Ranolazine Unveiled: Rediscovering an Old Solution in a New Light.

Ranolazine is an anti-anginal medication that has demonstrated antiarrhythmic properties by inhibiting both late sodium and potassium currents. Studies have shown promising results for ranolazine in treating both atrial fibrillation and ventricular arrhythmias, particularly when used in combination with other medications. This review explores ranolazine's mechanisms of action and its potential role in cardiac arrhythmias treatment in light of previous clinical studies.

Type and dimensions can predict ventricular arrhythmias and cardiac death in primary benign cardiac tumors in children.

Despite being extremely rare in children, primary benign cardiac tumors can cause malignant ventricular arrhythmias (VA) or even sudden cardiac death. To assess the predictors of cardiovascular death and malignant VAs, we designed a retrospective single-center study enrolling paediatric patients. We defined as primary outcome a composite of cardiovascular death, sustained VT, ventricular fibrillation and rapid, symptomatic non-sustained VT. Our secondary endpoint was to assess the prevalence of clinically significant arrhythmias in our population. METHODS AND RESULTS: We fitted a multivariate Cox regression model to assess the predictors of the primary outcome. Over a period of 38 years, a total of 97 children were enrolled in the study. Among them, there were 73 rhabdomyomas, 13 fibromas, 3 myxomas, 3 teratomas, 1 lipoma, 2 haemangiomas and 2 fibroelastomas. Over a median follow up of 10.53 years, 16 patients met the primary outcome. Kaplan Meier unadjusted survival estimates showed that tumor dimensions larger than 2.3 cm and diagnosis of fibroma predicted worse outcomes compared with smaller tumors or other histotypes, (log rank p < 0.0002 and < 0.0001 respectively). In multivariate Cox proportional hazards analysis, diagnosis of fibroma and tumor dimensions were independently associated to the primary endpoint (HR: 5.06, 95 %CI (1.3-19); and 1.26 • (1.05-11), respectively). Clinically significant arrhythmias were reported in 24.5 % of the study population. CONCLUSIONS: Among paediatric primary cardiac tumors, type and dimensions may predict the hazard of malignant VAs and cardiac death.

Vascular Access Complications Following Catheter Ablation of Ventricular Arrhythmias: Impact of Vascular Closure Devices.

BACKGROUND: Vascular access-site complications are the most frequent complications of percutaneous catheter ablation (CA) of ventricular arrhythmias (VAs). Whether arterial/venous vascular closure devices (VCDs) prevent vascular complications is unknown. OBJECTIVE: We investigated the benefit of VCDs in patients undergoing CA of VAs. METHODS: Consecutive CA of VAs were included (2018-2022). Vascular accesses were obtained with ultrasound guidance. At the discretion of the operator, arterial and/or venous VCDs were used. Cases were divided into 3 groups: no use of VCDs for any of the arterial/venous accesses (manual compression - MC), use of VCDs for some but not the all of the accesses (Partial-VCDs), use of VCDs for all of the accesses (Complete-VCDs). Vascular complications were defined minor if they didn't require intervention or major if they required intervention. RESULTS: A total of 1,016 procedures were performed in 872 patients (62±13 years, BMI 30±6 kg/m2, 27% female) during the study period. Femoral arterial access was obtained in 887 procedures (875 single access - 7.4±1.5 Fr size, 12 two accesses - 7.3±3 Fr and 6.9±1.8 Fr). Femoral venous access was obtained in 1,014 procedures (unilateral in 17%, bilateral in 83%, mean N. 2.6±0.7, 8.4±1.3 Fr). Hemostasis was achieved with MC in 192 (19%) procedures, Partial-VCD in 275 (27%), and Complete-VCD in 549 (54%). A vascular complication occurred in 52 (5.1%) procedures, including a minor hematoma in 3.9% and/or a major complication in 1.7%. The rate of vascular complications was 6.8% (5.2% minor and 1.6% major) in the MC group, 7.6% (5.1% minor and 3.3% major) in the Partial-VCD group, and 3.3% (2.9% minor and 0.9% major, P=0.014 for comparison) in the Complete-VCD group. At multivariable analysis, Complete-VCD remained independently associated with lower risk of vascular complications (odds ratio 0.69, 95% confidence interval 0.48 to 0.96, P=0.036). CONCLUSIONS: In patients undergoing CA of VAs, Complete-VCD is associated with lower rates of vascular-related complications compared to MC or Partial-VCD.

