Ventricular Fibrillation In Patients Research Articles

Mode of onset of ventricular fibrillation in patients with early repolarization pattern vs. Brugada syndrome

The aim of the present study was to identify specific electrocardiogram (ECG) features that predict the development of multiple episodes of ventricular fibrillation (VF) in patients with an early repolarization (ER) pattern and to compare the mode of VF initiation with that observed in typical cases of Brugada syndrome (BrS). The mode of the onset and the coupling intervals of the premature ventricular contractions (PVCs) initiating VF episodes were analysed in patients with BrS (n = 8) or ER who experienced sudden cardiac death/syncope or repeated appropriate implantable cardioverter defibrillator shocks. Among the 11 patients with ER, 5 presented with electrical storm (ES, four or more recurrent VF episodes/day). The five ES patients displayed a dramatic but very transient accentuation of J waves across the precordial and limb leads prior to the development of ES. Ventricular fibrillation episodes were more commonly initiated by PVCs with a short-long-short (SLS) sequence in ER (42/58, 72.4%) vs. BrS patients (13/86, 15.1%, P < 0.01). Coupling intervals were significantly shorter in the ER group compared with those with BrS [328 (320, 340) ms vs. 395 (350, 404) ms, P < 0.01]. Our study provides additional evidence in support of the hypothesis that ER pattern in the ECG is not always benign. Transient augmentation of global J waves may be indicative of a highly arrhythmogenic substrate heralding multiple episodes of VF in patients with ER pattern. Ventricular tachycardia/VF initiation is more commonly associated with an SLS sequence, and PVCs display a shorter coupling interval in patients with ER pattern compared with those with BrS.

RR-interval irregularity precedes ventricular fibrillation in ST elevation acute myocardial infarction

Sudden cardiac arrest is a leading cause of death in industrialized countries, and ischemic ventricular fibrillation (VF) is a frequent cause. The purpose of this study was to determine whether patients with ST elevation myocardial infarction (STEMI) who develop ischemic VF show more overall RR-interval irregularity (RRI) than do STEMI patients without ischemic VF. Ischemic VF was identified in 41 patients from 1,473 digital 12-lead Holter recordings from three separate STEMI studies. Continuous 3-lead and 12-lead electrocardiogram (ECG) snapshots recorded every minute were compared between all ischemic VF patients and 123 random patients without ischemic VF. Time intervals from start of Holter to ischemic VF and equivalent intervals in the controls were used for calculations. ECG variables related to conduction intervals and severity of ischemia were measured using the most ischemic 12-lead ECG. RRI was calculated as the square root of the mean squared differences of successive RR intervals. For RRI, all QRS complexes, including ventricular ectopic beats, were used. No baseline differences were observed between the study and control groups, except for male preponderance among ischemic VF patients (90% vs 72%, P = .019). QRS interval, ECG ischemia severity, RRI, and number of ventricular ectopic beats were significantly associated with ischemic VF. Multivariate analysis revealed RRI (odds ratio 1.006, 95% confidence interval 1.001-1.010, P = .016) and ST deviation score (odds ratio 1.073, 95% confidence interval 1.041-1.106, P <.001) as the only statistically significant predictors of ischemic VF. In the period before ischemic VF, RRI and ST deviation score are associated with ischemic VF in STEMI patients. These findings could have important pathophysiologic and clinical implications.

Prognosis among survivors of primary ventricular fibrillation in the percutaneous coronary intervention era

