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PubMed1998

Emergency defibrillation performed by coronary nursing staff: A pilot report.

The time taken to initiate defibrillation is a key factor in determining survival after cardiac arrest; all first-responding medical or paramedical personnel are thus recommended to receive training in defibrillation skills. We have recently established a working programme that allows trained coronary care nurses to defibrillate in emergencies. Prospective data collected from 1 October 1996 to 31 January 1997 showed that a total of 11 witnessed episodes of ventricular fibrillation or pulseless ventricular tachycardia occurred in nine patients, and were defibrillated by nurses. All the defibrillations were started within 1 minute of cardiac arrest. In five patients, defibrillation was commenced before the arrival of the crash team of doctors; three of the five patients survived. There were no violations of the resuscitation protocol or complications relating to defibrillation. Through programmed training in advanced cardiac life-support, coronary care nurses are capable of providing safe and prompt defibrillation. The importance of training and re-certification is also stressed.

Journal Article↗
PubMed2006

Early outcomes of out-of-hospital cardiac arrest after early defibrillation: a 24 months retrospective analysis.

INTRODUCTION: Cardiovascular disease remains the most common cause of death in the United States and most other Western nations. Among these deaths, sudden, out-of-hospital cardiac arrest claims approximately 1000 lives each day in the United States alone. Most of these cardiac arrests are due to ventricular fibrillation. Though highly reversible with the rapid application of a defibrillator, ventricular fibrillation is otherwise fatal within minutes, even when cardiopulmonary resuscitation is provided immediately. The overall survival rate in the United States is estimated to be less than 5 percent. Recent developments in automated-external-defibrillator technology have provided a means of increasing the rate of prompt defibrillation after out-of-hospital cardiac arrest. After minimal training, nonmedical personnel (e.g., flight attendants and casino workers) are also able to use defibrillators in the workplace, with lifesaving effects. Nonetheless, such programs have involved designated personnel whose job description includes assisting persons who have had sudden cardiac arrest. Data are still lacking on the success of programs in which automated external defibrillators have been installed in public places to be used by persons who have no specific training or duty to act. MATERIALS AND METHODS: All patients who had an out-of-hospital cardiac arrest between January 2003 and December 2004 and who received early defibrillation for ventricular fibrillation were included. We conducted a 24 months retrospective population-based analysis of the outcome in our population. RESULTS: Over a 24 month period, 446 people had non-traumatic cardiac arrest, and in all of them it was observed to be ventricular fibrillation. In a very few cases, the defibrillator operators were good Samaritans, acting voluntarily. Eighty-nine patients (about 19%) with ventricular fibrillation were successfully resuscitated, including eighteen who regained consciousness before hospital admission. CONCLUSION: Automated external defibrillators deployed in readily accessible, well-marked areas, are really very effective in assisting patients with cardiac arrest. However, it's quite true that, in the cases of survivors, most of our users had good prior training in the use of these devices.

Journal Article↗
PubMedDate not supplied

A statewide early defibrillation initiative including laypersons and outcome reporting.

Rapid delivery of defibrillatory shocks increases survival in patients with cardiac arrest. The automated external defibrillator interprets cardiac rhythms and delivers electrical shocks, permitting appropriate defibrillation by persons with minimal training. California initiated a program for early defibrillation by basic emergency medical technicians, using manual or automated external defibrillators, and by public safety personnel (fire fighters, peace officers, and public lifeguards), using automated external defibrillators. The program includes a system for reporting outcomes statewide. In the first 46 months under this program, 1487 patients received defibrillatory shocks; 1009 (68%) of these patients had witnessed ventricular fibrillation. Of the latter group, 191 were discharged from the hospital, representing 19% of those with witnessed ventricular fibrillation and 13% of all patients who had had shocks applied. California also implemented a framework of training and medical direction for defibrillation by laypersons using automated external defibrillators. Early defibrillation by basic emergency medical technicians and public safety personnel, encouraged by appropriate regulatory changes, results in gratifying survival rates.

California↗
PubMedDate not supplied

Improvement of defibrillators for EMS use: a problem in engineering and medicine.

