively studied 80 consecutive patients with chronic AF (9.8 +/- 7.9 months) who were randomly assigned to undergo internal cardioversion either via defibrillation electrodes placed in the right atrium and coronary sinus (coronary sinus group) or via defibrillation electrodes placed in the right atrium and left pulmonary artery (pulmonary artery group). Intracardiac shocks were delivered by an external defibrillator synchronized to the QRS complex. After conversion, all patients were treated orally with sotalol (mean daily dose, 189 +/- 63 mg/day). For conversion to sinus rhythm, the overall mean energy requirement was 5.6 +/- 3.1 J. In the coronary sinus group, cardioversion was achieved in 35 of 38 patients at a mean energy level of 4.1 +/- 2.3 J (range 1.0 to 9.9), and in the pulmonary artery group in 39 of 42 patients with 7.2 +/- 3.1 J (range 2.5 to 14.8). Although there was no difference with regard to success rate, the energy differed significantly between the 2 groups (p < 0.01). Mean lead impedance was 56.4 +/- 7.0 omega and 54.6 +/- 8.5 omega, respectively (p = NS). No serious complications were observed in either lead group. At a mean follow-up of 14.2 +/- 7.0 months, 54% and 56%, respectively, of patients who had been converted successfully remained in sinus rhythm. Thus, low-energy biphasic shocks delivered between the right atrium and coronary sinus or pulmonary artery are equally effective for cardioversion of patients with chronic AF. The energy requirements for conversion from a pulmonary artery electrode position are higher than for the coronary sinus position.

Absence of an impact of emotional distress on the perception of intracardiac shock discharges

The pain of transvenous cardioversion shocks in awake patients is an important clinical problem. It is unknown whether psychological factors modulate any observed variation in pain perception. Thirty-seven patients with chronic atrial fibrillation (AF; mean age 61.9 years, 29 men, 8 women) were consecutively included in the study. Pain perception of a low energy test shock (60V, 0.1J) during internal cardioversion was assessed immediately following the stimulus. Before treatment anxiety, depression, somatization were evaluated.The intracardiac shock was perceived as hypalgesic in 15 (41%) patients, as normalgesic in 10 (27%), and as hyperalgesic in 10 (32%) patients. Pain threshold was significantly lower in patients in which AF was accidentally diagnosed (p < 0.029). Age, sex, and the level of education were equally distributed over the three pain groups. The hyperalgesic pain threshold was not associated with anxiety, depression, or the patients’ tendency to amplify benign bodily sensations.This study discloses a wide range of perceived pain intensity caused by a homogenous intracardiac stimulation. Anxiety and depression do not amplify perception of intracardiac shocks. Sensory gating mechanisms may play a more important role in the level of intracardiac shock perception than distressing affective factors.

Efficacy of a new balloon catheter for internal cardioversion of chronic atrial fibrillation without anaesthesia

Objective To compare a new internal cardioversion system incorporated into a balloon guided catheter with a conventional two electrode system in patients with atrial fibrillation (AF). Design Prospective study. Patients 74 patients with chronic AF treated by internal cardioversion. Materials A 7.5 F balloon catheter with high energy electrode arrays each consisting of six 0.5 cm platinum rings. Brachial vein access enables one electrode array to be placed in the left pulmonary artery (distal pole) and the other at the lateral right atrial wall (proximal pole). The conventional two electrode system consists of 6 F electrodes placed in the proximal left pulmonary artery (anode) and the lower right atrium. Interventions Internal cardioversion was performed by shocks delivered in 40 V incremental steps from an external defibrillator. Shocks were applied by the new device to 32 patients (group A) and by the conventional sysytem to 42 patients (group B). Results The groups differed with respect to system positioning (9.2 (7.3) v 12.3 (8.1) minutes, p < 0.05) and fluoroscopy times (1.7 (1.0) v 3.3 (2.1) minutes, p < 0.01). Sinus rhythm was restored in 30 patients of group A and in 39 of group B (NS) with mean (SD) energy requirements of 8.4 (3.1) J and 7.2 (3.1) J, respectively (NS). Conclusions This new method of internal cardioversion has comparably high primary success rates and low sedation requirements with single and two lead systems.

Marked reduction in atrial defibrillation thresholds with repeated internal cardioversion.

OBJECTIVES This study was performed to assess the atrial defibrillation threshold in patients with recurrent atrial fibrillation (AF) using repeated internal cardioversion. BACKGROUND Previous studies in patients with chronic AF undergoing internal cardioversion have shown this method to be effective and safe. However, current energy requirements might preclude patients with longer-lasting AF from being eligible for an implantable atrial defibrillator. METHODS Internal shocks were delivered via defibrillation electrodes placed in the right atrium (cathode) and the coronary sinus (anode) or the right atrium (cathode) and the left pulmonary artery. After cardioversion, patients were orally treated with sotalol (mean 189 +/- 63 mg/day). Eighty consecutive patients with chronic AF (mean duration 291 +/- 237 days) underwent internal cardioversion, and sinus rhythm was restored in 74 patients. Eighteen patients underwent repeated internal cardioversion using the same electrode position and shock configuration after recurrence of AF (mean duration 34 +/- 25 days). RESULTS In these 18 patients, the overall mean defibrillation threshold was 6.67 +/- 3.09 J for the first cardioversion and 3.83 +/- 2.62 J for the second (p = 0.003). Mean lead impedance was 55.6 +/- 5.1 ohms and 57.1 +/- 3.7 ohms, respectively (not significant). For sedation, 6.7 +/- 2.9 mg and 3.9 +/- 2.2 mg midazolam were administered intravenously (p = 0.003), and the pain score (0 = not felt, 10 = intolerable) was 5.1 +/- 1.9 and 2.7 +/- 1.8 (p = 0.001). Uni- and multivariate analyses revealed only the duration of AF before cardioversion to be of relevance, lasting 175 +/- 113 days before the first and 34 +/- 25 days before the second cardioversion in these 18 patients (p = 0.002). CONCLUSIONS If the duration of AF is reduced, a significant reduction in defibrillation energy requirements for internal cardioversion ensues. This might extend the group of patients eligible for an implantable atrial defibrillator despite relatively high initial defibrillation thresholds.

