Success changes the problem: why ventricular fibrillation is declining, why pulseless electrical activity is emerging, and what to do about it

Association Between QRS Characteristics in Pulseless Electrical Activity and Survival Outcome in Cardiac Arrest Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Recent studies have shown inconsistent results regarding the association between QRS characteristics and survival outcomes in patients with cardiac arrest and pulseless electrical activity (PEA) rhythms. This meta-analysis aimed to identify the usefulness of QRS width and frequency as prognostic tools for outcomes in patients with cardiac arrest and PEA rhythm.

METHODS

Extensive searches were conducted using Medline, Embase, and the Cochrane Library to find articles published from database inception to 4 June 2023. Studies that assessed the association between the QRS characteristics of cardiac arrest patients with PEA rhythm and survival outcomes were included. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies.

RESULTS

A total of 9727 patients from seven observational studies were included in this systematic review and meta-analysis. The wide QRS group (QRS ≥ 120 ms) was associated with significantly higher odds of mortality than the narrow QRS group (QRS < 120 ms) (odds ratio (OR) = 1.86, 95% confidence interval (CI) = 1.11-3.11, I2 = 58%). The pooled OR for mortality was significantly higher in patients with a QRS frequency of < 60/min than in those with a QRS frequency of ≥ 60/min (OR = 1.90, 95% CI = 1.19-3.02, I2 = 65%).

CONCLUSIONS

Wide QRS width or low QRS frequency is associated with increased odds of mortality in patients with PEA cardiac arrest. These findings may be beneficial to guide the disposition of cardiac arrest patients with PEA during resuscitation.

Can absence of cardiac activity on point-of-care echocardiography predict death in out-of-hospital cardiac arrest? A systematic review and meta-analysis

AIM

The purpose of this systematic review and meta-analysis was to evaluate the accuracy of the absence of cardiac motion on point-of-care echocardiography (PCE) in predicting termination of resuscitation (TOR), short-term death (STD), and long-term death (LTD), in adult patients with cardiac arrest of all etiologies in out-of-hospital and emergency department setting.

METHODS

A systematic review and meta-analysis was conducted based on PRISMA guidelines. A literature search in Medline, EMBASE, Cochrane, WHO registry, and ClinicalTrials.gov was performed from inspection to August 2022. Risk of bias was evaluated using QUADAS-2 tool. Meta-analysis was divided into medical cardiac arrest (MCA) and traumatic cardiac arrest (TCA). Sensitivity and specificity were calculated using bivariate random-effects, and heterogeneity was analyzed using I2 statistic.

RESULTS

A total of 27 studies (3657 patients) were included in systematic review. There was a substantial variation in methodologies across the studies, with notable difference in inclusion criteria, PCE timing, and cardiac activity definition. In MCA (15 studies, 2239 patients), the absence of cardiac activity on PCE had a sensitivity of 72% [95% CI 62-80%] and specificity of 80% [95% CI 58-92%] to predict LTD. Although the low numbers of studies in TCA preluded meta-analysis, all patients who lacked cardiac activity on PCE eventually died.

CONCLUSIONS

The absence of cardiac motion on PCE for MCA predicts higher likelihood of death but does not have sufficient accuracy to be used as a stand-alone tool to terminate resuscitation. In TCA, the absence of cardiac activity is associated with 100% mortality rate, but low number of patients requires further studies to validate this finding. Future work would benefit from a standardized protocol for PCE timing and agreement on cardiac activity definition.

Pulseless Electrical Activity: Echocardiographic Explanation of a Perplexing Phenomenon

Pulseless electrical activity (PEA) is considered an enigmatic phenomenon in resuscitation research and practice. Finding individuals with no consciousness or pulse but with continued electrocardiographic (EKG) complexes obviously raises the question of how they got there. The development of monitors that can display the underlying rhythm has allowed us to differentiate between VF, asystole, and PEA. Lack of clear understanding of the emergence of PEA has limited the research and development of interventions that might improve the low rates of survival typically associated with PEA. Over 30 years of studying and practicing resuscitation have allowed the authors to see a substantial rise in PEA with variable survival rates, based on the patients' illness spectrum and intensity of monitoring. This paper presents a small case series of individuals with brain death whose family members consented to the echocardiographic observation of the dying process after disconnection from life support. The observation from these cases confirms that PEA is a late phase in the clinical dying process. Echocardiographic images delineate the stages of pseudo-PEA with ineffective contractions, PEA, and then asystole. The process is contiuous with none of the sudden phase shifts seen in dysrhythmic events such as VF, VT or SVT. The implications of these findings are that PEA is a common manifestation of tissue hypoxia and metabolic substrate depletion. Our findings offer prospects for studies of the development of interventions to improve PEA survival.

Rhythms and prognosis of patients with cardiac arrest, emphasis on pseudo-pulseless electrical activity: another reason to use ultrasound in emergency rooms in Colombia

BACKGROUND

The cardiac arrest is still an emergency with a bad prognosis. The growing adoption of bedside ultrasound allowed to classify PEA in two groups: the true PEA and the pseudo-PEA. pPEA is used to describe a patient who has a supposed PEA in the absence of pulse, with evidence of some cardiac activity on the bedside ultrasound.

OBJECTIVE

This work aims to assess the bedside ultrasound use as a predictor for ROSC and survival at discharge in cardiac arrest patients and compare the pseudo-pulseless electrical activity to other cardiac arrest rhythms, including shockable rhythms.

MATERIALS AND METHODS

This is an observational, historic cohort study carried out in the emergency room of the University Hospital Mayor Méderi. Data were collected from all the adult patients treated for cardiac arrest from June 2018 to 2019. An ultrasound was performed to every cardiac arrest patient.

RESULTS

Of a total of 108 patients, the median of the age was 71 years, 65.8% were male subjects, and the most frequent cause for cardiac arrest was the cardiogenic shock (32.4%). ROSC was observed in 41 cases (37.9%) and survival at discharge was 18 cases (16.7%). VF/VT and pPEA were the two rhythms that showed the highest ROSC and survival at discharge. For the pPEA group, we were able to conclude that the cardiac activity type is related to ROSC.

