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Background: Implantation and testing of implantable defibrillators (ICDs) using local anesthetic and conscious sedation is widely practiced; however, some centers still use general anesthesia. We assessed safety and patient acceptability for implantation of defibrillators using local anesthetic and conscious sedation. Methods: The records of 500 consecutive device implants from two UK cardiac centers implanted under local anesthetic and conscious sedation from January 1996 to December 2004 were reviewed. Procedure time, left ventricular ejection fraction (LVEF) sedative dosage (midazolam), analgesic dosage (fentanyl or diamorphine), requirement for drug reversal, and respiratory support were recorded. Patient acceptability of the procedure was also assessed. Results: Of 500 implants examined, 387 were ICDs, 88 were biventricular ICDs, and 25 were generator changes. Patients with biventricular-ICDs had significantly longer (mean ± SD) procedure times 129.7 ± 7.6 minutes versus 63.3 ± 32.3 minutes; P < 0.0001 and lower LVEF 24.4 ± 8.4% versus 35.7 ± 15.4%; P < 0.0001. There were no differences in the doses (mean ± SD) of midazolam 8.9 ± 3.5 mg versus 8.0 ± 3.1 mg; P = NS, diamorphine 4.3 ± 2.0 mg versus 3.8 ± 1.7 mg; P = NS or fentanyl 94.4 ± 53.7 mcg versus 92.2 ± 48.6 mcg; P = NS, between the two groups. There were no deaths or tracheal intubations in either group. Acceptability was available for 373 of 500 (75%) patients, 41 of 373 (11%) described “discomfort,” but from these 41 patients only 14 of 373 (3.8%) declined a second procedure under the same conditions. Conclusions: Implantation of defibrillators under local anesthetic and sedation is safe and acceptable to patients. General anesthesia is no longer routinely required for implantation of defibrillators. [ABSTRACT FROM AUTHOR]

The presented case report describes a male patient with an implanted cardioverter–defibrillator (ICD) in whom a coadministration of ciprofloxacin and azimilide caused QT interval prolongation and multiple episodes of torsades de pointes (TdP) followed by ICD shocks (arrhythmic storm). The case highlights a not described drug interaction between azimilide and ciprofloxacin, which is believed to be the safest member of fluoroquinolones class. [ABSTRACT FROM AUTHOR]

Background: The time to skill deterioration between primary training/retraining and further retraining in cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) trial was a multi-center randomized controlled trial evaluating survival after CPR-only versus CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest.Aims: This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation.Methods: Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate versus not adequate) using chi(2)-test for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders was done.Results: The proportion of volunteers judged to be competent did not diminish by interval (3, 6, 9, and 12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores.Conclusions: After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to 1 year. AED skills do not deteriorate significantly and 90% of volunteers remain competent up to 1 year. [ABSTRACT FROM AUTHOR]

Background: Cardiac arrest due to ventricular arrhythmia in the absence of a reversible cause or contraindication has been a class I indication for insertion of an implantable cardioverter defibrillator since 1998. We compared and contrasted the use of implantable cardioverter defibrillator therapy in Canada and the United States among adults who survived a cardiac arrest. Method: Data on hospital separations from April 1, 1994 through March 31, 2003 were obtained from the Health Person-Oriented Information Database maintained by Statistics Canada and from the US National Hospital Discharge Survey on all patients with a primary diagnosis of cardiac arrest, ventricular fibrillation or ventricular flutter for the same 9-year period. We excluded all records of patients with a secondary diagnosis of acute myocardial infarction. Results: In Canada, 3793 patients survived to discharge after a cardiac arrest; 628 (16.6%) of these were implanted with a cardioverter defibrillator before discharge. The implant rate rose steadily from 5.4% in 1994/95 to 26.7% in 2002/03. In the United States, 23 688 (30.2%) of 78 538 such survivors received an implantable cardioverter defibrillator before discharge. Logistic regression analysis indicated that sex, age, fiscal year, the hospital's teaching status, hospital size and patient history of heart failure were positive predictors of implantable cardioverter defibrillator implantation. Age, renal failure, liver failure and cancer were negative predictors of receiving an implantable cardioverter defibrillator. Interpretation: The rate of use of implantable cardioverter defibrillator therapy for cardiac arrest survivors in Canada is increasing, but still is lower than the rate in the United States. [ABSTRACT FROM AUTHOR]

Background: We have observed a higher than expected rate of Sprint Fidelis model 6949 lead failures in our practice.Objective: The aim of this study was to assess the performance of small-diameter Sprint Fidelis high-voltage ICD leads.Methods: The actuarial survival of Sprint Fidelis model 6949 leads implanted at our center was compared with that of the Sprint Quattro Secure model 6947. The United States Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) database was searched for Sprint Fidelis models.Results: The survival of 583 Sprint Fidelis 6949 leads implanted at our center between September 2004 and February 2007 was significantly less than 285 Sprint Quattro Secure model 6947 leads implanted by us between November 2001 and February 2007 (P = .005). Six patients presented with Sprint Fidelis lead failure 4-23 months after implant. Five of the six patients experienced multiple inappropriate shocks associated with pace-sense conductor and coil fractures; the sixth patient had a fixation mechanism failure. The MAUDE search rendered reports for 679 Sprint Fidelis leads. The most frequent complaints or observations were inappropriate shocks (33%), high impedance (33%), and fracture (35%). Of 125 leads analyzed by the manufacturer, 62 involved fracture of the pace-sense conductor or coil and the high-voltage (defibrillation) conductor.Conclusions: The Sprint Fidelis high-voltage lead appears to be prone to early failure. Its use should be limited until the failure mechanism is identified and corrected. Patients should be evaluated quarterly, and automatic lead test features should be enabled. While more data are needed, routine prophylactic replacement of intact, normally functioning Sprint Fidelis leads does not appear justified. [ABSTRACT FROM AUTHOR]

Abstract  Electrical devices, Cardiac Resynchronization Therapy (CRT) pacemakers, the Implantable Cardiac Defibrillator (ICD) and a combination of both, constitute an important line of treatment in the therapy of moderate to severe chronic heart failure. The effectiveness of these devices in the treatment of acute decompensated heart failure has yet to be systematically evaluated. However, the beneficial clinical effects of CRT translate into a marked reduction of heart failure-related hospitalization. Devices also offer unique diagnostic applications by continuous measurement of clinically useful physiological parameters over time. Of particular interest, monitoring of intrathoracic impedance and right ventricular pressures allows to detect changes in volume load in an early stage prior to the development of clinical symptoms. This information could be helpful to stop further progression to acute cardiac decompensation and to avoid hospitalization and acute clinical events. Using modern telecommunication technology, patients can also be remotely monitored in their daily living environment. In consequence, the incorporation of device technology into heart failure management programs calls for a close cooperation between heart failure specialists and electrophysiologists. This review addresses therapeutic and diagnostic aspects of device therapies in the context of acute heart failure. [ABSTRACT FROM AUTHOR]