Recent improvement in defibrillators has been limited mostly to decreased size and weight of portable units. An overview of the scientific literature indicates that the main limitation to further improvement in defibrillators is the lack of medical and physiologic information. Technology probably exists to change defibrillators if the manufacturers know what changes would be desirable. Clinical studies are needed for determining (a) more accurate quantitation of electrical dose for human use, (b) the relative effectiveness of different waveforms, (c) the toxicity and damage of electrical shocks to the heart, (d) the effects of drugs upon defibrillation threshold, (e) improvement of defibrillation techniques, (f) optimal placement and size of electrodes, and (g) the effects of cardiac disease on defibrillation threshold. Most of the needed studies are not technically difficult to carry out but they will be moderately expensive. In some cases special equipment may be needed or special techniques may have to be developed. The experimental animal studies appropriate as background for these clinical studies have been completed. With limited resources available, it is important to ask the most important questions first in order to develop improved defibrillation techniques and defibrillators.

Animals↗
PubMed1978

The electrical dose for direct ventricular defibrillation in man.

The threshold electrical energy for direct ventricular defibrillation was measured in 100 patients whose hypothermic hearts were fibrillated for cardiac operations. In 93 cases 10 joules or less was sufficient, and in 48 of these cases 5 joules or less defibrillated the ventricles. Because a shock of 10 joules defibrillated the heart of most of our patients, we recommend an initial shock of 5 to 10 joules rather than the 20 joules used more commonly. Until the safety margin between defibrillation threshold and damage threshold is established for direct defibrillation, use of shocks with adequate but not excessive strength may avoid unnecessary damage to the myocardium. When hearts refibrillate after defibrillation, it is unnecessary to use higher energy settings for subsequent defibrillation attempts. Instead, an antiarrhythmic drug should be administered and another shock of the same intensity that defibrillated the first time should be applied.

Adult↗
PubMedDate not supplied

Effects of myocardial infarction on catheter defibrillation threshold.

Because the automatic implantable defibrillator may be used in patients having ischemic heart disease, it is important to know whether myocardial ischemia changes the threshold for ventricular defibrillation under experimental conditions simulating automatic internal defibrillation. We determined changes in ventricular defibrillation threshold following coronary occlusion, using an electrode catheter designed for use with an automatic implantable defibrillator. Acute myocardial ischemia was produced without thoracotomy in 10 dogs (experimental group) by embolization with a plastic bead injected via a catheter into the left coronary artery. A control group of 4 dogs had only saline injected into the artery. Defibrillation threshold was measured at 15-min intervals from 1 hour before embolization to 2 hours after embolization. In the control group, voltage, current, energy, and impedance were unchanged after injection of saline into the coronary artery, and india ink perfusion revealed no ischemic areas. In the experimental group postembolization threshold current and energy were significantly higher than preembolization values: 0.47 vs 0.40 A/kg and 1.01 vs 0.80 J/kg, respectively (p less than 0.01). The magnitude of the peak change in threshold current after embolization was positively correlated (r = 0.79) with the size of the ischemic zone, determined by weighing unstained areas after india ink perfusion. Defibrillation threshold for a catheter electrode configuration increases for at least 2 hours following onset of acute myocardial ischemia. This finding must be accounted for in the design and use of an automatic implantable defibrillator.

Animals↗
PubMedDate not supplied

Ventricular defibrillation with myocardial electrodes in the dog, calf, pony, and pig.

The defibrillation effectiveness of 4-msec rectangular wave shocks was evaluated using myocardial electrodes with 25-kg dogs and (nominally) 100-kg calves, ponies, and pigs as part of an evaluation of the suitability of these animals as models for automatic implanted defibrillator research. The percent success of defibrillation attempts in dogs ranged from 44% with 4-A, 6-J shocks to 93% with 8-A, 16-J shocks. The success achieved in calves with scaled electrodes was uniformly lower and reached a maximum of 28% with 23-A, 107-J shocks. Pigs defibrillated with scaled electrodes at a success level (43%) more comparable to dogs (54%) at the 12-A, 25-J level. Using larger electrodes in calves, only 63% success was attained with 25-A, 52-J shocks; lower (14-A, 22-J) and higher (35-A, 100-J; 47-A, 176-J) shocks were less than 30% effective. Ponies were refractory to defibrillation at up to the 25-A, 100-J level with the large electrodes; with 21-A, 43-J shocks only 42% success in pigs was achieved. In general, there were marked differences between the responses of dogs and calves that are inconsistent with the closed-chest defibrillation behavior of both animals. Failure to achieve reliable and highly successful defibrillation in the larger animals may indicate their possible unsuitability as models in implanted defibrillator research.

