bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of Cardiac Autonomic Nervous Activity Indices in Patients Presenting with Transient Left Ventricular Apical Ballooning
Authors: ORTAK JASMIN , KHATTAB KERSTIN , BARANTKE MELANIE , WIEGAND UWE K.H. , BÄNSCH DIETMAR , INCE HÜSEYIN , NIENABER CHRISTOPH A. , BONNEMEIER HENDRIK
Published: February 2009

Backround: Transient left ventricular (LV) apical ballooning (AB) is characterized by a rapidly reversible, acute LV systolic dysfunction, triggered by physical or emotional stress. Despite observations strongly suggesting catecholamine‐mediated myocardial stunning due to enhanced sympathetic activity, the early time course of heart rate variability (HRV) has not been described.

Methods: We prospectively enrolled 39 consecutive patients (median age = 68 years, range 35–85 years, 38 women) with LV AB. Indices of HRV were extracted from 24‐hour ambulatory electrocardiograms on the day of hospital admission, on days 2 and 3, and 3 months after the hospitalization.

Results: Within 48 hours after hospital admission, the indices of HRV were markedly depressed (standard deviation of normal‐to‐normal [NN] intervals [SDNN] 89.6 ± 19.9 ms; mean standard deviation of NN intervals for 5‐minute segments [SDNNi] 37.8 ± 6.2 ms; root mean square of consecutive difference of normal‐to‐normal intervals [rMSSD] 23.0 ± 9 ms; standard deviation of the averages of NN intervals for all 5‐minute segments [SDANN] 70.1 ± 18.0 ms; geometric triangular index [TI] 23.7 ± 5.9 ms), recovered in the subacute phase and had normalized at 3 months follow‐up (SDNN 124.7 ± 24 ms; SDNNi 47.1 ± 5.7 ms; rMSSD 31.1 ± 10.5 ms; SDANN 118.5 ± 27 ms; TI 31.2 ± 8 ms; all P < 0.05). Mean RR‐interval increased from 845 ± 121 ms on day 1, to 929 ± 84 ms at 3 months (P=0.06).

Conclusions: A marked depression of cardiac parasympathetic activity was observed in the acute phase of LV AB, followed by recovery of autonomic modulation between the subacute and the chronic phases. The rapid return of parasympathetic function may partially explain the favorable outcomes of patients presenting with LV AB.
Survival and Appropriate Device Interventions in Recipients of Cardioverter Defibrillators Implanted for the Primary Versus Secondary Prevention of Sudden Cardiac Death
Authors: STOCKBURGER MARTIN , KREBS ALICE , NITARDY AISCHA , HABEDANK DIRK , CELEBI ÖZLEM , KNAUS THOMAS , DIETZ RAINER
Published: February 2009

Background: Implantable cardioverter‐defibrillators (ICD) implanted after an episode of ventricular tachyarrhythmia (VTA) or in patients at high risk of VTA lower the long‐term mortality. Comparisons of the clinical outcomes of the two indications are scarce.

Methods: The study enrolled 360 consecutive ICD recipients. The device was implanted for secondary prevention in 150 patients, whose mean age was 60 ± 14 years, and mean left ventricular ejection fraction (LVEF) was 40 ± 16%, and for primary prevention in 210 patients, whose mean age was 61 ± 11 years, and mean LVEF was 31 ± 13%. All‐cause mortality and time to first appropriate ICD therapy were measured.

Results: The two study groups were similar with respect to age and prevalence of coronary artery disease. Mean LVEF was higher in the secondary prevention group (P = 0.001). Cox regression analysis revealed a significantly shorter time to first appropriate ICD therapy in the secondary prevention group (HR = 0.51, 95% CI = 0.30 – 0.87, P = 0.01). Over a mean follow‐up of 37 ± 19 months, the all‐cause mortality in the overall population was 12.7%, and was similar in both subgroups (HR = 0.99, 95% CI = 0.55–1.77, P = 0.97).

Conclusions: The long‐term mortality in this unselected population of ICD recipients was low. Patients treated for secondary prevention received earlier appropriate ICD therapy than patients treated for primary prevention. Long‐term mortality was similar in both groups. The higher VT incidence of VTA was effectively treated by the ICD and was not associated with a higher mortality.
Depression of Heart Rate Variability in Patients with Increased Ventricular Wall Stress
Authors: ALTER PETER , RUPP HEINZ , ROMINGER MARGA B. , CZERNY FRIEDERIKE , VOLLRATH ANNA , KLOSE KLAUS J. , MAISCH BERNHARD
Published: February 2009

Background: Heart failure is characterized by neurohumoral dysfunction that can be assessed by measurement of heart rate variability (HRV). Depression of HRV is related to several hemodynamic parameters. We hypothesized that an increased left ventricular (LV) wall stress is related to a depressed HRV in patients with LV dilatation or dysfunction.

Methods: Cardiac function and mass were measured in 31 patients with LV dilatation or dysfunction and 21 controls using cardiac magnetic resonance (CMR) imaging. LV wall stress was calculated using a CMR‐based thick‐walled sphere model. Standard deviation of normal‐to‐normal (NN) intervals (SDNN) and average NN intervals over 5 minutes (SDANN‐i) were calculated.

Results: LV end‐diastolic (ED) and end‐systolic (ES) wall stress were significantly increased in patients with SDNN < 75 ms (P < 0.05). SDNN and SDANN‐i were decreased (P = 0.001, P < 0.001) in patients with LVED wall stress >8 kPa and LVES wall stress >30 kPa (P < 0.05). To examine potential effects of LVEF, LVED and LVES volume, and wall stress on HRV, a multiple linear regression analysis was performed, which revealed LVED wall stress as the only independent parameter influencing SDNN (P = 0.039). LV ejection fraction, LV mass, and volumes were not significantly related to HRV.

