Distinct Substrates of Idiopathic Ventricular Fibrillation Revealed by Arrhythmia Characteristics on Implantable Cardioverter-Defibrillator.

BACKGROUND: Idiopathic ventricular fibrillation (IVF) can be associated with undetected distinct conditions such as microstructural cardiomyopathic alterations (MiCM) or Purkinje (Purk) activities with structurally normal hearts. OBJECTIVE: This study sought to evaluate the characteristics of recurrent VF recorded on implantable defibrillator electrograms, associated with these substrates. METHODS: This was a multicenter collaboration study. At 32 centers, we selected patients with an initial diagnosis of IVF and recurrent arrhythmia at follow-up without antiarrhythmic drugs, in whom mapping demonstrated Purk or MiCM substrate. We analyzed variables related to previous ectopy, sinus rate preceding VF, trigger, and initial VF cycle lengths. Logistic regression with cross validation was used to evaluate the performance of criteria to discriminate Purk or MiCM substrates. RESULTS: Among 95 patients (35 women, age 35 ± 11 years) meeting the inclusion criteria, IVF was associated with MiCM in 41 and Purk in 54 patients. A total of 117 arrhythmia recurrences including 91% VF were recorded on defibrillator. Three variables were mostly discriminant. Sinus tachycardia (≤570 ms) was more frequent in MiCM (35.9% vs 13.4%, P = 0.014) whereas short-coupled (<350 ms) triggers were most frequent in Purk-related VF (95.5% vs 23.1%, P = 0.001), which also had shorter VFCLs (182 ± 15 ms vs 215 ± 24 ms, P < 0.001).The multivariable combination provided the highest prediction (accuracy = 0.93 ± 0.05, range 0.833-1.000), discriminating 81% of IVF substrates with a high probability (>80%). Ectopy were inconsistently present before VF. CONCLUSIONS: Characteristics of arrhythmia recurrences on implantable cardioverter- defibrillator provide phenotypic markers of the distinct and hidden substrates underlying IVF. These findings have significant clinical and genetic implications.

Wireless Device Therapy in Hypertrophic Cardiomyopathy Using the Combination of a Leadless Pacemaker and a Subcutaneous Defibrillator: A Report with 2-year Follow-up of Two Patients.

Cardiac implantable electronic devices (CIEDs) are essential tools in cardiology for tackling rhythm disturbances and have come a long way over the last decades. Technology is shifting toward leadless devices that spare the complications and limitations of traditional intravascular CIEDs. Herein, we report the simultaneous implantation of a leadless pacemaker (LP) and a subcutaneous implantable cardioverter-defibrillator (S-ICD) in two patients with hypertrophic cardiomyopathy, as well as their 2-year follow-up results, while explaining the preventive measures taken to steer around unwanted device interaction. Implantation of an S-ICD with an LP is reserved for unique cases but is a feasible approach when there is a contraindication for intravascular CIED implantation. Furthermore, this technique may be used in younger patients with cardiomyopathies in whom multiple generator replacements are expected, along with their known adverse effects.

Predictors of appropriate therapies delivered by the implantable cardioverter-defibrillator in patients with coronary artery disease during long-term period.

This prospective study aimed to investigate the ability of cardiac autonomic nervous system (CANS) activity assessment to predict appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with coronary artery disease (CAD) during long-term follow-up period. We enrolled patients with CAD and ICD implantation indications that included both secondary and primary prevention of sudden cardiac death. Before ICD implantation CANS was assessed by using heart rate variability (HRV), myocardium scintigraphy with 123I-meta-iodobenzylguanidine (123I-MIBG) and erythrocyte membranes ß-adrenoreactivity (EMA). The study's primary endpoint was the documentation of appropriate ICD therapy. Of 45 (100.0%) patients, 15 (33.3%) had appropriate ICD therapy during 36 months follow-up period. Patients with appropriate ICD therapy were likely to have a higher summed 123I-MIBG score delayed (p < 0.001) and lower 123I-MIBG washout rate (p = 0.008) indicators. These parameters were independently associated with endpoint in univariable and multivariable logistic regression. We created a logistic equation and calculated a cut-off value. The resulting ROC curve revealed a discriminative ability with AUC of 0.933 (95% confidence interval 0.817-0.986; sensitivity 100.00%; specificity 93.33%). Combined CANS activity assessment is useful in prediction of appropriate ICD therapy in patients with CAD during long-term follow-up period after device implantation.