Animals↗
PubMed2006

Relations among renal function, risk of sudden cardiac death, and benefit of the implanted cardiac defibrillator in patients with ischemic left ventricular dysfunction.

Implanted cardioverter defibrillator therapy has been shown to be associated with a significant reduction in the risk of sudden cardiac death (SCD) in patients with ischemic left ventricular dysfunction. However, data on the relation between renal function and SCD in this population are limited, and the effect of renal dysfunction on the implanted cardioverter defibrillator benefit has not been determined. We performed a retrospective analysis of the outcome associated with renal dysfunction, as determined by the estimated glomerular filtration rate (eGFR), in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-II. Multivariate analysis in conventionally treated patients showed that for each 10-U reduction in eGFR, the risk of all-cause mortality and SCD increased by 16% (p = 0.005) and 17% (p = 0.03), respectively. Defibrillator therapy was associated with a survival benefit in each eGFR category of > or = 35 ml/min/1.73 m2 (overall risk reduction for all-cause mortality 32%, p = 0.01 and for SCD 66%, p < 0.001). However, no implanted cardioverter defibrillator benefit was shown among patients with an eGFR < 35 ml/min/1.73 m2 (all-cause mortality hazard ratio 1.09, p = 0.84; SCD hazard ratio 0.95, p = 0.95). In conclusion, in patients with high-risk cardiac disease enrolled in the Multicenter Automatic Defibrillator Implantation Trial-II, a significant increase was found in the risk of SCD with declining renal function. Defibrillator therapy was associated with a significant survival benefit among the study patients with mild to moderate or no renal disease, but no benefit was shown among patients with more advanced renal dysfunction.

Aged↗
PubMed2003

The Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial: rationale, design, results, clinical implications and lessons for future trials.

T he Dual Chamber and VVI Implantable Defibrillator (DAVID) trial randomized 506 patients and tested the hypothesis that the dual-chamber pacing mode would produce improved hemodynamics and would in turn reduce congestive heart failure, heart failure hospitalizations, heart failure deaths, atrial fibrillation, strokes, ventricular arrhythmias, and total mortality compared to backup ventricular pacing in patients indicated for implantable defibrillator therapy. Patients had either primary prevention indications (47%) or secondary prevention indications (53%) for implantable defibrillator therapy but had no indications for bradycardia pacemaker support. All the patients had moderate to severe left ventricular dysfunction with a left ventricular ejection fraction of 40% or less (mean = 27%) and were consistently treated with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers (86%) and beta adrenergic blocking agents (85%). The primary combined endpoint of hospitalization for congestive heart failure or death was paradoxically increased and statistically significant ( p = 0.03) at one year in the patients paced in the dual chamber mode (22.6%) compared to patients randomized to ventricular backup pacing (13.3%). Both heart failure hospitalization and mortality contributed outcome. Another perspective would consider this a randomized controlled study of presence or absence of pacemaker therapy in patients with left ventricular dysfunction and indications for implantable defibrillator therapy. Ventricular backup pacing produced less than 3% ventricular and no atrial pacing, while dual chamber pacing produced approximately 60% atrial and ventricular paced heart beats. The poor outcome in the dual chamber paced group correlated with the percentage of right ventricular pacing and suggests that right ventricular pacing caused ventricular dyssynchrony. The poor outcome associated with right ventricular pacing compared to intrinsic activation in the control group of the DAVID trial is reminiscent of the poor outcome associated with prolonged intraventricular conduction activation in the control groups compared to biventricular pacing in the intervention groups of the cardiac resynchronization trials. The direct conclusion from these results are that patients with indications for implantable defibrillators and no indication for pacing should not be paced in the dual chamber pacing mode. It is not appropriate to conclude that only single chamber implantable defibrillators should be implanted. There are other potential advantages to having an implanted atrial lead including improved secondary outcomes. However the DAVID trial results suggest that the dual chamber paced mode was not associated with improved quality of life or decreased frequency of hospitalization, inappropriate shocks from the defibrillator or atrial fibrillation. The more important question is what is the optimal pacing mode in these patients? The AAIR mode is under investigation in the DAVID II study in an attempt to identify a pacing mode that preserves atrio-ventricular synchrony, normal atrio-ventricular timing, prevents bradycardia and also prevents right ventricular stimulation. Caution should be taken to not directly apply these results to patients with either an indication for pacemaker therapy or to patients with an indication for cardiac resynchronization therapy since patients from neither population were included. However, considering the large magnitude of the deleterious effects associated with dual chamber pacing in the DAVID trial future studies should explore the possibility that left ventricular stimulation may be the only pacing mode capable of preventing bradycardia without increasing death and congestive heart failure.

