Prevalence of supraventricular arrhythmias from the automated analysis of data stored in the DDD pacemakers of 617 patients: the AIDA study

The confirmation of the occurrence of supraventricular arrhythmias (SVAs) is possible only if a surface electrocardiogram (ECG) is recorded during an episode, or if SVAs occur during 24 h ambulatory monitoring (Holter). The automatic interpretation of memory functions in DDD pacemakers may be useful in this diagnostic task over longer periods of follow up. This hypothesis was tested in 384 men and 233 women (mean age = 70 ± 11 years) who had received Chorus 6034/6035, 6234 or 7034 pacemakers (ELA Medical, Montrouge, France) with fall-back function in case of sustained SVAs. The Automatic Interpretation for Diagnostic Assistance (AIDA) algorithm included in these pacemakers was compared with 24 h Holters recorded simultaneously (DI) and with the clinical history of symptoms consistent with SVAs up to 28 days of follow up (D28). Indications for pacing were atrioventricular block (AVB) in 269 patients, sinus node dysfunction (SND) in 248, and AVB + SND in 100. SVAs were documented before implant in 199 patients (32%). Among the 617 patients included at D1. 76 (12.4%) developed at least one SVA episode, lasting between 1 min and 24 hours, simultaneously recorded on Holter and by AIDA with a 93.8% sensitivity and 94.2% specificity. Data from 354 patients were available for analysis at D28. AIDA diagnosed SVAs in 179 patients (50.6%), 104 of whom (65%) had remained asymptomatic and 117 of whom (65%) had had no SVA documented before implant. Among the 354 patients, AIDA diagnosed SVAs in 76 (21%) asymptomatic patients who had no known SVA before implant. The prevalence of SVA in our AVB population was higher than reported in previous studies: 89 patients (56.3%) with AVB had SVAs versus 90 patients (45.9%) with other diagnoses (p=0.55). Furthermore atrial pacing was associated with fewer SVAs. These first clinical results of the AIDA study demonstrate that the memory functions of Chorus pacemakers and the AIDA software are reliable to analyze the prevalence of SVA at 1 month of follow-up. From a clinical point of view, AIDA is a valuable tool to evaluate the efficacy of antiarrhythmic therapy, particularly as it pertains to the prevention of stroke due to atrial fibrillation.     

Holter monitoring in the evaluation of congenital long QT syndrome

Background: Long QT syndrome (LQTS) is a potentially lethal cardiac channelopathy that affects one in 2,000 persons; causes syncope, seizures, and sudden death; and is both under‐ and overdiagnosed. LQTS diagnostic miscues have stemmed from assessment of ambulatory electrocardiographic monitoring (Holter) results. Objective: We sought to determine the prevalence of positive Holter monitor tests and its diagnostic significance in evaluating LQTS. Methods: We performed an institutional review board‐approved review of patients evaluated in our LQTS clinic from 2000 to 2009 who had Holter testing during their evaluation. Included patients (N = 473) were diagnosed with LQTS or dismissed as otherwise normal. Holters classified as positive had an episode of nonsustained ventricular tachycardia, supraventricular tachycardia, ≥4 couplets/day, ≥10 premature ventricular contractions/hour, or >5‐second sinus pause. Results: Among 209 patients dismissed as normal (128 females, average age 21 ± 15 years, average QTc 424 ± 39 ms), 27 (12.9%) had a positive Holter, while among 264 patients with LQTS (149 females, average age 22 ± 16 years, average QTc 472 ± 41 ms), 30 (11.3%) had a positive Holter (P = NS). Patients with LQT3 (5/23, 21%) and genotype‐negative LQTS (5/19, 26%) had a higher rate of positive Holter testing compared to LQT1 patients (7/124, 6%, P < 0.03). Among the 473 Holters, only one (0.2%) impacted clinical decision making. Conclusion: Routine Holter monitoring appears to be of minimal clinical utility from a diagnostic and prognostic perspective in evaluating LQTS, and may not be cost effective. Whether Holter monitoring aids in therapeutic decisions such as dosing or whether ambulatory QTc measurements, provided by some newer devices, might help in the diagnostic evaluation warrants further scrutiny. (PACE 2011; 34:1100–1104)     

Assessment of VVI Diagnostic Pacing Mode in Patients with Cardioinhibitory Carotid Sinus Syndrome

In this study, we used Holter pacemakers in a group of 13 patients affected by severe carotid sinus syndrome in order to evaluate its evolution. All the patients had one to three syncopal episodes and frequent other symptoms such as fainting, dizziness, lightheadedness and pre-syncope interferring with their daily activity so that pacemaker therapy was considered necessary. Patient selection criteria were: presence of the isolated cardioinhibitory type, absence of associated sinus dysfunction and absence of symptomatic WI pacemaker effect. All the patients received a Micropacer 1 device; among special functions, bradycardia events counter was activated and programmed so that each sequence of three consecutives beats at a cycle length 1.5 sec (i.e., 4.5 sec total interval) could he recognized and stored in its memory. The follow-up lasted 13±7 months. Brady events occurred in eight out of 13 patients (62%), during this period. Syncope and major symptoms disappeared in ail the patients; mild dizziness recurred rarely in two patients and were not linked to brady-events recording. In conclusion, disappearance of severe symptoms observed after pacemaker implant in cardioinhibitory carotid sinus syndrome seems to depend from pacing therapy, in most cases, yet from the benign natural course of the disease in some other cases.     