Sudden cardiac death (SCD) constitutes one of the most prevalent modes of death and is mainly caused by primary ventricular fibrillation (VF), that is, VF in the acute setting of a first acute myocardial infarction (MI). Current guidelines for secondary prevention of SCD are based on data from the thrombolysis era. We analyzed follow-up data of a large group of primary VF survivors to determine prognosis and risk of SCD in patients who received contemporary MI treatment. Patients in this study were included in the ongoing Dutch multicenter primary VF study between December 1999 and April 2007. Primary VF was defined as VF during the first ST-elevation myocardial infarction (STEMI). Patients surviving the first 30 days were analyzed in this study. Data on mortality, cause of death, hospitalization, and implantable cardioverter-defibrillator (ICD) implantation were retrieved from national databases. In addition, data on left ventricular ejection fraction and medication use during follow-up were retrieved. In total, 341 primary VF patients (cases) and 292 STEMI patients without VF (controls) were included in the study. Demographic and infarct characteristics were comparable between both groups. The median follow-up was 3.33 years for cases and 3.69 for controls (P = .02). The left ventricular ejection fraction post-STEMI was 45.1% versus 46.5% (P = .342). During follow-up, 19 cases died versus 24 controls. Cox regression analysis showed no significant difference in survival between cases and controls (relative risk 0.59, 95% CI 0.15-2.30). Implantable cardioverter-defibrillators were implanted in 22 cases and 2 controls (P < .001), but only 2 cases and 1 control patient received appropriate ICD shocks. beta-Blocker use during follow-up was 84.4% in cases versus 76.2% in controls (P = .049). Of cases, 2.5% were rehospitalized for acute MI versus 10.1% of controls (P < .001). The numbers of admissions for acute coronary syndromes and chest pain were not different between groups. In conclusion, patients who survive the first month after primary VF have a similar prognosis as patients with a STEMI without VF. This is the first study to address this question in the modern era of reperfusion therapy. Implantable cardioverter-defibrillator treatment in primary VF patients without residual ischemia or other risk factors can be safely withheld.

Spectral Analysis of Sustained and Non-Sustained Ventricular Fibrillation in Patients With an Implantable Cardioverter-Defibrillator

The mechanisms responsible for the maintenance and termination of ventricular fibrillation (VF) are poorly understood. The aim of this study was to compare the spectral characteristics of the electrical signal during sustained and non-sustained VF in patients with an implantable cardioverter-defibrillator. The study included 51 patients who had had at least one episode of sustained VF (i.e., duration >5 s and requiring shock administration) and non-sustained VF (i.e., duration >3 s and spontaneously terminated) that were recorded by the device set in a unipolar configuration. Spectral analysis of the first 3 s of each episode was performed. The dominant frequency was higher in sustained VF (4.6+/-0.7 Hz) than in non-sustained VF (4.3+/-0.6 Hz; P=.01), while the other parameters were similar. Although the spectral characteristics of sustained and non-sustained VF were similar, differences were observed during the first 3 s that could be used in algorithms for the early detection of non-sustained VF.

Shortening of cardiopulmonary resuscitation time before the defibrillation worsens the outcome in out-of-hospital VF patients

Objective The purpose of the study is to investigate the influence of cardiopulmonary resuscitation (CPR) time before the first defibrillation. Methods The present study retrospectively analyzed the Utstein template records from April 1, 2002, to June 30, 2005. Patients who had out-of-hospital–witnessed cardiac arrest caused by cardiac disease and who presented with ventricular fibrillation (VF) as the initial cardiac rhythm were included in the study. Before April 1, 2003, the emergency medical technician (EMT) needed to obtain telephone permission before attempting defibrillation, and CPR was continued until permission was received (CPR first). On and after April 1, 2003, the EMT was immediately able to attempt a defibrillation without obtaining permission (shock first). Results In 143 patients who had out-of-hospital–witnessed VF, 43 patients and 100 patients were treated with the CPR-first strategy and the shock-first strategy, respectively. The duration of CPR before the first defibrillation was longer in the CPR-first group than that in the shock-first group. The CPR-first group showed a higher rate of favorable neurologic outcome 30 days after (28% vs 14%; P = .048) and 1 year after cardiac arrest (26% vs 11%; P = .033) than those of the shock-first group. In the patients with witnessed VF, a stepwise multiple logistic regression analysis showed the CPR-first strategy to improve the neurologic outcome. Conclusions In patients with out-of-hospital–witnessed VF, sufficient CPR before the first defibrillation is considered to improve the neurologic outcome in comparison to the performance of immediate defibrillation.

Contemporary Analysis of Predictors and Etiology of Ventricular Fibrillation During Diagnostic Coronary Angiography