Anti-Arrhythmia Agents↗
PubMedDate not supplied

Implantable or external defibrillators for individuals at increased risk of cardiac arrest: where cost-effectiveness hits fiscal reality.

OBJECTIVES: Implantable cardioverter defibrillators (ICDs) are highly effective at preventing cardiac arrest, but their availability is limited by high cost. Automated external defibrillators (AEDs) are likely to be less effective, but also less expensive. We used decision analysis to evaluate the clinical and economic trade-offs of AEDs, ICDs, and emergency medical services equipped with defibrillators (EMS-D) for reducing cardiac arrest mortality. METHODS: A Markov model was developed to compare the cost-effectiveness of three strategies in adults meeting entry criteria for the MADIT II Trial: strategy 1, individuals experiencing cardiac arrest are treated by EMS-D; strategy 2, individuals experiencing cardiac arrest are treated with an in-home AED; and strategy 3, individuals receive a prophylactic ICD. The model was then used to quantify the aggregate societal benefit of these three strategies under the conditions of a constrained federal budget. RESULTS: Compared with EMS-D, in-home AEDs produced a gain of 0.05 quality-adjusted life-years (QALYs) at an incremental cost of $5225 ($104,500 per QALY), while ICDs produced a gain of 0.90 QALYs at a cost of $114,660 ($127,400 per QALY). For every $1 million spent on defibrillators, 1.7 additional QALYs are produced by purchasing AEDs (9.6 QALYs/$million) instead of ICDs (7.9 QALYs/$million). Results were most sensitive to defibrillator complication rates and effectiveness, defibrillator cost, and adults' risk of cardiac arrest. CONCLUSIONS: Both AEDs and ICDs reduce cardiac arrest mortality, but AEDs are significantly less expensive and less effective. If financial constraints were to lead to rationing of defibrillators, it might be preferable to provide more people with a less effective and less expensive intervention (in-home AEDs) instead of providing fewer people with a more effective and more costly intervention (ICDs).

Adult↗
PubMed2000

[Implantable cardioverter/defibrillator: long-term stability of the defibrillation threshold with a unipolar electrode configuration (active-can")].

The majority of cardioverter/defibrillator (ICD) implantations are currently performed with a non-thoracotomy approach. From November 1993 to January 1995, 46 patients underwent implantation of a PCD 7219C with an "active-can" lead configuration at our institution. While the chronic stability of the defibrillation threshold (DFT) for an epicardial lead system is well established, the results are still inconsistent for non-thoracotomy lead systems. Accordingly, the aim of the present study was to compare the acute and chronic defibrillation thresholds of the ICDs implanted with an "active-can" lead system in order to assess the chronic stability of these systems. The defibrillation energy requirements were measured at implant, prior to hospital discharge, three, six and twelve months after implantation of the defibrillator. The patient group consisted of 8 females and 38 males with a mean age of 57.2 years. The mean left ventricular ejection fraction was 43.8%. The most frequent underlying heart disease was coronary artery disease in 31 of 46 patients. Eight patients had idiopathic dilated cardiomyopathy. In 39 of 46 patients, the defibrillation threshold could be successfully determined at all 4 time points after implantation. The mean defibrillation energy requirement at the time of implantation was 9.2 +/- 5.9 Joules (J). The subsequent mean energy requirements were 7.6 +/- 4.8 J at pre-hospital discharge, 8.6 +/- 5.7 J at the 3 month, 8.1 +/- 6.0 J at the 6 month and 8.6 +/- 5.8 J at the 12 month follow-up visits. The mean defibrillation threshold was lowest at the time of prehospital discharge, significantly lower than at the time of initial implantation (p = 0.021). However, at all later time points up to one year, there was no significant difference in the DFT as compared with the time of initial implantation. Comparing the DFT at the time of implantation and the DFT at all other time points, there were no significant differences (9.23 vs. 8.56 J, p = 0.291). Although there was an initial decrease in the DFT at seven to ten days, the long-term stability of the DFT up to one year remained stable in the devices with the "active-can" lead system.