Circadian Variation in Atrial Fibrillation in Patients with Frequent Paroxysms

Determinants of the duration of episodes of atrial fibrillation (AF) in patients with paroxysmal atrial fibrillation (PAF) are poorly understood. However, autonomic tone shows circadian variation and is known to affect atrial electrophysiology. We therefore compared the duration of episodes of AF with an onset during the day (08:00 - 22:00) to those with an onset during the night in a database of 24-hour ECG recordings in patients with frequent symptomatic PAF. The heart rate in the 30 seconds prior to AF onset was also compared. From 42 recordings, 296 episodes of AF > 30 seconds duration and preceded by > 60 seconds sinus rhythm were identified. The 165 nocturnal episodes tended to be shorter (median =1.15 min) than the 131 diurnal episodes (median =1.5 min) and the distribution of nocturnal and diurnal durations was significantly different (P = 0.007; Kolgomorov-Smirnov test). This was also true in recordings containing at least 1 diurnal and at least 1 nocturnal episode. The mean heart rate prior to AF onset was lower at night (62.2 ± 11.8 vs 75.6 ± 16.4 beats/min; P < 0.0001 Wilcoxon test). These findings suggest that in patients with frequent symptomatic PAF, autonomic influences affect the duration of episodes of AF and has pathphysiohgical and therapeutic implications.     

动态心电图诊断冠心病的价值分析

目的：比较12导联动态心电图与冠状动脉造影对冠心病的诊断价值。方法选取2011年11月~2014年9月本院拟诊为冠心病的114例患者作为研究对象,给予24 h动态心电图检查,以冠状动脉造影为标准进行对比分析。结果114例患者中,冠状动脉造影检查阳性84例,阴性30例,阳性率73.7%;其中单支病变36例,双支病变26例,多支病变22例。动态心电图诊断阳性66例,阴性48例,阳性率为57.9%,敏感性为70.2%,特异性为76.7%,假阳性率为23.3%,假阴性率为29.8%。随着冠状动脉病变支数的增多,动态心电图诊断冠心病的阳性率亦增高,差异有统计学意义（P<0.05）。结论动态心电图是目前开展的无创、安全、价廉的诊断冠心病方法之一,尤其对冠状动脉双支及多支病变的阳性检出率高,可作为冠心病诊断的初筛检查。     

动态血压与动态心电图结合对心血管神经源性晕厥的诊断价值

目的：探讨心血管神经源性景厥的临床特征。方法：本文对32例经综合检查确诊为此病因患者行24h动态血压（ABPM）与24h动态心电图（Holter）检查，对其中某些指标变化及其相互关系进行分析。结果：32例心血管神经源性晕厥患者心率变异性（HRV）和平均白昼、夜间、24h血压值与对照组相比，差异均有显著性（P＜0．05）。结论：心血管神经源性晕厥患者可能存在植物神经调节失衡，这为诊治心血管神经源性晕厥提供帮助。     

Ambulatory Blood Pressure and Holter Monitoring of Emergency Physicians before, during, and after a Night Shift

Abstract. Background: Occupational stress may affect measured hemodynamic and electrocardiographic variables. Data describing the physiologic effects of work on the emergency physician (EP) are sparse. Objective: lb determine whether blood pressure (BP) and heart rate variability (HRV) of the EP are affected during a night shift in the ED. Methods: This prospective study evaluated BP and HRV in attending EPs at an urban academic medical center for a 24-hour period during which a night shift was scheduled. Participants were fitted with an oscillometric ambulatory BP device and a Holter monitor at 1500 hours on the day of a night shift. The monitors were worn continuously before, during, and after a night shift (2300-0700) in the ED and were removed at 1500. Systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), heart rate (HR), measures of HRV, and occurrence of cardiac dysrhythmias were evaluated. Comparisons were made for ED and non-ED awake periods and non-ED sleep periods. Results: Twelve participants completed the study. Eight (67%) subjects were men and 4 (33%) were women. Age ranged from 28 to 40 years (mean 34.1 ± 4.1). Results were analyzed using repeated-measures AN-OVA. An elevation of mean DBP (5.5 mm Hg ± 4.37; p < 0.05; 95% CI 1–10) during night shift activity was seen. A trend toward elevation of SBP, MAP, and HR was discernible. HRV measures indicated a significant relative increase in sympathetic vs parasympathetic tone and an increase in HR of prework and work compared with postwork. Dysrhythmias observed included sinus tachycardia, sinus bradycardia, sinus pause, atrial premature beats, atrial couplets and triplets, supraventricular tachycardia, and premature ventricular contractions. Conclusions: The elevation of DBP during a night shift suggests that these patterns of BP variability are activity- or stress-related rather than a result of a true diurnal variation. HRV analysis suggests that sympathetic tone is heightened both before work and during work. The implications of such findings to the health of the EP warrant further investigation.