Time to First Shock in Implantable Cardioverter Defibrillator (ICD) Patients with Chagas Cardiomyopathy

The time to first ICD shock has been extensively studied in patients with coronary artery disease (CAD). However, there are no published data on ICD shocks in patients with Chagas cardiomyopathy (ChC). The occurrence of the first appropriate ICD shock during the first 6 months of follow-up in 20 patients with ChC (group 1) and 35 CAD patients (group 2) was analyzed retrospectively. All patients had received a third-generation pectoral ICD for ventricular tachycardia or fibrillation (VT/VF). Indications for ICD implantation were refractoriness to drug therapy or noninducibility of VT/VF at EPS in cardiac arrest survivors. Results: The mean age, left ventricular ejection fraction (LVEF), and sex in groups I and II were 57.4 ± 7 years versus 64 ± 9 (P < 0.01), 30.9%± 10% versus 32.9%± 10% (P = NS), and 10 men versus 31 women (P < 0.005), respectively. Six months after ICD implantation, 85% (17/20) group I patients received appropriate ICD shocks versus 51 % (18/35) in group 2, a statistically significant difference (P < 0.02, RR: 1.65, OR: 5.35). Conclusions: The incidence of appropriate ICD shocks within the first 6 months postimplantation was significantly higher in ChC patients than in CAD patients. ChC patients were younger and more often women than CAD patients.     

Patient Acceptance of the Implantable Cardioverter Defibrillator in Ventricular Tachyarrhythmias

Besides surgical problems, recipierifs of implantable cardioverter defibrillators (ICDs) are faced with psychological and social adjustments. Successful ICD therapy is influenced by the patients' perceived concerns regarding device, discharge, changes in life style, and complications. In order to assess patients' acceptance of the ICD, the psychological profile of 57 consecutive patients was evaluated using a specifically designed questionnaire and the State Trait Anxiety Inventory (STAI). The results showed that 20 patients staled fear of ICD discharge, 12 patients revealed physical discomfort due to the device, and limited quality-of-life occurred in 8 patients. Fifty-five of 57 patients answered that it was worth having an ICD device implanted, 30 (53%) patients returned to active life, and 56 (98%) would advise another patient to undergo implantation if necessary. Overall, there was only a slight, but insignificant, decrease in the level of anxiety within the total patient population after ICD implantation. However, a comparison of two subgroups indicated that the state of anxiety was significantly higher in patients < 50 years of age as well as in patients having received > 5 shocks versus those > 50 years of age and having experienced < 5 shocks. In general, the acceptance of the ICD as a tool in managing life-threatening ventricular tachyarrhythmias is high. Besides the increased survival rate, quality-of-life and patient acceptance are important criteria for successful ICD therapy.     

Health-Related Quality-of-Life Assessment of Patients with Life-Threatening Ventricular Arrhythmias

The purpose of this study was to determine whether treatments for life-threatening ventricular arrhythmias are associated with quality-of-life (QOL) and psychological distress. Multidimensional measures of QOL and psychological distress were used to cross-sectionally compare patients with ICDs to patients treated with antiarrhythmic drugs and patients without serious cardiac conditions. The sample consisted of 157 patients: 35 patients treated with antiarrhythmic medication only, 24 patients treated with ICD only, 25 patients treated with ICD and antiarrhythmic medication, and 73 controls. Patients completed the Medical Outcomes Study SF-36 health survey, the Brief Symptom Inventory, and background questionnaires. There were no significant differences in self-reported QOL and psychological distress between patients with or without ICD, and the occurrence of defibrillator shocks was unrelated to QOL and psychological distress. However, patients treated with antiarrhythmic drugs reported greater QOL impairment in physical functioning, vitality, emotional role limitations, and sleep, as well as greater psychological distress than patients not treated with antiarrhythmics. These limitations may be attributed to adverse effects arising from antiarrhythmic pharmacotherapy. Results of the present investigation suggest that QOL and psychological distress are maintained among ICD patients, whereas treatment with antiarrhythmic drugs are associated with a diminished QOL and greater psychological distress. These findings may assist cardiologists to select the optimal treatment for life-threatening ventricular arrhythmias that minimizes disturbances in health-related QOL and psychological distress and increases patient compliance.     