CONCLUSION

There is a significant difference for ROSC and survival at discharge prognosis among the cardiac arrest rhythms, with better outcomes for VF/VT and pPEA. Among patients with PEA, a routine ultrasound assessment is recommended. The type of cardiac activity recorded during the ultrasound of the cardiac arrest patient might be related to the ROSC and survival at discharge prognosis.

Out-of-hospital cardiac arrest patients with implantable cardioverter-defibrillators: What are their outcomes?

THE AIM OF THE STUDY

To identify the prognostic factors and effects of implantable cardioverter-defibrillators (ICDs) in out-of-hospital cardiac arrest (OHCA) patients with ICDs because the clinical characteristics and outcomes of OHCA patients with ICDs are unknown.

METHODS

The North American Resuscitation Outcomes Consortium (ROC) Cardiac Epistry Version 3 dataset was analyzed. Eligible patients were divided into OHCA patients with and without ICDs. Multivariable regressions were employed to analyze.

RESULTS

Of 51,634 eligible OHCA patients, 581 (1.13%) had implanted ICDs. Among them, 53 (9.1%) patients survived to hospital discharge, and 40 (6.9%) patients had favorable neurological outcome at hospital discharge. Multivariable regression showed ICDs were not associated with OHCA outcomes in the total OHCA patients. In the OHCA patients with ICDs, shockable initial emergency medical services (EMS)-recorded rhythms and the ICD-shock-only defibrillation pattern were independent favorable factors for survival to hospital discharge(OR = 3.3, 95%CI 1.7-6.2, P < 0.001; OR = 2.4, 95%CI 1.1-5.5, P = 0.035, respectively) and neurological outcome at hospital discharge (OR = 6.5, 95%CI 2.9-14.4, P < 0.001; OR = 3.6, 95%CI 1.4-9.1, P = 0.006, respectively). During field resuscitation in OHCA patients with ICDs, at least 34.9% of total patients and 64.6% of patients with initial EMS-recorded VT/VF rhythms needed additional external shocks.

CONCLUSIONS

Shockable initial EMS-recorded rhythms and ICD-shock-only defibrillation pattern were independent factors for the favorable outcomes of OHCA patients with ICDs. ICDs were not associated with the outcomes of OHCA, and additional external shocks were needed in a substantial number of OHCA patients with ICDs during field resuscitation.

Sudden cardiac arrest and ventricular arrhythmias following first type I myocardial infarction in the contemporary era

INTRODUCTION

Myocardial infarction (MI) is associated with an increase in subsequent heart failure (HF), recurrent ischemic events, sudden cardiac arrest, and ventricular arrhythmias (SCA-VA). The primary objective of the study to determine the role of intercurrent HF and ischemic events on the development of SCA-VA following first type I MI.

METHODS AND RESULTS

A retrospective cohort study of patients experiencing first type 1 MI in Olmsted County, Minnesota (2002-2012) was conducted by identifying patients using the medical records linkage system (Rochester epidemiology project). Patients aged ≥18 years were followed from the time of MI till death or 31 July, 2017. Intercurrent HF and ischemic events were the primary exposures following MI and their association with outcome SCA-VA was assessed. Eight hundred and sixty-seven patients (mean age was 63 ± 14.5 years; 69% male; 49.8% ST-elevation myocardial infarction) who had their first type I MI during the study period were included. Majority of acute MI patients were revascularized using percutaneous coronary intervention and bypass surgery (628 [72.43%] and 87 [10.03%] respectively). During a mean follow-up of 7.69 ± 4.17 years, HF, recurrent ischemic events and SCA-VA occurred in 155 (17.9%), 245 (28.3%), and 40 (4.61%) patients respectively. Low ejection fraction (adjusted hazard ratio [HR] 0.95; 95% confidence interval [CI], 0.93-0.98; P < .001), intercurrent HF (adjusted HR 3.11; 95% CI, 1.39-6.95; P = .006) and recurrent ischemic events (adjusted HR 3.47; 95% CI, 1.68-7.18; P < .001) were associated with subsequent SCA-VA.

CONCLUSION

SCA-VA occurred in a small proportion of patients after MI and is associated with intercurrent HF and recurrent ischemic events.

Cardiopulmonary resuscitation in newborn infants with ultrasound in the delivery room

Point of care ultrasound has emerged as useful tool in cardiac arrest situations in adult population. Despite of these, there is not a protocol for cardiopulmonary resuscitation in the delivery room for newborns. We describe two case were ultrasound helped to rule out the cardiopulmonary arrest case and we propose and algorithm were ultrasound is integrated in the newborn resuscitation and may help to diagnose the cardiac arrest cause.

Communicating resuscitation. The importance of documentation in cardiac arrest

OBJECTIVES

To primarily assess documentation during in-hospital cardiopulmonary arrest resuscitation and to secondarily observe cardiopulmonary resuscitation event and outcome variables.

METHODS

A retrospective review of 360 code blue forms and medical records at King Fahad General Hospital, King Abdulaziz General Hospital (Almahjar), and Althghar Hospital in Jeddah was performed between 2015 to 2016.

RESULTS

Survival to discharge rates and neurological outcomes were not documented at all. Other undocumented variables include gender 9 (2.5%), nationality 12 (3.3%), code blue announcement time 130 (36%), initial rhythm 10 (2.8%), time to airway placement 154 (57.2%), time to cardiology arrival 181 (50.27%), and time to anesthesia arrival 145 (40.27%).

CONCLUSION

We strongly recommend the use of standardized cardiopulmonary arrest sheets among all hospitals and follow up of neurological outcomes and survival to discharge as outcome variables.

Accuracy of point-of-care focused echocardiography in predicting outcome of resuscitation in cardiac arrest patients: A systematic review and meta-analysis

OBJECTIVE

We aim to summarize current evidence on the value of point-of-care (POC) focused echocardiography in the assessment of short-term survival in patients with cardiac arrest.

METHODS

PubMed and EMBASE were searched from inception to July 2016 for eligible studies that evaluated the utility of POC echocardiography in patients with cardiac arrest. Modified QUADAS was used to appraise the quality of included studies. A random-effect bivariate model and a hierarchical summary receiving operating curve were used to summarize the performance characteristics of focused echocardiography.