Efficacy and safety of implantable cardioverter-defibrillator implantation in the elderly-The I-70 Study: A randomized clinical trial.

Background: There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly. Objective: The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older. Methods: Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82). Results: Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence interval 0.53-1.57), but there was a trend favoring the ICD over the first 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock. Conclusion: The study did not recruit to target sample size, and accumulated data did not show benefit of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolonging life among elderly device candidates.

The Impact of Ipsilateral Implantable Cardioverter Defibrillator in Axillary Intra-Aortic Balloon Pump Support as Bridge to Heart Transplantation.

BACKGROUND: The axillary artery (AX) access for intra-aortic balloon pump (IABP) as a bridge to heart transplant (HT) allows mobility while awaiting a suitable donor. As end-stage heart failure patients often have an implantable cardioverter defibrillator (ICD) on the left side, the left AX approach may be avoided due to the perception of difficult access and proximity of two devices. We aimed to evaluate the outcomes of patients bridged to HT with a left-sided AX IABP with or without ipsilateral ICDs. METHODS: We retrospectively reviewed HT candidates at our institution supported by left-sided axillary IABP from November 2019 to February 2024, dividing them into two groups based on the presence (Group ICD, n = 48) or absence (Group No-ICD, N = 19) of an ipsilateral left-sided ICD. The exposure time was defined as the time from skin incision to the beginning of anastomoses of a Dacron graft. RESULTS: Technical success was achieved in 100% of the cohort, with median exposure times for AX access similar between groups (ICD, 12 [7.8, 18.2] vs. No ICD, 11 [7, 19] min; p = 0.75). The rate of procedural adverse events, such as significant access site bleeding and ipsilateral limb ischemia, did not significantly differ between both groups. Device malfunction rates were comparable (ICD, 29.2% vs. No ICD, 15.8%; p = 0.35). Posttransplant, in-hospital mortality, severe primary graft dysfunction, and stroke rates were comparable in both groups. CONCLUSION: The presence of an ipsilateral left-sided ICD does not adversely impact the procedural efficacy, complication rates, or posttransplant outcomes of left-sided AX IABP insertion in HT candidates.

Effects of Implantable Cardioverter-Defibrillator Leads on the Tricuspid Valve and Right Ventricle: A Randomized Trial.

BACKGROUND: There are no randomized data to inform the extent to which transvenous cardiac leads cause tricuspid regurgitation (TR). OBJECTIVES: This study sought to determine the effect of a transvenous implantable cardioverter-defibrillator (TV-ICD) on TR severity, and secondarily, on right ventricular (RV) size and function. METHODS: We evaluated TR severity before and 6 months after implantable cardioverter-defibrillator insertion in a post hoc analysis of adults randomized to receive a transvenous (n = 252) or subcutaneous implantable cardioverter-defibrillator (S-ICD) (n = 251) device. TR and RV size and systolic function were assessed by echocardiographic images analyzed in a core laboratory. RESULTS: At baseline, at least mild TR was present in 30% of individuals. At 6 months, the proportion of participants with any TR in the TV-ICD group was 42% vs 19% in the S-ICD group (P < 0.001). The proportion with moderate or severe TR was 7% in the TV-ICD group vs 2% in the S-ICD group (P = 0.021). At 6 months, the OR of at least 1 grade worsening of TR in the TV-ICD group as compared with the S-ICD group was 7.2 (95% CI: 3.3-15.8; P < 0.001). There were no differences between groups with respect to RV size or systolic function. CONCLUSIONS: Six months following TV-ICD insertion, there was a 7-fold increase in the risk of at least 1 grade worsening of TR, with 7% of individuals having TR that was moderate or severe. There was no detectable difference in RV size or function; however, longer follow-up is needed.

Clinical use of CRT-D devices with left ventricular sensing: Impact of the desynchronization-detection algorithm.