Conclusions: LV wall stress was independently related with depression of HRV. Therefore, LV wall stress might be prognostically important and a therapeutic target in heart failure.
Magnetic Resonance Imaging is Superior to Cardiac Scintigraphy to Identify Nonresponders to Cardiac Resynchronization Therapy
Authors: YOKOKAWA MIKI , TADA HIROSHI , TOYAMA TAKUJI , KOYAMA KEIKO , NAITO SHIGETO , OSHIMA SHIGERU , TANIGUCHI KOICHI
Published: February 2009

Background: Left ventricular (LV) postero‐lateral scar and total scar burden are factors responsible for a poor response to cardiac resynchronization therapy (CRT). Contrast‐enhanced magnetic resonance imaging (CMR) and 99mTc‐2‐methoxy isobutyl isonitrile single photon emission computed tomography (SPECT) perfusion imaging are widely used to detect myocardial scar tissue; however, their ability to detect regional scars and predict a positive response to CRT has not been fully evaluated.

Methods: CMR and SPECT were performed in 17 patients with dilated cardiomyopathy (DCM) and seven patients with ischemic cardiomyopathy (ICM) before CRT. All images were scored, using a 17‐segment model. To analyze the LV scar regions by CMR, we assessed the transmural delayed enhancement extent as the transmural score in each segment (0 = no scar, 4 = transmural scar). Similarly, a perfusion defect score was assigned to each segment by SPECT (0 = normal uptake, 4 = defect).

Results: By both SPECT and CMR imaging, the total scar score was significantly higher in the ICM than in the DCM group. An LV postero‐lateral wall scar region was detected using both imaging modes. By SPECT imaging, the percentage of regional scar score in the LV inferior wall was significantly higher in the DCM than in the ICM group.

Conclusions: By SPECT imaging in the DCM group, severe perfusion defects, due to attenuation artifacts, were frequently observed in the LV inferior wall, resulting in the overestimation of scar tissue. CMR identified nonresponders to CRT more reliably than SPECT in patients with DCM.
Analysis of 57,148 Transmissions by Remote Monitoring of Implantable Cardioverter Defibrillators
Authors: THEUNS DOMINIC A.M.J. , RIVERO‐AYERZA MAXIMO , KNOPS PAUL , RES JAN C.J. , JORDAENS LUC
Published: February 2009

Introduction: Remote monitoring of implantable cardioverter defibrillators (ICD) is designed to decrease the number of ambulatory visits and facilitate the early detection of adverse events. We examined the impact of remote monitoring on clinical workload by a comprehensive analysis of transmitted events.

Methods: The study population consisted of 146 recipients of ICD capable of remote monitoring. Data were transmitted daily or in case of pre‐specified events (e.g., arrhythmia, out‐of‐range lead and/or shock impedance). Transmitted events were classified as clinical (disease‐related) or system‐related. Event rates/patient/month were calculated and compared according to events classification and clinical groups.

Results: During a mean follow‐up of 22 ± 16 months, a total of 57,148 remote transmissions were recorded. Of these transmissions, 1009 (1.8%) were triggered by a pre‐specified event, including induced ventricular fibrillation (VF) episodes during defibrillation threshold testing. The median number of events/patient/month was 0.14. Event rates were similar in patients with primary and secondary prevention indications for ICD (0.15 vs. 0.11). After exclusion of the induced VF episodes, 5.6% of transmitted events were classified as system‐related and 94.4% as clinical. The median number of clinical events/patient/month was 0.023. The clinical event‐free rates were 62% and 45%, at 1 and 4 years, respectively.

Conclusion: Remote monitoring of ICD patients is feasible. Despite the large number of data transmissions, remote monitoring imposed a minimal additional burden on the clinical workload. The rate of triggered data transmissions by critical events was, relatively, very low.
Predictive Value of Repeated Versus Single N‐Terminal Pro B‐Type Natriuretic Peptide Measurements Early After‐Myocardial Infarction
Authors: SANDHU SABRINA , HAR BRYAN J. , AGGARWAL SANDEEP G. , KAVANAGH KATHERINE M. , RAMADAN DARLENE , EXNER DEREK V. ,   for the REFINE Investigators
Published: February 2009

Background: A single, markedly elevated B‐type natriuretic peptide (BNP) serum concentration predicts an increased risk of death after myocardial infarction (MI), though its sensitivity and predictive accuracy are low. We compared the predictive value of a modestly and persistently elevated, versus a single, markedly elevated measurement of N terminal pro‐BNP (NT‐BNP) early after MI.

Methods and Results: NT‐BNP was measured 2–4, 6–10, and 14–18 weeks after MI. The median age of the 100 patients was 61 years, median left ventricular ejection fraction (LVEF) was 0.40, and 88% were males. Over a median follow‐up of 39 months, 10 patients died. The initial median NT‐BNP was 802 pg/mL and declined over time (P = 0.002). An initial NT‐BNP ≥2,300 pg/mL (upper quintile) was observed in 19 patients and predicted a 3.4‐fold higher independent risk of death (P = 0.05), with modest sensitivity (30%) and positive predictive accuracy (16%). A NT‐BNP consistently ≥1,200 pg/mL (upper tertile) was observed in 19 patients, and was associated with a 5.7‐fold higher independent risk of death (P = 0.01), with a higher sensitivity (50%) and positive predictive accuracy (26%) than a single, markedly elevated NT‐BNP measurement.

Conclusions: A moderately and persistently elevated NT‐BNP in the early post‐MI period was associated with a 5.7‐fold higher risk of death, independent of age, LVEF, and functional class. Compared with a single measurement, serial NT‐BNP measurements early after MI were more accurate predictors of risk of death.
Effects of Cardiac Resynchronization Therapy on Heart Rate Turbulence
Authors: SREDNIAWA BEATA , LENARCZYK RADOSLAW , MUSIALIK‐LYDKA AGATA , KOWALSKI OSKAR , KOWALCZYK JACEK , CEBULA SYLWIA , SLIWINSKA ANNA , SZULIK MARIOLA , KALARUS ZBIGNIEW
Published: February 2009

Background: Cardiac resynchronization therapy (CRT) improves the clinical status of patients with heart failure (HF), though its effects on heart rate turbulence (HRT) are unknown.