Introduction: Recent recalls of pacemakers and defibrillators cast a spotlight on product reliability. Universal postmortem device analysis could yield valuable information, but little data exist on the rate and feasibility of device examinations following death. This study investigated how morticians manage pacemakers and defibrillators and surveyed morticians and device patients regarding routine postmortem device interrogation and explantation. Methods and Results: Seventy-one morticians were surveyed on device interrogation and explantation practices. One hundred fifty patients presenting for routine device interrogation were interviewed regarding preferences for what should be done with devices postmortem and willingness to execute “device advance directives” authorizing analysis and retrieval. The average number of devices annually explanted per mortician was 7 ± 10 (range = 1 to 50). The most common methods of disposal were placement in medical waste (44%) and donation for human reimplantation in developing nations (18%). Only 4% of morticians reported ever returning devices to manufacturers, but 87% agreed that routine explantation and return of devices to manufacturers would be feasible. Eighty-seven percent of device patients had no understanding of how their device would be handled after death. However, a majority (82%) indicated a willingness to have their device interrogated after death, and most (79%) were willing to have it returned to manufacturers. Willingness was not associated with age, sex, time since device implantation, or device type. Conclusions: Implantable pacemakers and defibrillators are rarely analyzed after patients die. Systematic postmortem device retrieval appears feasible and acceptable to morticians and patients. Further efforts are needed to implement universal postmortem device evaluation. [ABSTRACT FROM AUTHOR]

Background: The placement of automated external defibrillators (AEDs) in schools and public sporting venues is a growing national trend. Objective: To determine the prevalence and use of AEDs in Washington State high schools and to examine the existing emergency preparedness for sudden cardiac arrest (SCA). Design: Cross-sectional survey. Setting: High schools in Washington State. Participants: The principal at each high school in the Washington Interscholastic Activities Association (n = 407) was invited to complete a web-based questionnaire using the National Registry for AED Use in Sports (http://www.AEDSPORTS.com). Main outcome measurements: The primary outcome measures studied included AED prevalence and location, funding for AEDs, AED training of school personnel, coordination of AED placement with local emergency response agencies, and prior AED use. Results: 118 schools completed the survey (29% response rate). 64 (54%) of the schools have at least one AED on school grounds (mean 1 .6, range 1-4). The likelihood of AED placement increased with larger school size (p = 0.044). 60% of AEDs were funded by donations, 27% by the school district and 11% by the school or athletic department itself. Coaches (78%) were the most likely to receive AED training, followed by administrators (72%), school nurses (70%) and teachers (48%). Only 25% of schools coordinated the implementation of AEDs with an outside medical agency and only 6% of schools coordinated with the local emergency medical system. One school reported having used an AED previously to treat SCA in a basketball official who survived after a single shock. The estimated probability of AED use to treat SCA was 1 in 154 schools per year. Conclusions: Over half of Washington State high schools have an AED on school grounds. AED use occurred in <1% of schools annually and was effective in the treatment of SCA. Funding of AED programmes was mostly through private donations, with little coordination with local emergency response teams. Significant improvement is needed in structuring emergency response plans and training targeted rescuers for an SCA in the high-school setting. [ABSTRACT FROM AUTHOR]

A mobile ecg-system for an online analysis of electrocardiogram signals is presented. The analysis is based on an energy-saving procedure, which offers the advantage of an acceptable undersampling of the signal, and which allows an interaction between the measuring electronic and the radio-bound analysis-computer. In this interaction both the front-end circuit in the ecg-sensor and the A/D converter, which is embedded in the ATmega8L, are steered by the analysis computer. The data requirement of the computer is also dynamically adapted to the requirements of the analysis-program. The developed ecg-system supplies successful characterisations of measured electrocardiograms. [ABSTRACT FROM AUTHOR]

Background: The strength duration curve for endocardial stimulation has been extensively studied. Little information is available on the left ventricular epicardial strength duration curve. In view of the large number of patients treated with resynchronization therapy, left ventricular epicardial stimulation parameters have practical importance. Methods: Twelve patients who underwent implant of a biventricular defibrillator were available for at least 4 months of follow up and accurate determination of strength duration curves were studied. Strength duration curves were constructed at 30 days (subacute phase) and 4 or more months (chronic phase) after the implant for right ventricular endocardial, left ventricular epicardial unipolar, and left ventricular bipolar stimulation. The goal was to determine the chronaxie, which correlates with the most economical stimulation. Results: There was no significant difference between the right ventricular endocardial and left ventricular epicardial bipolar chronaxie (P = 0.57 subacute and 0.6 chronic) or right ventricular endocardial and left ventricular unipolar chronaxie (P = 0.93 subacute and 0.92 chronic). Most chronaxie values were lower than the factory default values. Conclusion: The left ventricular unipolar or bipolar epicardial chronaxie is not significantly different from the right ventricular endocardial chronaxie. Both values are lower than the pulse duration used as default setting in most devices as well as in clinical practice. Individual determination of the chronaxie could lead to energy savings. [ABSTRACT FROM AUTHOR]

Malfunction of a dual chamber system pacemaker due to a current leak in the output circuitry leading to a rapid decline in battery longevity is described. Serial pulse amplitude alterations in defined device configurations enabled location of the defect in the 2.5-V output voltage level; the current leak disappeared in the 5-V output voltage level, and recurred in the 7.5-V output voltage level which combines both 2.5-V and 5-V output circuitries. Reprogramming of pulse amplitudes rectified device malfunction. Circuitry reprogramming of pacemakers with faulty unexplained high battery current can circumvent early replacement in management of device malfunction. [ABSTRACT FROM AUTHOR]

The article focuses on ethical issues in defibrillator patients' quality of life. It examines the mental and social consequences that may follow implantation of cardioverter defibrillators. It notes the lack of standards for educating defibrillator patients about their condition or about the device itself. It provides recommendations on how to improve patients' quality of life.