The use of CRT-D devices with left ventricular (LV) sensing has created controversy about programming various parameters especially the left ventricular T wave protection (LVTP) designed to prevent the delivery of a pacing stimulus into the LV vulnerable period. Such devices are available from two manufacturers. This review focuses only on those provided by Biotronik. As the LVTP controls LV sensing, some investigators have advocated turning off the LVTP to prevent episodic desynchronization known a CRT pacing interrupt. However, LVTP off reduces but does not eliminate this type of desynchronization if triggering of an LV stimulus upon right ventricular sensing (RVs) is programmed on. Deactivation of the LVTP incurs loss of diagnostic data provided by CRT pacing interrupt itself. By choice, the occurrence of CRT pacing interrupt can be totally eliminated by appropriate programming of the LV upper rate interval, LVTP and triggering of an LV pacing event upon RVs. Various programmability options are available according to clinical circumstances. As a rule, clinical judgement must weigh the potential diagnostic benefit of preserving the LVTP capable of recording of episodic CRT pacing interrupt against the loss of diagnostic benefit when LVTP is programmed off (with or without triggering of an LV stimulus upon RVs).

The Plumber Versus Electrician Dilemma: To Bypass or to Defibrillate?

We present a unique case of an 80-year-old male who presented to our emergency department following cardiac defibrillation when he was found to be in polymorphic ventricular tachycardia (VT) after a syncopal event while at cardiac rehabilitation. He had known coronary artery disease and had a four-vessel coronary artery bypass graft (CABG) 20 years prior to presentation. He underwent left heart catheterization (LHC) two months prior to the syncopal event for worsening shortness of breath and the decision at that time was to proceed with medical management and intervene with redo-CABG if shortness of breath did not improve or progressively worsened. While admitted under our care after the polymorphic VT event, we faced the dilemma of whether to proceed with redo-CABG first since cardiac ischemia is a common cause of polymorphic VT or whether to insert an implantable cardioverter-defibrillator (ICD) before proceeding with redo-CABG. We present the current literature that addresses ICD implantation for secondary prevention and our approach to this complicated case.

EFFICACY AND SAFETY OF THE SUBCUTANEOUS IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IN PATIENTS WITH AND WITHOUT OBESITY: A META-ANALYSIS.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to transvenous systems for preventing sudden cardiac death. However, concerns have been raised regarding its efficacy and safety in obese individuals. OBJECTIVE: This meta-analysis aims to evaluate the efficacy and safety of the S-ICD in patients with obesity by assessing the relationship between body mass index (BMI) and clinical outcomes. METHODS: A comprehensive search of multiple databases was conducted for English-language peer-reviewed studies reporting clinical outcomes in S-ICD recipients with (BMI ≥30 kg/m2) and without obesity (BMI <30 kg/m2). Data on pre-implantation screening failure, defibrillation testing, complications, appropriate and inappropriate shocks, and survival were analysed using standard random-effect meta-analytical techniques. RESULTS: Twenty-nine studies involving 20,486 patients were included. There was no statistically significant difference in the mean BMI values of patients with failed or successful preimplantation screening (mean difference -0.60 kg/m2, 95% CI -2.06 to 0.86). Obesity was associated with higher rates of failed defibrillation testing at ≤65J (OR 2.16, 95% CI 1.39-3.35), and mal-/suboptimal positioning occurred more frequently in obese compared to non-obese patients (OR 3.37, 95% CI 1.76-6.44). Increased BMI as a continuous variable (per increase in 1 kg/m2 BMI) was associated with elevated defibrillation thresholds (OR 1.05, 95% CI 1.03-1.08), a higher risk of complications (HR 1.04, 95% CI 1.02-1.05), a trend towards increased number of appropriate shocks (HR 1.02, 95% CI 1.00-1.04), and no significant increase in the risk for inappropriate shocks (HR 1.01, 95% CI 0.99-1.03). CONCLUSION: This meta-analysis underscores the importance of considering obesity in S-ICD implantation decisions. While S-ICD remains effective in obese patients, attention to potential technical challenges and higher complication rates is warranted.

Subcutaneous versus transvenous implantable cardioverter defibrillator in hypertrophic cardiomyopathy: a systematic review and meta-analysis.

