Defibrillators: Selecting the Right Device for the Right Patient

Validity and reliability of the Brazilian Portuguese version of the Florida Patient Acceptance Survey for patients with implantable cardioverter defibrillators

Device acceptance is a crucial factor in identifying implantable cardioverter defibrillator (ICD) patients at risk for psychosocial distress and unfavorable quality of life outcomes. The purpose of this study was to examine the evidence of the validity of internal structure (construct) and reliability of the Florida Patient Acceptance Survey (FPAS) in a sample of ICD patients, comparing the psychometric indicators of the complete (FPAS-18 item) and abbreviated (FPAS-12 item) versions. The sample included 151 participants (97 males, mean age of 55.7 ± 14.1 years) who completed the cross-culturally adapted version of the FPAS instrument for the Brazilian context. The psychometric properties of both versions of the FPAS instrument were evaluated by two distinct approaches:•Exploratory and confirmatory factor analysis: used to test the internal structure of the instrument•Cronbach's Alpha and McDonald's Omega: used to determine the reliability of the instrument The two versions of the FPAS-Br instrument showed consistent evidence of internal structure validity and reliability. However, the FPAS-Br 12-item showed a better psychometric adjustment, confirmed by the analysis of the quality indicators of the models.

Inappropriate Shocks With Subcutaneous Implantable Cardioverter-Defibrillator in a Young Patient: A Case Report

Implantable cardioverter-defibrillators (ICDs) are increasingly used for the primary and secondary prevention of sudden cardiac death (SCD). Currently, transvenous (TV) and subcutaneous (S) ICDs are the two different types used. Preservation of central venous vasculature, no risk of vascular or myocardial injury during implant, easier explantation, and lower risk of systemic infections have driven the increased use of S-ICDs. The shocks delivered by ICDs for non-life-threatening arrhythmias or because of oversensing T waves or noise are known as inappropriate shocks. Here, we present the case of a 33-year-old man who had an S-ICD implanted in 2019 for hypertrophic cardiomyopathy. He had a TV-ICD implanted in 2010 which was explanted in 2013 due to infective endocarditis, and the patient underwent a mechanical mitral valve replacement. He was at intermediate risk for SCD over the next five years. He had an S-ICD implanted in 2019 and had never received any shock before. Electrocardiogram showed normal sinus rhythm, left axis deviation, QRS 110 ms, hyperacute T waves in inferior leads, and T-wave inversion in lateral leads. He then began experiencing inappropriate shocks three years after S-ICD placement due to a drop in R wave amplitude secondary to noise oversensing in October 2022. Despite reprogramming the device from the primary vector to an alternate vector, the patient had further inappropriate shocks two months later due to noise oversensing. The patient was discussed in a multidisciplinary team meeting and the S-ICD was explanted according to the patient's wishes and a loop recorder was implanted.

Inappropriate Subcutaneous Implantable Cardioverter Defibrillator Shocks Secondary to Cardiac Remodeling: A Unique Case of T Wave Oversensing

Implantable cardioverter defibrillators (ICD) are used for the primary and secondary prevention of sudden cardiac death (SCD). Currently, two different modalities of ICDs are in use: transvenous (TV) and subcutaneous (S-ICD). The use of S-ICDs has been driven by several potential benefits of this technology: preservation of central venous vasculature, no risk of vascular or myocardial injury during implant, easier explanation, and lower risk of systemic infections. Inappropriate shocks are defined as shocks delivered for non-life-threatening arrhythmias or because of oversensing. Here, we present a case of a 58-year-old man who began experiencing inappropriate shocks three years after S-ICD placement. Careful analysis of the ICD showed T wave oversensing with no malfunction of the device. The shocks persisted even after reprogramming, leading to subsequent ICD removal and loop recorder implantation. The onset of shock episodes coincided with the improvement of left ventricular ejection fraction (LVEF). To the best of our knowledge, this is the first published report of cardiac remodeling leading to uncorrectable T wave oversensing that subsequently required S-ICD explant. This represents a potentially important limitation of S-ICD technology, especially as S-ICD use rises and medical therapy for cardiomyopathy continues to improve.