Methods: We measured HRT indices in 58 recipients of CRT systems (mean age = 56 ± 9 years, 41 men) in New York Heart Association HF functional class III–IV, and with a left ventricular (LV) ejection fraction ≤35%. At 6 months of follow‐up, 42 patients were responders and 13 nonresponders to CRT, and three patients died suddenly. The HRT indices turbulence onset (TO%) and turbulence slope (TS ms/RR interval) were calculated from digital 24‐hour electrocardiogram before and after 6 months of CRT. TO ≥ 0% and TS ≤ 2.5 ms/RR interval were considered abnormal.

Results: Mean TO in the entire population was 0.4 ± 1.5 before CRT, and decreased to −0.8 ± 7.0 during the 6 months of CRT (ns). TS increased significantly from 2.0 ± 1.7 at baseline, to 3.9 ± 3.1 (P < 0.05), and a significantly lower proportion of patients had abnormal HRT indices at 6 months. In contrast to the significant increase observed in responders, not significant change in TS was observed among the nonresponders.

Conclusions: During 6 months of CRT, improvements in HRT indices and a decrease in the proportion of patients with abnormal HRT were observed. CRT may have beneficial effects on baroreflex sensitivity.
Timing of the Left Ventricular Electrogram and Acute Hemodynamic Changes During Implant of Cardiac Resynchronization Therapy Devices
Authors: VAN GELDER BERRY M. , MEIJER ALBERT , BRACKE FRANK A.
Published: February 2009

Study Objective: To examine the relationship between timing of the left ventricular (LV) electrogram (EGM) and its acute hemodynamic effect on instantaneous change in LV pressure (LVdP/dtMAX).

Patients and Methods: In 30 patients (mean = age 67 ± 7.9 years) who underwent implant of cardiac resynchronization therapy systems, the right ventricular (RV) lead was implanted at the RV apex (n = 23) or RV septum (n = 7). The LV lead was placed in a posterior (n = 14) or posterolateral (n = 16) coronary sinus tributary. QRS duration, interval from Q wave to intrinsic deflection of the LV EGM (Q‐LV), and interval between intrinsic deflection of RV EGM and LV EGM (RV‐LV interval) were measured. The measurements were correlated with the hemodynamic effects of optimized biventricular (BiV) stimulation, using the Pearson correlation coefficient.

Results: The mean LVdP/dtMAX at baseline was 734 ± 180 mmHg/s, and increased to 905 ± 165 mmHg/s during simultaneous BiV pacing, and to 933 ± 172 mmHg/s after V‐V interval optimization. The Pearson correlation coefficient R between QRS duration, the Q‐LV interval, and the RV‐LV interval at the respective LVdP/dtMAX was 0.291 (P = 0.66), 0.348 (P = 0.030), and 0.340 (P = 0.033).

Conclusions: Similar significant correlations were observed between the acute hemodynamic effect of optimized BiV stimulation and the Q‐LV and the RV‐LV intervals. However, individual measurements showed an 80‐ms cut‐off for the Q‐LV interval, beyond which the increase in LVdP/dtMAX was <10%..
U22, a Protocol to Quantify Symptoms Associated with Supraventricular Tachycardia
Authors: KESEK MILOS , TOLLEFSEN TITTI , HÖGLUND NIKLAS , RÖNN FOLKE , NÄSLUND ULF , JENSEN STEEN M.
Published: February 2009

Background: The main indication for ablation of supraventricular tachyarrhythmias (SVTA) is symptomatic relief. Specific paroxysmal symptoms cannot be quantified with general measures of quality of life, such as with the SF‐36 questionnaire. U22 is a new protocol which measures the effects of arrhythmia on well‐being, the intensity of discomfort during an episode, the type and temporal characteristics of dominant symptoms, and the duration and frequency of episodes. Discrete 0–10 scales are used. Unlike SF‐36, U22 can be used in individual patients.

Methods: U22 and SF‐36 protocols were used in the symptomatic evaluation of 88 patients (mean age = 49.6 ± 16.4 years; 43 men), who underwent catheter ablation of SVTA.

Results: The U22 scores (SD) for (a) well‐being (10 being best), (b) effects of arrhythmia on well‐being (10 being worst), and (c) discomfort during arrhythmia (10 being worst) were 5.6 (2.7), 7.5 (2.8), and 8.0 (2.4), respectively. For comparison, the physical and mental component summaries of SF‐36 were 45.3 (11.0) and 45.2 (12.1), respectively, slightly lower than the expected normal of 50. The intensity of dominant symptom scored by U22 was 9.7 (1.2), 10 being worst. In 29% of patients ≥4 symptoms were equally dominant. Multiple dominant symptoms in U22 were associated with a low general well‐being in SF‐36.

Conclusion: We found U22 useful to quantify symptoms associated with SVTA.
Decrease in Patient Radiation Exposure by a Tantalum Filter during Electrophysiological Procedures
Authors: ROSSI PIER LUCA , MARISELLI MATTEO , CORAZZA IVAN , BIANCHINI DAVID , BIFFI MAURO , MARTIGNANI CRISTIAN , ZANNOLI ROMANO , BORIANI GIUSEPPE
Published: February 2009

Aim: Minimization of X‐ray exposure remains a primary issue in cardiac electrophysiology. The effectiveness of X‐ray beam filtration during cardiac electrophysiological procedures was therefore studied, using a 0.05‐mm‐thick tantalum (Ta) foil, as a filter on the primary X‐ray beam, to reduce the patient dose without degradation of image quality.

Method: Preliminary tests were made on a phantom developed with polymethylmethacrylate, catheters, and guide wires. The filter was then used in patients during cardiac procedures. Identical patient images were obtained with and without the Ta filter insertion and the ratio between image quality and patient dose was evaluated. Changes in patient dose and signal‐to‐noise ratio, as image quality index were measured on the phantom and in patients.