To assess the incidence, investigate the predictors and analyze the causes of ventricular fibrillation (VF) during coronary angiography (CA) on the condition of current techniques. From April 2004 to January 2007, a total 22,254 patients (27,798 procedures) received CA procedures in our center; 27 patients developed VF during CA. This report was to retrospectively analyze the clinical basic characteristics, coronary angiographic characteristics and CA procedure records of these patients. The incidence of VF during CA was 0.097%. The incidence of VF in radial approaches and femoral approaches was 0.076% and 0.147% (p = 0.085). The VF patients had higher coronary artery bypass grafting (CABG) rates (11.1% vs 2.3%, p = 0.024) and were more likely to have a three-vessel disease (59.3% vs 31.2%, p = 0.002) and a total occlusion lesion (25.9% vs 11.1%, p = 0.014) than non-VF patients. On logistic regression analysis, three-vessel disease (OR: 2.582, 95% CI: 1.165-5.720, p = 0.019) and the history of CABG (OR: 3.959, 95% CI: 1.160-13.513, p = 0.028) were the two independent predictors of VF occurrences. Among 27 episodes of VF, 13 were ischemia-related; 11 were manipulation-related; two were contrast-related; one was hypokalemia-related; and the causes remain unclear in five episodes. The incidence of VF during CA is low on the condition of current techniques. The severity of coronary artery disease (CAD) is an independent predictor of VF occurrence during CA. Acute ischemia and inappropriate manipulation may be the two main causes in VF development.

Oral Magnesium Prophylaxis Provides Spontaneous Resumption of Cardiac Rhythm in Patients Undergoing Cardiac Surgery

Evidence is growing that magnesium supplementation in patients undergoing cardiac surgery is beneficial, however the best administration route has not been established. Previously, we showed that intra-operative direct flush infusion of magnesium into the aortic root before reperfusion was effective. The present study compared pre-operative oral administration of magnesium for 10 days with intra-operative flush infusion of magnesium for spontaneous resumption of cardiac rhythm and ventricular fibrillation in patients undergoing cardiac surgery with cardiopulmonary bypass (CBP). The rate of spontaneous resumption of cardiac rhythm, the number of shocks required for defibrillation, the energy required for defibrillation and the occurrence of post-CPB ventricular tachyarrhythmias were not significantly different between the groups. Serum magnesium levels were minimally increased following administration of magnesium but were within the normal range at all times in both groups. Oral administration of magnesium might provide my oprotective effects during cardiac surgery, but larger trials with a greater statistical power need to be carried out in order to show this.

Differential effects of cardiac sodium channel mutations on initiation of ventricular arrhythmias in patients with Brugada syndrome

Premature ventricular contractions (PVCs) do not occur frequently but can induce ventricular fibrillation (VF) in patients with Brugada syndrome. The effect of SCN5A mutation on the onset of ventricular arrhythmias is unknown. The purpose of this study was to evaluate PVC morphology and onset of VF in patients with Brugada syndrome. Morphology of PVCs was evaluated by 12-lead ECG in 32 patients with Brugada syndrome. Patients had spontaneous ventricular arrhythmia (n = 17) or sodium channel blocker-induced ventricular arrhythmia (n = 19). Patients were classified into two groups according to the existence of SCN5A mutation (22 mutation negative, 10 mutation positive). Patients without mutation often had PVCs of left bundle branch block (LBBB) morphology (82%), especially with inferior axis (77%). Patients with mutation had PVCs of both right bundle branch block (36%) and LBBB (64%) morphologies. Only two patients with mutation had PVCs of LBBB, inferior-axis morphology. Patients without SCN5A mutation often had PVCs of LBBB, inferior-axis morphology, suggesting a right ventricular outflow tract origin. Patients with SCN5A mutations had PVCs that originated from both the right and left ventricles.

Electrical storm reversible by isoproterenol infusion in a striking case of early repolarization

A 40-year-old woman was referred to intensive care unit after recurrent ventricular fibrillation. She was free of cardiac medical history or medications. The resting ECG displayed an extended early repolarization in the inferior leads and all the precordial leads. Incessant ventricular fibrillations justified a treatment by intravenous amiodarone associated with general anaesthesia and mechanical ventilation without success on ventricular fibrillation. Because of a low heart rate intravenous isoproterenol infusion was initiated. Isoproterenol infusion was associated with heart rate acceleration and a decrease in J point elevation and the disappearance of ventricular fibrillation episodes. No cardiac disease was documented and the patient was implanted of a single chamber ICD. Six months later the patient was free of syncope and ventricular fibrillation on ICD memory. This case report demonstrates the usefulness and efficiency of the isoproterenol infusion to eliminate recurrent ventricular fibrillation in patients with early repolarization.