RESULTS

Initial search identified 961 citations of which 15 were included in our final analysis. A total of 1695 patients had POC echocardiography performed during resuscitation. Ultrasonography was mainly utilized to detect spontaneous cardiac movement (SCM) and identify reversible causes of cardiac arrest. Subcostal, apical and parasternal views were used to identify cardiac tamponade, pulmonary embolism, and pleural view for tension pneumothorax. Results of meta-analysis showed that SCM detected by focused echocardiography had a pooled sensitivity (0.95, 95%CI: 0.72-0.99) and specificity (0.80, 95%CI: 0.63-0.91) in predicting return of spontaneous circulation (ROSC) during cardiac arrest, with a positive likelihood ratio of 4.8 (95% CI: 2.5-9.4) and a negative likelihood ratio of 0.06 (95%CI: 0.01-0.39).

CONCLUSION

POC focused echocardiography can be used to identify reversible causes and predict short-term outcome in patients with cardiac arrest. In patients with a low pretest probability for ROSC, absence of SCM on echocardiography can predict a low likelihood of survival and guide the decision of resuscitation termination.

Role of risk stratification and genetics in sudden cardiac death

Sudden cardiac death (SCD) is a major public health issue due to its increasing incidence in the general population and the difficulty in identifying high-risk individuals. Nearly 300 000 - 350 000 patients in the United States and 4-5 million patients in the world die annually from SCD. Coronary artery disease and advanced heart failure are the main etiology for SCD. Ischemia of any cause precipitates lethal arrhythmias, and ventricular tachycardia and ventricular fibrillation are the most common lethal arrhythmias precipitating SCD. Pulseless electrical activity, bradyarrhythmia, and electromechanical dissociation also result in SCD. Most SCDs occur outside of the hospital setting, so it is difficult to estimate the public burden, which results in overestimating the incidence of SCD. The insufficiency and limited predictive value of various indicators and criteria for SCD result in the increasing incidence. As a result, there is a need to develop better risk stratification criteria and find modifiable variables to decrease the incidence. Primary and secondary prevention and treatment of SCD need further research. This critical review is focused on the etiology, risk factors, prognostic factors, and importance of risk stratification of SCD.

Subsequent shock deliveries are associated with increased favorable neurological outcomes in cardiac arrest patients who had initially non-shockable rhythms

Introduction

Previous studies evaluating whether subsequent conversion to shockable rhythms in patients who had initially non-shockable rhythms was associated with altered clinical outcome reported inconsistent results. Therefore, we hypothesized that subsequent shock delivery by emergency medical service (EMS) providers altered clinical outcomes in patients with initially non-shockable rhythms.

Methods

We tested for an association between subsequent shock delivery in EMS resuscitation and clinical outcomes in patients with initially non-shockable rhythms (n = 11,481) through a survey of patients after out-of-hospital cardiac arrest in the Kanto region (SOS-KANTO) 2012 study cohort, Japan. The primary investigated outcome was 1-month survival with favorable neurological functions. The secondary outcome variable was the presence of subsequent shock delivery. We further evaluated the association of interval from initiation of cardiopulmonary resuscitation to shock with clinical outcomes.

Results

In the univariate analysis of initially non-shockable rhythms, patients who received subsequent shock delivery had significantly increased frequency of return of spontaneous circulation, 24-hour survival, 1-month survival, and favorable neurological outcomes compared to the subsequent not shocked group (P <0.0001). In the multivariate logistic regression analysis, subsequent shock was significantly associated with favorable neurological outcomes (vs. not shocked; adjusted P = 0.0020, odds ratio, 2.78; 95 % confidence interval, 1.45–5.30). Younger age, witnessed arrest, initial pulseless electrical activity rhythms, and cardiac etiology were significantly associated with the presence of subsequent shock in patients with initially non-shockable rhythms.

Conclusions

In this study of cardiac arrest patients with initially non-shockable rhythms, patients who received early defibrillation by EMS providers had increased 1-month favorable neurological outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1028-0) contains supplementary material, which is available to authorized users.

Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms

BACKGROUND

Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.

OBJECTIVE

To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.

METHODS

Secondary analysis of data in Epistry - Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.

RESULTS

A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p=0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60-1.30).

CONCLUSION

For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.

Role of KATP channel in electrical depression and asystole during long-duration ventricular fibrillation in ex vivo canine heart

Long-duration ventricular fibrillation (LDVF) in the globally ischemic heart is characterized by transmurally heterogeneous decline in ventricular fibrillation rate (VFR), emergence of inexcitable regions, and eventual global asystole. Rapid loss of both local and global excitability is detrimental to successful defibrillation and resuscitation during cardiac arrest. We sought to assess the role of the ATP-sensitive potassium current (I(KATP)) in the timing and spatial pattern of electrical depression during LDVF in a structurally normal canine heart. We analyzed endo-, mid-, and epicardial unipolar electrograms and epicardial optical recordings in the left ventricle of isolated canine hearts during 10 min of LDVF in the absence (control) and presence of an I(KATP) blocker glybenclamide (60 μM). In all myocardial layers, average VFR was the same or higher in glybenclamide-treated than in control hearts. The difference increased with time of LDVF and was overall significant in all layers (P < 0.05). However, glybenclamide did not significantly affect the transmural VFR gradient. In epicardial optical recordings, glybenclamide shortened diastolic intervals, prolonged action potential duration, and decreased the percentage of inexcitable area (all differences P < 0.001). During 10 min of LDVF, asystole occurred in 55.6% of control and none of glybenclamide-treated hearts (P < 0.05). In three hearts paced after the onset of asystole, there was no response to LV epicardial or atrial pacing. In structurally normal canine hearts, I(KATP) opening during LDVF is a major factor in the onset of local and global inexcitability, whereas it has a limited role in overall deceleration of VFR and the transmural VFR gradient.

Dynamic effects of adrenaline (epinephrine) in out-of-hospital cardiac arrest with initial pulseless electrical activity (PEA)

BACKGROUND

In cardiac arrest, pulseless electrical activity (PEA) is a challenging clinical syndrome. In a randomized study comparing intravenous (i.v.) access and drugs versus no i.v. access or drugs during advanced life support (ALS), adrenaline (epinephrine) improved return of spontaneous circulation (ROSC) in patients with PEA. Originating from this study, we investigated the time-dependent effects of adrenaline on clinical state transitions in patients with initial PEA, using a non-parametric multi-state statistical model.

