Automatic Implantable Cardioverter Defibrillator Implantation Research Articles

Automatic implantable cardioverter defibrillator (AICD) implantation as secondary prevention of cardiac sarcoidosis-associated ventricular tachycardia

Background: Cardiac sarcoidosis can cause a wide range of symptoms, including shortness of breath, chest pain, oedema, and fatal arrhythmias such as ventricular tachycardia (VT). Because the symptoms can be nonspecific, diagnosing cardiac sarcoidosis can be challenging. Treatment options may include corticosteroids to reduce inflammation, immunosuppressive drugs to prevent further damage, medications to control symptoms, ablation procedures, and defibrillators to prevent cardiac arrest. Case: A 60-year-old woman who has sarcoidosis affecting multiple organs including cardiac sarcoidosis, non-ischemic cardiomyopathy with reduced ejection fraction, and hypertension, was admitted with tachycardia, shortness of breath, and a recently fired automatic implantable cardioverter defibrillator (AICD). Three months prior, the patient was admitted for a syncopal episode and diagnosed with cardiac sarcoidosis through cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET), which demonstrated active inflammation, and an AICD was implanted. During this admission, the patient had an episode of ventricular tachycardia and was treated with amiodarone and lidocaine. The patient received steroids, sacubitril/valsartan, and methotrexate. After 48 hours of observation, the patient was discharged without further events. Conclusion: Cardiac sarcoidosis is a rare but serious disease that can lead to life-threatening cardiac complications such as ventricular tachycardia. Early diagnosis and aggressive management are crucial for improving outcomes and preventing sudden cardiac death. AICD implantation as a secondary prevention in cardiac sarcoidosis might prevent cardiac arrest.

Cardiology Research Institute, Tomsk National Research Medical Center

Aim. To assess the prognostic role of cardiac biomarkers (galectin-3, soluble ST2 (sST2), and N-terminal pro-brain natriuretic peptide (NT-proBNP)) in risk stratification of adverse cardiovascular events (CVEs) in patients with heart failure (HF) after implantation of an automatic implantable cardioverter-defibrillator (AICD) within 12-month follow-up period.Material and methods. The study included 57 patients (men, 41; mean age, 65 (59; 68) years) with coronary artery disease and NYHA class II-III HF with left ventricular ejection fraction of 34 [26; 40]%. All patients were implanted with AICD. Serum levels of NT-proBNP, sST2, and galectin-3 were determined by enzyme immunoassay prior to AICD implantation.Results. It has been established that in order to stratify the risk of unfavorable HF in patients after AICD implantation for 12-month follow-up, all three studied biomarkers can be considered as prognostic factors. Thus, an increase in the level of NT-proBNP ≥1046,6 pg/ml (AUC=0,68; p=0,009), sST2 ≥34,43 ng/ml (AUC=0,78; p<0,0001) and galectin-3 ≥11,6 ng/l (AUC=0,72; p=0,0014) predicts a high risk of adverse CVEs. The combination of sST2 and galectin-3 increased the predictive value of the analysis (AUC=0,84; p<0,0001), while the addition of NTproBNP did not increase the accuracy of risk stratification.Conclusion. The determination of the combination of galectin-3 and sST2 can potentially help identify a group of patients with HF after AICD implantation with a high risk of adverse CVEs for intensification and optimization of treatment.

Catheter ablation of well tolerated ventricular tachycardia in patients with structural heart disease: long term follow-up of 62 cases without automatic defibrillator implantation