Objectives: The purpose of this study was to evaluate potential interference between the Pill-cam™ video-capsule and implanted cardio-defibrillators (ICD) in both in vitro and in vivo test environments. Methods: Phase I consisted of in vitro testing utilized 6 ICD models. Each was placed in a saline gel bath in conjunction with a tool designed to emit the same wave length as the Pill-Cam™ (the Test Cap). Tests were performed at both the manufacturer's nominal and most sensitive settings with the test probe placed at 1, 5, 10, and 15 cm from three different points. There were emissions of 10-, 30-, and 60- second duration at each location. Phase II was the in vivo study utilizing patients with implanted ICDs for standard clinical reasons who were undergoing evaluation with the Test Cap. Results: In Phase I, 864 tests were performed involving the 6 ICDs. There was totally normal behavior in 5 of the devices. The Biotronik Belos (Berlin, Germany) demonstrated oversensing and delivery of inappropriate therapy. In phase II, 6 patients underwent a total number of 288 tests (48 in each patient). There were 4 men and 2 women, mean age 61 (33–77) and none demonstrated any adverse interactions. Conclusions: In patients with devices identical to those evaluated that showed no interference, the use of the Pill-Cam is safe. However, in patients with a Biotronik Belos ICD (or any other nontested ICD) the use of the Pill-Cam should be done only in-hospital, after suspended ICD therapy and in conjunction with close monitoring. [ABSTRACT FROM AUTHOR]

Background: In cardiac resynchronization therapy (CRT), the atrio-ventricular (AV) and interventricular (VV) intervals have to be optimized. For maximal optimization, the paced and sensed AV intervals have to be determined. We hypothesized that the morphology of the paced QRS complex at the optimal paced AV interval (PAV) can be used to determine the optimal sensed AV (SAV) interval in patients with normal AV conduction. Patients and Methods: In 16 patients with implanted CRT devices, the optimal PAV and V-V interval were determined by invasive measurement of left ventricle (LV) dP/dtmax. A 12-lead electrocardiogram (ECG) was recorded at the optimum setting. Subsequently, during atrial sensing ventricular pacing, the SAV interval was changed until the QRS morphology was identical to the morphology at the optimal PAV interval. The optimal SAV interval was verified by repeated measurement of LV dP/dtmax. Results: By optimization of the PAV and VV interval, the LV dP/dtmax increased from 639 ± 204 to 789 ± 223 mmHg/s (+23%; P = 0.0000002). The optimized PAV was 149 ± 19 ms; the optimized SAV was 100 ± 20 ms and the corresponding LV dP/dtmax at this interval was 774 ± 204 ms (+21%; P = 0.000004). LV dP/dtmax at optimized SAV − 20 ms and optimized SAV + 20 ms was 747 ± 213 mmHg/s (P = 0.00004) and 751 ± 203 mmHg/s (P = 0.0000003), respectively. The mean difference in optimized PAV and optimized SAV was 49 ± 17 ms, ranging from 20 to 80 ms. Conclusions: The QRS morphology at optimized PAV can be used as a template to determine the optimal SAV, provided that the patient has normal AV conduction. [ABSTRACT FROM AUTHOR]

This article is going to be somewhat different than the typical article you might read on the treatment of heart failure. My goal is to get you to think in a different way about the use of primary prevention implantable cardioverter defibrillators and β-blockers in patients with left ventricular dysfunction. Specifically, using the results from 3 landmark clinical trials—MADIT II, SCD-HeFT, and COMET—I am going to discuss the economic, ethical, and legal principles that underpin the use of these 2 therapies in patients with heart failure. [Copyright &y& Elsevier]

Forty-nine patients scheduled for implantable cardioverter defibrillator (ICD) implantation completed self-report psychological questionnaires prior to surgery and at 2, 4 and 6 months after surgery. The most common psychological problem identified was anxiety, with clinically significant cases based on the Depression Anxiety and Stress Scale (DASS) ranging between 26% and 34%. Clinically significant depression ranged between 8% and 20%. Anxiety sensitivity was associated with high levels of anxiety, depression and stress at baseline, but not at follow-up assessments. It is possible that within this population anxiety sensitivity is associated with distress during high-threat situations, but the relationship diminishes once the threat has passed. In addition, the reassurance provided by the ICD may reduce negative perceptions of symptoms, promoting psychological adaptation. [ABSTRACT FROM AUTHOR]

The article presents a study emergency preparedness and management of sudden cardiac arrest (SCA) in high school and college athletic programs. It has been explained that SCA is the leading cause of death in young athletes. With this, it has been recommended that comprehensive emergency planning is essential for high school and college athletic programs to ensure an efficient and structured response to SCA. The important elements of an emergency action plan include establishing an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and an access to automated external defibrillators use.

Background: In this study we evaluate load-independent ventricular function during left ventricular assist device (LVAD) support based solely on telemetered measurements of left ventricular (LV) pressure, which has not been reported previously. Methods: Adult sheep underwent placement of an axial-flow LVAD, a telemetered LV pressure manometer and instruments for pressure–volume analysis. In unsedated sheep, the simultaneous determination of both stroke work/end-diastolic volume (SW/EDP [PRSW]; slope: MW) and LV triple-product (TP = LVSP · dP/dt · HR) vs LV end-diastolic pressure (TP/EDP; slope: MTP) were performed before and then after β1-blockade using the LVAD to acutely unload the ventricle. Results: LVAD support (4.5 ± 0.31 liters/min) was maintained for 1 week. During LV unloading “runs,” the LVAD flow (QV) increased (up to 5.8 ± 0.71 liters/min), although there were decreases in SW (3,061 ± 747 to 1,556 ± 410 mm Hg ml−1), LV TP (3,127 ± 397 to 1,019 ± 335 × 105) and LV EDP (18.2 ± 1.2 to 9.7 ± 1.8 mm Hg). The TP/EDP and SW/EDV relationships established during the unloading runs were highly linear (R 2 up to 0.95) and their slopes were reduced by β-adrenergic blockade (p < 0.001). Conclusions: The TP/EDP relationship established during LVAD unloading of the LV was load-independent and sensitive to changes in cardiac inotropy, and correlated with PRSW. [Copyright &y& Elsevier]

Commercial aviation in-flight emergencies are relatively common, so it is likely that a doctor travelling frequently by air will receive a call for help at some stage in their career. These events are stressful, even for experienced physicians. The present paper reviews what is known about the incidence and types of in-flight emergencies that are likely to be encountered, the international regulations governing medical kits and drugs, and the liability, fitness and indemnity issues facing ‘Good Samaritan’ medical volunteers. The medical and aviation literature was searched, and information was collated from airlines and other sources regarding medical equipment available on board commercial aircraft. Figures for the incidence of significant in-flight emergencies are approximately 1 per 10–40 000 passengers, with one death occurring per 3–5 million passengers. Medically related diversion of an aircraft following an in-flight emergency may occur in up to 7–13% of cases, but passenger prescreening, online medical advice and on-board medical assistance from volunteers reduce this rate. Medical volunteers may find assisting with an in-flight emergency stressful, but should acknowledge that they play a vital role in successful outcomes. The medico-legal liability risk is extremely small, and various laws and industry indemnity practices offer additional protection to the volunteer. In addition, cabin crew receive training in a number of emergency skills, including automated defibrillation, and are one of several sources of help available to the medical volunteer, who is not expected to work alone. [ABSTRACT FROM AUTHOR]