METHODS AND RESULTS

Patients with available defibrillator recordings were included, of whom 101 received adrenaline and 73 did not. There were significantly more state transitions in the adrenaline group than in the no-adrenaline group (rate ratio = 1.6, p<0.001). Adrenaline markedly increased the rate of transition from PEA to ROSC during ALS and slowed the rate of being declared dead; e.g. by 20 min 20% of patients in the adrenaline group had been declared dead and 25% had obtained ROSC, whereas 50% in the no-adrenaline group have been declared dead and 15% had obtained ROSC. The differential effect of adrenaline could be seen after approx. 10 min of ALS for most transitions. For both groups the probability of deteriorating from PEA to asystole was highest during the first 15 min. Adrenaline increased the rate of transition from PEA to ventricular fibrillation or -tachycardia (VF/VT), and from ROSC to VF/VT.

CONCLUSIONS

Adrenaline has notable clinical effects during ALS in patients with initial PEA. The drug extends the time window for ROSC to develop, but also renders the patient more unstable. Further research should investigate the optimal dose, timing and mode of adrenaline administration during ALS.

Sudden cardiac death after treatment with low dose risperidone in combination with cotrimoxazole

Risperidone as an antipsychotic drug raises the risk of serious ventricular tachyarrhythmias and sudden cardiac death; co-administered with other potentially arrhythmogenic drugs the risk escalates. There are some electrocardiographic markers which may help predict such events.

CASE REPORT

We describe a 47-year-old woman with acute psychosis, who died suddenly subsequent to refractory ventricular arrhythmia, while on low dose risperidone combined with cotrimoxazole.

CONCLUSION

This case report suggests that use of risperidone even at a low dose and in an apparently healthy individual is associated with a heightened risk of lethal ventricular tachyarrhythmia. Therefore, clinicians should always be aware of such awkward effect. It is recommended to obtain baseline electrocardiogram in all patients and follow up electrocardiograms in selected patients when considering such therapy in order to avoid fatal outcomes.

Out-of-hospital cardiac arrest: early in-hospital hypotension versus out-of-hospital factors in predicting in-hospital mortality among those surviving to hospital admission

OBJECTIVE

The purpose of this study was to determine the prevalence of in-hospital hypotension in patients surviving to admission after resuscitation from out-of-hospital cardiac arrest and compare it to that of traditional Utstein factors in predicting in-hospital mortality.

METHODS

Single-center retrospective cohort of adult patients surviving to hospital admission after resuscitation from out-of-hospital sudden death between January 1, 2006 and October 31, 2009. Study variables included Utstein template data: age, sex, initial rhythm, witnessed or nonwitnessed arrest, presence or absence of bystander CPR, location of arrest, response time (time of 9-1-1 dispatch to first vehicle arrival), and hypotension (systolic pressure<90 or mean arterial pressure<60) within 24h of ROSC. Univariate comparisons of categorical variables were performed and the Wilcoxon rank-sum test was used to compare continuous variables. Multivariable logistic regression was then performed after inclusion of Utstein variables.

RESULTS

73 patients met the inclusion criteria, and in-hospital mortality occurred in 54 (74%). On univariate analysis, in-hospital hypotension (OR=3.5, 95%CI 1.1-10.0, p=0.02), pre-hospital rhythm other than VF/VT (OR 4.3, 95%CI 1.4-13.3, p=0.008), and an unwitnessed arrest (OR=6.9, 95%CI 0.8-56.5, p=0.04), were significant predictors of in-hospital mortality. On multivariable analysis, in-hospital hypotension (OR=9.8, 95%CI 1.5, 63.0, p=0.02), pre-hospital rhythm other than VT/VF (OR=8.5, 95%CI 1.3-58.8, p=0.03), and lack of bystander CPR (OR=13.2, 95%CI 1.6-111, p=0.02) remained statistically significant predictors of in-hospital mortality.

CONCLUSIONS

In-hospital hypotension was predictive of mortality, as was a pre-hospital nonshockable rhythm and lack of bystander CPR. In contrast, traditional pre-hospital risk factors: age, gender, public location of arrest, response time, and witnessed arrest, were not predictive.

Factors associated with pulseless electric activity versus ventricular fibrillation: the Oregon sudden unexpected death study

BACKGROUND

Corresponding with a continuing decline in the prevalence of sudden cardiac arrest cases presenting with ventricular fibrillation (VF), there has been a significant rise in the prevalence of pulseless electrical activity (PEA). Given significantly lower survival from PEA versus VF, we comprehensively investigated PEA correlates by incorporating first-responder data with lifetime clinical history information.

METHODS AND RESULTS

In the Portland, Ore, metropolitan area (population ≈1 million), cases of out-of-hospital sudden cardiac arrest who underwent attempted resuscitation were identified prospectively (2002-2007). Those presenting with PEA versus VF and asystole were compared with χ² tests, ANOVA, and logistic regression. A total of 1277 cases aged ≥18 years underwent resuscitation by first responders (mean age, 65±16 years; 67% male). Presenting arrhythmia was VF in 48%, PEA in 25%, and asystole/other in the remainder. Compared with VF cases, PEA cases were older (mean age, 68 versus 63 years; P=0.0002), more likely to be female (37% versus 26%; P=0.0008), and less likely to survive to hospital discharge (6% versus 25%; P<0.0001). A history of syncope was strongly associated with PEA (odds ratio, 2.6; confidence interval, 1.3 to 5.3) after adjustment for age, gender, response time, and arrest circumstances. Black race was also independently associated with PEA (odds ratio, 2.6; confidence interval, 1.3 to 5.4). Pulmonary disease and female gender were significant factors associated with PEA (P for interaction=0.04). In a subgroup analysis of resting ECGs (n=391), there were no differences in cardiac clinical history or prevalence of cardiac conduction system disease (PEA, 31.6% versus VF, 32.2%; P=0.48).

CONCLUSIONS

PEA cases had a significantly higher prevalence of syncope in their lifetime, with other correlates, including black race, that were distinct from VF cases. Potential mechanistic links between syncope and future manifestation with PEA warrant further exploration.

The Changing Epidemiology of Sudden Cardiac Death

Sudden cardiac death (SCD) is a devastating complication of myocardial infarction. The global incidence of coronary artery disease and heart failure has been increasing greatly in recent years. As a consequence, there is expected to be an increase in the incidence of SCD manifesting as a shared worldwide public health problem. This article summarizes SCD epidemiology, with a focus on the anticipated global rise in incidence.