Abstract Funding Acknowledgements Type of funding sources: None. Background The occurrence of a sustained monomorphic ventricular tachycardias (SMVT) in patients with underlying structural heart disease (SHD) is considered correlated to a poor prognosis, based on historical data in patients with heterogeneous heart disease and clinical presentation; therefore the recommendation for implantation of automatic implantable cardioverter defibrillator (AICD) is strong. Information about prognosis of patients with SMVT is still limited, but recent studies have established that these patients represent a low-risk subgroup for sudden death that could benefit from radiofrequency (RF) ablation of the arrhythmic substrate and the AICD implantation could be deferred during the follow up. Purpose Patients with well-tolerated SMVT, SHD and left ventricular ejection fraction (LVEF) over 30% can benefit from a primary VT ablation strategy without the immediate need for AICD implantation. Methods We reviewed consecutive SHD patients with LVEF over 30% admitted for the occurrence of SMVT and who were treated by RF ablation as a first-choice therapy in a single Italian center, between 2009 and 2020 and who were discharged without AICD implantation. The primary outcome of the study was a composite of all-cause death and recurrence of VT. The secondary outcome was death from all causes. Patients with similar characteristics but who underwent AICD implantation during the same period served as control group. Results Clinical and electrophysiological features of 62 patients were analyzed (Table 1). In the study group, 88% were male; the median age was 72 years (IQR 55-81) and the median LVEF was 50.0% (IQR 40.0-55.0). The estimated success rate of ablative procedures (defined as VT no longer inducible) was around 82%. After a median follow-up of 38.8 months (IQR 15.6-76.1), the primary outcome occurred in 24 patients and the secondary outcome in 11 patients. All-cause mortality was 17%, corresponding to an annual mortality rate of 4.3%. Ten patients died for non-cardiovascular causes and one for advanced heart failure. No patient in the study died from sudden death. During the follow-up, 10 patients (16.1%) underwent AICD implantation due to VT relapse. At 36 months, between study and control groups, there was no difference in either the primary composite outcome (HR 1.03, 95% CI 0.45-2.21, p = 0.98) or in the secondary outcome (HR 1.4, 95% CI 0.48-4.54, p = 0.49). Conclusions Patients with well-tolerated SMVT, SHD and LVEF over 30% represent a subgroup of patients at lower risk that can benefit of RF ablation as a first-choice therapy. Delay in AICD implantation, after a possible VT relapse or clinical worsening, appears to represent a safe therapeutic strategy. Therefore, it is ethical and desirable to start a prospective randomized clinical trial to evaluate the benefit and cost-effectiveness of this strategy, as an alternative to AICD implantation.

Arrhythmogenic Right Ventricular Dysplasia Diagnosed in a Patient with Long-term Undiagnosed Syncope

Arrhythmogenic Right Ventricular Dysplasia (ARVD) is an inherited cardiomyopathy which represents progressive replacement of right ventricular myocardium with fibrofatty tissue. In the present case, a 42-year-old male presented to the hospital as he fell down, due to syncope. He had a history of recurrent syncopal in past 4-5 years. His chest radiogram revealed cardiomegaly (CT ratio 0.64), repeat electrocardiogram showed symmetric T-wave inversions and epsilon waves in right precordial V1, V2 and V3 leads, and echocardiogram revealed mild left ventricular dysfunction (ejection fraction - 45%) and dilated right atrium and ventricle. Cardiac Magnetic Resonance Imaging (MRI) confirmed the diagnosis of ARVD.The patient was advised for the placement of an Automatic Implantable Cardioverter Defibrillator (AICD), but he denied for this treatment. Thus, he was managed with anti-arrhythmic drugs and was advised for regular follow-up. The patient was followed-up for six months where episodes of syncope had significantly reduced to one in six months but need of AICD implantation was still there to avoid sudden cardiac death.

Defibrillator-Heart Pump: An Implantable Ventricular Assist Device With Integrated Defibrillator Component-The First In Vitro Testing.

Left ventricular assist devices (LVADs) are an important therapeutic option for patients with end-stage heart failure waiting for heart transplantation or in older patients as definite therapy for heart failure. Interestingly, about 62% of patients receiving LVADs do not have an automatic implantable cardioverter-defibrillator (AICD) at the time of implantation, although these patients have increased risk of being confronted with dangerous arrhythmia. Therefore, an LVAD system including AICD function is a reasonable alternative for such heart failure patients thereby avoiding a second surgical intervention for AICD implantation. In this article, a newly developed system including LVAD and AICD function is introduced, and we also report its first in vitro testing.