Brugada Syndrome: Anesthetic Implications in an Incidentally Diagnosed Patient.

Brugada syndrome (BS) is characterized by abnormal repolarization in cardiac cells, occurring in the absence of structural heart disease, which elevates the risk of ventricular arrhythmias and sudden cardiac death. While most BS patients are asymptomatic, a notable percentage experience syncope or sudden cardiac death. Diagnosis is primarily based on electrocardiographic (ECG) findings. A 40-year-old male with a history of syncope and a family history of sudden cardiac death was scheduled for urgent clavicle osteosynthesis. Preoperative ECG revealed type 1 BS. A multidisciplinary approach was taken, and anesthetic management involved combined general and regional anesthesia, utilizing ultrasound-guided clavipectoral and superficial cervical blocks. Postoperative pain was managed with paracetamol and ketorolac. The patient remained stable throughout the procedure, was monitored for 36 hours postoperatively, and was discharged without complications. BS poses significant perioperative risks, necessitating careful anesthetic management. This case report highlights the successful use of combined general and regional anesthesia in a BS patient, contributing to the limited evidence on safe anesthesia practices for this pathology.

Clinical Course and Treatment of Patients With Apical Aneurysms Due to Hypertrophic Cardiomyopathy.

Background: There is controversy about risk of malignant arrhythmias and stroke in patients with apical aneurysms in hypertrophic cardiomyopathy (HCM). Objectives: The aim of this study was to estimate the associations of aneurysm size and major HCM risk factors with the incidence of lethal and potentially lethal arrhythmias and to estimate incidence of unexplained stroke. Methods: In 108 patients (age 57.4 ± 13.5 years, 37% female) from 3 HCM centers, we assessed American Heart Association/American College of Cardiology guidelines risk factors and initial aneurysm size by echocardiography and cardiac magnetic resonance imaging and assessed outcomes after median 5.9 (IQR: 3.7-10.0) years. Results: Implantable cardioverter defibrillator discharges or sudden cardiac death (SCD) occurred in 21 (19.4%) patients. Of patients with a risk factor, 55% subsequently had ventricular tachycardia (VT), ventricular fibrillation (VF), or SCD at follow-up, compared with 10% in those who did not (P < 0.001). The upper tercile of size had a 5-year cumulative risk of 35%, while the lower tercile had 5-year risk of 6% (P = 0.0046). In those with the smallest aneurysms <2 cm2 and also without risk factors VT, VF, or SCD occurred in only 2.5%. Clinical atrial fibrillation (AF) was prevalent, occurring in 49 (45%). Stroke was commonly associated with AF. Stroke without conventional cause had an incidence of 0.5%/year. Surgery in 19% was effective in reducing symptoms. VT ablation and surgery were moderately effective in preventing recurrent VT. Conclusions: Risk factors and aneurysm size were associated with subsequent VT, VF, or SCD. Patients with aneurysms in the lowest tercile of size have a low cumulative 5-year risk. Clinical AF occurred frequently. Stroke prevalence in absence of known stroke etiologies is uncommon and comparable to risk of severe bleeding.

From genes to clinical management: A comprehensive review of long QT syndrome pathogenesis and treatment.