Clustering of device-related concerns and type D personality predicts increased distress in ICD patients independent of shocks

BACKGROUND: This study examined the impact of clustering of device-related concerns and Type D personality on anxiety and depressive symptoms during a six-month period and the clinical relevance of shocks, implantable cardioverter defibrillator (ICD) concerns, and Type D. METHODS: Consecutively implanted ICD patients (n = 176) completed questionnaires at baseline and six months and were divided into four risk groups: (1) No risk factors (neither ICD concerns nor Type D); (2) ICD concerns only; (3) Type D only; (4) Clustering (both ICD concerns and Type D). RESULTS: The prevalence of Type D and concerns were 21.6% and 34.7%. Analysis of variance for repeated measures showed a reduction in anxiety over time (P < 0.001), with the risk groups exerting a stable (P = 0.14) but differential effect (P < 0.001); the highest level was seen in the clustering group. Similar results were found for depression, although depressive symptoms did not decrease (P = 0.08) and the impact of clustering was less clear. These results were confirmed in adjusted analysis, with shocks (P = 0.024) also being associated with anxiety but not depression. The impact of ICD concerns and Type D personality on anxiety and depression at baseline and six months was large (>or=0.8) compared to negligible to moderate for shocks (0.0-0.6). CONCLUSIONS: ICD patients with psychosocial risk factor clustering had the highest level of anxiety, whereas the pattern for depression was less consistent. Shocks influenced outcomes, but the impact was smaller compared to ICD concerns and Type D personality. It may be timely to expand the focus beyond shocks when seeking to identify ICD patients at risk for adverse clinical outcome due to their psychological profile.     

Effect of Antiarrhythmic Drug Therapy on the Incidence of Shocks in Patients who Receive an Implantable Cardioverter Defibrillator after a Single Episode of Sustained Ventricular Tachycardia/Fibrillation

Seventy-four patients (16 women, 58 men, age 58 ± 21 years, mean ± standard deviation) who received an implantable Cardioverter de/ibrillator (ICD) after experiencing a single episode of ventricular tachycardia or ventricular fibrillation were followed to determine if antiarrhythmic drug therapy affects the incidence of ICD discharges. Thirty-three patients (group A) were treated with an antiarrhythmic drug that was either untested or previously demonstrated during electropharmacological testing to be ineffective in suppressing the induction of ventricular tachycardia. Forty-one patients (group B) were not treated with an antiarrhythmic drug. There were no significant differences between the two groups in regards to age, sex, incidence of coronary artery disease, left ventricular function or the type of ICD pulse generator used. During a mean follow-up of 14 months for the entire cohort, 15 patients (46%) in group A and 18 patients (44%) in group B experienced at least one ICD shock. The time to the first appropriate shock (5 ± 5 months in both groups) and the frequency of ICD shocks (0.3 ± 0.2/month in group A vs 0.4 ± 0.5/month in group B) were similar in both groups. The incidence of syncope at the time of ICD discharge was higher in group A than group B patients (31% vs 5%, P < 0.05). In conclusion, antiarrhythmic drugs that are untested or have failed electropharmacological testing do not appear to reduce the probability of ICD discharge over a short-term (mean 14 months) follow-up in patients who have had only one clinical episode of VT/VF and may increase the risk of syncope during ICD discharge. Studies with a larger sample size and longer follow-up period will be needed to confirm these findings.     

Clinical Significance of Consecutive Shocks in Patients with Left Ventricular Dysfunction Treated with Implantable Cardioverter Defibrillators

The purpose of the present study was to determine the clinical significance of consecutive automatic shocks delivered by implantable cardioverter defibrillators (ICDs). Sixty-four patients who received ICDs at our institution between January 1990 and July 1997 were included in this study. There were 53 men and 11 women with a mean age of 50 ± 14 years. During a follow-up period ranging between 0.2 and 73 months (mean 23 ± 21 months), 17 patients received consecutive shocks (group A), 29 patients received single shocks (group B), and 18 patients received no ICD therapy (group C). Clinical characteristics, episodes of ICD therapy, and prognosis were compared among the three groups. There were no significant differences among the three groups with regard to clinical characteristics, time to first ICD therapy, number of antitachycardia pacing episodes, or frequency of inappropriate discharges. The mortality rate was higher in group A than in groups B and C (P = 0.0021). The sensitivity of consecutive shocks in predicting death was 70%, the specificity was 88%, and the predictive accuracy was 81% in patients with left ventricular ejection fractions < 35%. In summary, consecutive shocks are a clinically important event in patients with ICDs. Specifically, patients who receive consecutive shocks and have a depressed left ventricular function should be considered particularly high risk.     