Contactless Electrocatheter Tracing within Human Body via Magnetic Sensing: A Feasibility Study

During surgical procedures, real-time estimation of the current position of a metal lead within the patient's body is obtained by radiographic imaging. The inherent opacity of metal objects allows their visualization using X-ray fluoroscopic devices. Although fluoroscopy uses reduced radiation intensities, the overall X-ray dose delivered during prolonged exposure times poses risks to the safety of patients and physicians. This study proposes a potential alternative to real-time visualization of a lead inside the human body. In principle, by making a weak current flow through the lead and measuring the related magnetic field generated outside the body, it is possible to trace the position of the lead. This hypothesis was verified experimentally via two tests: one carried out on a curved copper wire in air and one carried out on a real pacemaker lead in a saline solution. In the second test, a pacemaker lead and a large return electrode were placed in a tank filled with a saline solution that reproduced the mean resistivity of the human torso. In both tests, a current flowed through the lead, which consisted of square pulses with short duration, to avoid any neuro-muscular stimulation effects in a real scenario. A small coil with a ferrite core was moved along a grid of points over a plastic sheet and placed just above the lead to sample the spatial amplitude distribution of the magnetic induction field produced by the lead. For each measurement point, the main coil axis was oriented along the x and y axes of the plane to estimate the related components of the magnetic induction field. The two matrices of measurements along the x and y axes were further processed to obtain an estimate of lead positioning. The preliminary results of this study support the scientific hypothesis since the positions of the leads were accurately estimated. This encourages to deepen the investigation and overcome some limitations of this feasibility study.

Experience with a Wearable Cardioverter-defibrillator in 436 Patients

The aim of the present study was to review the safety and efficiency of wearable cardioverter-defibrillators (WCDs) under current guideline-directed medical therapy (GDMT). We retrospectively analyzed 436 consecutive WCD patients seen in the years 2014–2020. Detected automatic arrhythmia alarm (AA) episodes were validated and classified as correct or incorrect. The positive predictive value (PPV) was calculated. GDMT was optimized in our outpatient clinic to maximal tolerated doses. During a total wear time (WT) of 23,527 days, 3,135 AAs were transmitted from 206 of 436 (47.2%) patients. Visual analysis revealed correct diagnoses of non-sustained ventricular tachycardia (VT) in 38 AAs from 6 patients (total PPV, 1.21%; PPV in VT patients, 41%); the remaining AAs were artifacts. No appropriate or inappropriate shocks and fatalities were recorded. LVEF significantly improved (P < .001) during the WT from 25% (range, 20%–30%) to 40% (range, 34%–46%). Defibrillators were implanted in 109 patients (27%). The PPV for VT of the WCD was very low. There were fewer instances of true VT than previously reported, and no shocks (appropriate or inappropriate) were delivered. The majority of patients greatly improved with GDMT, and device implantation rates were lower than previously reported. Improvements in arrhythmia detection algorithms are warranted. Based on our results, WCDs are rarely needed for lifesaving shocks under optimal GDMT.

Laminopathies: should Wenckebach be a cause for concern? A case report

Background

LMNA cardiomyopathy is a cause of dilated cardiomyopathy (DCM) characterized by aggressive heart failure, high risk of arrhythmias, and sudden cardiac death. We present a case of a male presenting with an LMNA mutation with an aggressive DCM leading to sudden cardiac death (SCD).

Case summary

A 42-year-old male presented with the feeling of lethargy and intermittent dizziness. Electrocardiogram demonstrated atrioventricular block in keeping with Mobitz type 1, at a rate of 40 b.p.m. and cardiac monitoring showed non-sustained ventricular tachycardia. Cardiac magnetic resonance imaging showed preserved left ventricular (LV) ejection function (59%) but features suggesting DCM. These included mild LV dilatation with an end diastolic volume (EDV) of 213 mL and late enhancement showing a single mid myocardial focus of high signal over the distal right ventricular insertion point inferiorly and a linear area of high signal over the basal septum. After discussion at the cardiology multi-disciplinary meeting, a pacemaker was implanted so that beta-blockers could be initiated to suppress the ventricular arrhythmias. A laminopathy was suspected and if this was confirmed from genetic testing the plan was to upgrade to an implantable defibrillator. Due to stability, this was decided to be done in an outpatient setting. He unfortunately had an out-of-hospital VF arrest and died. Post-mortem showed subtle cardiomyopathy in keeping with a DCM. Genetic tests results were returned a few months later which confirmed a pathogenic variant in LMNA.

Discussion

Because of the complexity of LMNA-related cardiac disease, they should be managed and followed up in centres with special expertise in inherited cardiomyopathy.