Electrocardiographic algorithm for assignment of occluded vessel in acute myocardial infarction

BACKGROUND This study was performed to elaborate an electrocardiographic (ECG) algorithm enabling assignment of an occluded coronary artery in acute myocardial infarction (AMI). PATIENTS AND INTERVENTIONS In 109 patients (age, 59+/-12 years) with AMI (pain onset, 3.6+/-1.7 h), coronary angiography with PTCA/stenting of the culprit lesion was performed. The diagnosis of AMI was confirmed by emergency coronary angiography and laboratory analyses. Admission ECG parameters (amplitude of R-wave, ST-segment deviation, presence of Q-wave, deflection of T-wave) in standard 12-lead ECG plus extended (V(3)R to V(6)R and V(7-9)) leads were subjected to classification and regression tree (CART) analysis. RESULTS Continuous CART analysis assessed ST-segment deviations in V(2) and V(5)R. AMI of the left anterior descending (LAD), right coronary artery (RCA) and left circumflex coronary artery (CX) were correctly classified in 94, 64, and 91% of cases, respectively. Dichotomised CART analysis assessed ST-segment deviations in V(2), V(5)R, and aVF. True classification rates for LAD, RCA, and CX amounted to 84, 74, and 71%, respectively. CONCLUSIONS Dichotomised CART analysis is a simple means of differentiation of CX from RCA occlusion during AMI.

Digitoxin intoxication in a 79-year-old patient.: A description of a case and review of the literature

Abstract This report concerns a 79-year-old patient with a pacemaker who presented with exertional shortness of breath, fatigue and peripheral pulse rates of about 35/min which had been present for about 3 weeks. An electrocardiogram at rest revealed paced QRS complexes at a rate of 38/min (1579 ms) followed by monomorphic ventricular extrasystoles at 480 ms. On exercise, the peripheral pulse rose to only 42 beats/min with spontaneous ventricular bigeminy. Serum digitoxin concentration was 32.9 μg/l (therapeutic range, 13–25). Two days later, at a digitoxin concentration of 29 μg/l, there was paced rhythm together with ventricular bigeminy only on effort, but not so at rest. On day 6 after admission, at a digitoxin concentration of 24.5 μg/l, isolated ventricular extrasystoles and fusion beats were present exclusively on termination of exercise. Thus, there is a clear correlation between serum digitoxin concentrations and the occurrence of ventricular ectopy. The latter was apparently precipitated by adrenergic drive during exertion.

Infusions with molsidomine and isosorbide-5-mononitrate in congestive heart failure: Mechanisms underlying attenuation of effects

The use of nitrates for treatment of heart failure is encumbered by tolerance, caused by whatever mechanism, which has been reported only in a few instances with sydnonimines. Accordingly, we compared molsidomine (6 mg/h) and isosorbide-5-mononitrate (3.75 mg/h) with respect to maximal hemodynamic effects, rapidity and extent of attenuation, and underlying mechanisms by means of constant infusions over 24 h each in 15 patients with chronic congestive heart failure (NYHA II-III) with a placebo-controlled, double-blind, randomized, crossover protocol. Hemodynamic measurements and determinations of neurohormones were performed at baseline and at 2, 8, and 24 h after the beginning of infusions. With molsidomine, reductions of diastolic pulmonary artery pressure by 29% (p < 0.001), by 24% (p < 0.01), and by 24% (p < 0.01) versus placebo were found at 2, 8, and 24 h, which amounted to 19% (p < 0.01), 10% (NS), and 14% (NS) with the nitrate. Cardiac output was meaningfully affected only with molsidomine (+5%, NS, at 2 h; +9%, p < 0.05, at 8 h; and +15%, p < 0.05, at 24 h), as was systemic vascular resistance (-13%, p < 0.05; -9%, NS; and -18%, p < 0.01) at the corresponding times. Increases in renin activity amounted to 130% (p < 0.001), 117% (p < 0.001), and 112% (p < 0.001) with molsidomine, and to 14, 16%, and 0 (each NS) with the nitrate at the corresponding times. Hematocrit was reduced by 5% (p < 0.001), 7% (p < 0.001), and 12% (p < 0.01) with molsidomine and by 5% (NS), 5% (p < 0.05), and 5% (NS) with the nitrate. We conclude that neurohumoral counterregulation or fluid shift, which is even more pronounced with molsidomine despite longer-lasting effects, has no essential role in nitrate-tolerance development. With molsidomine, such a role cannot be ruled out, although alternatively, a fluid shift from arterial to the low-pressure arm of circulation during the later course of infusion would be even more likely.

Anti-ischemic effects of first and second dose of 20 mg isosorbide dinitrate administered 5 hours apart : attenuation of effects despite rising plasma concentration

SummaryBased on evidence that there may be early tolerance development even within the first daily cycle of treatment, this study was undertaken to evaluate the duration and extent of the antiischemic effects of two 20 mg doses of isosorbide dinitrate as used in a well-established regimen documented to maintain effectiveness during long-term treatment. Ischemia parameters were analyzed at 2 and