Abstract: The artificial heart is no more a dream but a reality. Over the last 40 years, many circulatory assist devices have been developed. First were the pneumatic devices, external or implantable, providing uni- or biventricular support; next were the partially implantable electromecanical devices. We went from the first generation of devices with all components (pump, energy power, control system) outside of the body to the second generation of devices with the pump and the motor implanted inside the body. Recently, the third generation of artificial hearts appeared with all components implanted inside the body allowing better mobility and quality of life. Results depend on the indication and on the kind of artificial heart implanted: partial (native heart still in place) or total (native heart removed). Essentially developped as a bridge to transplant, the artificial heart is now allowed as destination therapy. [Copyright &y& Elsevier]

A pivotal component in automated external defibrillators (AEDs) is the detection of ventricular fibrillation (VF) by means of appropriate detection algorithms. In scientific literature there exists a wide variety of methods and ideas for handling this task. These algorithms should have a high detection quality, be easily implementable, and work in realtime in an AED. Testing of these algorithms should be done by using a large amount of annotated data under equal conditions. For our investigation we simulated a continuous analysis by selecting the data in steps of 1 s without any preselection. We used the complete BIH-MIT arrhythmia database, the CU database, and files 7001-8210 of the AHA database. For a new VF detection algorithm we calculated the sensitivity, specificity, and the area under its receiver operating characteristic curve and compared these values with the results from an earlier investigation of several VF detection algorithms. This new algorithm is based on time-delay methods and outperforms all other investigated algorithms. [ABSTRACT FROM AUTHOR]

There has been great controversy related to performance of magnetic resonance imaging in patients with pacemakers and implantable cardiac defibrillators. Recent questions have been raised regarding whether contraindications are absolute or relative. Although there are theoretical as well as documented issues relating to device malfunction, data suggest that scanning patients with devices may be feasible when important clinical questions need to be addressed by following strict guidelines. Advanced knowledge and understanding of electrophysiologic as well as magnetic resonance imaging-related issues, and a multidisciplinary, collaborative approach is required to further define the role of MR in patients with pacemakers and implantable cardiac defibrillators. [ABSTRACT FROM AUTHOR]

Background: There is no clear methodology for implantation of an internal cardioverter-defibrillator (ICD) in infants and small children. The aim of this study was to assess efficacy and safety of an extracardiac ICD implantation technique in pediatric patients. Patients and Methods: An extracardiac ICD system was implanted in eight patients (age: 0.3–8 years; body weight: 4–29 kg). Under fluoroscopic guidance a defibrillator lead was tunneled subcutaneously starting from the anterior axillar line along the course of the 6th rib until almost reaching the vertebral column. After a partial inferior sternotomy, bipolar steroid-eluting sensing and pacing leads were sutured to the atrial wall (n = 2) and to the anterior wall of the right ventricle (n = 8). The ICD device was implanted as “active can” in the upper abdomen. Sensing, pacing, and defibrillation thresholds (DFTs) as well as impedances were verified intraoperatively and 3 months later, respectively. Results: In seven of eight patients, intraoperative DFT between subcutaneous lead and device was <15 J. In the eighth patient ICD implantation was technically not feasible due to a DFT >20 J. During follow-up (mean 14.5 months) appropriate and effective ICD discharges were noted in two patients. DFT remained stable after 3 months in four of six patients retested. A revision was required in one patient due to lead migration and in another patient due to a lead break. Conclusions: In infants and small children, extracardiac ICD implantation was technically feasible. Experience and follow-up are still limited. The course of the DFT is unknown, facing further growth of the patients. [ABSTRACT FROM AUTHOR]

Background: Pacemaker-induced superior vena cava (SVC) syndrome is a rare but serious complication of permanent pacemaker implantation. Because of its rarity, little is known about the long-term prognoses of such patients. Methods: Five patients, mean age 62 ± 11.4 years, with pacemaker-induced SVC syndrome for more than 10 years were investigated. The clinical evaluation included: exercise testing, thrombophilia lab tests, and a chest CT. Results: Two of the patients manifested complications of SVC syndrome which included thoracoabdominal subcutaneous collaterals. One of these patients simultaneously developed an increase in the pacing threshold which required the implantation of epicardial leads. Three of the five patients had normal age-adjusted VO2 AT und VO2 max. Four of the patients were both heterozygous for a polymorphism of PAI-1 and were homozygous for a polymorphism of t-PA. One of these patients also was heterozygous for a polymorphism of factor V and glycoprotein IIb/IIIa. The chest CTs revealed extensive and varying collateral circulation patterns in all of the patients. Conclusions: The development of pacemaker-induced SVC syndrome is the result of various predisposing factors including thrombophilia. Many patients retain normal age-adjusted cardiopulmonary capacity and demonstrate stable clinical findings on the long-term as the result of the development of extensive collateral vessel systems. The most serious complication was the combination of SVC syndrome and the simultaneous malfunctioning of one of the leads requiring implantation of a new lead. [ABSTRACT FROM AUTHOR]

Person-to-person psychosocial interventions (e.g., psychological, social) enhance the well-being of implantable cardioverter defibrillator (ICD) patients. Computerized care, though, represents an opportunity to further capitalize on techniques that have already been deemed effective. This includes the provision of tailored, effective patient education; reducing device-specific anxiety; and enhancing social support networks. The aim of this paper is to identify the ways in which computerized psychosocial care could potentially enhance the well-being of ICD recipients. For example, computers may be particularly adept at providing patient education due to the ease in which content can be adapted to meet patient needs. Further, evidenced-based treatments for anxiety and depression (e.g., cognitive behavioral therapy) have demonstrated good applicability to computerized formats. Social support can also be provided online in the form of bulletin boards, email list-servs, or structured online support groups. Despite the existence of some limitations, the use of computers in affecting psychosocial outcomes in implantable defibrillator recipients warrants greater attention. [ABSTRACT FROM AUTHOR]

The article discusses the means to prevent sudden cardiac death (SCD). The first clinical event of the disease is often fatal, thus, it requires primary prevention. This basic move calls for the identification of future sudden death victims before the first arrhythmia episode. The used of cardioverter-defibrillator has been proven to be effective for primary prevention of SCD in patients with severely reduced left ventricular function.