Background: A subcutaneous implantable cardioverter-defibrillator (S-ICD) is an alternative to a transvenous implantable cardio defibrillator (TV-ICD). An S-ICD reduces the risk of transvenous lead placement. However, further research is required to determine how S-ICDs affect patients with hypertrophic cardiomyopathy (HCM). In this study, we investigated the comparative efficacy and safety of S-ICDs versus TV-ICDs in HCM. Methods: On December 6th, 2023, we performed a comprehensive search of the PubMed, Embase, Scopus, and Cochrane databases to identify randomized clinical trials (RCTs) and observational studies comparing S-ICDs with TV-ICDs in HCM patients published from 2004 until 2023. No language restrictions were applied. The primary outcome was appropriate shocks (AS), with inappropriate shocks (IAS), and device-related complications considered as secondary outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random effects model. The ROBINS-I tool was used to assess the risk of bias of the studies. Results: The search yielded 1,114 records. Seven studies comprising 4,347 HCM patients were included, of whom 3,325 (76.0%) had TV-ICDs, and 1,022 (22.6%) had S-ICDs. There were 2,564 males (58.9%). The age range was from 39.1 to 49.4 years. Compared with the TV-ICD group, the S-ICD cohort had a significantly lower incidence of device-related complications (OR 0.52; 95% CI: 0.30-0.89; P=0.02; I2=4%). Contrastingly, there were no statistically significant differences in the occurrences of AS (OR 0.49; 95% CI: 0.22-1.08; P=0.08; I2=75%) and IAS (OR 1.03; 95% CI: 0.57-1.84; P=0.93; I2=65%) between the two device modalities. In the analysis of the overall risk of bias in the studies, we found 42% of them with several, 28% with moderate, and 14% with low risk of bias. Conclusions: In HCM patients, S-ICDs were associated with a lower incidence of device-associated problems than TV-ICDs. AS and IAS incidence rates were similar between groups. These findings may assist clinicians in determining the most suitable device for treating patients with HCM.

Effects of Irradiation During Computed Tomography Scanning on the Function of Implantable Cardioverter-defibrillators.

The effect of irradiation during computed tomography (CT) imaging on implantable cardioverter-defibrillators (ICDs) has not been fully evaluated in various settings. The purposes of this study were to evaluate the occurrence of electromagnetic interference (EMI) during CT irradiation in various clinically available ICDs with phantom experiments and to determine the potential risks related to irradiation during CT imaging. Five types of clinically available ICDs from five manufacturers were tested. An ICD was combined with an electrocardiogram (ECG) simulator, mounted in a chest phantom, and subjected to CT imaging. Each ICD was irradiated at the maximal power level (tube voltage, 135 kVp; tube current, 510 mA; rotation time, 1.5 s). EMI was defined as oversensing, ventricular tachycardia/ventricular fibrillation (VT/VF) detection, noise, or shock delivery during CT imaging. For ICDs in which EMI was observed, EMI was then evaluated under 144 different irradiation conditions (tube voltage [four patterns from 80-135 kVp], tube current [six patterns from 50-550 mA], and rotation time [six patterns from 0.35-1.5 s]). Testing was also performed during irradiation at the typical doses in three clinical settings and in two settings with inappropriate irradiation of ICDs due to incorrect setup. Among the five ICDs, a shock was delivered by one ICD manufactured by Medtronic (Minneapolis, MN, USA) due to oversensing during irradiation, which occurred at the maximal power level. No oversensing was observed in other ICDs. In the malfunctioned ICD, oversensing was observed in 134 of 144 irradiation patterns, even at a low power in the ICD. The VF-detection criterion was fulfilled in 20 of 134 tests and was significantly associated with tube voltage, tube current, ration time, and tube voltage × rotation time interaction. Although oversensing was observed in three clinical settings (typical chest CT, CT coronary angiography after coronary artery bypass graft, and dynamic assessment for pleural tumors) and one situation during an incorrect scan range on the chest for head perfusion CT, they were not recognized as tachycardia beats. Oversensing was observed when scans were incorrectly set over the ICD during bolus tracking of contrast-enhanced CT. Maximal power CT imaging induced VT/VF detection and shock delivery in one model of ICD placed in a chest phantom. VT/VF detection was observed when tube voltages were high and irradiation times were longer. Oversensing can occur during inappropriate CT imaging, particularly when slices are positioned over the ICD.

Utility of an Externalized Temporary Transvenous Implantable Cardioverter-defibrillator System in the Setting of Ventricular Tachycardia Storm and Concurrent Device Infection Requiring Extraction.