Non-Compaction Cardiomyopathy. Risk Stratification of Sudden Death for Automatic Cardioverter Defibrillator Implantation

SUMMARY Non-compaction cardiomyopathy is a rare disease. Its natural history includes heart failure, thromboembolic events, arrhythmias and sudden death (SD). In the absence of data from randomized studies or records, the ACC / AHA / HRS 2008 guidelines recommend the automatic implantable cardioverter defibrillator (AICD) in all patients with non-compaction cardiomyopathy to reduce the risk of suden death. Objective Describe the outcomes of patients with non-compaction cardiomyopathy according to selected criteria for risk stratification of sudden death to decide the implantation of an AICD. Material and Methods A total of 80 patients were analyzed. The diagnosis was established by echocardiography and nuclear cardiac magnetic resonance imaging criteria. The criteria for implantation of an AICD as a secondary prevention included sudden death and sustained ventricular tachycardia (SVT); as primary prevention included left ventricular ejection fraction (LVEF) < 30% or ≥ 2 risk factors (family history of sudden death [FHSD], syncope and non-sustained VT). Background

Practice viewpoints: AICD, who and when?

Automatic implantable cardioverter-defibrillator (AICD) is a costly but effective treatment modality for the prevention of sudden cardiac death (SCD). Causes of SCD are age-dependent, disease-specific and affected by racial/ethnic differences....

Comparative costs of home positive inotropic infusion versus in-hospital care in patients awaiting cardiac transplantation

BackgroundOutpatient positive inotropic support combined with implantation of an automatic implantable cardioverter defibrillator (AICD) may be used as a successful bridge to cardiac transplantation in patients with end-stage heart failure. A detailed comparative cost analysis of this outpatient strategy versus in-hospital care has not been previously reported. Methods and resultsTwenty-one United Network for Organ Sharing 1B patients awaiting cardiac transplantation received continuous outpatient inotropic therapy for a total of 3070 patient-days. Daily costs for outpatient and in-hospital treatment were calculated. Nonparametric decision analysis was used to determine the strategy with greatest cost savings (immediate hospital discharge after AICD implantation versus in-hospital care). A threshold analysis was performed to test the robustness of the decision analysis model. The outpatient strategy realized an average savings of $71,300 to $120,500 per patient. Decision analysis showed that no fixed period of in-hospital monitoring was more cost-saving than immediate hospital discharge after AICD implantation. Threshold analysis revealed that AICD costs would need to exceed $82,000 (currently $62,000) or that the difference between the outpatient and the in-hospital costs would need to be ≤$475 per day for any other intermediate strategy to be considered cost-saving. ConclusionOutpatient inotropic therapy combined with AICD implantation in selected patients awaiting cardiac transplantation is an effective cost-minimizing strategy.

Implantation of the Automatic Implantable Cardioverter Defibrillator for Coronary Artery Disease - Surgical Experience in 185 Patients

The results in 185 patients with coronary artery disease undergoing implantation of an automatic implantable cardioverter defibrillator (AICD) were reviewed with regard to the operative technique applied and problems observed. In 123 patients (group I) only AICD implantation was performed. Ninety patients were operated through sternotomy or thoracotomy while in 33 patients an endovenous/subcutaneous technique was used. Sixty-two patients (group II) underwent simultaneous coronary artery bypass grafting (CABG) and AICD implantation by median sternotomy. Perioperative mortality was 2.4% in group I with one fatality in the subgroup of endevenous/AICD placements and 11.3% in group II (p < 0.01). Overall infectious complications were low with 2 removals in group I and 1 in group II; however, no infections were observed after endovenous system implantation. It is concluded that the operative mortality rate of a combined approach is significantly higher, when compared to isolated AICD placement. However, the greater risk of the former cohort is mainly due to the impaired ventricular performance. Further investigations will have to prove whether a two-step approach using the endovenous technique in patients with a need for AICD and CABG will reduce the operative mortality.

