The German CPU registry: Comparison of smokers and nonsmokers.

BACKGROUND: Chest pain is a major reason for admission to an internal emergency department, and smoking is a well-known risk factor for coronary artery disease (CAD) and acute coronary syndrome (ACS). The aim of this analysis is to illustrate the differences between smokers and nonsmokers presenting to German chest pain units (CPU) in regard to patient characteristics, CAD manifestation, treatment strategy, and prognosis. METHODS: From December 2008 to March 2014, 13,902 patients who had a complete 3­month follow-up were enrolled in the German CPU registry. The analysis comprised 5796 patients with ACS and documented smoking status. RESULTS: Of all the patients in the CPU registry, 35.2% were smokers. Compared with nonsmokers, they were 13.5 years younger (58.2 vs. 71.7 years, p < 0.001), predominantly men (77.1% vs. 65.2%, p < 0.001), and were more frequently diagnosed with single-vessel disease (32.1% vs. 25.2%) as well as ST-elevation myocardial infarction (STEMI; 23.8% vs. 15.5%, p < 0.001). Although the Global Registry of Acute Coronary Events (GRACE) Risk Score for hospital mortality was lower in the group of smokers (106.1 vs. 123.3, p < 0.001), we did not observe any differences in CPU death (0.4% vs. 0.4%, p = 0.69) and CPU major adverse cardiac event (MACE) rates (3.8% vs 2.9%, p = 0.073) between the groups. In the 3­month follow-up, we documented higher mortality rates in the nonsmoker group (1.9% vs. 2.9%, p = 0.035) in correlation with the GRACE Risk Score (80.3 vs. 105.2, p < 0.001). MACE rates were similar during the follow-up (3.1% vs. 4.1%, p = 0.065). CONCLUSION: Observations from the German CPU registry demonstrate that smoking is a strong predictor of acute CAD manifestation early in life, especially STEMI. In spite of a lower GRACE Risk Score and fewer comorbidities, smokers had a rate of hospital mortality similar to the older group of nonsmokers.

[Use of the OUTBACK Re-entry Catheter for recanalization of a joint-transversing extensive occlusion of the femoral and popliteal arteries]. / Einsatz des Outback-Reentry-Katheters zur Rekanalisation eines gelenküberschreitenden langstreckigen Verschlusses der A. femoralis und A. poplitea.

Application of modern techniques for recanalization can now serve to reopen extensive chronic occlusions of the femoral artery with good results. A guide catheter and stiff J Terumo wires are used to perform subintimal recanalization. Once the occlusion site has been traversed in the subintimal plane the challenge lies in the re-entry maneuver to restore the true vessel lumen. Use of the OUTBACK catheter has proven to be particularly well suited for this purpose during which a biopsy of the true vessel lumen is obtained by advancing a needle.

Detection of coronary artery disease with MCG.

The diagnosis of cardiac ischemia related to coronary artery disease (CAD) is a clinical challenge. Despite many methods clinically available, the predictive value of each is still limited. Magnetocardiography (MCG) offers new insights in the electrogenesis of the disease. In the last decade a number of studies using biomagnetometers have dealt with the identification of CAD patients using coronary angiography as a gold standard. As the availability of these systems is limited, studies have focused either on exercise-induced ischemia or on chronic ischemia and the infarct scar at rest. Different parameters have been developed based on signal morphology, time intervals, source parameters or magnetic field map analysis. Concerning signal morphology, main work concentrates on ST-depression, ST-T signal amplitude as well as QRS and ST-T integrals. Dealing with time intervals, most studies focus on the QT interval. The evaluation of of QT dispersion spatially in the MCG, reflecting regional heterogeneity of repolarization, improved the identification of CAD patients. Besides the calculation of the equivalent current dipole during de- and repolarization, parameters of the magnetic field orientation were used to identify CAD patients and localize exercise-induced ischemic regions. Heart rate adjusted alteration in the magnetic field orientation allowed the quantification of ischemia-induced changes in MCG. The estimation of current density (CDV) further enabled to separate healthy subjects from CAD patients at rest. In the course of interventional therapy CDV maps returned toward that of healthy subjects.Thus, there is justification for routine clinical use of the MCG in the diagnosis of CAD.