Results and Conclusions: When the Ta filter was used, the mean effective individual patient dose decreased by 3 to 40% (mean reduction = 27%), with no perceivable difference in image quality estimated by electrophysiologists. This Ta filter may be useful to limit the radiation exposure of patients and operators during cardiac procedures.
Variable Effects of Physical Training of Heart Rate Variability, Heart Rate Recovery, and Heart Rate Turbulence in Chronic Heart Failure
Authors: PIOTROWICZ EWA , BARANOWSKI RAFAŁ , PIOTROWSKA MAŁGORZATA , ZIELIŃSKI TOMASZ , PIOTROWICZ RYSZARD
Published: February 2009

Background: Heart rate variability (HRV), heart rate turbulence (HRT), and heart rate recovery (HRR), indices that reflect autonomic nervous system (ANS) activity, are outcome predictors in patients with chronic heart failure (CHF). It is not clear, however, whether they reflect the same components of ANS activity. No study has examined the effects of physical training (PT) training on HRV, HRT, and HRR in CHF.

Study Objective: To examine the responses of HRV, HRT, and HRR to a PT program in patients presenting with CHF.

Methods: In 41 patients (mean age = 58.7 ± 10.2 years) in New York Heart Association CHF functional classes II or III, and with a left ventricular ejection fraction <40%, HRV, HRT, and HRR were measured before and after 8 weeks of PT.

Results: The training was clinically effective in all patients. Before versus after PT, standard deviation of all normal RR intervals increased from 107 ± 30 to 114 ± 32 ms (P = 0.047), high frequency increased from 210 ± 227 to 414 ± 586 ms2/Hz (P = 0.02), and the low/high frequency ratio decreased from 1.8 ± 1.55 to 1.1 ± 1.2 (P = 0.002). HRT and HRR did not change significantly after PT.

Conclusions: In patients with CHF, the positive effects of PT were limited to HRV indices, which reflect parasympathetic activity, without significantly changing HRR and HRT. These observations indicate that different mechanisms modulate HRV, HRR, and HRT, which provide complementary information regarding ANS activity. The 8‐week PT program failed to completely normalize ANS function.
Cavotricuspid Isthmus Ablation with Large‐Tip Gold Alloy Versus Platinum‐Iridium‐Tip Electrode Catheters
Authors: KARDOS ATTILA , FOLDESI CSABA , MIHALCZ ATTILA , SZILI‐TOROK TAMAS
Published: February 2009

Background: Gold has excellent electrical conductive properties and creates deeper and wider lesions than platinum‐iridium during radiofrequency (RF) ablation in vitro. We tested the maximum voltage‐guided technique (MVGT) of cavotricuspid isthmus (CTI) ablation using two 8‐mm tip catheters containing gold (group G) or platinum‐iridium (group PI).

Methods: We enrolled 31 patients who underwent CTI ablation. In group G (n = 15) CTI ablation was performed with a gold‐tip ablation catheter, while in group PI (n = 16) a platinum‐iridium tip was used. Ablation was guided by CTI potentials with the highest amplitude until achievement of bidirectional block (BIB). If BIB was not achieved after 10 RF applications, RF was delivered via a 3.5‐mm irrigated‐tip catheter. Success rate, procedure duration, duration of fluoroscopic exposure, and number of RF applications were measured.

Results: BIB was achieved in all patients in group G, while in group PI an irrigated tip was used in four patients (0% vs 25%, P < 0.001). These four patients required a total of 21 additional RF applications (5.25 ± 2.22). Procedure time (56.4 ± 12 vs 73.1 ± 15 minutes P < 0.05) and fluoroscopic explosure (4.9 ± 2.3 vs 7.1 ± 3.8 minutes, P < 0.01) were shorter in group G than in group PI. Mean number of RF applications was lower (4.6 ± 1.9 vs 6.6 ± 3.1 P < 0.001) and total RF duration shorter (280 ± 117 vs 480 ± 310 seconds) in group G than in group PI. No difference was observed in the number of recurrences at a 6 month‐follow up (1 in group G vs 1 in group PI).

Conclusion: Using the MVGT of CTI ablation, gold‐tip catheters were associated with shorter procedural and fluoroscopic times, and fewer RF applications.
Diabetes Does Not Affect Ventricular Repolarization and Sudden Cardiac Death Risk in Patients with Dilated Cardiomyopathy
Authors: VRTOVEC BOJAN , FISTER MISA , POGLAJEN GREGOR , STARC VITO , HADDAD FRANCOIS
Published: February 2009

Background: We studied the effects of diabetes on ventricular repolarization parameters and sudden cardiac death in patients with dilated cardiomyopathy (DCM).

Methods: We enrolled 132 consecutive patients in New York Heart Association (NYHA) heart failure functional classes II or III and left ventricular ejection fraction <40% without evidence of coronary artery disease. In 45 patients (34%), diabetes was diagnosed according to standard criteria (study group), and the remaining 87 (66%) had no diabetes (controls). All patients underwent a 5‐minute high‐resolution electrocardiogram recording for determination of QT variability (QTV) index and were followed for 1 year thereafter.

Results: At baseline, the two groups did not differ in age, gender, left ventricular ejection fraction, NYHA functional class, or plasma brain natriuretic peptide levels. Similarly, QTV index did not differ between the study group (−0.51 ± 0.55) and controls (−0.48 ± 0.51; P = 0.48). During follow‐up, 18 patients (14%) died of cardiac causes. Of the 18 deaths, eight were attributed to heart failure, and 10 to sudden cardiac death. Mortality was higher in the study group (10/45, 20%) than in controls (8/87, 10%) (P = 0.03). The same was true of the heart failure mortality (6/45 [13%] vs 2/87 [2%], P = 0.01), but not of the sudden cardiac death rate (3/45 [7%] vs 7/87 [8%], P = 0.78). By multiple variable analyses, diabetes predicted total and heart failure mortality, and a high QTV predicted sudden cardiac death.