Epidemiology of sudden cardiac death: clinical and research implications

The current annual incidence of sudden cardiac death in the United States is likely to be in the range of 180,000 to 250,000 per year. Coinciding with the decreased mortality from coronary artery disease, there is evidence pointing toward a significant decrease in rates of sudden cardiac death in the United States during the second half of the 20th century. However, the alarming rise in prevalence of obesity and diabetes in the first decade of the new millennium both in the United States and worldwide, would indicate that this favorable trend is unlikely to persist. We are likely to witness a resurgence of coronary artery disease and heart failure, as a result of which sudden cardiac death will have to be confronted as a shared and indiscriminate, worldwide public health problem. There is also increasing recognition of the fact that discovery of meaningful and relevant risk stratification and prevention methodologies will require careful prospective community-wide analyses, with access to large archives of DNA, serum, and tissue that link with well-phenotyped databases. The purpose of this review is to summarize current knowledge of sudden cardiac death epidemiology. We will discuss the significance and strengths of community-wide evaluations of sudden cardiac death, summarize recent observations from such studies, and finally highlight specific potential predictors that warrant further evaluation as determinants of sudden cardiac death in the general population.

A swine model of pseudo-pulseless electrical activity induced by partial asphyxiation

BACKGROUND

The incidence of pulseless electrical activity (PEA) as a presenting rhythm during cardiac arrest is increasing. The current animal models of PEA arrest, post-countershock or total asphyxiation, unreliably generate PEA for a specific time period. Neither of these models predictably generate pseudo-PEA. The purpose of this study was to create an animal model of pseudo-PEA that will allow for a prolonged time period in this arrest state for future research.

METHODS

In a laboratory setting, five ventilated swine on inhaled anesthesia and 100% oxygen with continuous EKG recordings were instrumented with central aortic and venous pressure-transducing catheters. Animals were then switched to intravenous anesthesia while being ventilated with a 16% oxygen/84% nitrogen mix. Continuous EKG, aortic and venous pressures were recorded to a computerized data collection program. Arterial blood gas samples were taken every 10min. Time until onset of pseudo-PEA, duration of pseudo-PEA, and cardiac rhythm during pseudo-PEA were recorded.

RESULTS

Mean time to onset of pseudo-PEA was 80.6+/-47.3min. Mean duration of pseudo-PEA was 18.6+/-6.2min. Mean arterial pH at pseudo-PEA onset was 7.20+/-0.05 with a mean associated base excess of -11.4+/--5.94. No significant differences were noted in other recorded variables.

CONCLUSIONS

Partial asphyxiation using a 16% oxygen/84% nitrogen mix is a reliable laboratory method to create a prolonged state of pseudo-PEA in a swine model. The mechanism generating pseudo-PEA is hypoxemia-induced systemic acidosis. This model will allow sufficient time in this low-flow cardiac state for future research to be conducted.

C.A.U.S.E.: Cardiac arrest ultra-sound exam—A better approach to managing patients in primary non-arrhythmogenic cardiac arrest

Cardiac arrest is a condition frequently encountered by physicians in the hospital setting including the Emergency Department, Intensive Care Unit and medical/surgical wards. This paper reviews the current literature involving the use of ultrasound in resuscitation and proposes an algorithmic approach for the use of ultrasound during cardiac arrest. At present there is the need for a means of differentiating between various causes of cardiac arrest, which are not a direct result of a primary ventricular arrhythmia. Identifying the cause of pulseless electrical activity or asystole is important as the underlying cause is what guides management in such cases. This approach, incorporating ultrasound to manage cardiac arrest aids in the diagnosis of the most common and easily reversible causes of cardiac arrest not caused by primary ventricular arrhythmia, namely; severe hypovolemia, tension pneumothorax, cardiac tamponade, and massive pulmonary embolus. These four conditions are addressed in this paper using four accepted emergency ultrasound applications to be performed during resuscitation of a cardiac arrest patient with the aim of determining the underlying cause of a cardiac arrest. Identifying the underlying cause of cardiac arrest represents the one of the greatest challenges of managing patients with asystole or PEA and accurate determination has the potential to improve management by guiding therapeutic decisions. We include several clinical images demonstrating examples of cardiac tamponade, massive pulmonary embolus, and severe hypovolemia secondary to abdominal aortic aneurysm. In conclusion, this protocol has the potential to reduce the time required to determine the etiology of a cardiac arrest and thus decrease the time between arrest and appropriate therapy.

Erythropoietin improves the postresuscitation myocardial dysfunction and survival in the asphyxia-induced cardiac arrest model

To investigate the effect of erythropoietin for the management of postresuscitation myocardial dysfunction following asphyxia-induced cardiac arrest. Male adult Wistar rats were used for the prospective controlled animal study. Asphyxia-induced cardiac arrest was performed by turning-off the ventilator and clamping the endotracheal tube. Cardiopulmonary resuscitation with an intravenous injection of 0.01 mg/kg epinephrine and mechanical ventilation were started after 6.5 minutes of asphyxia. The resuscitated animals received either erythropoietin (5000 U/kg) or equivalent volume of 0.9% saline as placebo intravenously 3 minutes after return of spontaneous circulation. The erythropoietin treatment produced better left ventricular dP/dt40 and -dP/dt in the invasive hemodynamic measurements, and left ventricular fraction shortening by echocardiography. Administration of erythropoietin also improved three days survival among those successfully resuscitated. The molecular effects of erythropoietin were shown by activation of its down streaming Akt and ERK 42/44 signaling pathways. EPO has the potential to improve postresuscitation myocardial dysfunction and short term survival in rats after asphyxia-induced cardiac arrest.