Objectives: Aim of this work is to study the impact of left ventricular rotary blood pump assistance, on energetic variables, when mechanical ventilation (MV) of the lungs is applied.Methods: Computer simulation was used to perform this study. Lumped parameter models reproduce the circulatory system. Variable elastance models reproduce the Starling's law of the heart for each ventricle. After the reproduction of ischemic heart disease left ventricular assistance was applied using a model of rotary blood pump. The pump speed was changed in steps and was assumed to be constant during each step. The influence of mechanical ventilation was introduced by different values of positive mean thoracic pressure.Results: The increase of the rotational speed has a significant influence on some ventricular energetic variables. In fact it decreased left ventricular external work, left and right ventricular pressure-volume area and the left ventricular efficiency. Finally, it increased the right ventricular efficiency but had no influence on the right ventricular external work. The increase of thoracic pressure from -2 to +5 mmHg caused a significant decrease of external work, pressure-volume area (right ventricular pressure-volume area dropped up to 50%) and an increase of right ventricular efficiency (by 40%) while left ventricular efficiency remained almost stable.Conclusions: Numerical simulation is a very suitable tool to predict changes of not easily measurable parameters such as energetic ventricular variables when mechanical assistance of heart and/or lungs is applied independently or simultaneously. [ABSTRACT FROM AUTHOR]

Objectives: In this paper, we present a unified electrodynamic heart model that permits simulations of the body surface potentials generated by the heart in motion. The inclusion of motion in the heart model significantly improves the accuracy of the simulated body surface potentials and therefore also the 12-lead ECG.Methods: The key step is to construct an electromechanical heart model. The cardiac excitation propagation is simulated by an electrical heart model, and the resulting cardiac active forces are used to calculate the ventricular wall motion based on a mechanical model. The source-field point relative position changes during heart systole and diastole. These can be obtained, and then used to calculate body surface ECG based on the electrical heart-torso model.Results: An electromechanical biventricular heart model is constructed and a standard 12-lead ECG is simulated. Compared with a simulated ECG based on the static electrical heart model, the simulated ECG based on the dynamic heart model is more accordant with a clinically recorded ECG, especially for the ST segment and T wave of a V1-V6 lead ECG. For slight-degree myocardial ischemia ECG simulation, the ST segment and T wave changes can be observed from the simulated ECG based on a dynamic heart model, while the ST segment and T wave of simulated ECG based on a static heart model is almost unchanged when compared with a normal ECG.Conclusions: This study confirms the importance of the mechanical factor in the ECG simulation. The dynamic heart model could provide more accurate ECG simulation, especially for myocardial ischemia or infarction simulation, since the main ECG changes occur at the ST segment and T wave, which correspond with cardiac systole and diastole phases. [ABSTRACT FROM AUTHOR]

The article focuses on the biophysical model approach for the analysis of electrocardiograms during atrial fibrillation. The standard 12-lead electrocardiogram is the most common noninvasive diagnostic tool for electrically manifested cardiac abnormalities like arrhythmias. Modeling of the normal activation process depends on the properties of the membrane kinetics and on the way cells are electrically coupled.

The article discusses the interpretation of intracardiac electrograms which are recorded from different parts of the atria during atrial fibrillation (AF). It is important to interpret fibrillation electrograms to understand the pathophysiologic mechanisms of AF and to monitor the effects of ablation procedures and drug treatment. Template matching is a well known processing technique which provides objective characterization of fibrillation electrograms.

Device-based care such as implantable cardioverter-defibrillators and cardiac resynchronization therapy extends congestive heart failure (CHF) care into a new era. The purpose of this paper is 2-fold: (1) to review the development of device-based CHF management and the implications from a medical and patient management perspective, and (2) to provide assessment and treatment approaches on how to clinically manage patient outcomes optimally. Quality of life, depression, and anxiety are targeted as concerns for patients with CHF and cardiac resynchronization therapy/implantable cardioverter-defibrillators. Brief clinic-based interview questions and formal assessment tools are reviewed. Furthermore, a cognitive-behavioral paradigm using the "Appropriate Education, Behavioral Support, and Cognitive Coping" (ABC) model is proposed to aid health care professionals in addressing patients" device-specific concerns. Available research suggests the need for future studies assessing the efficacy of cognitive-behavioral treatments in patients with CHF and cardiac resynchronization therapy/implantable cardioverter-defibrillators. [ABSTRACT FROM AUTHOR]

Background: Athough clinical trials have expanded implantable defibrillator (ICD) indications, octogenarians have been poorly represented in these studies. Overall, survival in this subgroup is ill-defined. Methods: Consecutive patients ≥80 years of age at ICD implant between July 1995 and September 2003 were retrospectively analyzed. Kaplan-Meier survival analysis was performed, and mortality predictors were identified. Consecutive nonelderly patients aged 60 to 70 years (60-70 group) who received ICDs over the same period were analyzed as a reference. Mortality predictors in the ≥80 group were compared to the 60-to-70 group. Results: A total of 348 patients (age, ≥80 years [n = 107]; age, 60-70 years [n = 241]) were included. Mean follow-up time for the entire cohort was 3.3 ± 2.2 years. Other than the estimated glomerular filtration rate (eGFR) (58 ± 22 vs 66 ± 22 mL/min) in the ≥80 group versus the 60-to-70 group, no other differences in baseline characteristics were observed. Median survival was 4.2 years after implant in the ≥80 group versus 7 years in the 60-to-70 group (P < .01). Mortality predictors in the ≥80 group included ejection fraction (EF) ≤30% (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.3-4.0) and eGFR <60 mL/min (HR, 2.2; 95% CI, 1.3-3.7). In the 60-to-70 group, EF ≤30% (HR, 2.7; 95% CI, 1.6-4.5), eGFR <60 mL/min (HR, 3.4; 95% CI, 2.2-5.3), diabetes (HR, 1.8; 95% CI, 1.9-2.9), and QRS width >120 ms (HR, 2.1; 95% CI, 1.4-3.3) predicted mortality. QRS >120 ms and diabetes were not predictors in octogenarians (HR, 1.1 and 1.5, respectively; 95% CI, 0.7-1.9 and 0.8-2.7, respectively). Analysis of octogenarians subgrouped by EF ≤30% and eGFR <60 mL/min identified patients whose median survival was 6.1 years (neither predictor present; n = 28), 4.7 years (either predictor present; n = 46), and 19 months (both predictors present; n = 33) (P < .01 between groups). Survival analysis in the ≥80-year-old cohort grouped by eGFR quartile identified groups with median survival of 5.6, 4.7, 3.5 years, and 18 months, respectively, in the highest to the lowest eGFR quartile (>75, 61-75, 41-60, and <41 mL/min). Conclusions: Median survival in octogenarian ICD recipients is greater than 4 years. In addition to baseline EF, eGFR is a strong predictor of mortality in elderly ICD candidates. These easily identifiable clinical variables may assist clinical decision making and help to provide appropriate post-ICD implant survival expectations in this elderly patient group. [Copyright &y& Elsevier]

The article focuses on the impact of recalls and field corrections by the U.S. Food and Drugs Administration (FDA) to the scientific work related to automatic external defibrillators (AEDs). The retrospective analysis affected by corrections is entitled "Recalls and Safety Alerts Affecting Automated External Defibrillators," by William H. Maisel, Jignesh S. Shah, and Beth Israel. The FDA disagree on some statement of the authors such as the inability of manufacturers to track AED unit.