With the expanding use of cardiac implantable electronic device (CIED) therapy, intravascular device infections are becoming more common. In the case of transvenous implantable cardioverter-defibrillator (ICD) infections requiring extraction for bacterial clearance, there remains no standard method to deliver temporary ICD therapy following device removal. We present a case of persistent bacteremia complicated by monomorphic ventricular tachycardia (VT) electrical storm where biventricular ICD system extraction was performed and a temporary transvenous dual-coil lead with an externalized ICD generator was used to treat VT episodes prior to the re-implantation of a new permanent system. This case demonstrates the utility of a temporary externalized transvenous ICD system in the successful detection and pace-termination of VT, thereby reducing episodes of painful and potentially harmful external defibrillator shocks during the treatment of CIED infection.

Depression and Implantable Cardioverter-Defibrillator Implantation in Black Patients at Risk for Sudden Cardiac Death.

BACKGROUND: Black patients meeting indications for implantable cardioverter-defibrillators (ICDs) have lower rates of implantation compared with White patients. There is little understanding of how mental health impacts the decision-making process among Black patients considering ICDs. Our objective was to assess the association between depressive symptoms and ICD implantation among Black patients with heart failure. METHODS AND RESULTS: This is a secondary analysis of the VIVID (Videos to Address Racial Disparities in ICD Therapy via Innovative Designs) randomized trial, which enrolled self-identified Black individuals with chronic systolic heart failure. Depressive symptoms were assessed by the Patient Health Questionnaire-2 and the Mental Component Summary of the 12-Item Short-Form Health Survey. Decisional conflict was measured by an adapted Decisional Conflict Scale (DCS). ANCOVA was used to assess differences in Decisional Conflict Scale scores. Multivariable logistic regression was used to examine the association between depressive symptoms and ICD implantation. Among 306 participants, 60 (19.6%) reported depressed mood, and 142 (46.4%) reported anhedonia. Participants with the lowest Mental Component Summary of the 12-Item Short-Form Health Survey scores (poorer mental health and higher likelihood of depression) had greater decisional conflict regarding ICD implantation compared with those with the highest Mental Component Summary of the 12-Item Short-Form Health Survey scores (adjusted mean difference in Decisional Conflict Scale score, 3.2 [95% CI, 0.5-5.9]). By 90-day follow-up, 202 (66.0%) participants underwent ICD implantation. There was no association between either the Patient Health Questionnaire-2 score or the Mental Component Summary of the 12-Item Short-Form Health Survey score and ICD implantation. CONCLUSIONS: Depressed mood and anhedonia were prevalent among ambulatory Black patients with chronic systolic heart failure considering ICD implantation. The presence of depressive symptoms did not impact the likelihood of ICD implantation in this population.

Predictors of Shock-Reduction Programming and Its Impact on Implantable Cardioverter-Defibrillator Therapies and Mortality: The CERTITUDE Registry.

BACKGROUND: Shock-reduction implantable cardioverter-defibrillator programming (SRP) was associated with fewer therapies and improved survival in randomized controlled trials, but real-world studies investigating SRP and associated outcomes are limited. METHODS AND RESULTS: The BIOTRONIK CERTITUDE registry was linked with the Medicare database. We included all patients with an implantable cardioverter-defibrillator implanted between August 22, 2012 and September 30, 2021 in the United States. SRP was defined as programming to either a therapy rate cutoff ≥188 beats per minute or number of intervals to detection ≥30/40 for treatment. Among 6781 patients (mean 74±9 years; 27% women), 3393 (50%) had SRP. Older age, secondary prevention indication, and device implantation in the southern or western United States were associated with lower use of SRP. The cumulative incidence rate of implantable cardioverter-defibrillator shocks was lower in the SRP group (5.1% shocks/patient year) compared with the non-SRP group (7.2% shocks/patient year) (adjusted hazard ratio [HR], 0.83 [95% CI, 0.73-0.96]; P=0.005). Over a median follow-up of 2.9 years, 739 deaths occurred in the SRP group and 822 deaths occurred in the non-SRP group (adjusted HR, 0.97 [95% CI, 0.88-1.07]; P=0.569). SRP was associated with a lower all-cause mortality among patients without ischemic heart disease compared with patients with ischemic heart disease (adjusted HR, 0.64 [95% CI, 0.48-0.87] versus adjusted HR, 1.02 [95% CI, 0.92-1.14]; Pinteraction=0.004). CONCLUSIONS: Adoption of SRP is low in real-world clinical practice. Age, clinical variables, and geographic factors are associated with use of SRP. In this study, SRP-associated decrease in mortality was limited to patients without ischemic heart disease.