Unexpected fatal neurological deterioration after successful cardio-pulmonary resuscitation and therapeutic hypothermia

A 77-year-old woman was admitted to the intensive care unit after successful cardiopulmonary resuscitation for out-of-hospital cardiac arrest due to pulseless electrical activity. She was treated with mild therapeutic hypothermia to minimise secondary anoxic brain damage. After a 24 h period of therapeutic hypothermia with a temperature of 32.5 degrees C, the patient was rewarmed and sedation discontinued. Neurological evaluation after 24 h revealed a maximum Glasgow Coma Score of E4M4Vt with spontaneous breathing. However the patient developed a fever reaching 39 degrees C for several hours that was unresponsive to conventional cooling methods. In the subsequent 24 h patient developed apnoea, hypotension and bradycardia with deterioration of the coma score. Diabetes insipidus was confirmed. Cerebral CT was performed which showed diffuse brain oedema with herniation and brainstem compression. The patient died within hours. Autopsy showed massive brain swelling and tentorial herniation. Hyperthermia possibly played a pivotal role in the development of this fatal insult to this vulnerable brain after cardiac arrest and therapeutic hypothermia treatment. The acute histopathological alterations in the brain, possibly caused by the deleterious effects of fever after cardiac arrest in human brain, may be considered a new observation.

Cost-effectiveness of automated external defibrillators in public places: con

PURPOSE OF REVIEW

To discuss the clinical effectiveness, public health impact and cost-effectiveness of public access defibrillation.

RECENT FINDINGS

High rates of survival from prehospital ventricular fibrillation have been documented in patients treated by first responders using automated external defibrillators. The recent Public Access Defibrillation trial demonstrated a doubling of cardiac arrest survival in community units where volunteers trained in cardiopulmonary resuscitation were additionally equipped with automated external defibrillators. The cost-effectiveness analysis of the Public Access Defibrillation trial has not yet been published, and previous analyses have lacked full data on cost, outcome, or both. Data from many sources indicate that automated external defibrillator placement at sites with an expected rate of one cardiac arrest per defibrillator per 5 years, as recommended by the American Heart Association, addresses only around 1-2% of prehospital arrests, and will have a minimal impact on population survival.

SUMMARY

While highly targeted provision of automated external defibrillators in areas of greatest risk, such as casinos and airports, may be cost-effective, it will have little impact at a population level. Provision of more widespread public access defibrillation to sites with lower incidence of cardiac arrest is unlikely to be cost-effective, and may represent poorer value for money than alternative healthcare interventions in coronary artery disease.

Epidemiology, trends, and outcome of out-of-hospital cardiac arrest of non-cardiac origin

INTRODUCTION

The majority of victims who experience out-of-hospital cardiac arrest (OHCA) have ventricular fibrillation (VF) as the presenting rhythm and are thought to have a cardiac etiology for their arrest. Over the past decade, the incidence of VF OHCA has declined. The aims of this study were to describe the epidemiology of OHCA of non-cardiac origin in Olmsted County MN and to determine the trends that have occurred over time.

METHODS

All residents with a traumatic OHCA from 1995 to 2005 were included for analysis. OHCA data were collected prospectively according to the Utstein method. Cardiac arrests were classified as cardiac or non-cardiac in origin and the etiology determined based on autopsy reports, electronic medical records, and/or emergency medical services reports.

RESULTS

During the study period, 414 OHCAs were identified, 90 (21.7%) of which were classified as non-cardiac. Mean age was 61.5+/-19.7 years. Response time was 7.73+/-2.9 min, and 40 (44.4%) were bystander-witnessed. Sixty-eight (75.6%) arrests occurred at home, 13 (14.4%) in a public place, and 9 (10%) in other locations. Bystander CPR was performed in 17 (18.9%) cases. The presenting rhythm was VF in 2 (2.2%) cases, PEA in 54 (60%), and asystole in 34 (37.8%). Eight (8.9%) patients survived to hospital discharge. Respiratory failure (35.6%), unknown (15.6%), and pulmonary embolism (13.3%) were the most common etiologies. The mean percentage of arrests due to a non-cardiac cause in three sequential time-periods (1995-1999, 2000-2002, 2003-2005) was 9.4%, 20.1% and 37.7%, respectively.

CONCLUSIONS

Over the study period, 21.7% of OHCAs were non-cardiac in origin. PEA was the most common presenting rhythm and respiratory failure the most common etiology. 8.9% of patients survived. The decreasing number of VF arrests may be a contributing factor to the increasing proportion of OHCAs of non-cardiac etiology observed in the out-of-hospital setting.

The natural biochemical changes during ventricular fibrillation with cardiopulmonary resuscitation and the onset of postdefibrillation pulseless electrical activity

OBJECTIVE

The objective of this study was to document the biochemical changes during ventricular fibrillation (VF) with cardiopulmonary resuscitation (CPR), and to identify factors associated with postdefibrillation pulseless electrical activity (PD-PEA).

BACKGROUND

It has been reliably estimated that as much as 60% of out-of-hospital sudden cardiac death can be attributed to the onset of PD-PEA (Niemann JT, Cruz B, Garner D et al. Immediate countershock versus CPR before countershock in a 5-minute swine model of ventricular fibrillation arrest. Ann Emerg Med 2000;36:543-6). Previous attempts to treat reversible causes of pulseless electrical activity have not been successful clinically (Niemann JT, Stratton SJ, Cruz B, Lewis RJ. Outcome of out-of-hospital postcountershock asystole and pulseless electrical activity versus primary asystole and pulseless electrical activity. Crit Care Med 2001;29:2366-70).

METHODS

This investigation used 22 studies on 14 anesthetized pigs breathing 100% oxygen. Ventricular fibrillation was induced with a right ventricular catheter electrode, and the chest was compressed with a pneumatically driven Chest Thumper (Michigan Instruments) (80-100 lb at 60/min). The electrocardiogram and aortic pressure were recorded continuously. Arterial pH, P(O2), P(CO2), Na+, K+, Ca2+, Cl-, SaO2, glucose, hematocrit, and hemoglobin level were measured at selected times. Ventricular defibrillation was achieved with transchest electrodes.

RESULTS

Typically, during VF with CPR, mean aortic pressure was 20 to 25 mm Hg. In all cases aortic P(O2) decreased to about 20% of the initial value in 10 minutes, and aortic blood K+ increased by 50% in 6 minutes. By 5 to 8 minutes, the incidence of PD-PEA was 50%.

CONCLUSION

Ventricular fibrillation duration, arterial K+, and arterial P(CO2) were statistically correlated with the onset of PD-PEA in this study. In addition, trends suggest an association of mean arterial blood pressure and arterial P(O2) with the onset of PD-PEA.