Objectives: The purpose of this randomized study was to determine whether a strategically chosen standardized set of programmable settings is at least as effective as physician-tailored choices, as measured by the shock-related morbidity of implantable cardioverter-defibrillator (ICD) therapy. Background: Programming of ventricular tachyarrhythmia (ventricular tachycardia [VT] or ventricular fibrillation [VF]) detection and therapy for ICDs is complex, requires many choices by highly trained physicians, and directly influences the frequency of shocks and patient morbidity. Methods: A total of 900 ICD patients were randomly assigned to standardized (EMPIRIC, n = 445) or physician-tailored (TAILORED, n = 455) VT/VF programming and followed for 1 year. Results: The primary end point was met: the adjusted percentages of both VT/VF (22.3% vs. 28.7%) and supraventricular tachycardia or other non-VT/VF event episodes (11.9% vs. 26.1%) that resulted in a shock were non-inferior and lower in the EMPIRIC arm compared to the TAILORED arm. The time to first all-cause shock was non-inferior in the EMPIRIC arm (hazard ratio = 0.95, 90% confidence interval 0.74 to 1.23, non-inferiority p = 0.0016). The EMPIRIC trial had a significant reduction of patients with 5 or more shocks for all-cause (3.8% vs. 7.0%, p = 0.039) and true VT/VF (0.9% vs. 3.3%, p = 0.018). There were no significant differences in total mortality, syncope, emergency room visits, or unscheduled outpatient visits. Unscheduled hospitalizations occurred significantly less often (p = 0.001) in the EMPIRIC arm. Conclusions: Standardized empiric ICD programming for VT/VF settings is at least as effective as patient-specific, physician-tailored programming, as measured by many clinical outcomes. Simplified and pre-specified ICD programming is possible without an increase in shock-related morbidity. [Copyright &y& Elsevier]

Background: The cephalic vein approach is a preferred route for endocardial lead implantation; however, it is associated with a significant failure rate. Anatomic abnormalities likely play an important role, but specific features have not been well characterized. Methods: Color Doppler ultrasonography was performed in 82 consecutive patients prior to endocardial lead implantation. Venous diameter, depth, flow velocity, and morphology were evaluated and comparisons made between the successful and failed implantations at various stages of the procedure. Results: Endocardial lead implantation was unsuccessful in 14 patients (17%), with eight patients of venous isolation failure, 4 patients of cannulation failure, and 2 patients of guidewire crossing failure. Venous diameter was found to be the only independent predictor for isolation and implantation failure. The best cutoff value of cephalic venous diameter to predict unsuccessful cephalic venous approach was ≤2.2 mm. In total, there were 10 patients with extensive cephalic vein tortuosity. In seven of these 10 patients, the incidence of standard guidewire crossing failure was significantly higher than that without a tortuous cephalic vein (7/10 vs 6/60, P < 0.001). After switching to a hydrophilic guidewire, crossing and navigation were successful in five of the seven patients. Conclusions: Color Doppler imaging is useful to identify cephalic vein characteristics. A small venous diameter is the ultrasonographic predictor for failure of cephalic vein approach. A tortuous venous morphology is associated with a high incidence of guidewire crossing failure, which can be mostly overcome by using a hydrophilic guidewire. [ABSTRACT FROM AUTHOR]

Background: Interference between pacemaker (PM) lead and tricuspid apparatus may cause tricuspid regurgitation (TR). However, data regarding TR in patients with implanted PM are controversial. Our aim is to find out the degree of TR in a group of patients before and following PM implantation in a prospective manner. Methods: The study group consisted of the patients referred for implantation of permanent PM or implantable cardioverter defibrillator (ICD). All patients underwent two-dimensional and Doppler echocardiographic evaluation before and after device implantation. The severity of TR was qualitatively classified into four groups as normal or trivial, mild, moderate, or severe. All studies were reviewed for accuracy by a second independent interpreter. Results: Sixty-one patients (mean age 53 ± 8 years, 44 male) referred for PM (n = 55) or ICD (n = 6) implantation consisted of the study population. Echocardiographic degree of TR was mild in 21 (70%), moderate in 7 (23%) and severe in 2 (7%) patients before PM implantation. Following device implantation, mild TR was noted in 23 (76%), moderate in 10 (33%), and severe in 2 (6%) cases. After the procedure, the TR severity was increased from normal/trivial to mild in 5 (16%) cases and from mild to moderate in 3 (10%). There was no worsening of the severity of TR in patients with moderate regurgitation following device implantation. The severity of TR did not change at a mean follow-up of 6 ± 3 months. Conclusions: New or worsening TR is relatively rare after PM implantation. It is not associated with an acute worsening or clinical deterioration. But echocardiographic follow-up is recommended to monitor other complications in chronic phase. [ABSTRACT FROM AUTHOR]

Objectives: We sought to evaluate the cost implications of the implantable cardioverter-defibrillator (ICD), using utilization, cost, and survival data from the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II. Background: This trial showed that prophylactic implantation of a defibrillator reduces the rate of mortality in patients who experienced a previous myocardial infarction and low left ventricular ejection fraction. Given the size of the eligible population, the cost effectiveness of the ICD has substantial implications. Methods: Our research comprises the cost-effectiveness component of the randomized controlled trial, MADIT-II, based on utilization, cost, and survival information from 1,095 U.S. patients who were assigned randomly to receive an ICD or conventional medical care. Utilization data were converted to costs using a variety of national and hospital-specific data. The incremental cost-effectiveness ratio (iCER) was calculated as the difference in discounted costs divided by the difference in discounted life expectancy within 3.5 years. Secondary analyses included projections of survival (using three alternative assumptions), corresponding cost assumptions, and the resulting cost-effectiveness ratios until 12 years after randomization. Results: During the 3.5-year period of the study, the average survival gain for the defibrillator arm was 0.167 years (2 months), the additional costs were $39,200, and the iCER was $235,000 per year-of-life saved. In three alternative projections to 12 years, this ratio ranged from $78,600 to $114,000. Conclusions: The estimated cost per life-year saved by the ICD in the MADIT-II study is relatively high at 3.5 years but is projected to be substantially lower over the course of longer time horizons. [Copyright &y& Elsevier]