Importance of Dual Induction Tests for Coronary Vasospasm and Ventricular Fibrillation in Patients Surviving Out-of-Hospital Cardiac Arrest

The pathogenesis of out-of-hospital cardiac arrest (OHCA) without organic heart disease has not been fully investigated. Induction tests were performed in 12 consecutive patients with OHCA for both coronary vasospasm with intracoronary acetylcholine and ventricular fibrillation (VF) with programmed stimulation at 1 month after the event. All patients were positive for 1 of the tests: coronary vasospasm alone in 3, VF alone in 2, and both in 7. All patients underwent implantable cardioverter defibrillator (ICD) implantation and appropriate ICD shock was documented in 1 patient. OHCA has a heterogeneous pathogenesis and so dual induction tests are necessary.

The Effect of Paramedic Experience on Survival from Cardiac Arrest

AbstrastObjective. We hypothesized that paramedics with more experience would be more successful at treating patients in ventricular fibrillation (VF) cardiac arrest than those with less experience. We conducted a study examining the relationship between the years of experience of paramedics and survival from out-of-hospital cardiac arrest. Methods. This retrospective cohort study examined all witnessed, out-of-hospital VF cardiac arrests (n = 699) that occurred between January 1, 2002, and December 31, 2006. Logistic regression was used to determine the odds of survival and the 95% confidence intervals (95% CIs) relating to the number of years of experience that each of the treating paramedics had. Results. We found that every additional year of experience of the medic in charge of implementing procedures such as intravenous line insertions, intubations, and provision of medications was associated with a 2% increase in the likelihood of survival of the patient (95% CI: 1.00–1.04). The number of years of experience of the paramedic who did not perform procedures but instead was in charge of treatment decisions was not significantly associated with survival (odds ratio [OR] 1.01, 95% CI: 0.99–1.03). When we combined both paramedics' years of experience, we saw a 1% increase in the odds of survival for every additional year of experience (95% CI: 1.00–1.03). Conclusions. This study suggests that the amount of experience of the paramedic who performed procedures on cardiac arrest patients was associated with increased rates of survival. However, we did not find an association between survival from VF and the number of years of experience of the paramedic who made treatment decisions.

Effect of fish oil on ventricular tachyarrhythmia in three studies in patients with implantable cardioverter defibrillators

To determine the effects of omega-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish on the incidence of recurrent ventricular arrhythmia in implantable cardioverter defibrillator (ICD) patients by combining results from published trials. We searched in the Medline, EMBASE, and Cochrane databases and performed a meta-analysis on all three available trials on fish oil and ventricular arrhythmia. Furthermore, we pooled individual data of two of these randomized, double-blind, placebo-controlled trials (Raitt et al. Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial. JAMA 2005;293:2884-2891 and Brouwer et al. Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial. JAMA 2006;295:2613-2619). The main outcome was time to first confirmed ventricular fibrillation (VF) or ventricular tachycardia (VT) combined with death for the meta-analysis, and time to first spontaneous confirmed VF or VT for the pooled analysis. The meta-analysis (n = 1148) showed no convincing protective effect of fish oil (RR 0.90; 95% CI 0.67-1.22). The hazard ratio for the subgroup of patients with coronary artery disease at baseline (0.79; 0.60-1.06) tended towards a protective effect. The pooled analysis (n = 722) showed that time to appropriate ICD intervention was similar for fish oil and placebo treatment (log-rank P = 0.79). These findings do not support a protective effect of omega-3 PUFAs from fish oil on cardiac arrhythmia in all patients with an ICD. Current data neither prove nor disprove a beneficial or a detrimental effect for subgroups of patients with specific underlying pathologies.

Does Atrial Fibrillation Beget Ventricular Fibrillation in Patients with Acute Myocardial Infarction?

Atrial fibrillation (AF) is associated with increased mortality and a higher complication rate postmyocardial infarction (MI), but the exact mechanisms are unknown. We investigated whether AF predisposes to ventricular arrhythmia in postmyocardial infarct patients, thereby accounting for increased mortality. Five hundred consecutive patients admitted to our coronary care unit with acute MI were monitored for in-hospital arrhythmias. Detailed information was also compiled on past history, co-morbidities, electrolyte disturbances, drug therapies, and ejection fraction. Mortality data were collected for an average of 5.5 years. The results have shown that the incidence of ventricular fibrillation (VF) is much greater in patients presenting with AF (P=0.03) and multivariate analysis has shown that AF is independently associated with the development of VF. This association occurs principally in patients who are admitted with AF (P=0.01) rather than those who develop it during their admission, although these patients are also at mildly increased risk. The increased incidence of VF does account for increased mortality in the AF patients but does not explain all of their excess risk. There was no association between AF and ventricular tachycardia (VT); P=0.50. In conclusion, AF on admission to the hospital with acute MI is associated with an increased risk of VF and subsequent mortality.