Background: Long QT syndrome (LQTS) is a rare cardiac disorder characterized by prolonged ventricular repolarization and increased risk of ventricular arrhythmias. This review summarizes current knowledge of LQTS pathogenesis and treatment strategies. Objectives: The purpose of this study was to provide an in-depth understanding of LQTS genetic and molecular mechanisms, discuss clinical presentation and diagnosis, evaluate treatment options, and highlight future research directions. Methods: A systematic search of PubMed, Embase, and Cochrane Library databases was conducted to identify relevant studies published up to April 2024. Results: LQTS involves mutations in ion channel-related genes encoding cardiac ion channels, regulatory proteins, and other associated factors, leading to altered cellular electrophysiology. Acquired causes can also contribute. Diagnosis relies on clinical history, electrocardiographic findings, and genetic testing. Treatment strategies include lifestyle modifications, ß-blockers, potassium channel openers, device therapy, and surgical interventions. Conclusion: Advances in understanding LQTS have improved diagnosis and personalized treatment approaches. Challenges remain in risk stratification and management of certain patient subgroups. Future research should focus on developing novel pharmacological agents, refining device technologies, and conducting large-scale clinical trials. Increased awareness and education are crucial for early detection and appropriate management of LQTS.

Impact of cardiac conduction disease in patients with cardiac amyloidosis: A national retrospective cohort study.

BACKGROUND: There is a paucity of data regarding the impact of cardiac conduction disease (CD) on clinical outcomes in patients with cardiac amyloidosis (CA). METHODS: The National Inpatient Sample (NIS) was queried to identify all CA admissions and those with CD using ICD-10 codes from 2016 to 2019. We explored baseline characteristics and used multivariate logistic regression to assess the association between CD and several clinical outcomes during index admission; a p-value of <0.05 was significant. Propensity score matching (PSM) was performed to validate our results. RESULTS: A total of 12,185 patients with CA were identified. Of these, 920 (7.6 %) had CD. The median age of the sample was 72 years (IQR: 64-80). After multivariate adjustment and PSM, the presence of CD in CA was associated with higher odds of ventricular arrhythmias (VA) (aOR = 2.97, 95 % CI 1.78-4.96, p < 0.001), syncope (aOR = 3.44, 95 % CI 1.51-7.83, p = 0.003), and cardiovascular implantable electronic device (CIED) implantation (aOR = 12.86, 95 % CI 5.50-30.04, p < 0.001) but not with sudden cardiac arrest (p = 0.092), acute heart failure (p = 0.060), all-cause in-hospital mortality (p = 0.384), and non-routine discharge in patients admitted for CA (p = 0.271). CONCLUSIONS: Although CD was not associated with all-cause in-hospital mortality, there was a significant association with VAs and syncope. Syncope is associated with worse survival in patients with CA. Further studies that prospectively follow patients are needed to determine the true effect of cardiac CD on mortality in patients with CA.

Cardiac resynchronization therapy in heart failure based on Strauss criteria for left bundle branch block.

AIMS: The left bundle branch block (LBBB) is a strong predictor of response to cardiac resynchronization therapy (CRT). However, a significant number of patients do not respond to the treatment. The study sought to evaluate the impact of the stricter Strauss criteria for left bundle branch block (St-LBBB) on CRT response, hospitalizations, ventricular arrhythmia (VA) events and mortality. METHODS: This study is a retrospective analysis of prospectively collected data on heart failure (HF) patients with LBBB admitted for CRT implantation. Patients were divided into two groups according to the fulfilment or not of St-LBBB criteria. RESULTS: The study included 82 patients with ischaemic (ICM) and non-ischaemic (NICM) cardiomyopathy [46 (56%) with St-LBBB and 36 (44%) with non-St-LBBB]. Patients with St-LBBB showed higher CRT response rates compared with those with non-St-LBBB (P < 0.01), while the group with NICM exhibited the greatest benefit (P < 0.01). St-LBBB CRT responders displayed significantly lower rates of HF hospitalization (P < 0.0001) compared with the non-St-LBBB group. According to Kaplan-Meier time curves, this was primarily evident in patients with NICM (P < 0.0001). CRT responders displayed significantly fewer VA events (P < 0.001) and lower mortality rates (P < 0.0001) than non-responders. Kaplan-Meier estimates demonstrated a significantly lower incidence of VAs in NICM patients with St-LBBB (P = 0.049) compared with ICM patients with St-LBBB (P = 0.25). Lower mortality rates were observed in CRT responders than non-responders (P < 0.0001), with the group of NICM with St-LBBB criteria exhibiting the greatest benefit (P = 0.0238). CONCLUSIONS: Patients with NICM and St-LBBB present the greatest benefit concerning CRT response, HF hospitalizations, VA events and mortality. Although St-LBBB criteria seem to improve patient selection for CRT, more data are needed to elucidate the role of St-LBBB criteria in this setting.