Automatic implantable cardioverter defibrillator: cost effectiveness.

Unexpected out-of-hospital cardiac arrest is in most cases due to ventricular fibrillation or rapid ventricular tachycardia. The usual therapeutic strategy in survivors starts with drug treatment, in case of failure followed by nonpharmacological therapy, which may include catheter ablation, ablative surgery, and finally defibrillator implantation. In most cases, this strategy is long lasting and very expensive. Implantation of a defibrillator as a first choice therapy may be cost effective, especially if the probability of successful drug treatment is low. However, cost-effective aspects have been studied only retrospectively and in models. In 1989 we started a prospective cost-effectiveness analysis of implantation of the automatic implantable cardioverter defibrillator (AICD) as first choice therapy ("early" AICD implantation) in successfully resuscitated postinfarct patients. Evaluation is being done in a randomized way with one group having early AICD implantation and the other group following the usual conventional therapeutic strategy. We compare medical, economic, and quality-of-life aspects. As of June 1992, 46 patients have entered the study. Totally 60 patients will be included. Results are expected in 1993 and will be expressed as cost effectiveness ratios in both study arms.

Long-term surgical results in sudden death syndrome associated with cardiac dysfunction after myocardial infarction.

To evaluate the surgical results in patients with inducible ventricular tachyarrhythmias due to coronary disease and left ventricular dysfunction, the authors reviewed their experience in 170 patients who had survived one or more cardiac arrests after myocardial infarction and were unresponsive to drug therapy based on electrophysiologic studies (EPS). There were nine operative deaths (5%). Based on intraoperative EPS, surgical remodeling of left ventricular dysfunction (aneurysm resection, infarct debulking, and septal reinforcement) with map-guided cryoablation and coronary artery bypass graft was performed in 34 patients (group A), and left ventricular remodeling and coronary artery bypass graft without guided endocardial resection was performed in 25 patients (group B). Forty-three patients (group C) had coronary artery bypass graft with implantation of an automatic implantable cardioverter defibrillator (AICD). Group D (68 patients) received AICD only. After operation, based on EPS results, four patients in group A (12%) and three patients in Group B (15%) required AICD implantation. Overall survival at 6 years was 65%, 48%, 85%, and 58% in patient groups A, B, C, and D, respectively (p = not significant). During follow-up in group A patients, none died suddenly and none needed AICD. In group B, two patients required AICD 3 and 5 years later, and five patients died suddenly. The incidence of sudden death was 2.3%/patient/year and 3.5%/patient/year after AICD implantation (groups C and D). At 6 years, cardiac-event-free survival was 80% and 70% for groups A and B and 38% and 24% for groups C and D, respectively (p less than 0.001). Patients receiving map-guided ablative procedures had significantly improved cardiac-event-free survival rates.

Strategies in the surgical treatment of malignant ventricular arrhythmias. An 8-year experience.

Introduction of the automatic implantable cardioverter defibrillator (AICD) has dramatically affected the surgical treatment of malignant ventricular tachyarrhythmias. The authors continue to perform electrophysiologically directed subendocardial resection (SER) of left ventricular (LV) scars in selected patients, and we revascularize (CABG) those patients undergoing AICD implantation who have significant myocardial ischemia. In an attempt to define the optimal role of each procedure, this report analyzes our 8-year experience with 348 consecutive patients treated surgically for these arrhythmias (SER since 1983 and AICD since 1986). All patients undergoing SER had organized ventricular tachycardia (VT) as a result of myocardial infarction, and most had LV aneurysms; of those undergoing AICD or AICD/CABG, 60% had VT, 15% had ventricular fibrillation, and 25% had both or were noninducible. The thirty-day mortality rate was 1.5% (3/197) for AICD, 5.4% (5/93) for AICD/CABG, and 8.6% (5/58) for SER; these mortality figures are not significant different. Late deaths in all groups were predominantly due to congestive heart failure, and actuarial survival as well as freedom from sudden death was similar between the groups at 4 years. Recurrent VT occurred in 167 of 282 (59%) of long-term survivors of AICD or AICD/CABG during follow-up and in nine of 53 (17%) of those with SER. Forty-eight per cent of survivors of AICD or AICD/CABG required antiarrhythmic medications, whereas only 11% of those with SER required antiarrhythmics. Long-term survival in each group is much higher than that reported for comparable patients with severe LV dysfunction treated medically. In those patients with organized VT and LV aneurysm who are judged able to survive the procedure, SER offers a high likelihood of cure rather than simple prevention of sudden death.