Conclusions: Diabetes appears to increase the risk of heart failure in patients with DCM without affecting ventricular repolarization parameters and sudden cardiac death risk.
Transvenous Pacing in Children Weighing Less than 10 Kilograms
Authors: ROBLEDO‐NOLASCO ROGELIO , ORTIZ‐AVALOS MARTÍN , RODRIGUEZ‐DIEZ GERARDO , JIMENEZ‐CARRILLO CESAR , RAMÍREZ‐MACHUCA JORGE , DE HARO SERGIO , CASTRO‐VILLACORTA HUMBERTO
Published: February 2009

Pacemakers are used in small children with increasing frequency for the treatment of life‐threatening bradyarrhythmias. The epicardial approach is generally preferred in these patients, to avoid the risks of vessel thrombosis. We examined the feasibility and safety of transvenous pacemaker implantation in children weighing <10 kg, via subclavian puncture, using a 4 Fr sheath introduced after a venogram was performed to evaluate the vein diameter. Progressive dilation with 5, 6, and 7 Fr sheaths preceded the insertion and placement of the endocardial lead. A subaponeurotic pocket was created in the abdominal or pectoral regions, depending upon the patient's size. Between 2001 and 2007, we treated 12 patients (median age = 16 months; range 1–32; median weight = 7.9 kg; range 2.3–10.0; 7 males), of whom four weighed <5 kg. Indications for permanent pacing included postsurgical complete atrioventricular block (n = 8), sinus node dysfunction (n = 2), congenital atrioventricular block (n = 1), and long QT syndrome (n = 1). Single‐chamber pacemakers were implanted in 10, and dual‐chamber pacemakers in two patients. The patients were evaluated at 48 hours, 10 days, and at 3 and 6 months. The mean follow‐up was 31.8 ± 23.5 months. There were no procedural complications. Lead dislodgment occurred in one patient and required replacement of the ventricular lead. One patient died from septicemia. Endocardial pacemaker implantation was feasible and safe in children weighing <10 kg. This procedure is less invasive than the standard epicardial approach.
Gender Effects on Novel Time Domain Parameters of Ventricular Repolarization Inhomogeneity
Authors: KRAUSS THOMAS TIMOTHY , MÄUSER WANDA , REPPEL MICHAEL , SCHUNKERT HERIBERT , BONNEMEIER HENDRIK
Published: February 2009

Introduction: Parameters of ventricular repolarization variability are increasingly being used in an attempt to understand better and predict the occurrence of ventricular tachycardia. Nevertheless, some of the measures used have thus far not been analyzed regarding gender differences in a large group of healthy subjects. Furthermore, new parameters might give further insight.

Methods and Results: We investigated 139 healthy volunteers (mean age 41.6 ± 15.3 years, range 20–77, median 40.0 years, 76 women) without evidence of organic cardiac disease. Mean RR interval and established time domain parameters of heart rate variability (rMSSD; SDNN) were measured for each subject. Beat‐to‐beat QT interval and time‐domain QT interval variability were analyzed. Characteristics of the QT interval and QT interval variability were determined as hourly mean values. The standard deviation of all QT intervals/hour (SDQT) and the standard deviation of all QTc intervals/hour (SDQTc) were used to measure QT interval variability. Four novel ratios of repolarization inhomogeneity (VRI: SDQT/SDNN; VR II: SDQT/rMSSD; VR III: SDQTc/SDNN; VR IV: SDQTc/rMSSD) were introduced. Female subjects exhibited significantly higher values in all four ratios of variability.

Conclusion: The obvious gender differences in repolarization inhomogeneity found in this study might be valuable in better understanding differences between men and women in the genesis of ventricular tachycardia.
Cardiac Resynchronization Therapy in Patients with Mildly Impaired Left Ventricular Function
Authors: FOLEY PAUL W.X. , STEGEMANN BERTHOLD , SMITH RUSSELL E.A. , SANDERSON‡ JOHN E. , LEYVA FRANCISCO
Published: February 2009

Aims: We sought to determine the unknown effects of cardiac resynchronization therapy (CRT) in patients with a left ventricular ejection fraction (LVEF) >35%. Because of its technical limitations, echocardiography (Echo) may underestimate LVEF, compared with cardiovascular magnetic resonance (CMR).

Methods: Of 157 patients undergoing CRT (New York Heart Association [NYHA] functional class III or IV, QRS ≥ 120 ms), all of whom had a preimplant Echo‐LVEF ≤35%, 130 had a CMR‐LVEF ≤35% (Group A, 19.7 ± 7.0%[mean ± standard deviation]) and 27 had a CMR‐LVEF >35% (Group B, 43.6 ± 7.7%). All patients underwent a CMR scan at baseline and a clinical evaluation, including a 6‐minute walk test and a quality of life questionnaire, at baseline and after CRT.

Results: Both groups derived similar improvements in NYHA functional class (A =−1.3, B =−1.2, [mean]), quality of life scores (A =−21.6, B =−33.0; all P < 0.0001 for changes from baseline), and 6‐minute walking distance (A = 64.5, B = 70.1 m; P < 0.001 and P < 0.0001, respectively). Symptomatic response rates (increase by ≥1 NYHA classes or 25% 6‐minute walking distance) were 79% in group A and 92% in group B. Over a maximum follow‐up period of 5.9 years for events, patients in group A were at a higher risk of death from any cause, hospitalization for major cardiovascular events (P = 0.0232), or cardiovascular death (P = 0.0411). There were borderline differences in the risk of death from any cause (P = 0.0664) and cardiovascular death or hospitalization for heart failure (P = 0.0526).