Changes of QT dispersion in patients with coronary artery disease dependent on different methods of stress induction.

BACKGROUND: Episodes of stress-induced myocardial ischemia in patients with coronary artery disease (CAD) may cause increases of QT dispersion (QTd). HYPOTHESIS: Aim of this study was to analyze the effect of increasing heart rates on QTd and to compare the effect of different methods of stress induction in patients with varying degrees of CAD when estimating QTd. METHODS: We studied 58 patients, 22 with prior myocardial infarction (MI), 25 without MI or wall motion disturbances at rest, and 11 patients without evidence of CAD. Prior to coronary angiography, standard 12-lead ECGs were obtained at rest as well as during dynamic exercise and pharmacologic stress using arbutamine simultaneously with echocardiography. QTd was determined at each stress level by subtracting minimal from maximal QT interval duration. RESULTS: QTd values at rest were not consistently higher in the patients with CAD. At maximal heart rate, QTd was statistically significantly higher in patients with CAD with a better discrimination between groups for pharmacologic stress (p < 0.005 for exercise, p < 0.0001 for arbutamine). Patients after MI had higher QTd values under all conditions than did the groups without MI. As in patients with CAD, the values of this group changed more radically as a result of pharmacologic stress. CONCLUSION: Patients with CAD can be identified on the basis of QTd under stress. These changes were not as marked in patients with MI as their rest values were already increased. Overall, drug-induced stress produced greater differences than dynamic exercise, suggesting that the ischemic threshold might be lower in the former.

Magnetocardiography in the diagnosis of fetal arrhythmia.

OBJECTIVE: To examine the possible use of magnetocardiography in the diagnosis of fetal arrhythmias. DESIGN: Investigation of routinely examined pregnant women, as well as women referred because of arrhythmias or other reasons. PARTICIPANTS: Sixty-three women between the 13th and 42nd week of pregnancy. METHODS: Recording of 189 fetal magnetocardiograms, of which 173 traces (92%) demonstrated sufficient fetal signal strength to permit evaluation. After digital subtraction of the maternal artefact, all fetal complexes were identified and the recording was examined for arrhythmic events. RESULTS: Short bradycardic episodes, not associated with any pathological condition, were found in 26% of all recordings, usually in mid-pregnancy. In 12 cases, isolated extrasystoles of no clinical importance could be identified. There were nine traces which revealed multiple arrhythmias including ventricular and supraventricular ectopic beats, bigeminy and trigeminy, sino-atrial block and atrio-ventricular conduction disturbances. Furthermore, two cases with tachycardia were found. CONCLUSION: Magnetocardiography offers a simple noninvasive method for examination of the fetal cardiac electrophysiological signal. It may thus be useful in the identification and classification of clinically relevant arrhythmia and aid in decisions concerning treatment.

Spatial distribution of QT dispersion measured by magnetocardiography under stress in coronary artery disease.

This study investigated changes in spatial distribution of QT duration in patients with and without coronary artery disease (CAD) using magnetocardiography. Thirty-six-channel magnetocardiograms (MCGs) were registered at rest and under stress in 15 patients with chest pain, seven of whom had significant coronary stenosis. QT dispersion (QTd) was calculated for MCG and 12-lead electrocardiogram (ECG) under both conditions. For MCG, homogeneity of repolarization was measured using a smoothness index (SI). Also, at each registration site, the intraindividual difference between QT at rest and under stress was determined (deltaQT). QTd values as determined by standard 12-lead configurations were not significantly different between groups. MCG QTd values were significantly higher in the CAD group at rest only when all available channels were taken into consideration (P < .05); SI values differed significantly between groups under both conditions (rest, P < .005; stress, P < .01). Good separation between groups was possible using the range of deltaQT (P < .05) and SI (deltaQT) (P < .005). Consideration of the spatial distribution of QTd increases its sensitivity in the detection of CAD, suggesting that CAD involves complex changes in repolarization, not apparent in limited lead sets such as standard 12-lead configurations.

[Relevance of magnetocardiography in coronary artery disease and myocardial infarction]. / Die Bedeutung der Magnetokardiographie bei koronarer Herzerkrankung und Myokardinfarkt.