Procedural Outcome and 1-Year Follow-Up of Young Patients Undergoing Implantable Cardioverter-Defibrillator Implantation-Insights from the German DEVICE I+II Registry.

Background: The number of young patients receiving ICDs or CRT-Ds has been increasing in recent decades and understanding the key characteristics of this special population is paramount to optimized patient care. Methods: The DEVICE I+II registry prospectively enrolled patients undergoing ICD/CRT-D implantation or revision from 50 German centers between 2007 and 2014 Data on patient characteristics, procedural outcome, adverse events, and mortality during the initial stay and 1-year follow-up were collected. All patients under the age of 45 years were identified and included in a comparative analysis with the remaining population. Results: A total number of 5313 patients were enrolled into the registry, of which 339 patients (6.4%) were under the age of 45 years. Mean age was 35.0 ± 8.2 vs. 67.5 ± 9.7 years, compared to older patients (≥45 years). Young patients were more likely to receive an ICD (90.9 vs. 69.9%, p < 0.001) than a CRT-D device (9.1 vs. 30.1%). Coronary artery disease was less common in younger patients (13.6 vs. 63.9%, p < 0.001), whereas hypertrophic cardiomyopathy (10.9 vs. 2.7%, p < 0.001) and primary cardiac electrical diseases (11.2 vs. 1.5%, p < 0.001) were encountered more often. Secondary preventive ICD was more common in younger patients (51.6 vs. 39.9%, p < 0.001). Among those patients, survival of sudden cardiac death (66.7 vs. 45.4%, p < 0.001) due to ventricular fibrillation (60.6 vs. 37.9%, p < 0.001) was the leading cause for admission. There were no detectable differences in postoperative complications requiring intervention (1.5 vs. 1.9%, p = 0.68) or in-hospital mortality (0.0 vs. 0.3%, p = 0.62). Median follow-up duration was 17.9 [13.4-22.9] vs. 16.9 [13.1-23.1] months (p = 0.13). In younger patients, device-associated complications requiring revision were more common (14.1 vs. 8.3%, p < 0.001) and all-cause 1-year-mortality after implantation was lower (2.9 vs. 7.3%, p = 0.003; HR 0.39, 95%CI: 0.2-0.75) than in older patients. Conclusions: Young patients < 45 years of age received defibrillator therapy more often for secondary prevention. Rates for periprocedural complications and in-hospital mortality were very low and without differences between groups. Young patients have lower mortality during follow-up but experienced a higher rate of postoperative complications requiring revision, potentially due to a more active lifestyle.

Respiratory Function of Mitochondria in Patients with Coronary Heart Disease with Implantable Cardioverter-Defibrillator.

We studied the respiratory activity of mitochondria in peripheral blood leukocytes from 36 patients with coronary heart disease (CHD) and a history of ventricular tachyarrhythmias required cardioverter-defibrillator implantation. The measurements were carried out in incubation buffers with different oxidation substrates (succinate and pyruvate-malate mixture). In pyruvate-malate incubation buffer, oxygen consumption rate and respiratory control coefficients in patients with triggered device did not differ significantly from those in patients without cardioverter-defibrillator triggering. At the same time, respiratory control coefficients were below the reference values. In succinate buffer, values of mitochondrial parameters were significantly lower in patients with triggered devices. Our findings indicate that mitochondria of patients with non-triggered cardioverters-defibrillators have better functional and metabolic plasticity. It was concluded that activity of respiratory processes in mitochondria could be an indicator that should be taken into the account when assessing the risk of developing ventricular tachyarrhythmias.

Brugada syndrome: identification of subjects at risk and therapy.