Adult↗
PubMed1994

Clinical predictors of successful implantable cardioverter defibrillator implantation.

Successful implantation of an implantable cardioverter defibrillation system is critically dependent on demonstration that the lead system to be implanted can defibrillate reliably. Defibrillation efficacy in turn is dependent on several sets of factors that include: (1) defibrillation technique and the lead system being tested; (2) defibrillation testing protocol and criteria for implantation; and (3) clinical variables that may be intrinsic to the patient or extrinsic factors to which the patient is being exposed. Existing clinical data are limited but suggest that poor left ventricular function is the clinical variable most consistently associated with poor defibrillation efficacy and a failure to meet implant criteria of the epicardial lead systems. Antiarrhythmic drugs may elevate the defibrillation threshold, but evidence that this has important clinical ramifications on implantation success rates is very limited and incomplete.

Anti-Arrhythmia Agents↗
PubMed1994

Feasibility of concomitant implantation of permanent transvenous pacemaker and defibrillator systems.

In 17 patients (14 men and 3 women aged 69 +/- 10 years), a transvenous pacemaker was implanted before (8 patients), following (7 patients), or simultaneously (2 patients) with the insertion of a transvenous defibrillator. Indications included malignant ventricular arrhythmias and symptomatic bradycardia in all patients. All patients had structural heart disease. All pacemakers were non-programmable bipolar, either single chamber (n = 7) or dual chamber (n = 10). Eleven pacemakers were rate responsive. The Transvene system was implanted in 7 patients (Pacer-Cardioverter-Defibrillator in 6 patients and the Cadence defibrillator in 1). The Endotak lead system was implanted in 10 patients (Ventak in 7 patients and the Cadence in 3). The mean defibrillation threshold was 16 +/- 5 J. Repositioning of the pacemaker leads eliminated undersensing of ventricular fibrillation by the defibrillator, which occurred during asynchronous pacing in 2 patients. During a mean follow-up of 11 +/- 6 months, 2 patients died because of pump failure and 7 patients received defibrillator therapy for ventricular arrhythmias. No significant complications were noted. Successful concomitant implantation of transvenous pacemakers and defibrillators was thus accomplished in 17 patients, which suggests that insertion of a second transvenous device can be safely accomplished.

Adult↗
PubMed1993

Ventricular fibrillation in patients without significant structural heart disease: a multicenter experience with implantable cardioverter-defibrillator therapy.

OBJECTIVES: This study was undertaken to characterize the outcome of survivors of ventricular fibrillation with no or minimal structural heart disease who received an implantable cardioverter-defibrillator. BACKGROUND: The prognosis among survivors of ventricular fibrillation with minimal or no structural cardiac abnormalities remains unclear. Since the advent of implantable cardioverter-defibrillators, this question takes on added importance. METHODS: This 10-center retrospective study provided information on 28 survivors of ventricular fibrillation (mean age 42 years) with minimal or no structural abnormalities who were treated with an implantable cardioverter-defibrillator. RESULTS: Ventricular tachyarrhythmias (polymorphic in all but one patient) were induced during baseline programmed stimulation in 39% of patients. During a median 30.6-month follow-up period after implantable cardioverter-defibrillator implantation, there were no cardiac deaths and two noncardiac deaths. Sixteen patients experienced 36 shock episodes (total 88 shocks). The majority of shocks were classified as "indeterminate"; one patient received 47 "spurious" shocks during one shock episode and each of four patients received one "appropriate" shock. Ventricular arrhythmias were not inducible in any of these latter four patients. CONCLUSIONS: Survivors of ventricular fibrillation with minimal or no structural cardiac abnormalities receiving an implantable cardioverter-defibrillator have an excellent 3-year survival rate. The occurrence, albeit infrequent, of appropriate implantable cardioverter-defibrillator shocks in this group suggests that these patients have a potential risk of recurrent cardiac arrest whose fatal outcome may be avoided by implantable cardioverter-defibrillator therapy.