Time to first pulse after automatic implantable cardioverter defibrillator implantation

Should automatic implantable cardioverter defibrillator (AICD) power sources be explanted and discontinued if they have not pulsed during the first generator life? We have followed 59 patients an average of 23 months (range, 3 days to 8.4 years) after AICD implantation. The indication for AICD implantation was based on clinical dysrhythmia, history of sudden death, and findings at electrophysiologic study. Thirty-eight of 59 patients (64%) had experienced sudden death and 52 / 58 (90%) were inducible at electrophysiologic study. Excluding 5 inappropriate pulsing episodes, 31 of 59 patients (53%) had 235 pulses (range, 1 to 36; median, 2 pulses). The time to first pulse after implantation ranged from 1 day to 3.5 years with a median time of 2 months. In 6 patients, the first pulsing occurred later than 1 year after AICD implantation. Fifteen generators demonstrating impending power source failure have been replaced in 11 patients. Power source depletion occurred at an average of 24.1 months (range, 8 to 40 months). In 3 patients, the first pulsing occurred after generator depletion and replacement. By univariate analysis, none of 13 variables (sex, age, cardiac disease process, functional class, previous myocardial infarction, sudden death history, ejection fraction, type of dysrhythmia, inducibility with electrophysiologic testing, number of extra stimuli required for induction, left ventricular aneurysm resection, endocardial resection, or concomitant operation) was found to be a predictor of pulsing ( p > 0.05). We conclude that the majority of patients with pulses after AICD implantation will have them during the first 6 months. However, in this group of patients at high risk for sudden death by ventricular dysrhythmia, absence of pulsing during the first battery life does not justify explantation and discontinuance of AICD back-up.

Continuing experience with the automatic implantable cardioverter defibrillator

The automatic implantable cardioverter defibrillator (AICD) is now used commonly in the management of malignant ventricular arrhythmias. Its use may obviate the need for antiarrhythmic drugs or endocardial resection. We reviewed our continuing experience with the AICD to determine its safety and efficacy. Since June 1987, 102 patients (mean age: 63 years) who survived out-of-hospital ventricular fibrillation or hemodynamically unstable ventricular tachycardia not associated with acute myocardial infarction underwent implantation of an AICD. There were three operative deaths and nine complications. Eighty-nine patients are alive. No patient has experienced sudden cardiac death. Forty-two patients (43%) have had 1 or more AICD discharges associated with symptoms of cardiac arrest. During AICD implantation, it appears preferable to configure lead placement by individual patient characteristics rather than by a rigid protocol. The relative safety and efficacy of the AICD support its use as an alternative to toxic medications or more dangerous endocardial resection in suboptimal candidates.