Psychosocial Outcome after ICD Implantation: A Current Perspective

Depression and reduced sexual functioning have been identified as problems following ICD placement. We examined these issues, and multiple other quality-of-life measures, and their relationship to ICD and ICD discharge. Patients were 64 ± 11 years old, 72% male, and had undergone ICD 20 ± 14 months previously. Fifty-eight patients responded to a confidential biopsychosocial questionnaire. Positive attitudes toward the procedure increased from 52% before to 76% after implantation. Satisfaction correlated most strongly with less anger (P = 0.002, r = 0.45), less worry about ICD size (P = 0.007, r = 0.38), less sadness (P = 0.01, r = 0.37), and perceived better health (P = 0.01, r = 0.35). Of these ICD patients, 20%–58% reported measures of depression, and sexual frequency was reduced in 45%. Despite successful ICD placement, health concern increased in 62 % of the respondents. Thirty-nine percent attended support groups; 96% found them very helpful. Mean number of ICD discharges described by responders was 5 ± 11. Fifty percent of our sample reported ≥ 1 shock; equal numbers had 1, 2–5, 6–10, and more than 10 shocks. Sixty-two percent of men had at least one discharge compared to 13% of women. After controlling for cardiac clinical variables, experiencing ≥ 1 ICD shock was strongly associated with anxiety about family (odds ratio = 7.3), reduced new activities (odds ratio = 6.9), increased sadness (odds ratio = 6.2), and health worry (odds ratio = 5.8). Experiencing ≥ 5 ICD shocks was strongly associated with increased health concern (odds ratio = 13.6), increased sadness (odds ratio = 12.5), increased fatigue (odds ratio = 6.1), current sadness (odds ratio = 5.8), and increased nervousness (odds ratio = 5.3). ICD implantation powerfully affects quality-of-life. Postimplantation health concern is paradoxically increased despite improvement in actual health. Negative emotions are associated with defibrillator discharge.     

Quality-of-Life Six Months After CABG Surgery in Patients Randomized to ICD Versus No ICD Therapy: Findings from the CABG Patch Trial

ICDs can affect a patient's perceived quality-of-life (QOL). This article describes the QOL in patients who participated in The CABG Patch Trial. This trial evaluated the potential benefit of empiric ICD implantation in patients with an increased risk of arrhythmic cardiac death as determined by reduced ejection fraction (<0.36) and an abnormal signal-averaged ECG. Patients were randomized to control (no ICD) or treatment (ICD) limbs. QOL was measured using the SF-36 and other measures among 490 (68%) of 719 patients available at 6-month follow-up. Analysis was performed on 228 control patients (those without ICDs) and 262 patients with ICDs. RESULTS: Six months after having CABG surgery, patients in the ICD group had lower levels of psychological well-being than those in the control group. In addition, compared to controls, patients whose ICDs had delivered therapy reported feeling less healthy, had reduced physical and emotional role functioning, and had lower levels of psychological well-being. CONCLUSION: Strategies aimed at easing patients' adjustment to ICDs should be developed and tested for efficacy in the setting of ICD prophylaxis.     

The Effect of Psychological Intervention on Patients' Long-Term Adjustment to the ICD: A Prospective Study