Actuarial Analysis↗
PubMed1993

Importance of abortive shock capability with electrogram storage in cardioverter-defibrillator devices.

OBJECTIVES: This study evaluates the ability of a third-generation cardioverter-defibrillator to abort energy delivery and the importance of electrogram storage in analyzing the aborted events. BACKGROUND: In the Cadence Tiered Therapy Defibrillator, when a tachycardia satisfies detection criteria for cardioversion or defibrillation therapy, high voltage capacitors begin charging. The Cadence defibrillator continues monitoring the rhythm during charging and if the rate decreases to below the rate triggering therapy, charging is terminated. This event is registered as an aborted shock. The defibrillator also has the ability to store intracardiac electrogram recordings of the electrical events that precipitate device therapy or aborted shocks. METHODS: During a mean follow-up interval of 10 +/- 7 months, 55 aborted events were registered by the Cadence defibrillator in 18 of the 49 patients who received it. Thirty-two stored ventricular electrograms of events leading to aborted shocks were available for analysis in 15 patients. RESULTS: Intracardiac electrogram recordings demonstrated the probable electrical events leading to these aborted shocks included nonsustained ventricular tachycardia (n = 10), nonsustained rapid polymorphic ventricular tachycardia/ventricular fibrillation (n = 2), atrial fibrillation (n = 5), supraventricular tachycardia (n = 2) and electrical noise (n = 13). Eleven patients had a therapeutic intervention initiated as a consequence of the diagnostic information provided by analysis of intracardiac electrogram recordings. Four of the 15 patients had no changes made. During a follow-up period of 9 +/- 5 months after therapy was altered, no patient had subsequent aborted shocks. Five patients have had seven appropriate shocks for sustained ventricular tachycardias. CONCLUSIONS: The ability of Cadence defibrillator to continue tachycardia sensing during capacitor charging and to abort shock therapy for self-terminating events prevented unnecessary shocks in 18 (37%) of the 49 patients. Intracardiac electrogram recordings were critical for instituting appropriate therapy that may have prevented unnecessary device charging and inappropriate discharges.

Adult↗
PubMed1994

Lessons learned from data logging in a multicenter clinical trial using a late-generation implantable cardioverter-defibrillator. The Guardian ATP 4210 Multicenter Investigators Group.

OBJECTIVES: This study examined patterns of implantable cardioverter-defibrillator use as documented by data logging. BACKGROUND: Implantable cardioverter-defibrillators are accepted therapy for malignant ventricular tachyarrhythmias; however, relatively little is known about their patterns of use. Incorporation of data-storage capacities into these devices provides insight into long-term defibrillator function. METHODS: Stored data-logging information was retrieved from 401 implanted cardioverter-defibrillators in 393 patients over an average of 303 days of follow-up. RESULTS: A total of 91,443 detections were recorded in 299 patients. One hundred-six patients (26%) had detections due to supraventricular tachycardias, electrical noise or other causes, resulting in inappropriate therapy delivery to 92 patients (23%). Two hundred eighty-one patients recorded 66,276 episodes of ventricular tachycardia or ventricular fibrillation. Of these, 74.4% episodes terminated spontaneously without any delivered therapy, 22.1% terminated after antitachycardia pacing, and 1.7% terminated after shock therapy. Antitachycardia pacing was activated without formal testing in 47% of all patients receiving this therapy and was successful in 96% of all episodes receiving this therapy. Acceleration of tachycardia to shock therapy occurred in 1.3% of all episodes and in 30.5% of patients receiving antitachycardia pacing. Thirty-four patients (8.7%) died during follow-up. Mortality was associated with patient age, heart failure functional class at implantation and frequency of shocks received during follow-up (all p < or = 0.05). CONCLUSIONS: Most ventricular tachyarrhythmia detections by this noncommitted implantable cardioverter-defibrillator resolve spontaneously, whereas the majority receiving therapy can be treated with antitachycardia pacing. Mortality after implantable cardioverter-defibrillator implantation is associated with age, heart failure class and frequency of shocks received during follow-up. Data-logging capabilities provide valuable insights into the patterns of defibrillator use.