A new device producing manual sternal compression with thoracic constraint for cardiopulmonary resuscitation

OBJECTIVE

Blood flow during conventional cardiopulmonary resuscitation (CPR) is usually less than adequate to sustain vital organ perfusion. A new chest compression device (LifeBelt) which compresses both the sternum and the lateral thoraces (compression and thoracic constraint) has been developed. The device is light weight, portable, manually powered and mechanically advantaged to minimize user fatigue. The purpose of this study was to evaluate the mechanism of blood flow with the device, determine the optimal compression force and compare the device to standard manual CPR in a swine arrest model.

METHODS

Following anesthesia and instrumentation, intravascular contrast injections were performed in four animals and the performance characteristics of the device were evaluated in eight animals. In a comparative outcome study, 42 anesthetized and instrumented swine were randomized to receive LifeBelt or manual CPR. Ventricular fibrillation (VF) was induced electrically and was untreated for 7.5 min. After 7.5 min, countershocks were administered and chest compressions initiated. Pulseless electrical activity (PEA) was observed after one to three shocks in all animals. CPR was continued until restoration of spontaneous circulation (ROSC) or for 10 min after the first shock. If ROSC had not occurred within 5 min of beginning CPR, 0.01 mg/kg of epinephrine (adrenaline) was administered. During CPR, peak systolic aortic pressure (Ao), diastolic coronary perfusion pressure (CPP-diastolic aortic minus diastolic right pressure) and end-tidal CO(2) were measured.

RESULTS

Angiographic studies demonstrated cardiac compression as the mechanism of blood flow. Optimal performance, determined by coronary perfusion pressure, was observed at a sternal force of 100-130 lb (45-59 kg). In the comparative trial, significant differences in the measured CPP were observed between LifeBelt and manual CPR both at 1 min (15+/-8 mmHg versus 10+/-6 mmHg, p<0.05) and 5 min (17+/-4 mmHg versus 13+/-7 mmHg, p<0.02) of chest compression. A greater (p<0.05) ETCO(2), a marker of cardiac output and systemic perfusion, was observed with LifeBelt CPR (20+/-7 mmHg) than with manual CPR (15+/-5 mmHg) at 1 min. Peak Ao pressures were not different between methods. With the device, 86% of animals were resuscitated compared to 76% in the manual group.

CONCLUSIONS

Blood flow with the LifeBelt device is primarily the result of cardiac compression. At a sternal force of 100-130 lb (45-59 kg), the device produces greater CPP than well-performed manual CPR during resuscitation from prolonged VF.

The effect of global hypoxia on myocardial function after successful cardiopulmonary resuscitation in a laboratory model

Most laboratory studies of cardiac arrest use models of ventricular fibrillation, but in the emergency room, operating room or intensive care unit, cardiac arrest frequently results from asphyxia. We sought to investigate the effect of different durations of asystole secondary to asphyxia on myocardial function after resuscitation. In a laboratory based experimental series, anaesthetized rats received either 4 or 8 min of asphyxial cardiac arrest, and following standardized resuscitation, serial transthoracic echocardiography was performed. Severe depression of left ventricular fractional shortening occurred in both groups with partial recovery only in the 4-min arrest group, while left ventricular end-diastolic diameter was increased in the 4-min group. The pH, HCO3(-) and SBE were reduced in both groups after resuscitation, but the degree of acidosis was greater in the 8-min group. In this model, transthoracic echocardiography demonstrated both systolic and diastolic impairment following asphyxial cardiac arrest, and a clear dose-effect relationship between duration of asphyxia and degree of impairment. A shorter duration of asphyxia was associated with a lesser increase in left ventricular end-diastolic dimension, compared with more protracted asphyxia; the shorter arrest was associated with better recovery of contractile function and acidosis. Increased duration of asphyxia causes increased systolic and diastolic dysfunction. These findings may have significant implications for resuscitative therapeutics. ECHO assessment may permit specific targeting of therapy directed towards systolic or diastolic function during CPR.

Clinical evaluation of an inspiratory impedance threshold device during standard cardiopulmonary resuscitation in patients with out-of-hospital cardiac arrest*

OBJECTIVE

To determine whether an impedance threshold device, designed to enhance circulation, would increase acute resuscitation rates for patients in cardiac arrest receiving conventional manual cardiopulmonary resuscitation.

DESIGN

Prospective, randomized, double-blind, intention-to-treat.

SETTING

Out-of-hospital trial conducted in the Milwaukee, WI, emergency medical services system.

PATIENTS

Adults in cardiac arrest of presumed cardiac etiology.

INTERVENTIONS

On arrival of advanced life support, patients were treated with standard cardiopulmonary resuscitation combined with either an active or a sham impedance threshold device.

MEASUREMENTS AND MAIN RESULTS

We measured safety and efficacy of the impedance threshold device; the primary end point was intensive care unit admission. Statistical analyses performed included the chi-square test and multivariate regression analysis. One hundred sixteen patients were treated with a sham impedance threshold device, and 114 patients were treated with an active impedance threshold device. Overall intensive care unit admission rates were 17% with the sham device vs. 25% in the active impedance threshold device (p = .13; odds ratio, 1.64; 95% confidence interval, 0.87, 3.10). Patients in the subgroup presenting with pulseless electrical activity had intensive care unit admission and 24-hr survival rates of 20% and 12% in sham (n = 25) vs. 52% and 30% in active impedance threshold device groups (n = 27) (p = .018, odds ratio, 4.31; 95% confidence interval, 1.28, 14.5, and p = .12, odds ratio, 3.09; 95% confidence interval, 0.74, 13.0, respectively). A post hoc analysis of patients with pulseless electrical activity at any time during the cardiac arrest revealed that intensive care unit and 24-hr survival rates were 20% and 11% in the sham (n = 56) vs. 41% and 27% in the active impedance threshold device groups (n = 49) (p = .018, odds ratio, 2.82; 95% confidence interval, 1.19, 6.67, and p = .037, odds ratio, 3.01; 95% confidence interval, 1.07, 8.96, respectively). There were no statistically significant differences in outcomes for patients presenting in ventricular fibrillation and asystole. Adverse event and complication rates were also similar.