This study prospectively examined the role of cognitive behavioral therapy (CBT) in (1) alleviating psychological and somatic distress, and (2) lowering arrhythmic events requiring shocks. Forty-nine of 61 consecutive patients were randomized into therapy (CBT, n = 25) or no therapy (NT. n = 24) and completed a battery of self-report questionnaires at baseline and at 9-month follow-up. CBT was administered at preimplant, predischarge, and at seven routine follow-up visits. Patients were 65 ± 10 years old. 65% were men, and 92% Caucasian. Eighteen (72%) CBT patients and 18 (75%) NT patients were retained at follow-up. Compared to CBT patients, NT patients reported higher levels of depression (P = 0.046), more anxiety (P = 0.013), more psychological distress (P = 0.015), poorer overall adjustment (P = 0.009), and poorer sexual functioning (P = 0.003). Mean number of shocks did not differ between the CBT and NT groups (2.85 vs 2.30. respectively); however, more patients in the CBT group (61%) than the NT group (33%) received shocks (P = 0.070). At follow-up, a subgroup analysis revealed that the significant differences observed between the CBT and NT groups were attributable to the patients who received shocks in both groups. In conclusion, CBT was associated with decreased depression, decreased anxiety, and increased adjustment for ICD recipients, particularly among those patients receiving shocks. CBT can be administered effectively at routine follow-up visits or transtelephonically with little added inconvenience to the ICD recipient.     

Assessing the psychosocial impact of the ICD: a national survey of implantable cardioverter defibrillator health care providers

The implantable cardioverter defibrillator (ICD) provides a survival advantage over antiarrhythmic medications for patients with life-threatening ventricular arrhythmias. However, the effect of ICD therapy on quality-of-life and psychosocial functioning are not as well understood. Health care providers (e.g., physicians, nurses) can serve as a valuable source of information related to these ICD outcomes. The purpose of this study was to investigate health care provider perceptions regarding: (1) the quality-of-life and psychosocial functioning of their ICD recipients, (2) the concerns or problems reported by ICD recipients, and (3) the degree of provider comfort in managing these concerns. The final sample of health care providers (n = 261) rated ICD recipients' global quality-of-life and psychosocial functioning, and specific concerns about health care, lifestyle, special population adjustment, marital and family adjustment, and emotional well-being. With regard to quality-of-life, health care providers reported that the majority of ICD recipients were functioning better (38%) or about the same (47%) than before implantation. However, health care providers reported that 15% of recipients experienced worse quality-of-life postimplantation. Similarly, health care providers indicated that 10%-20% of ICD recipients experienced worse emotional functioning and strained family relationships. Moreover, issues related to driving, dealing with ICD shocks, and depression were the most common ICD recipient concerns. Significant differences were noted between physicians and nurses/other health care professionals on a wide range of psychosocial issues. Health care providers generally reported the most comfort dealing with traditional medical issues (i.e., patient adherence), and the least comfort in managing emotional well-being issues (e.g., depression and anxiety). These results suggest that routine attention to ICD quality-of-life and psychosocial outcomes is indicated for health care providers who care for ICD recipients.     

Implantable cardioverter defibrillator storm: nursing care issues for patients and families

Implantable cardioverter defibrillators (ICDs) are being used for primary and secondary prevention of life-threatening cardiac arrhythmias, and evidence suggests that increased use is likely in the future. ICD storm, the delivery of two or more shocks within 24 hours, occurs in 10% to 20% of patients who have ICDs and can have long-lasting psychological and physical consequences. An understanding of the factors associated with ICD storm, relevant assessment, and patient and family teaching and counseling can help clinicians to better meet the needs of patients who have experienced ICD storm.     

Shock as a Determinant of Poor Patient‐Centered Outcomes in Implantable Cardioverter Defibrillator Patients: Is There More to It Than Meets the Eye?

The medical benefits of the implantable cardioverter defibrillator (ICD) are well established, but ICD shocks are known to influence patient‐centered outcomes. In this viewpoint, we examine the strength of the evidence as found in primary and secondary prevention trials that used quality of life as an outcome, and compare the influence of ICD shock with other factors (e.g., heart failure and psychological factors) as determinants of outcomes, with a view to providing recommendations for clinical practice and future research. Based on the large‐scale primary and secondary prevention trials (i.e., CABG‐PATCH, CIDS, AVID, AMIOVIRT, SCD‐HeFT, MADIT‐II, and DEFINITE), evidence for an association between ICD shocks and quality of life is mixed, with some indication that the influence of shocks may depend largely on the interval between shocks and assessment of quality of life. In order to improve the clinical management of ICD patients, we need to adopt a more rigorous and standardized methodology in future studies in order to be able to draw firm conclusions about the impact of ICD shocks on individual patients. We also need to acknowledge that the impact of shocks on psychological functioning and quality of life may not be as straightforward as previously assumed. Given that programming of the ICD is changing, leading to fewer shocks and improved quality of life, it may be timely to also examine the influence of other determinants (e.g., heart failure progression and the patient's psychological profile) of patient‐centered outcomes both in research and in clinical practice. (PACE 2010; 33:1430–1436)     