Algorithms↗
PubMed1994

Clinical outcome of patients with malignant ventricular tachyarrhythmias and a multiprogrammable implantable cardioverter-defibrillator implanted with or without thoracotomy: an international multicenter study. PCD Investigator Group.

OBJECTIVES: The long-term efficacy and safety of a third-generation implantable cardioverter-defibrillator implanted with thoracotomy and nonthoracotomy lead systems was evaluated in a multicenter international study. BACKGROUND: The clinical impact of transvenous leads for nonthoracotomy implantation and pacing for bradyarrhythmias and tachyarrhythmias in implantable cardioverter-defibrillator systems is not well defined. METHODS: The safety of the implantation procedure and clinical outcome of 1,221 patients with symptomatic and life-threatening ventricular tachyarrhythmias who underwent implantation of a third-generation cardioverter-defibrillator using either a thoracotomy approach with epicardial leads (616 patients) or a nonthoracotomy approach with endocardial leads (605 patients) in a nonrandomized manner was analyzed. The implantable cardioverter-defibrillator system permitted pacing, cardioversion, defibrillation, arrhythmia event memory and noninvasive tachycardia induction. RESULTS: Successful implantation of an endocardial lead system was achieved in 605 (88.2%) of 686 patients and an epicardial system in 614 (99.7%) of 616 (p < 0.05). Perioperative 30-day mortality rate was 0.8% (1.8% including crossovers) in endocardial implant recipients compared with 4.2% (p < 0.001) in epicardial implant recipients (3.6% without crossovers, p < 0.05, respectively). Implantation mortality risk was significantly lower for nonthoracotomy systems irrespective of left ventricular ejection fraction or New York Heart Association functional class. Pacing therapies prevented need for cardioversion or defibrillation shocks in 89% of all ventricular tachycardia episodes and were comparably effective for both lead systems. Total survival rate at 2 years was significantly higher in endocardial (87.6%) than epicardial (81.9%) lead recipients (p < 0.001). Elimination of perioperative mortality from the analysis demonstrated comparable survival in both groups (p > 0.2). CONCLUSIONS: Third-generation cardioverter-defibrillators with monophasic waveforms can be successfully implanted with epicardial (99.7%) and endocardial (88.2%) lead systems. We conclude that endocardial leads should be the implant technique of first choice. Improved patient management and tolerance for device therapy is achieved with the addition of antitachycardia pacemaker capability in these systems.

Defibrillators, Implantable↗
PubMed2006

A video based training program improves defibrillator inspection compliance.

Improperly maintained defibrillators are an important cause of defibrillation delay or failure during in-hospital cardiac arrest. This study investigated whether a brief training video of how to properly inspect crash carts and defibrillators would improve the quality and frequency of these inspections. The study was a before-after cohort design. Crash cart inspection logs were explicitly examined, and the electronic archive records of the defibrillators were interrogated. The compliance and quality of inspections were compared before and after the implementation of the training video program. The missed-inspection rate for defibrillators significantly improved from 8.9% to 6.9% (p= 0.037) after video training program implementation. The missed-inspection rate for crash carts, however, actually worsened from 2.7% before to 8.0% (p = 0.0001). The introduction of a new crash cart inspection training video program improved the frequency and quality of defibrillator inspections but not crash cart inspections. The inspection of crash carts and defibrillators is a vital hospital task. Because available training time for clinical personnel is limited, our 15-minute video can be viewed on a ward computer workstation at the most convenient time.

Cardiopulmonary Resuscitation↗