Conclusions: This observational study suggests that the benefits of CRT extend to patients with a LVEF > 35%.
Prevalence of Cancelled Shock Therapy and Relationship to Shock Delivery in Recipients of Implantable Cardioverter‐Defibrillators Assessed by Remote Monitoring
Authors: VARMA NIRAJ , JOHNSON MARK A.
Published: February 2009

Background: Cancelled shock therapy (CxTx) may presage shock delivery and shorten battery longevity of implantable cardioverter‐defibrillators (ICDs). However, it is silent and has received little attention. Remote home monitoring (HM) with continuous surveillance and automatic daily data archiving allows investigation of CxTx.

Methods and Results: We retrospectively analyzed a database of 4,960 recipients of HM ICD, from 2002 to 2007. Over a mean follow‐up of 445 ± 253 days, CxTx occurred in 1,392 (28%) patients, mostly as single episodes (n = 1,120). However, 142 patients (10% of patients with CxTx, 2.9% of the whole ICD population) had >10 CxTx. CxTx was followed by shock delivery in 432 patients, in 239 (55%) of whom CxTx occurred >10 days prior to shock delivery. In 113 patients (26%), CxTx occurred in the 72‐hour period preceding the shock. A single CxTx preceded the shock in 74 of these 113 patients, and only eight patients had >3 CxTx.

Conclusion: CxTx was highly prevalent in unselected ICD recipients, though the intraindividual density of episodes was low. In 2.9% of the overall population, the number of CxTx was sufficient to shorten the battery longevity. A high number of CxTx usually did not predict the delivery of shocks.
Long‐Term Effects of Dynamic Atrial Overdrive Pacing on Sleep‐Related Breathing Disorders in Pacemaker or Cardioverter Defibrillator Recipients
Authors: SINHA ANIL‐MARTIN , BAUER ALEXANDER , SKOBEL ERIC C. , MARKUS KAI‐U , RITSCHER GUIDO , NOELKER GEORG , BREITHARDT OLE‐ALEXANDER , BRACHMANN JOHANNES , STELLBRINK CHRISTOPH
Published: February 2009

Introduction: Sleep‐related breathing disorders occur in 20–30% of Europeans and North Americans, including 10% of sleep apnea syndrome (SAS). A preliminary study suggested that atrial overdrive pacing with a fixed heart rate might alleviate SAS. However, it is not known whether dynamic atrial overdrive pacing alleviates SAS.

Methods: Patients with indications for a dual chamber pacemaker or implantable cardioverter‐defibrillator (ICD) were screened for SAS using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. If PSQI was >5, cardio‐respiratory polygraphy was performed before and 4 and 7 months after device implantation. Patients were randomized to algorithm ON–OFF (group A) or OFF–ON (group B) and the apnea‐hypopnea index (AHI) was measured.

Results: Out of 105 consecutive patients, 46 (44%) had a positive PSQI. This analysis included 12 patients (mean age = 61 ± 10 years, body mass index 28.9 ± 6.5 kg/m2, left ventricular ejection fraction = 38.3 ± 13.6%; 10 men). All patients suffered from obstructive or mixed SAS. There were no significant differences in PSQI or AHI between baseline and follow‐up or between the two study groups. Therefore, the study was terminated ahead of schedule.

Conclusions: The prevalence of obstructive or mixed SAS was high in pacemaker or ICD recipients and reduced left ventricular ejection fraction. In these patients, long‐term dynamic atrial overdrive pacing using did not improve PSQI or SAS. Therefore, patients with relevant obstructive or mixed SAS should not be offered atrial pacing therapy.
Stepwise Evaluation of Unexplained Syncope in a Large Ambulatory Population
Authors: IGLESIAS JUAN F. , GRAF DENIS , FORCLAZ ANDREI , SCHLAEPFER JUERG , FROMER MARTIN , PRUVOT ETIENNE
Published: February 2009

Background: Up to 60% of syncopal episodes remain unexplained. We report the results of a standardized, stepwise evaluation of patients referred to an ambulatory clinic for unexplained syncope.

Methods and Results: We studied 939 consecutive patients referred for unexplained syncope, who underwent a standardized evaluation, including history, physical examination, electrocardiogram, head‐up tilt testing (HUTT), carotid sinus massage (CSM) and hyperventilation testing (HYV). Echocardiogram and stress test were performed when underlying heart disease was initially suspected. Electrophysiological study (EPS) and implantable loop recorder (ILR) were used only in patients with underlying structural heart disease or major unexplained syncope. We identified a cause of syncope in 66% of patients, including 27% vasovagal, 14% psychogenic, 6% arrhythmias, and 6% hypotension. Noninvasive testing identified 92% and invasive testing an additional 8% of the causes. HUTT yielded 38%, CSM 28%, HYV 49%, EPS 22%, and ILR 56% of diagnoses. On average, patients with arrhythmic causes were older, had a lower functional capacity, longer P‐wave duration, and presented with fewer prodromes than patients with vasovagal or psychogenic syncope.

Conclusions: A standardized stepwise evaluation emphasizing noninvasive tests yielded 2/3 of causes in patients referred to an ambulatory clinic for unexplained syncope. Neurally mediated and psychogenic mechanisms were behind >50% of episodes, while cardiac arrhythmias were uncommon. Sudden syncope, particularly in older patients with functional limitations or a prolonged P‐wave, suggests an arrhythmic cause.
Impact of AV Conduction Disorders on SafeR Mode Performance
Authors: THIBAULT BERNARD , SIMPSON CHRISTOPHER , GAGNÉ CARL‐ÉRIC , BLIER LOUIS , SENARATNE MANOHARA , McNICOLL SERGE , STUGLIN CARLO , WILLIAMS RANDY , PINTER ARNOLD , KHAYKIN YAARIV , NITZSCHE REMI
Published: February 2009

Purpose: CAN‐SAVE R is a Canadian multicenter study that compares the effects of a new pacing mode algorithm designed to minimize right ventricular (V) pacing versus DDD mode with a long atrioventricular (AV) delay in a general population of pacemaker (PM) recipients.