Prognostic significance of atrial arrhythmias in a primary prevention ICD population

Introduction : We investigated whether primary prevention implantable cardioverter defibrillator (ICD) patients with atrial arrhythmias are at higher risk for ICD shocks and mortality compared to patients without atrial arrhythmias in a subanalysis of the PREPARE study. Methods and Results : Details of the PREPARE study design and results have been previously reported. We now included 537 of the 700 patients enrolled in PREPARE. These patients had a dual or biventricular device and at least one device follow‐up after implantation. Continuously collected device diagnostics data were used to classify patients into two groups during follow‐up: with (n = 133) or without (n = 404) atrial tachycardia/atrial fibrillation (AT/AF). The primary outcomes were ICD shocks and mortality. Subjects were followed for a mean of 333 ± 73 (range 5–365) days. During a follow‐up of 1 year, ICD shocks occurred in 44 (8%) patients. Significantly, more patients with AT/AF received a shock (13.0% vs 6.9%, P = 0.03), with inappropriate shocks accounting for the majority of the difference (6.9% vs 2.6%, P = 0.02). There was no difference in prevalence of shocks between patients with and without a history of AF. Mortality was similar in patients with and without AT/AF, whether detected during the study or prior to the study. In addition, the 34 subjects with high average ventricular rate (≥110 beats per minute) during AT/AF had a higher risk of an inappropriate shock (21.0% vs 2.1%, P < 0.01). Conclusion : Primary prevention ICD patients with AT/AF are more likely to receive shocks, especially inappropriate shocks. Mortality was not higher in AT/AF patients. (PACE 2011; 34:1070–1079)     

EFFICACY OF LOWER-ENERGY BIPHASIC SHOCKS FOR TRANSTHORACIC DEFIBRILLATION: A FOLLOW-UP CLINICAL STUDY

Objective. This clinical study prospectively evaluated the first-shock defibrillation efficacy of 150-joule impedance-compensated, 200-µF biphasic truncated exponential (BTE) shocks in patients with electrically-induced ventricular fibrillation (VF), and compared it with a historical control group treated with 200-J monophasic damped sine (MDS) shocks. Methods. Ventricular tachyarrhythmias were induced in patients undergoing electrophysiologic (EP) testing for ventricular arrhythmias or testing of an implantable cardioverter-defibrillator (ICD). A 150-J shock was delivered as the primary therapy to terminate induced arrhythmias in the EP group, and as a “rescue” shock when a single ICD shock failed to terminate the arrhythmias in the ICD group. Results. Ninety-six patients received study shocks. The preshock rhythm was classified as VF in 77 patients and as ventricular tachycardia (VT) in 19 patients. First-shock success rates for VF and VT were 75 out of 77 (97.4%) and 19 out of 19 (100%) for the 150-J BTE compared with the historical control rates of 61 out of 68 (89.7%) and 29 out of 31 (94%) for 200-J MDS. The first-shock success rate for VF treated with 150-J BTE was technically equivalent to that of 200-J MDS (p = 0.001). The transthoracic impedance did not vary between groups, yet the peak current delivered by the 150-J BTE shock was about 50% lower. Conclusions. This study demonstrated that 150-J shocks of this impedance-compensated, 200-µF BTE waveform provided very high efficacy for defibrillation of short duration, electrically-induced VF. These lower-energy biphasic shocks had a success rate equivalent to that of 200-J MDS shocks, and they provided this efficacy while exposing patients to much less current than the monophasic shocks.     