Summary: Public access defibrillation (PAD) is a promising strategy to fight sudden cardiac death. The Austrian Red Cross provided automated external defibrillators (AEDs) and basic life support (BLS) training as an “all inclusive package” combined with on site consultation and maintenance with annual retraining as a part of a nationwide PAD programme. A multi media campaign was started to promote the package and to increase awareness about sudden cardiac death. Data about the campaign, its recognition by the public in Austria and the number of packages were recorded. Sixty-eight percent of the Austrian public above the age of 15 years were able to recall the multi media campaign. Comparing the periods before and after the campaign, the number of website hits climbed significantly from 2931 hits/month (1866–6168) to 4812 hits/month (3432–13,434) (p =0.0276). The number of AED services implemented before the campaign increased significantly (p =0.0026) in the time after the campaign. Therefore, we conclude that a multi media campaign is useful to stimulate public discussion and it encourages companies to buy “all inclusive packages” containing AEDs, BLS training, on site consultation and maintenance. These measures represent a possible first step in introducing PAD but it seems that they have to be continued on a constant basis. [Copyright &y& Elsevier]

Improvements in implantable ventricular assist device (VAD) performance will be required to obtain patient outcomes that are comparable with those of heart transplantation. The HeartQuest VAD (WorldHeart, Oakland, CA, U.S.A.) is an advanced device, with full magnetic suspension of the rotor, designed to address specific clinical shortcomings in existing devices and to maximize margins of safety and performance for an implantable assist device. The device dimensions are 35 × 75 mm, with a total weight of 440 g. The system was designed using extensive computer modeling of device function; a total of two iterations of device prototypes were built before building the clinical version. Animal study results have been very promising, with over 30 calf studies completed. Plasma-free hemoglobin levels returned to preoperative levels, and other hematology results were in the normal ranges. Highlights include clean surfaces seen in a 116-day experiment with no anticoagulation after day 43. Feasibility clinical trials are planned to start in 2006. [ABSTRACT FROM AUTHOR]

The magnetically levitated (Mag-Lev) centrifugal rotary blood pump (CRBP) with two-degrees-of-freedom active control is promising for safe and long-term support of circulation. In this study, Mag-Lev CRBP controllability and impeller behavior were studied in the simulated heart failure circulatory model. A pneumatically driven pulsatile blood pump (Medos VAD [ventricular assist device]-54 mL) was used to simulate the left ventricle (LV). The Mag-Lev CRBP was placed between the LV apex and aortic compliance tank simulating LV assistance. The impeller behavior in five axes ( x, y, z, Θ, and Φ) was continuously monitored using five eddy current sensors. The signals of the x- and y-axes were used for feedback active control, while the behaviors of the other three axes were passively controlled by the permanent magnets. In the static mock circuit, the impeller movement was controlled to within ±10–±20 µm in the x- and y-axes, while in the pulsatile circuit, LV pulsation was modulated in the impeller movement with the amplitude being 2–22 µm. The amplitude of impeller movement measured at 1800 rpm with the simulated failing heart (peak LV pressure [LVP] = 70 mm Hg, mean aortic pressure [AoPmean] = 55 ± 20 mm Hg, aortic flow = 2.7 L/min) was 12.6 µm, while it increased to 19.2 µm with the recovered heart (peak LVP = 122 mm Hg, AoPmean = 100 ± 20 mm Hg, aortic flow = 3.9 L/min). The impeller repeated the reciprocating movement from the center of the pump toward the outlet port with LV pulsation. Angular rotation (Θ, Φ) was around ±0.002 rad without z-axis displacement. Power requirements ranged from 0.6 to 0.9 W. Five-axis impeller behavior and Mag-Lev controller stability were demonstrated in the pulsatile mock circuit. Noncontact drive and low power requirements were shown despite the effects of LV pulsation. The impeller position signals in the x- and y-axes reflected LV function. The Mag-Lev CRBP is effective not only for noncontact low power control of the impeller, but also for diagnosis of cardiac function noninvasively. [ABSTRACT FROM AUTHOR]

We have developed a tiny rotary centrifugal blood pump for the purpose of supporting circulation of children and infants. The pump is designed to provide a flow of 0.1–4.0 L/min against a head pressure of 50–120 mm Hg. The diameter of the impeller is 30 mm with six straight vanes. The impeller is supported by a hydrodynamic bearing at its center and rotated with a radial coupled magnetic driver. The bearing that supports rotation of the impeller of the tiny centrifugal blood pump is very critical to achieve durability, and clot-free and antihemolytic performance. In this study, computational fluid dynamics (CFD) analysis was performed to quantify the secondary flow through the hydrodynamic bearing at the center of the impeller and investigated the effects of bearing clearance on shear stress to optimize hemolytic performance of the pump. Two types of bearing clearance (0.1 and 0.2 mm) were studied. The wall shear stress of the 0.1-mm bearing clearance was lower than that of 0.2-mm bearing clearance at 2 L/min and 3000 rpm. This was because the axial component of the shear rate significantly decreased due to the narrower clearance even though the circumferential component of the shear rate increased. Hemolysis tests showed that the normalized index of hemolysis was reduced to 0.0076 g/100 L when the bearing clearance was reduced to 0.1 mm. It was found that the CFD prediction supported the experimental trend. The CFD is a useful tool for optimization of the hydrodynamic bearing design of the centrifugal rotary blood pump to optimize the performance of the pump in terms of mechanical effect on blood cell elements, durability of the bearing, and antithrombogenic performance. [ABSTRACT FROM AUTHOR]

Optimization of a magnetically suspended left ventricular assist device (LVAD) is crucial. We desire a totally implantable, long-life LVAD that delivers the necessary flow rate, pressure rise, and blood compatibility. By using a novel combination of passive and active magnetic bearings (AMBs), we have developed an axial flow LVAD prototype, the LEV-VAD, which provides an unobstructed blood flow path, preventing stagnation regions for the blood. Our current effort is focused on the optimization of the magnetic suspension system to allow for control of the AMB, minimizing its size and power consumption. The properties of the passive magnetic bearings and AMBs serve as parameter space, over which a cost function is minimized, subject to constraints such as suspension stability and sufficient disturbance rejection capabilities. The design process is expected to lead to the construction of a small prototype pump along with the necessary robust controller for the AMB. Sensitivity of the LVAD performance with respect to various design parameters is examined in-depth and an optimized, more compact LVAD prototype is designed. [ABSTRACT FROM AUTHOR]