Safety and feasibility of implanting a transvenous implantable cardioverter defibrillator (TV-ICD) in the left axilla

BACKGROUND

Transvenous implantable cardioverter defibrillator (TV-ICD) systems are commonly implanted in the left anterior chest because of an easier implantation and better defibrillation threshold. This study aimed to evaluate the safety and feasibility of left axillary implantations of TV-ICD systems.

METHODS

We performed left axillary TV-ICD implantations and compared that to the major complication rate and operation time of the conventional TV-ICD implantation site (left anterior chest). The electrical parameter trends were also assessed in the left axilla group.

RESULTS

Seventy-six consecutive patients were evaluated for the analysis. Thirty-one patients had their system implanted in the left axilla and the reasons for the implantations included 29 patients for cosmetic reasons and two for post-infection conditions. The operation time and major complication rate were similar between the two groups (left anterior chest vs. left axilla: 134±62.4 min vs. 114±33.5 min, p = .11, 1/45 patient, 2.2% [pocket hematoma] vs. 1/31 patient, 3.2% [lead dislodgement], p = .77). During the follow up period (4.9±2.3years), no lead interruptions were observed in either group. The electrical lead parameters at the time of the implantation and follow up were similar in the study group (R wave sensing 20.8±33.4 vs. 11.2±7.42 mv, p = .34; lead impedance 464±64.7 vs. 418±135ohm, p = .22; pacing threshold [at 0.4 ms] 1.0±0.76 vs. 1.21±0.93V, p = .49).

CONCLUSION

TV-ICD implantations in the left axilla were performed safely without increasing the operation time as compared to the conventional ICD implantation site. ICD implantations in the left axilla are an alternative in those not suitable for implanting TV-ICDs in the conventional implantation site.

Nerve Blocks for Postoperative Pain Management in Children Receiving Subcutaneous Implantable Cardioverter-Defibrillators: A Case Series

Subcutaneous implantable cardioverter-defibrillator (S-ICD) placement may cause significant postoperative pain. Limited research exists on regional anesthesia for pediatric S-ICD placement. This case series examined transversus thoracic plane blocks (TTPBs), pectointercostal fascial plane blocks (PIFBs), pectoralis nerve I and II blocks, paravertebral, serratus anterior plane, and erector spinae plane blocks (ESPBs) in 10 children receiving S-ICDs. Parasternal nerve blocks consisting of TTPB or PIFB and left ESPB appeared to provide adequate pain control. These children had reduced opioid consumption, lower mean pain scores, longer delay in first postoperative analgesic, and no complications. Regional anesthesia may reduce pain after pediatric S-ICD implantation.

Comparing the safety of subcutaneous versus transvenous ICDs: a meta-analysis

PURPOSE

The use of transvenous implantable cardioverter defibrillators (TV-ICDs) is associated with multiple risks related to the presence of the defibrillator leads within the venous system and right side of the heart, including endocarditis, venous occlusion, tricuspid regurgitation, and potential lead failure. The emergence of subcutaneous ICDs (S-ICDs) may potentially overcome the aforementioned disadvantages. However, evidence validating the safety of S-ICDs relative to TV-ICDs is limited. The present study aimed to synthesize and analyze available data from published studies to comprehensively compare transvenous and subcutaneous ICDs.

METHODS

Different databases were searched for full-text publications with a direct comparison of TV- and S-ICDs. Fixed effect models were applied to pooled data, and no study-to-study heterogeneity was detected.

RESULTS

Data from 7 studies totaling 1666 patients were pooled together. Compared to S-ICDs, the risk of suffering device-related complications was higher in patients with TV-ICDs (OR = 1.71; 95% CI: 1.23-2.38). The number of patients with an S-ICD who suffered inappropriate shocks (IS) was not significantly different than patients with a TV-ICD (OR = 0.92; 95% CI: 0.65-1.30). Subgroup analysis indicated that the TV-ICD group had a higher risk of IS due to supraventricular oversensing (OR = 3.29; 95% CI: 1.92-5.63) while T-wave oversensing tending to cause IS in the S-ICD group (OR = 0.09; 95% CI: 0.03-0.23). The risk of device-related infection in the S-ICD group was not any lower than that in the TV-ICD group (OR = 1.57; 95% CI: 0.67-3.68). The survival rate without any complications during a 1-year follow-up period was similar between the 2 groups (HR = 1.23; 95% CI: 0.81-1.86), although it was assumed that the trend leaned toward more complications in patients with a TV-ICD.