Results of electrophysiologic testing and long-term prognosis in patients with coronary artery disease and aborted sudden death

The purpose of this study was to evaluate the results of electrophysiologic testing and the long-term prognosis of 56 patients with coronary artery disease who presented with aborted sudden death unrelated to acute myocardial infarction. The mean age of the patients was 62 ± 8 years (± standard deviation) and 48 were men. The mean left ventricular ejection fraction was 0.34 ± 0.16. During the baseline electrophysiology test, sustained monomorphic ventricular tachycardia (VT) was inducible in 22 patients who then underwent electropharmacologic testing: 11 patients were treated with antiarrhythmic drugs that suppressed the induction of VT or resulted in the VT becoming hemodynamically stable; 10 patients who failed drug testing received an automatic implantable cardioverter/defibrillator (AICD); one patient underwent endocardial resection. Among 34 patients who did not have inducible sustained VT, a precipitant of cardiac arrest (severe ischemia, proarrhythmia) was identified and was corrected in 9 of 34. An AICD was recommended in the remaining 25 patients; however, nine patients refused and were treated empirically with antiarrhythmic drugs. The mean follow-up was 22 ± 12 months. The 2-year actuarial incidence of sudden death was 31% in patients who were treated with drugs based on the results of electropharmacologic testing, 26% in patients who were treated with antiarrhythmic drugs on an empiric basis, 0% among patients in whom a correctable etiology for the cardiac arrest was identified, and 9% among patients who underwent implantation of an AICD. The 3-year actuarial incidence of sudden death among the 20 patients treated with antiarrhythmic drugs was 53%, compared with 9% among the 26 patients who underwent AICD implantation ( p = 0.03). In conclusion, antiarrhythmic therapy, whether guided by electrophysiologic testing or administered on an empiric basis, is associated with a high incidence of recurrent sudden death in patients with coronary artery disease and aborted sudden death. Implantation of an AICD may be advisable in all patients with coronary artery disease and aborted sudden death in whom a correctable precipitant cannot be identified.

Predictors of first discharge and subsequent survival in patients with automatic implantable cardioverter-defibrillators.

Two hundred eighteen patients were evaluated in a two-phase approach (time to first appropriate discharge, survival after discharge) to identify factors that may be related to maximal benefit derived from use of an automatic implantable cardioverter-defibrillator (AICD). One hundred ninety-seven patients survived implantation of AICD, with or without concomitant cardiac surgery. One hundred five patients had an AICD discharge associated with syncope, presyncope, documented sustained ventricular tachycardia or fibrillation, or sleep at 9.1 +/- 11.1 months after implantation. Patients survived 23.8 +/- 18.0 months after AICD discharge. Left ventricular dysfunction (p = 0.008 for ejection fraction less than 25%) was associated with earlier AICD discharge and shortened survival after AICD discharge (p = 0.008 for ejection fraction less than 25%; p = 0.01 for New York Heart Association functional class III and IV). beta-Blocker administration (p = 0.006) and coronary bypass surgery (p = 0.06) were associated with later AICD discharge. Coronary bypass surgery (p = 0.035) but not beta-blockers was associated with more prolonged survival after AICD discharge. These data suggest that a relatively easy algorithm can be applied to predict which patient will benefit most from AICD implantation.

Comparison of efficacy of automatic implantable cardioverter defibrillator in patients older and younger than 65 years of age