Abstract 5676: Elevated Oxidative Stress is Associated with Ventricular Fibrillation Episode in Patients with Brugada Syndrome without SCN5A Mutation

Background; Brugada Syndrome (BS) is a disease known to cause ventricular fibrillation (VF) with structurally normal heart. Gene mutation (i.e. SCN5A) has been proposed to be related to the development of BS and VF. However, the pathophysiological mechanism associated with VF development without SCN5A mutation has not been studied yet. Oxidative stress is a common disorder that is related to many heart diseases. We have previously demonstrated that oxidative stress is closely linked to the arrhythmic development. Accordingly, we examined 4-hydroxy-2-nonenal (HNE) modified protein, which is a common mediator of oxidative stress in the myocardium, and VF episodes in patients with BS. Methods; We collected sixty-eight BS patients that underwent right ventricular endomyocardial biopsy (66 males, 2 female; mean age 49.0±11.6 years old). VF was documented in 11 and SCN5A mutation was detected in 14 patients. Biopsy samples were processed for histology [Masson’s trichrome staining for fibrosis, immuno staining for CD45, CD68, and HNE modified protein]. All results from histology were compared with VF episodes. We also performed the analysis in VF patients with (n=14) or without SCN5A mutations (n=54). Results: HNE positive area was significantly larger in VF patients [VF(+): 16.3±10.5, VF(−): 9.3±5.7%: P=0.029]. All other parameters (fibrosis area, CD45, and CD68) were not different between the groups. In multivariable analysis, HNE positive area was most important risk factor of VF development in patients without SCN5A mutation (P=0.004). Conclusions ; These data suggested that oxidative stress is associated with VF development in BS patients, especially in patients without SCN5A mutation.

Abstract 653: SCN5A Mutation is Associated with Early and Frequent Recurrence of Ventricular Fibrillation in Patients with Brugada Syndrome

Mutation in SCN5A has been reported to be causally linked to Brugada syndrome (BrS), but recent observation revealed that this mutation is not necessarily associated with ventricular fibrillation (VF) or syncope episode in a case of BrS. We therefore examined the clinical importance of SCN5A mutation in BrS patients. Total 121 patients were examined. The existence of SCN5A mutation (n=14) was not associated with VF/syncope episode [SCN5A (+) vs SCN5A (−), 28.6% (4/14) vs 10.9% (10/92); P=NS]. ICD was implanted for secondary prevention (SP group) in 28 patients (54.9%) and for primary prevention n (PP group) in 23 of 51 patients (45.1%). During a mean follow-up period of 49.3 ± 33.7 months, 13 patients (46.4%) in SP group and 1 patient (4.3%) in PP group had received appropriate shocks. The shock free survival was significantly shorter in SP group than PP group (52.4% vs 88.9% at 5 years, p = 0.0016). Next, we examined SCN5A mutation on the recurrence of VF episode in SP group. The shock free survival was significantly shorter in BrS patients with SCN5A mutation than the patients without SCN5A mutation (0% vs. 76.4% at 1 years, p = 0.002, figure ). Moreover, the number of ICD shocks was significantly larger in BrS patients with SCN5A mutation than in BrS patients without SCN5A mutation (9.3 ± 6.4 vs. 1.7 ± 3.2, p = 0.001). VF inducibility by programmed electrical stimulation was not associated with shock free survival. SCN5A mutation is strongly associated with early and frequent VF recurrence. Additional medical management should be required in symptomatic BrS patients with SCN5A mutation.

Abstract P176: Resumption of Cardiopulmonary Resuscitation after Defibrillation Induces Recurrence of Ventricular Fibrillation