Psychopathology in Patients with ICDs over Time: Results of a Prospective Study

Introduction: The effects of implantable cardioverter defibrillators (ICDs) and ICD shocks on psychological state have previously been studied. However, it is still unclear how health‐related quality‐of‐life changes over time using standardized assessments. We sought to characterize the effects of ICDs and ICD shocks on psychological outcomes. Methods: Three hundred‐eight patients receiving ICDs were prospectively identified. Baseline QOL assessments including standardized psychological surveys [Hospital Anxiety and Depression Scale (HADS), Impact of Events Scale‐Revised (IES‐R), and Short Form 36 Health Survey (SF‐36)] were obtained within 2 months of device implantation and at 6 and 12 months, respectively. Outcomes including ICD shocks were followed over the 12‐month study period. Results: The number of patients meeting criteria for anxiety or posttraumatic stress disorder (PTSD) at baseline (78/223, 35%) was higher than at 6 (34/223, 15%) or 12 (34/223, 15%) months (P < 0.01). There was a significant improvement over time in HADS (P < 0.001) and IES‐R (PTSD) scores (P < 0.001). Amongst the 20 patients who received ICD shocks, no significant differences were observed in IES‐R, SF‐36, or HADS scores when compared with those who did not receive shocks at any time point. Patients who experienced electrical storms (N = 5) had significantly higher baseline PTSD scores (29.6 ± 11.4 vs 14.6 ± 11.6, P < 0.01). Conclusions: Patients receiving ICDs have significant rates of baseline psychopathology after implantation. However, psychological assessment scores tend to improve with time. ICD shocks do not appear to significantly impact psychological state. These results suggest the importance of close screening and referral for possible psychopathology in patients receiving ICDs, especially in the peri‐implant period. (PACE 2010; 33:198–208)     

Electrocardiographically Documented Unnecessary, Spontaneous Shocks in 241 Patients With Implantable Cardioverter Defibrillators

The incidence and cause of electrocardiographically documented spontaneous implantuble Cardioverter defibrillator (ICD) discharges for a rhythm other than ventricular tachycardia (VT) or fibrillation (VF) (unnecessary shocks) were determined in 241 patients who underwent ICD implantation between March 1983 and November 1991. During follow-up of 24 ± 20 months, 54 of 241 patients (22%) received a total of 132 unnecessary ICD shocks confirmed by Holler or telemetry monitoring or stored electrograms (Egs) from the ICD. The rhythm preceding these unnecessary ICD shocks was atrial fibrillation in 30 patients, sinus or supraventricular tachycardia (SVT) in 11 patients, antitachycardia pacing triggered by atrial fibrillation or SVT resulting in VT in 5 patients, nonsustained VT in 3 patients, and normal sinus or pacemaker rhythm in 10 patients. Unnecessary ICD discharges occurred most frequently during the first week after implantation or generator replacement (18 of 54 patients [33%]). Unnecessary ICD discharges could be documented more often by stored Egs in patients with devices with Eg storage capability (Ventritex Cadence(tm), 19 of 54 patients [35%]) than by Holter or telemetry monitoring in patients with devices without Eg storage capabilities (34 of 193 patients [18%], P < 0.01), despite a shorter mean follow-up duration of 14 ± 9 months versus 26 ± 21 months, respectively. Only six of 54 patients (11%) in whom unnecessary ICD discharges occurred had recurrent unnecessary shocks during 22 ± 20 months of follow-up after treatment directed at the cause of the first episode or device reprogramming to preclude non-VT rhythm detection. In conclusion, unnecessary ICD shocks are a frequent complication of ICD therapy occurring in at least 22% of patients. The cause of these shocks is most frequently atrial fibrillation with a rapid ventricular response. The availability of Eg storage capabilities facilitates the diagnosis of the electrical event precipitating inappropriate ICD shocks. Diagnosis of the cause of unnecessary shocks allows for the institution of therapy that may reduce the risk for subsequent events.     

Electrophysiologic study-guided therapy with sotalol for life-threatening ventricular tachyarrhythmias