Multichannel magnetocardiography (MCG) noninvasively registers the magnetic activity of the heart at different points above the thorax. This information can be used to determine the magnetic field produced by cardiac activity as well to reconstruct the current density distribution in the myocardium, which can then be examined during cardiac de- and repolarisation. First studies have shown that the detection of disease specific changes of the magnetic field and current density permit the diagnosis and localization of myocardial infaction (MI) and myocardial ischemia within the context of coronary artery disease (CAD). In these studies various approaches were used to quantify and condense the temporal and spatial changes in the magnetic signals. The integration of defined time intervals of cardiac de- and repolarisation in form of iso-integral magnetic field maps allowed a discrimination between myocardial infarct groups. Furthermore residual maps, calculated by subtracting the MCG map components of MI patients from those of normal subjects, were used to describe the infarcted region. On the basis of trajectory plots which represent the course of magnetic map extrema, patients with ventricular tachycardia after MI could be identified. Current density reconstruction during ST-segment permitted the visualization of biological injury currents during induced ischemia and infarction. Beyond the consideration of the overall magnetic activity, the signal in single channels may be examined and interpreted as is done in the body surface electrocardiogram. Morphological criteria such as the course of the ST-segment as well as the spatial distribution of cardiac time intervals may be considered. Risk stratification of patients after MI with regard to an increased risk of malignant arrhythmia is possible by making use of the spatial distribution of QT dispersion. The promising preliminary results suggest that the current methods must be developed and investigated further in studies with the appropriate number and kind of subjects in order to assess the clinical value of the MCG in patients with CAD and MI.

[Clinical experience with combined automatic implantable cardioverter-defibrillator and pacemaker systems]. / Klinische Erfahrungen einer kombinierten antitachykarden und antibradykarden Herzschrittmachertherapie.

Patients who need an implantable Cardioverter/Defibrillator (ICD) often require a cardiac pacemaker (PM) to treat underlying symptomatic bradycardia. In some cases the simultaneous therapy has caused interactions between the systems with defaults on both sides.Four patients with an ICD of the newer generation received a single or dual chamber pacemaker system. In all cases bipolar pacemaker electrodes were used. They were positioned together with the ICD-electrode in the right ventricular apex without regard to the distance between them. In order to exclude possible interference between systems special tests were performed during the operative procedure with respect to the system implanted first. In a follow-up period of 4-14 months all patients had episodes of ventricular tachycardia or ventricular fibrillation that were terminated successfully. Two patients with a bradycardia related arrhythmia after shock delivery showed a correct pacemaker stimulation. Subsequent to the start of pacemaker therapy improvement in stress capacity could be documented, partly on the basis of echocardiography.Combined ICD and PM therapy can thus be generally regarded as compatible. For AV-sequential pacing at least three electrodes and two aggregates are necessary. The development of an ICD with the option for a dual-chamber stimulation would simplify the therapy, along with a greater acceptance on part of the patients.

Spatial distribution of QT intervals: an alternative approach to QT dispersion.

QT dispersion (QTd) describes the heterogeneity of ventricular repolarization on the basis of the temporal range of QT intervals as measured in the 12-lead ECG. We examined the spatial distribution of QTd using multichannel magnetocardiograms (MCGs), which noninvasively register changes in magnetic field strength at 37 sites over the heart. As in ECG, the MCG signal in each channel may be used to measure QT interval. By calculating QT deviation from QTmin at each site, one can reconstruct the spatial distribution of QTd. Analysis of spatial QTd in ten healthy subjects and ten patients after acute myocardial infarction (MI) showed clear differences in spatial distribution. The healthy subjects generally displayed shorter QT intervals along a line corresponding to the approximate position of the septum with longer intervals in plateaus in the upper right and lower left. Spatial QTd of the post-MI patients deviated from this pattern, often displaying a sharp rise in QT duration over specific areas, which could be related to functional and morphological disturbances. The quantification of local irregularities as well as the overall pattern on the basis of a smoothness index allowed better discrimination between healthy subjects and post-MI patients than QTd. Distribution patterns of QTd which reflect local repolarization alterations may thus represent a more differentiated marker for pathology and risk.