Brugada syndrome mainly affects young subjects with structurally normal heart and can cause x syncope or sudden death due to ventricular arrhythmias, even as the first manifestation, in approximately 5-10% of cases. To date, two questions remain open: how to recognize subjects who will experience arrhythmic events and how to treat them. The guidelines suggest treating subjects with a previous history of cardiac arrest or arrhythmogenic syncope, while they are unconclusive about the management of asymptomatic patients, who represent ∼90% of Brugada patients. We recently demonstrated that in asymptomatic patients, the presence of spontaneous Brugada type 1 electrocardiogram (ECG) pattern and inducibility of ventricular arrhythmias at electrophysiological study allows us to identify a group of patients at greater risk who deserve treatment. Regarding treatment, there are three options: implantable cardioverter defibrillator, drugs, and epicardial transcatheter ablation. Recent studies have shown that the latter is effective and free from serious side effects, thus opening a new scenario in the treatment of Brugada patients at risk. Subjects who present drug-induced-only type 1 Brugada ECG pattern, in whom a spontaneous type 1 pattern has been ruled out with repeated ECGs and 12-lead 24-h Holter monitoring, represent a very low-risk group, provided they adhere to behavioural recommendations and undergo regular follow-up.

Mindfulness Is Associated with Lower Depression, Anxiety, and Post-Traumatic Stress Disorder Symptoms and Higher Quality of Life in Patients with an Implantable Cardioverter-Defibrillator-A Cross-Sectional Study.

Several studies suggested the efficacy of dispositional mindfulness and mindfulness-based interventions in reducing anxiety and depression in cardiovascular diseases. However, data on the impact of mindfulness on the psychological well-being of patients with an implantable cardioverter-defibrillator (ICD) are scarce. In this study, 422 patients with an ICD were prospectively recruited. Logistic regression was applied to determine associations between dispositional mindfulness (Freiburg Mindfulness Inventory), depression (Patient Health Questionnaire-8), anxiety (Generalized Anxiety Disorder-7 scale), and post-traumatic stress disorder (PTSD) symptoms (Post-Traumatic Stress Diagnostic Scale), adjusting for age, sex, educational status, number of ICD shocks after ICD implantation, and physical activity. The PROCESS regression path analysis modelling tool was used to identify indirect mediating effects of dispositional mindfulness on depression, anxiety, and PTSD symptoms and quality of life (QoL; EuroQol group 5-dimension questionnaire). Participants presented high baseline QoL (mean 1.06 to 1.72) and medium-high mindfulness scores (mean 40.85 points). Higher mindfulness scores were associated with lower levels of anxiety (OR 0.90, 95% CI 0.86 to 0.95, 0.001), depression (OR 0.93, 95% CI 0.88 to 0.98, p = 0.006), and PTSD symptoms (OR 0.94, 95% CI 0.89 to 0.98, p = 0.011). Furthermore, greater mindfulness partially mediated the relationship between anxiety (indirect effect 0.10, 95% CI 0.02 to 0.21), depression (indirect effect 0.08, 95% CI 0.01 to 0.17), or PTSD (indirect effect 0.04, 95% CI 0.01 to 0.17) as independent variables and the QoL as the dependent variable. This study suggests that greater dispositional mindfulness is associated with less anxiety, depression, and PTSD symptoms. Mindfulness might also increase the QoL in ICD patients by mitigating the impact of those with psychological distress.

Late recognition of cardiac implantable electronic device misplacement in left ventricle: a case report.

Background: Cardiac electronic device implantation may be associated with complications. Case Summary: This is a report of inadvertent implantation of implantable cardioverter-defibrillator lead through an unrecognized sinus venosus atrial septal defect into the left ventricle that was not diagnosed early after implantation. Six months later chest x-ray showed an abnormal lead course that was confirmed with echocardiography as to be in the left ventricle. Surgical removal of the implantable cardioverter-defibrillator lead, repair of atrial septal defect, and correction of abnormal pulmonary venous connections were performed. Meanwhile, follow-up of the patient receiving a new dual chamber permanent pacemaker from the contralateral side and discussion of the aforementioned complication are addressed. Conclusion: Early diagnosis of device implantation complication is of paramount importance and prevents potential catastrophic complications.

This is a report of a middle-aged woman who received a heart battery (pacemaker) without proper initial indication and faced unnecessary consequences/complications. The wire was supposed to be implanted in the right side of the heart, but due to the congenital heart disease of the patient (that was not diagnosed), the wire was erroneously passed through the congenital defect to the left side of the heart. After the diagnosis of the problem, we referred her to a heart surgeon to correct the congenital heart defect and also pull the wire out. After open surgery, a new pacemaker (with two wires) was implanted in the patient without any additional complications.