Impact on ventricular arrhythmic burden of SGLT2 inhibitors in patients with chronic heart failure evaluated with cardiac implantable electronic device monitoring.

BACKGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have revolutionized the therapeutic scenario of heart failure, demonstrating favorable effects on mortality and quality of life. Previous studies have yielded conflicting data regarding the effects on ventricular arrhythmias. METHODS: A prospective observational study was conducted to investigate the anti-arrhythmic properties of SGLT2 inhibitors evaluating the intra-patient difference in major adverse arrhythmic cardiac events (MAACE) over a six-month period in patients with chronic heart failure who were undergoing continuous monitoring using a cardiac implantable electronic device. RESULTS: From January 2022 to January 2023, 82 patients [median age 63 years (IQR 15), male 87 %] were enrolled in the study, with a median follow-up of 28 weeks (IQR 5). The rate of MAACE at baseline was 11 %, without relevant differences in the follow up in terms of major and minor arrhythmic events. In patients with an arrhythmic phenotype at baseline, a mild but non statistically significant reduction of MAACE (from 36 % to 28 %, p = 0.727) was observed and a significant decrease of non-sustained ventricular tachycardia (from 68 % to 32 %, p = 0.022). CONCLUSIONS: Our findings suggest potential anti-arrhythmic properties of SGLT2 inhibitors, evident in patients with arrhythmic events before the initiation of the drug.

Obesity Arrhythmias: Role of IL-6 Trans-Signaling.

Obesity is a chronic disease that is rapidly increasing in prevalence and affects more than 600 million adults worldwide, and this figure is estimated to increase by at least double by 2030. In the United States, more than one-third of the adult population is either overweight or obese. The global obesity epidemic is a major risk factor for the development of life-threatening arrhythmias occurring in patients with long QT, particularly in conditions where multiple heart-rate-corrected QT-interval-prolonging mechanisms are simultaneously present. In obesity, excess dietary fat in adipose tissue stimulates the release of immunomodulatory cytokines such as interleukin (IL)-6, leading to a state of chronic inflammation in patients. Over the last decade, increasing evidence has been found to support IL-6 signaling as a powerful predictor of the severity of heart diseases and increased risk for ventricular arrhythmias. IL-6's pro-inflammatory effects are mediated via trans-signaling and may represent a novel arrhythmogenic risk factor in obese hearts. The first selective inhibitor of IL-6 trans-signaling, olamkicept, has shown encouraging results in phase II clinical studies for inflammatory bowel disease. Nevertheless, the connection between IL-6 trans-signaling and obesity-linked ventricular arrhythmias remains unexplored. Therefore, understanding how IL-6 trans-signaling elicits a cellular pro-arrhythmic phenotype and its use as an anti-arrhythmic target in a model of obesity remain unmet clinical needs.

Characteristic of myocardial work in mitral valve prolapse with versus without mitral annular disjunction: A propensity-matched study.