CONCLUSIONS

During this first clinical trial of the impedance threshold device during standard cardiopulmonary resuscitation, use of the new device more than doubled short-term survival rates in patients presenting with pulseless electrical activity. A larger clinical trial is underway to determine the potential longer term benefits of the impedance threshold device in cardiac arrest.

The Department of Health National Defibrillator Programme: analysis of downloads from 250 deployments of public access defibrillators

From April 2000 to November 2002, the Department of Health (England) placed 681 automated external defibrillators (AEDs) in 110 public places for use by volunteer lay first responders. An audit has been undertaken of the first 250 deployments, of which 182 were for confirmed cardiac arrest. Of these, 177 were witnessed whilst 5 occurred in situations that were remote or initially inaccessible to the responders. The response interval between collapse and the initiation of CPR or AED placement was estimated to be 3-5 min in most cases. Ventricular fibrillation or rapid ventricular tachycardia (one case) was the first recorded rhythm in 146 cases (82%). In all, 44 of the 177 witnessed cases are known to have survived to hospital discharge (25%). Complete downloads are available for 173 witnessed cases and of these 140 were shocked: first-shock success, defined as termination of the fibrillatory waveform for 5 s or more, was achieved in 132 of them. When data quality permitted, the downloads were analysed with special reference to the numbers of compressions given and also to interruptions in compression sequences for ventilations, for rhythm analysis by the AED, for clinical checks, and for unexplained operator delays. The average rate of compressions during sequences was 120 min(-1), but because of interruptions, the actual number administered over a full minute from the first CPR prompt was a median of only 38. The speed of response by the lay first responders in relation to AED use was similar to that reported for healthcare professionals.

Localization of out-of-hospital cardiac arrest in Göteborg 1994–2002 and implications for public access defibrillation

PURPOSE

The purpose of this study was to report the locality of out-of-hospital cardiac arrest (OHCA) in the city of Goteborg and to identify implications for public access defibrillation (PAD).

METHODS

Ambulance run reports for the years 1994-2002 were studied retrospectively and manually to establish the location of the cardiac arrest.

RESULTS

The location could be identified in 2194 of 2197 patients (99.9%). One thousand four hundred and twenty-nine (65%) of the arrests took place in the victims' homes. Two hundred eighty-five (13%) were outdoors and 57 (3%) in cars. Fifty-one (2%) took place en route in ambulances. These arrests were regarded not to be generally suitable for PAD. One hundred thirty-five (6%) of the arrests happened in a public building. Eighteen of these 135 were in 15 different general practitioners' offices. A ferry terminal had 11 cardiac arrests. One hundred fifty (7%) of the arrests took place in different care facilities. Twenty-one (1%) patients had their cardiac arrest in public transport locations. Twenty-two (1%) patients arrested at work in 20 different sites. In total, 17% of the cardiac arrests were regarded as generally suitable for PAD. Several sites with more than one cardiac arrest in five years could be identified and 54 patients (2.5%) had their cardiac arrest in these high-incidence sites.

CONCLUSION

Among patients suffering from out-of-hospital cardiac arrest in Goteborg in whom resuscitation efforts were attempted 17% of all cardiac arrests were regarded as generally suitable for PAD. According to previous suggestions, the indication for public access defibrillation is in a place with a reasonable probability of use of one AED in 5 years. Several high-incidence sites that probably would benefit from defibrillator availability could be identified, and 54 patients (2.5%) arrested in these sites.

Survival from in-hospital cardiac arrest: the potential impact of infection

OBJECTIVE

The aim of this study was to examine the relationship between outcome from cardiac arrest and infection status at the time of in-hospital cardiac arrest.

DESIGN

This was a retrospective database review from a single resuscitation service supporting two major hospitals.

SETTING

Two urban University Hospitals in London.

PATIENTS

Data from 1436 in-patient cardiac arrest were available for analysis.

INTERVENTIONS

Nil.

MEASUREMENTS AND RESULTS

Patients were classified into infected or non-infected groups by the resuscitation audit process and the hospitals diagnostic coding unit. Survival was followed according to the in-hospital Utstein timepoints. In addition, the data were examined by presenting the cardiac rhythm. Age and length of prior hospitalisation were recorded. Infection associated diagnoses appear to be increasing in prevalence. Initial survival from cardiac arrest was not affected by infection status, but this did have a substantial impact on chance of leaving the initial hospital (odds ratio 0.52, confidence intervals 0.3-0.8), or being discharged to home (odds ratio 0.48, confidence intervals 0.4-0.8). The outcome from ventricular fibrillation/pulseless ventricular tachycardia was worse for infected patients (odds ratio for home discharge 0.37, confidence intervals 0.2-0.9), although initial survival was not significantly different.

CONCLUSIONS

Infection may be becoming an increasingly important association with cardiac arrest in the hospitalised population. Initial survival from cardiac arrest is the same as for non-infected patients, but longer term survival is much poorer. Long-term survival from ventricular fibrillation or pulseless ventricular tachycardia is relatively poor, in spite of similar initial success.

Are the MADIT II Criteria for ICD Implantation Appropriate for Japanese Patients?

BACKGROUND

The Multicenter Automatic Defibrillator Implantation Trial (MADIT) II investigators concluded that prophylactic use of an implantable cardioverter defibrillator (ICD) improved survival in patients with prior myocardial infarction (MI) and reduced the left ventricular ejection fraction (LVEF). However, it is unclear whether MADIT II criteria for ICD implantation are appropriate for Japanese patients.

METHODS AND RESULTS

During the period 1997 to 2001 90 (M/F: 75/15; mean age: 65+/-9 years) of the 3,258 patients who underwent elective cardiac catheterization met MADIT II criteria (Q-wave MI more than 4 weeks prior; LVEF <or=0.30; >21 years of age; electrophysiologic testing not required) and were selected in this retrospective study of patient prognosis after catheterization. During the 37+/-12-month follow-up period, 15 patients died of congestive heart failure (n=9), sudden cardiac death (n=2), acute MI (n=1), or noncardiac causes (n=3). The survival rate in the present series was comparable with that in the MADIT II defibrillator group, but higher than that in the MADIT II conventional therapy group. A significantly greater percentage of the present patients were found to be in New York Heart Association class I and have undergone percutaneous coronary intervention than in MADIT II.

CONCLUSION

These results suggest that it may be inappropriate to apply MADIT II criteria to Japanese patients.