CONCLUSION

The present study verified the safety of S-ICDs based on pooled data. Although there were no differences between TV- and S-ICDs in the short term, fewer adverse events were found in patients with S-ICDs during long-term follow-up.

Nerve Blocks for Postoperative Pain Management in Children Receiving a Subcutaneous Implantable Cardioverter-Defibrillator: A Case Series

Subcutaneous implantable cardioverter-defibrillator (S-ICD) placement causes significant postoperative pain. Limited research exists on nerve blocks for treating pediatric S-ICD pain. This case series presents pain outcomes in 10 children receiving nerve blocks for S-ICD placement. Nerve blocks performed include bilateral parasternal with left erector spinae plane (ESP), pectoralis with left ESP, fascial plane, and paravertebral blocks. The predominant combination of bilateral parasternal blocks with a left ESP block seemed to contribute toward adequate pain control. These children appeared to have low pain scores, low opioid consumption, and no block complications. Nerve blocks may benefit pediatric patients after S-ICD implantation.

Validity Evidence of the Brazilian Version of the Florida Shock Anxiety Scale for Patients with Implantable Cardioverter Defibrillators

BACKGROUND

In spite of proven effectiveness of implantable cardioverter defibrillators (ICDs), shock therapy delivered by the device may result in increased levels of anxiety and depression, leading to deleterious effects on quality of life.

OBJECTIVE

To carry out the translation, cross-cultural adaptation and validation of the Florida Shock Anxiety Scale (FSAS) scale into Brazilian Portuguese.

METHODS

In this psychometric study, construct validity was performed by exploratory (EFA) and confirmatory (CFA) factor analyses, and by item response theory (IRT). The adjustment indexes of the CFA were: Robust Mean-Scaled Chi Square/df NNFI, CFI (Comparative Fit Index), GFI (Goodness Fit Index), AGFI (Adjusted Goodness Fit Index), RMSEA (Root Mean Square Error of Approximation) and RMSR (Root Mean Square of Residuals). Reliability was evaluated through Cronbach's Alpha, McDonald's Omega and Greatest Lower Bound (GLB). The analyses were carried out with the programs SPSS 23 and Factor 10.8.01. A 5 percent significance level was used.

RESULTS

The final Portuguese version of the FSAS was administered to 151 ICD patients, with a mean age of 55.7 ± 14.1 years, and predominantly male. The parallel analysis indicated that the FSAS is unidimensional, with an explained variance of 64.4%. The correlations ranged from 0.31 to 0.77, factor loadings from 0.67 to 0.86, and communalities from 0.46 to 0.74. The adjustment indexes of the CFA were above the quality threshold. Satisfactory reliability evidence was provided by the FSAS.

CONCLUSIONS

The FSAS-Br showed consistent validity and reliability evidence. Therefore, it can be used in ICD patients in Brazil. (Arq Bras Cardiol. 2020; 114(5):764-772).

Personality traits, ventricular tachyarrhythmias, and mortality in patients with an implantable cardioverter defibrillator: 6 years follow-up of the WEBCARE cohort

OBJECTIVE

Risk stratification within the ICD population warrants the examining of the role of protective- and risk factors. Current study examines the association between Type D personality, pessimism, and optimism and risk of ventricular tachyarrhythmias (VTa's) and mortality in patients with a first-time ICD 6 years post implantation.

METHODS

A total of 221 first-implant ICD patients completed questionnaires on optimism and pessimism (Life Orientation Test) and Type D personality (Type D scale DS14) 10 to 14 days after implantation. VTa's and all-cause mortality 6 years post implant comprised the study endpoints.

RESULTS

Ninety (40.7%) patients had experienced VTa's and 37 (16.7%) patients died, 12 (5.4%) due to a cardiac cause. Adjusted logistic regression analysis showed that pessimism was significantly associated with increased risk of VTa's (OR = 1.09; 95% CI = 1.00-1.19; p = .05). Type D personality (OR = 1.05; 95% CI = 0.47-2.32; p = .91) and optimism (OR = 1.00; 95% CI = 0.90-1.12; p = .98) were not associated with VTa's. None of the personality types were associated with mortality.