BACKGROUND: Mitral annular disjunction (MAD) tends to coexist with mitral valve prolapse (MVP) and mitral regurgitation (MR), and is also highly associated with arrhythmias. Myocardial work (MW) analysis is dedicated to estimate myocardial performance by integrating strain analysis and afterload. We aimed to use MW analysis to investigate the cardiac remodeling and dysfunction in MAD, particularly the damage of some segments, and to enhance the understanding of the correlations between MW parameters and VAs within MVP patients. METHODS: A total of 22 consecutive MVP patients with MAD (MAD+) and 44 consecutive MVP patients without MAD (MAD-) (50 ± 11yeas; 18% females) were screened by propensity score matching (PSM), and were divided into subgroups based on MR severity (MR+: Grade 2+; MR-: ≤1), GWI median (GWI ≤ 2079.5 mmHg%; GWI>2079.5 mmHg%), as well as the presence of VAs (VAs+; VAs-). MW parameters consist of global work efficiency (GWE), global work index (GWI), global constructive work (GCW) and global wasted work (GWW). RESULTS: The MAD+ patients had larger LVEDD and LAVI, as well as lower GWE, GWI, and GCW (all P<0.05) compared to the MAD- patients, regardless of similar GLS and regurgitant volume(both P>0.05). When categorized by MR severity, GWI (P = 0.049) and GCW (P = 0.040) were diminished in the MR-MAD+ group. The regional analysis showed MAD+ patients had decreased MW index in the basal (posterior and inferior) and mid (posterior and inferior) segments. Multivariate linear regression showed MAD phenotype, but not MR severity, was independently associated with diminished GWE, GWI, and GCW (all P<0.05). When divided by GWI median, MAD phenotype [OR (95%CI): 5.189 (1.193-22.572), P = 0.028] was an independent predictor of decreased GCW. The receiver-operating characteristic curve identified bileaflet prolapse [AUC (95%CI): 0.664 (0.502-0.825), P = 0.045], and GWI for basal inferior [(AUC (95%CI): 0.679 (0.538-0.819), P = 0.020] as the predictors of the VAs. CONCLUSION: MAD phenotype has the ability to compromise cardiac structure and function, irrespective of volume overload, as evidenced by dilated LV and impaired MW index in basal and mid segments. Excessively decreased regional MW index can identify patients with the high risk of VAs. MW analysis can be a valuable imaging marker for detecting myocardial impairment induced by MAD.

Hospital Outcomes of Spontaneous Coronary Artery Dissection With Concurrent Ventricular Arrhythmias.

Background: While patients with spontaneous coronary artery dissection (SCAD) occasionally present with concurrent ventricular arrhythmias (VA), the impact of VA on in-hospital outcomes in the United States (US) is not well-established. This study aims to analyze in-hospital outcomes of patients with SCAD and concurrent VA and to determine the factors associated with VA occurrence in this high-risk population in the US. Methods: Using the Nationwide Readmissions Database, our study included patients age 18 years or older who had SCAD between 2017 and 2020. We categorized the cohort into 2 groups depending on the presence of VA during hospitalization. In-hospital outcomes were assessed between SCAD patients with VA and those without. Weighted analysis was performed. We analyzed the independent factors associated with VA occurring among SCAD patients through univariable and multivariable analyses. Results: Eight hundred seventy-seven SCAD patients were included in the study: 118 (13.5%) with VA and 759 (86.6%) without. SCAD patients with concurrent VA were associated with higher rates of early mortality (10.2% vs 2.0%; P < .01), prolonged index hospital stay (≥7 days) (33.1% vs 11.7%; P < .01), and non-home discharge (21.2% vs 5.9%; P < .01). The length of hospital stay was longer in the SCAD with concurrent VA group (7.39 days vs 3.58 days; P < .01), and the median cumulative cost of hospitalization was also higher in this group ($31,451 vs $13,802; P < .01). SCAD patients with concurrent VA had increased in-hospital adverse events: acute heart failure, cardiac arrest, cardiogenic shock, cerebral infarction, pulmonary edema, and acute kidney injury. In multivariable analysis, the independent factors associated with VA occurrence among SCAD patients were chronic liver disease (aOR, 3.42; 95% CI, 1.43-8.20; P < .01) and heart failure (aOR, 5.63; 95% CI, 3.36-9.42; P < .01). Conclusions: Concurrence of VA among SCAD patients was associated with poorer in-hospital outcomes. Heart failure and chronic liver disease were the independent factors associated with VA occurrence in SCAD patients.

Safety and efficacy of same-day discharge for premature ventricular complex ablations.