The efficacy of the automatic implantable cardioverter defibrillator (AICD) was compared in elderly patients and younger patients with life-threatening ventricular tachyarrhythmias. Clinical characteristics, surgical complications, and long-term survival rates were compared between the two age groups. A retrospective study was conducted of 54 elderly patients (greater than 65 years) and 79 younger patients (less than 65 years) who had had AICDs implanted for recurrent symptomatic ventricular tachycardia and/or ventricular fibrillation. In 85% of elderly patients and 78% of younger patients, coronary artery disease was the underlying disease (NS). The mean left ventricular ejection fraction was 31.4 +/- 14.3% in the elderly patients and 35.7 +/- 17.6% in the younger patients (NS). Concomitant myocardial revascularization was performed in 37% of elderly patients and 29% of younger patients (NS); however, only 4% of elderly patients had concomitant left ventricular resection or cryoablation, compared with 15% of younger patients (p less than 0.001). Two patients in each age group died perioperatively (4% versus 3%, NS), and no significant difference in surgical morbidity or length of hospital stay following AICD implantation was noted between the age groups. In conjunction with AICD, elderly patients more commonly received antiarrhythmic drugs, with 54% of elderly patients taking amiodarone at the time of hospital discharge compared with 29% of the younger patients (p less than 0.008). In contrast, beta-blockers were more commonly used in younger patients (16% versus 2%, p less than 0.03). At a mean follow-up of 25 months, 11 (20%) elderly patients and 16 (20%) younger patients had died. Six deaths in elderly patients and five deaths in younger patients were classified as arrhythmic deaths (NS); however, only one younger patient and three elderly patients died suddenly (NS). Calculated survival curves demonstrated similar survival rates in the two age groups with approximately 90%, 87%, and 80% of the patients alive at 1, 2, and 3 years, respectively. Theoretic survival curves calculated from appropriate AICD shocks demonstrated significantly lower survival compared with actual survival. It is concluded that AICD is a very effective treatment for life-threatening ventricular tachyarrhythmias, and this benefit applies to elderly patients as well as younger patients.

The Surgical Aspects of Automatic Implantable Cardioverter‐Defibrillator Implantation

Since February 1980, the automatic implantable cardioverter-defibrillator (AICD) has been implanted in over 12,000 patients. This report examines the surgical aspects of AICD implantation. The various surgical techniques, their indications, and our recent clinical experience in over 250 patients are reviewed.

The automatic implantable cardioverter-defibrillator: Effect of patch polarity on defibrillation threshold

An automatic implantable cardioverter-defibrillator (AICD) was implanted in 40 patients with sudden cardiac arrest (n = 29), sustained monomorphic ventricular tachycardia (n = 10) or recurrent syncope (n = 1) who were unsuitable for direct ablative surgery or had had unsuccessful medical therapy. The effect of patch electrode polarity on the defibrillation threshold was prospectively evaluated. Two large epicardial patches were used. Initial polarity was selected at random. Ventricular fibrillation was induced by direct current and a preestablished defibrillation protocol employed to assess the minimal energy that would reproducibly defibrillate the heart. Nineteen patients had a lower defibrillation threshold with the inferior left ventricular patch as an anode and nine patients had a lower defibrillation threshold with this patch as a cathode. In general, the defibrillation threshold was lower when this patch was used as an anode than when it was used as a cathode (18 +/- 10 versus 22.6 +/- 12.2 J; p less than 0.01). No preoperative variable predicted optimal polarity. Therefore, the effect of patch polarity on defibrillation threshold should be assessed in each patient at the time of AICD implantation so that the safety margin for satisfactory device function can be maximized.

Anxiety and Depression in Patients with Life‐Threatening Ventricular Arrhythmias: Impact of the Implantable Cardioverter‐Defibrillator

In order to assess the psychological responses to the automatic implantable cardioverter-defibrillator (AICD), 18 patients with a history of life-threatening ventricular arrhythmias were requested to complete the Spielberger State-Trait Anxiety Inventory and the Beck Depression Inventory. The patients were divided into three groups of six and matched for age, sex, underlying cardiac disease, ejection fraction, and NYHA Functional Classification. Group I had experienced conscious discharges from the AICD, group II had the AICD but without discharges, and group III without the AICD were treated with antiarrhythmic medications alone based on electrophysiological guided testing. Patients with the AICD were also requested to complete a questionnaire directed specifically at their experiences with the AICD. All of the 18 patients completed the study responses and results were analyzed by blinded review. There were no significant differences in anxiety and depression scores in the three groups studied, nor any significant differences in responses to the questionnaire in group I versus group II. One patient in group I reported experiencing adverse psychological responses to the AICD. Although there appears to be no significant differences in psychological responses as a result of the AICD implantation in patients with life-threatening ventricular arrhythmias, further study with larger patient groups is needed to identify and support patients who may develop adverse responses to the AICD.