Introduction: Atrial fibrillation impacts the clinical course of up to 50% of patients with advanced heart failure (HF) who are eligible for cardiac resynchronization therapy with a defibrillator (CRT-D). While RV-based defibrillators are available with advanced atrial diagnostics and therapies that provide rapid diagnosis and treatment of spontaneously occurring atrial tachycardia/fibrillation (AT/AF) episodes, there is no CRT-D device that combines atrial/ventricular and CRT therapies. Purpose: The purpose of the prospective multicenter RENEWAL® 3 AVT study is to assess the performance of atrial diagnostics and therapies used in combination with a CRT-D device. Methods: Enrolled patients were required to have indications for a CRT-D device and a documented episode of AT/AF within 12 months of enrollment. A total of 170 patients were enrolled over 9 months (85% male; mean age 72 ± 10 years; NYHA classification: 88% III, 12% IV; left ventricular ejection fraction [LVEF] mean 23 ± 6%; mean QRS duration 150 ± 25 msec; 78% ischemic etiology). The documented atrial arrhythmia was AF in 77% of patients. A total of 60% of patients had the CRT-D device placed for primary prevention of sudden death and 40% of patients had a history of ventricular arrhythmia in addition to HF. The device operates in the biventricular (BiV) triggered mode for sensed ventricular events associated with AF. Results: A total of 159 patients (95%) had a successful CRT-D implant. Over a mean follow-up of 5.7 ± 2.3 months, there were a total of 152 atrial shocks delivered in 108 patients for induced (93%) or spontaneous (7%) occurring episodes of AF. Spontaneously occurring AF was observed in 40 patients (25%). The rate of first shock conversion was 118/152 (78%, mean energy 11.6 ± 5.9 J). Overall shock therapy conversion rate was 138/152 (91%). The number of shock conversions resulting in sinus rhythm maintained for at least 2 minutes postshock was 87% for induced episodes. Therapy was delivered for spontaneous ventricular tachycardia/fibrillation in nine patients (6%). There was no instance of ventricular proarrhythmia associated with atrial shock therapies, undersensing of ventricular arrhythmias, or interruption of CRT therapy associated with the combined device. Conclusions: In CRT-D candidates with a history of AF, 25% experience recurrent AF within 6 months of implant. Atrial detection and ventricular detection, shock, and resynchronization therapies are not compromised by the addition of atrial therapies to a CRT-D device. [ABSTRACT FROM AUTHOR]

The discharge characteristics of silver vanadium oxide (SVO) as a cathode in lithium–silver vanadium oxide (Li–SVO) primary battery was studied under various operating conditions. The cathode yielded a capacity of 260 mAh g−1 at a current density of 0.08 mA cm−2, although the theoretical capacity of this material is 315 mAh g−1. The pulse discharge characteristics were studied under conditions that simulate battery operation inside an implantable cardio-verter defibrillator (ICD). The variation of the ohmic resistance of the system was studied as a function of depth of discharge. Rate capability and impedance studies indicated high diffusion limitations for this system especially at high depth of discharge. Morphological changes during discharge were also discussed using scanning electron microscopic studies. [ABSTRACT FROM AUTHOR]

Objective: This retrospective analysis of electrocardiographic (ECG) data investigated the cardiovascular effects of paroxetine 10–50 mg/day in pediatric patients (7–18 years of age). Data were collected from three 8- to 10-week, randomized, placebo-controlled, double-blind trials of paroxetine in pediatric patients with major depressive disorder or obsessive-compulsive disorder. Method: Electrocardiograms (ECGs) were retrospectively retrieved from 63 study sites in the United States and Canada. Only patients with at least one screening and one on-treatment ECG were included. ECGs were analyzed for heart rate, QT interval corrected using Bazett's formula (QTcB) and Fridericia's formula (QTcF), at screening and while being treated. PR, R-R, and QRS intervals and the maximum change in QTcB and QTcF from screening to endpoint were determined. Clinically significant thresholds were defined a priori. Results: A total of 1,451 ECGs from 449 patients receiving placebo (n = 207), paroxetine (n = 200), or imipramine (n = 42) were analyzed. Treatment with paroxetine did not significantly increase QTcB or QTcF or any ECG parameters compared with placebo. Treatment with imipramine significantly increased heart rate and QTcB, R-R, and QRS intervals compared with either paroxetine or placebo. Conclusions: Data from this retrospective study indicate that paroxetine (10–50 mg/day) is unlikely to be associated with significant ECG changes in medically healthy pediatric patients. [ABSTRACT FROM AUTHOR]

Attempting to guarantee the quality of cardiac defibrillators, a study was performed at a Brazilian public hospital applying the Health Care Failure Mode and Effect Analysis. Although this technique was developed for applications within the healthcare process, it can be adapted for usage by the clinical engineering to identify the failure modes of medical equipment and to assess the involved risks. Through this study, problems that interfere with the performance of cardiac defibrillators were identified and, subsequently, some actions were proposed to help reduce the risks of these potential problems. These actions certify the safe functioning of this device within the standards of safety and quality. [ABSTRACT FROM AUTHOR]

Aim: Diagnosis of early stages of arrhythmogenic right ventricular cardiomyopathy (ARVC) with minimal structural abnormalities is challenging. The purpose of this study was to assess the value of repeated cardiac magnetic resonance imaging (CMR) in patients referred for right ventricular arrhythmias and clinical suspicion of ARVC. Methods and Results: Prospective follow-up study of 18 patients (8 females) studied with CMR for suspected ARVC. Patients with implanted defibrillators (ICD) were excluded. Mean follow-up was 37 ± 16 (12–59) months. Patients were assigned to 2 categories (ARVC likely or ARVC unlikely) according to a CMR-score based on right ventricular abnormalities. Clinical follow-up revealed no disease progression in 17 patients (94%). In 1 patient, an ICD was implanted because of disease progression. Of 9 patients with initial findings suggestive of ARVC, follow-up CMR remained positive in 3 and was diagnosed as normal in 6, mainly due to the inability to confirm the presence of fatty infiltrates at follow-up (5 of 6 patients). Initially, 9 patients had a normal CMR and 8 of those remained normal during follow-up. Conclusion: Repeated CMR after an average follow-up of 3 years was normal in 6 of 9 patients with clinical findings consistent with early stages of ARVC at the time of baseline CMR. Thus, CMR diagnosis of early stage ARVC is difficult and should be made with caution. [ABSTRACT FROM AUTHOR]

We developed a rule-based data filter for the automatic interpretation of data transmitted from implantable cardioverter defibrillators (ICDs). The feasibility and user acceptability of the data filter were tested in a multicentre study. Fifteen European centres analysed 10 cases each. The cases represented ICD follow-up findings, e.g. new tachycardia, battery depletion or sensing defects. The mean follow-up period was 68 days (SD 35). A questionnaire was used to collect information regarding the functionality and general concept of automatic data interpretation. A score of five or above (range 1–9) was classified as acceptable. According to the questionnaires, there was a high degree of satisfaction with the general concept of automatic data interpretation (mean 6.7, SD 1.2) and with user guidance (mean 7.1, SD 0.8). Safety (mean 7.0, SD 1.4) and accuracy (mean 6.7, SD 1.4) of the evaluation of device-related and clinical problems were regarded as high. Support in daily routine was considered to be high (mean 7.3, SD 1.1) as the system was easy to understand (mean 7.5, SD 0.9). The results indicated a high user acceptance with easy system handling. [ABSTRACT FROM AUTHOR]