CONCLUSION

Pessimism was associated with VTa's but not with mortality. No significant association with either of the endpoints was observed for Type D personality and optimism. Future research should focus on the coexistent psychosocial factors that possibly lead to adverse cardiac prognosis in this patient population.

Risk Factors and Temporal Trends of Complications Associated With Transvenous Implantable Cardiac Defibrillator Leads

Background

The transvenous implantable cardioverter‐defibrillator (ICD) lead is the most common source of complications in a traditional ICD system. This investigation aims to determine the incidence, predictors, and costs associated with these complications using a large insurance database.

Methods and Results

Data from the OptumLabs™ Data Warehouse, which include diagnosis, physician and procedure codes, and claims from patient hospitalizations, were analyzed. Patients with a de novo ICD or cardiac resynchronization therapy defibrillator implanted from January 1, 2003, through June 30, 2015, were included; those who did not have continuous coverage beginning 1 year before implantation were excluded, resulting in 40 837 patients followed up over an average of 2.3±2.1 years. Patients were followed up until they had the procedure or their last active date in the database. Of 20 580 device procedures, 2165 (5.3%) and 771 (1.9%) had mechanical and infectious complications, respectively. The 5‐year rate of freedom from mechanical complication was 92.0% and 89.3% for ICDs and cardiac resynchronization therapy defibrillators, respectively. Infectious complications were more likely in patients with a history of atrial fibrillation, diabetes mellitus, and renal disease, and the risk increased with subsequent device procedures. Younger age, female sex, lack of comorbidities, and implantations between 2003 and 2008 were associated with more mechanical complications.

Conclusions

Incidence of mechanical and infectious complications of transvenous ICD leads over long‐term follow‐up is much higher in the real world than in clinical studies. In our study cohort, 1 of 4 transvenous ICD leads had mechanical complications when followed up to 10 years. The high rate of reintervention leads to additional complications.

Comparison of single-coil lead versus dual-coil lead of implantable cardioverter defibrillator on lead-related venous complications in a canine model

PURPOSE

Dual- coil lead (DCL) of implantable cardioverter defibrillator (ICD) is preferred clinically in patients. However, it is related to higher risk of venous stenosis and thrombosis. The present study was done to compare the fibrosis and extraction of the leads between the single-coil lead (SCL) and DCL in animal models.

METHODS

This was a chronic animal study with a follow-up duration of 6 months. Twenty mongrel dogs were randomly divided into DCL group or SCL group. Venography was performed before the sacrifice to evaluate the venous stenosis in vivo. The maximum pulling-out tension of the ICD lead was measured by a tensometer. Hematoxylin-eosin stain and toluidine blue O stain were applied to show the pathological changes of the superior vena cava (SVC) to evaluate the fibrosis and the thickness of the SVC adjacent to the leads.

RESULTS

The DCL group showed higher incidence of venous stenosis (OR = 31.5; 95% CI, 2.35-422.3; p = 0.005). It revealed increased tension to extract the leads in the DCL group (5.96 ± 1.86 vs. 3.68 ± 1.46 N, p = 0.027). The difference of venous wall thickness of SVC was 4.3 ± 0.3 fold-changes between two groups (p = 0.007). Moreover, the degree of venous wall fibrosis in DCL group was more serious than that it in SCL group (3.61 ± 1.26 vs. 1.08 ± 1.35 mm², p = 0.015).

CONCLUSION

The DCL was proved to increase thrombosis, fibrosis, and stenosis in the SVC. Likewise, the DCL was mechanically harder to be extracted than the SCL. Our study showed that lead-related complications of the DCLs were higher than those of the SCLs regardless of the equal defibrillation thresholds between them. Results of the present study would help to choose the proper lead which could be removed.

Cardiac arrest due to ventricular fibrillation in a 23-year-old woman with broken heart syndrome

Broken heart syndrome, also known as takotsubo cardiomyopathy, is a syndrome characterized by a transient regional systolic dysfunction of the left ventricle associated to a psychological stress. We herein describe a case of a 23-year-old female habitual marijuana user who was resuscitated after cardiac arrest and then diagnosed with midventricular stress cardiomyopathy complicated by subendocardial hemorrhage. We discuss this unique pathological finding, the incidence of arrhythmias in this syndrome, and the possible relation with chronic cannabis and tobacco use. Unfortunately, the patient did not survive, but had she survived, the management of the patient for secondary prevention would have been challenging considering the risk of recurrence with this disease.