Study Participants: Patients with permanent atrial fibrillation (AF) or high‐degree AV block (AVB) were excluded. We present preliminary data collected in 208 patients (mean age=71 ± 11 years, 68% men), for the 2‐month baseline period during which all PM were programmed in the new pacing mode. The pacing indications were sinus node disease (SND) without AVB in 39%, AVB without SND in 30%, SND and AVB in 16%, and miscellaneous in 15% of patients.

Results: The mean percent V pacing in the overall population was 9.5 ± 23.8% (range=0–100%, median <1%), ranging between 0.5 ± 1.5% (median=0) in patients without AVB and 18.7 ± 31.2% in patients (median = 1) with AVB. Adverse events potentially related to the new pacing mode were observed in two patients with AVB.

Conclusions: A new pacing mode was effective and safe in a general population of PM recipients without permanent AVB and was associated with an overall <1% median V pacing. CAN‐SAVE R will compare the long‐term effects of the new pacing mode with DDD with a long AV delay on clinical outcomes and cardiac function.
Prevention of Venous Thrombosis by Warfarin after Permanent Transvenous Leads Implantation in High‐Risk Patients
Authors: COSTA ROBERTO , DA SILVA KÁTIA REGINA , RACHED ROBERTO , FILHO MARTINO MARTINELLI , CARNEVALE FRANCISCO CÉSAR , MOREIRA LUIZ FELIPE PINHO , STOLF NOEDIR ANTONIO GROPPO
Published: February 2009

Background: The incidence of venous lesions following transvenous cardiac device implantation is high. Previous implantation of temporary leads ipsilateral to the permanent devices, and a depressed left ventricular ejection fraction have been associated with an increased risk of venous lesions, though the effects of preventive strategies remain controversial. This randomized trial examined the effects of warfarin in the prevention of these complications in high‐risk patients.

Method: Between February 2004 and September 2007, we studied 101 adults who underwent a first cardiac device implantation, and who had a left ventricular ejection fraction ≤0.40, or a temporary pacing system ipsilateral to the permanent implant, or both. After device implantation, the patients were randomly assigned to warfarin to a target international normalized ratio of 2.0–3.5, or to placebo. Clinical and laboratory evaluations were performed regularly up to 6 months postimplant. Venous lesions were detected at 6 months by digital subtraction venography.

Results: Venous obstructions of various degrees were observed in 46 of the 92 patients (50.0%) who underwent venography. The frequency of venous obstructions was 60.4% in the placebo, versus 38.6% in the warfarin group (P = 0.018), corresponding to an absolute risk reduction of 22% (relative risk = 0.63; 95% confidence interval = 0.013–0.42).

Conclusions: Warfarin prophylaxis lowered the frequency of venous lesions after transvenous devices implantation in high‐risk patients.
Early Conduction Disorders Following Percutaneous Aortic Valve Replacement
Authors: CALVI VALERIA , PUZZANGARA EUGLENA , PRUITI GIUSI PAOLA , CONTI SERGIO , DI GRAZIA ANGELO , USSIA GIAN PAOLO , CAPODANNO DAVIDE , TAMBURINO CORRADO
Published: February 2009

Background: Percutaneous aortic valve replacement (PAVR) may be an alternative therapy for patients with severe aortic stenosis who are denied valve surgery because of age and comorbidity. Data are few regarding the incidence of early conduction disorders (CD) after PAVR. We examined the incidence and characteristics of CD in the immediate postoperative period after PAVR, and the need for permanent pacemaker (PPM) implantation.

Methods and Results: Between June 2007 and June 2008 30 patients (mean age = 82.1 ± 8.5 years) underwent PAVR in our institution. The incidence of new, postoperative CD, diagnosed by 12‐lead or 24‐hour Holter electrocardiogram, was 68.0%. Left bundle branch block was the most common conduction abnormality, with an incidence of 45.8%. The incidence of complete atrioventricular block requiring PPM implantation was 20%.

Conclusions: We observed a higher incidence of early conduction disorders and need for PPM implantation after PAVR than generally reported after surgery. Whether this observation is clinically important requires larger prospective studies and follow up.
Policy Theory, Policy Theory Everywhere: Ravings of a Deranged Policy Scholar
Authors: Meier Kenneth J.
Published: February 2009

The field of policy theory abounds with numerous theories, with each theory having a set of practitioners that are working independently of the others. Resolving conflicts among policy theories as a result is difficult. This essay has a more modest goal of posing some questions and suggesting some avenues for future research. Key points include defining the purpose of policy theory, incorporating management into our theories, making strategic choices about areas of study, addressing the parsimony‐comprehensiveness tradeoff, and providing a more nuanced role for institutions.
The Implementation of Public Policy: Still the Missing Link
Authors: Robichau Robbie Waters , Lynn Jr. Laurence E.
Published: February 2009

Although theories of public policy and theories of governance both seek to establish relationships between policymaking and its consequences, they do not complement each other very well. Public policy models tend to de‐emphasize that which governance theories tend to emphasize: the influence on government performance of implementation, broadly described as the actions taken by those engaged in administration (including managers at all levels, those engaged in service delivery, and third‐party agents) after a policy has been lawfully promulgated by elected officials and interpreted by the courts. A comparison of a recently developed theory of public sector performance with several prominent theories of policymaking suggests that multilevel governance theories can supply what continues to be the missing link in public policy theories. At the same time, governance theories might be enriched by the process modeling of public policy theories.
Integrating Delegation into the Policy Theory Literature
Authors: Lavertu Stéphane , Weimer David L.
Published: February 2009

Public policy scholars have developed a number of theories of the policymaking process. Their work has come to define what some now refer to as the “policy theory” literature. Our task is to identify theoretical and empirical courses of study that will advance this research program. We limit ourselves to identifying an existing theory that already provides such an advance and discuss some of its theoretical benefits and empirical support. Specifically, we make the case that there exists a well‐developed theory of delegation that rivals what we deem to be the best of the existing policy theories. We also suggest that existing theoretical frameworks might benefit from incorporating delegation theory explicitly and conclude that policy research has much to contribute to the development and useful application of delegation models.
What Is Next for Policy Design and Social Construction Theory?1
Authors: Schneider Anne , Sidney Mara
Published: February 2009