The aim of this study was to investigate the long-term efficacy and safety of electrophysiologic study (EPS)-guided sotalol administration combined with implantable cardioverter defibrillators (ICD) for ventricular tachyarrhythmias (VTA). This study enrolled 92 patients with both structural heart disease and sustained VTA. Sotalol was administered to 57 patients, and its efficacy was assessed by EPS. Long-term treatment was continued in combination with ICD in 31 patients (57%) whose VTA was no longer inducible (responder group) and in 16 patients whose VTA remained inducible (nonresponder group). The long-term outcomes were compared among the responder group, the nonresponder group, and 35 ICD recipients untreated with antiarrhythmic drugs (ICD-only group). During a mean follow-up of 44 +/- 33 months, the recurrence of VTA was not significantly different between all patients treated with sotalol (30%) and patients in the ICD-only group (46%). However, the recurrence of VTA was significantly lower in the responder (13%) than in the nonresponder (63%) or the ICD-only groups (46%). There was no significant difference in VTA recurrence between the nonresponder and the ICD-only groups. One patient each in the responder and the ICD-only groups died suddenly, and all-cause mortality was similar in the three groups. The incidence of inappropriate ICD discharges was less in the sotalol than in the ICD-only groups. No patient had to discontinue long-term sotalol treatment because of the adverse effects. In conclusion, sotalol reduced VTA recurrence in the responding patients and inappropriate ICD discharge. EPS may predict the efficacy of sotalol for VTA recurrence.     

Transvenous Atrial Cardioversion Threshold in Patients with Implantable Cardioverter Defibrillator: Influence of Active Pectoral Can

Recent studies have shown that transvenous atrial cardioversion is feasible with lead configurations primarily designed for implantable cardioverter defibrillators (ICD). The purpose of this study was to examine the influence of an active pectoral ICD can on the atrial cardioversion threshold (ADFT). Forty consecutive patients received a transvenous single lead system (Endotak DSP 0125, CPI, St. Paul, MN, USA) in combination with a left subpectoral ICD (Ventak Mini, CPI) for treatment of malignant ventricular tachyarrhythmias. Patients were randomized into two groups: 21 received a Hot Can 1743 and 19 patients a Cold Can 1741. Step-down testing of the ventricular defibrillation threshold (VDFT) was performed intraoperatively and evaluation of the ADFT for induced atrial fibrillation (AF) at predischarge. After testing, each patient received a 2-J shock and was asked to quantify discomfort on a numerical scale ranging from 0 to 10. Both groups were comparable with regard to all clinical parameters studied. The mean VDFT in patients with a Hot Can device was significantly lower than in patients with a Cold Can (7.5 ± 2.3 J vs 9.8 ± 3.8 J; P < 0.03). The mean ADFT in the Hot Can group tended to be lower than in the group with Cold Cans (3.4 ± 1.4 J vs 4.5 ± 2.4 J; P = 0.07), and the proportion of patients in whom atrial cardioversion was accomplished at low energies (≤ 3 J) was higher in patients with active compared with patients with inactive pulse generators (57% vs 26%; P < 0.04). The mean discomfort reported after delivery of a 2-J shock was comparable in both groups (Hot Can 5.2 ± 1.9; Cold Can: 5.3 ± 2.1; P = NS). We conclude that the inclusion of an active left subpectoral can in the defibrillation vector of a ventricular ICD seems to reduce the energy requirements for atrial cardioversion without increasing the discomfort caused by low energy shocks.     

Economic analysis of a randomized trial of biventricular pacing in Canada

BACKGROUND: Congestive heart failure (CHF) has been shown to affect 5% of the Canadian adult population, and leads to 9.5 deaths per 100 cardiac-related hospitalizations in Canada. The economic outcomes from biventricular pacing for heart failure are not well understood. This study analyzes resource utilization and related costs associated with CHF for patients who receive standard implantable cardiac defibrillators (ICDs) versus those who receive ICD plus biventricular pacing or cardiac resynchronization therapy (CRT). METHODS: The Canadian analysis of resynchronization therapy in heart failure (CART-HF) study included 72 patients with New York Heart Association class II-IV CHF requiring an ICD. Patients were randomized to receive either ICD + CRT treatment or ICD treatment alone. Medical resource utilization data were collected for 6 months following treatment and were applied to representative costs for the provinces of Quebec and Ontario. Resource utilization was subcategorized into pharmacological therapy, physician visits, hospitalizations, adverse events, and productivity losses. RESULTS: Post-treatment, per patient costs for the CRT + ICD treatment group were less than the follow-up costs for patients receiving ICD treatment only in each province. Mean savings for patients receiving biventricular therapy were CAD 2,420 dollars in Quebec and CAD 2,085 dollars in Ontario during the 6-month follow-up. CONCLUSIONS: These analyses indicate that savings in post-implant health-care utilization (hospitalizations and pharmacological therapy) can offset some of the device and procedural costs associated with CRT devices.