Introduction- Resuscitation guidelines 2005 advise to resume cardiopulmonary resuscitation (CPR) immediately after defibrillation. We hypothesized that this promotes recurrence of ventricular fibrillation (VF). Methods- This was a prospective per-patient randomized controlled trial. We randomized Automated External Defibrillators (AEDs) used by first responders to either a) perform post-shock analysis and prompt rescuers to a pulse check - guidelines 2000 - or b) to resume CPR immediately after defibrillation - guidelines 2005. Between June 2006 and April 2008, we collected continuous ECG and impedance signal of all patients with a non-traumatic out-of-hospital cardiac arrest to whom a study AED was applied. We annotated and calculated time intervals between the first effective shock, moment of CPR resumption, moment of refibrillation, and subsequent defibrillation shock. Intervals are expressed as median and inter quartile range. Results- We collected 120 ECGs of patients with a shockable rhythm: 61 were randomized to guidelines 2000 and 59 patients to guidelines 2005. In respectively 54% (33/61) and 56% (33/59) of the patients VF recurred after the first effective shock. Rescuers resumed CPR after 32 (24–45) and 8 (7–9) seconds (P&lt;0.01), VF recurred at 35 (21–57) and 13 (8–25) seconds after the first effective shock (figure 1 ; P=0.02), the time interval between resumption of CPR and refibrillation was 4 (−8–20) and 6 (1–22) seconds (P=0.59), and VF sustained for 98 (63–204) and 150 (98–261) seconds (P=0.15). Conclusion- CPR induces recurrent VF. Immediate resumption of CPR after effective defibrillation is associated with early and longer lasting recurrence of VF.

Seasonal and circadian distributions of ventricular fibrillation in patients with Brugada syndrome

It is well-known that the incidence of ventricular tachyarrhythmias is the highest in winter and during the daytime in patients with structural heart disease. However, little is known about the seasonal and circadian distributions of ventricular fibrillation (VF) in patients with Brugada syndrome. The aim of this study was to investigate seasonal and circadian distributions of VF in patients with Brugada syndrome. We analyzed the data of appropriate shock episodes for VF recorded by an implantable cardioverter-defibrillator (ICD) in patients with Brugada syndrome. Among 62 consecutive Brugada syndrome patients with an ICD (48 +/- 14 years, 58 males), 19 patients had at least one episode of an appropriate ICD shock due to VF during a mean follow-up of 70 +/- 36 months, and 98 episodes were evaluated as isolated VF. There was a significant peak between March and June (P = .03). As for the circadian variation, significantly more VF occurred from midnight to 6:00 (P <.0001). Electrical storms of VF occurred in seven patients. The seasonal and circadian variations of electrical storms were similar to those of the isolated VF episodes. In patients with Brugada syndrome, there was a significant seasonal peak from spring to early summer and a significant circadian peak from midnight to early morning in terms of the occurrences of VF.

Using within-patient correlation to improve the accuracy of shock outcome prediction for cardiac arrest

Analysis of the electrocardiogram (ECG) can to a certain extent predict if a cardiac arrest patient in ventricular fibrillation will get return of spontaneous circulation (ROSC) if defibrillated. The accuracy of such methods determines how useful it is clinically and for retrospective analysis. We have tested the accuracy of a new shock outcome prediction algorithm that is the first to use an updating algorithm capable of learning from previous shocks within a resuscitation effort. The algorithm relies on known predictive features from the pre-shock ECG, but for each delivered shock it re-estimates the patient-dependent relationship between predictive feature value and probability of ROSC by incorporating the information from the already performed shocks. The predictive features mean-slope, median-slope, cardioversion-outcome-predictor and amplitude-spectrum-analysis originally had areas under the receiver operating characteristics curve of 0.843, 0.846, 0.837 and 0.819, respectively. The improvements in areas after applying the algorithm were (bootstrap estimate of mean improvement, 95% confidence interval in parentheses): mean-slope, 0.019 (0.00036, 0.042); median-slope, 0.024 (0.0013, 0.048); cardioversion-outcome-predictor, 0.021 (0.0010, 0.051); amplitude-spectrum-analysis, 0.026 (0.0016, 0.051). The predictions for the first shock to each patient were not included when calculating the areas, as for the first shocks the new algorithm has no previous shocks to learn from and give predictions identical to those of the original features. It is possible to improve current shock prediction methods by using an updating algorithm capable of learning from previous shocks within a resuscitation effort.

The effect of using within-patient correlation to improve shock outcome prediction

Introduction: The chance of a cardiac arrest patient in ventricular fibrillation (VF) getting return of spontaneous circulation if defibrillated can to a certain extent be predicted by analysis of the ECG. The accuracy of such methods determines how useful it is clinically and for retrospective analysis.

ブルガダ症候群での心室細動誘発に対するキニジン静脈内投与による抑制効果

ブルガダ症候群での心室細動誘発に対するキニジン静脈内投与による抑制効果