The study of policy design has made great progress over the past decade in leading scholars to understand why the American political system produces certain kinds of designs rather than others, and the consequences that policy designs have for democracy. This article outlines the distinctive and important elements of policy design theory—the centrality of policy design, the attention to social constructions, the attention to policy consequences (or feed‐forward effects), and the integration of normative and empirical research and theory. It then suggests how policy design theory can complement other policy theories in guiding research and evaluating the conditions of U.S. democracy, and how in its own right it can be further developed and used to guide important inquiry about public policy's politics and social impacts.
Chlorinated Opium Alkaloid Derivatives Produced by the Use of Aqueous Sodium Hypochlorite During the Clandestine Manufacture of Heroin
Authors: Casale John F. , Toske Steven G. , Hays Patrick A.
Published: February 2009

Abstract:  A clandestine chemist was observed producing heroin from crude morphine utilizing a solution of sodium hypochlorite during the process. Numerous chlorinated opium alkaloid derivatives were created when the morphine acetylation reaction was quenched and neutralized with a solution of sodium hypochlorite and ammonium hydroxide. Four of these compounds, 1‐chloroheroin, 1‐chloroacetylcodeine, 1‐chloro‐O6‐monoacetylmorphine, and 2′‐chloropapaverine, were characterized via preparative isolation, gas chromatography/mass spectrometry, nuclear magnetic resonance spectroscopy, and independent synthesis. These chlorinated derivatives were formed via electrophilic aromatic substitution with free chlorine during the illicit process. Although no illicit heroin exhibits containing these compounds have been observed in seizures to date, mass spectral data are provided for several of these compounds for their identification should they be seen within future seizures of illicit heroin.
The expression of six biomarkers in the four most common ovarian cancers: correlation with clinicopathological parameters
Authors: LIN CHIH‐KUNG , CHAO TAI‐KUANG , YU CHENG‐PING , YU MU‐HSIEN , JIN JONG‐SHIAW
Published: February 2009

This study aimed to evaluate the relationship of fascin‐1, matrix metalloproteinase (MMP)‐2, MMP‐9, cortactin, survivin, and epidermal growth factor receptor (EGFR) expression with clinicopathological parameters for the four most common ovarian surface epithelial carcinomas. Six biomarkers were investigated immunohistochemically using tissue microarrays of 185 specimens including 79 serous cystadenocarcinomas, 47 mucinous cystadenocarcinomas, 45 endometrioid adenocarcinomas, and 14 clear cell carcinomas. The four most common ovarian carcinomas showed significant expression of fascin‐1, cortactin, survivin, and EGFR, but not of MMP‐2 and MMP‐9. In addition, higher immunostaining scores for fascin‐1 in mucinous cystadenocarcinomas correlated with T stage, N stage, American Joint Committee on Cancer AJCC clinical stage, and a poorer survival rate; for cortactin in serous cystadenocarcinomas correlated with T stage; for cortactin in clear cell carcinomas correlated with T and clinical AJCC stages; and for survivin in clear cell carcinomas correlated with T stage and AJCC clinical stage. In addition, higher immunostaining scores for fascin‐1, cortactin, and survivin correlated with poorer tumor differentiation in serous, mucinous, and endometrioid adenocarcinomas. Thus, the expression of fascin‐1, cortactin, and survivin may be helpful in evaluating the aggressiveness of ovarian mucinous, serous, and clear cell adenocarcinoma. Additionally, the expression of fascin‐1 may be an independent prognostic risk factor in mucinous cystadenocarcinoma.
Self‐reported occupational skin contact with cleaning agents and the risk of disability pension
Authors: Feveile Helene , Christensen Karl Bang , Flyvholm Mari‐Ann
Published: February 2009

Background:  Occupational skin diseases often affect the hands and can lead to consequences at both the individual and the social level.

Objectives:  To investigate and quantify the association between self‐reported occupational skin contact with cleaning agents and subsequent transition to disability pension.

Methods:  A sample of 8337 employees between 18 and 59 years of age participated in the Danish Work Environment Cohort Study in 1990, 1995, or 2000. They were followed up regarding disability pension until 2006 using the DREAM register on social transfer payments for all inhabitants in Denmark. The Cox proportional hazards model was used to estimate the impact of occupational exposure to cleaning agents on subsequent disability pension.

Results:  Among women, 11% of the disability pension cases were attributable to exposure to cleaning agents and/or disinfectants.

Conclusions:  The study suggests a potential for prevention of work‐related disabilities among job groups exposed to cleaning agents.
Cobalt‐containing alloys and their ability to release cobalt and cause dermatitis
Authors: Julander Anneli , Hindsén Monica , Skare Lizbet , Lidén Carola
Published: February 2009

Background:  Cobalt, nickel, and chromium are important skin sensitizers. However, knowledge about cobalt exposure and causes of cobalt sensitization is limited.

Objectives:  To study release of cobalt, nickel, and chromium from some cobalt‐containing hard metal alloys and to test reactivity to the materials in cobalt‐sensitized patients.

Methods:  Discs suitable for patch testing were made of some hard metal alloys. Cobalt, nickel, and chromium release from the materials was determined by immersion in artificial sweat (2 min, 1 hr, 1 day, and 1 week). Patch test reactivity to the discs and to serial dilutions of cobalt and nickel was assessed in previously patch‐tested dermatitis patients (19 cobalt positive and 18 cobalt‐negative controls).

Results:  All discs released cobalt, nickel, and chromium. Some discs released large amounts of cobalt (highest concentration: 290 μg/cm2/week). Seven discs elicited three or more positive test reactions.

Conclusions:  The concentration of released cobalt was high enough to elicit allergic contact dermatitis in cobalt‐sensitized patients. As the materials in the discs are used in wear parts of hard metal tools, individuals with contact allergy to cobalt may develop hand eczema when handling such materials.