AIMS: Patients undergoing catheter ablation (CA) of ventricular arrhythmias (VAs) are generally observed overnight in the hospital given the concern for complications. To evaluate the efficacy and safety of same-day discharge (SDD) of patients undergoing elective CA of premature ventricular complexes (PVCs). METHODS AND RESULTS: A retrospective evaluation of all patients undergoing elective VA ablation at Ascension St Vincent Hospital from 1 January 2018 to 31 December 2019 was undertaken. Of those, the patients undergoing PVC ablation were divided into SDD and non-SDD. Patients underwent SDD at the discretion of the operator. The primary safety outcome was the 30-day incidence of complications and death. The primary efficacy outcome was procedural success. Among 188 patients who underwent VA ablation, 98 (52.1%) were PVC ablations, and of those, 55 (56.1%) were SDD. There was no difference in age, gender, comorbidities, or ejection fraction between the two groups. Patients that were non-SDD were more likely to be on chronic anticoagulation (P = 0.03), have ablation in the LV (P = 0.04), have retrograde access (P = 0.03), and receive heparin during the procedure (P = 0.01). There were no complications in the SDD group compared with one (2.3%) in the non-SDD group. There was no difference in primary efficacy between the two groups with a 90.9% acute success in the SDD and 88.4% in the non-SDD (P = 0.68). CONCLUSION: Same-day discharge for CA of PVCs is feasible and could lower healthcare resource utilization without compromising outcomes in this unique population.

Ventricular arrhythmias originating from different portions of the communicating vein of the left ventricular summit: electrocardiographic characteristics and catheter ablation.

BACKGROUND: Idiopathic ventricular arrhythmias (IVAs) arising from different portions of the communicating vein of the left ventricular summit (summit-CV) are not a rare phenomenon. Whereas its electrocardiographic (ECG) and electrophysiological characteristics are not fully investigated. OBJECTIVE: This study aimed to identify distinct ECG and electrophysiological features of IVAs originating from different portions of summit-CV. METHODS: Nineteen patients confirmed arising from summit-CV were included in this study. RESULTS: The 19 patients were divided into proximal and distal portion groups based on their target sites in summit-CV. In the proximal portion group, 100% (11/11) VAs showed dominant negative (rs or QS) waves in lead I, while in the distal portion group, 87.5% (7/8) showed dominant positive waves (R, Rs or r) (p < 0.000). In lead V1, 100% (11/11) of the proximal portion group showed dominant positive waves (R or Rs), while 62.50% (5/8) of the distal portion group showed positive and negative bidirectional or negative waves (RS or rS) (p < 0.005). RI>4mV, SI<3.5mV, RV1<13mV, SV1>3.5mV, RI/SI>0.83, and RV1/SV1< 2.6 indicated a distal portion of summit-CV with the predictive value of 0.909, 1.000, 0.653, 0.972, 0.903, 0.966, respectively. A more positive wave in lead I and a more negative wave in lead V1 indicated more distal origin in summit-CV. Target sites in proximal and distal summit-CV groups showed similar electrophysiological characteristics during mapping. CONCLUSIONS: There were significant differences in ECG characteristics of VAs at different portions of summit-CV, which could aid pre-procedure planning and facilitate radiofrequency catheter ablation (RFCA) procedures.

Sex Differences in Ventricular Arrhythmias and Adverse Outcomes Following Acute Myocardial Infarction.

Background: Ventricular arrhythmias (VAs) are a common cause of death in patients with acute myocardial infarction (AMI). Studies have shown sex differences in the incidence, presentation, and outcomes of AMI. However, less is known about sex differences in patients with AMI who develop VAs. Objectives: The authors assessed sex differences in incidence and in-hospital outcomes of patients with AMI and VAs. Methods: Using the National Inpatient Sample 2016 to 2020, we conducted a retrospective analysis of patients admitted for AMI with a secondary diagnosis of VAs. Multivariable logistic regression was performed to estimate the sex-specific differences in the rates and in-hospital outcomes of VAs post-AMI. Results: We identified 1,543,140 patients admitted with AMI. Of these, (11.3%) 174,565 patients had VAs after AMI. The odds of VAs after AMI were higher among men (12.6% vs 8.8% adjusted odds ratio [AOR]: 1.72; CI: 1.67-1.78; P < 0.001). Women had significantly higher odds of in-hospital mortality (AOR: 1.32; CI: 1.21-1.42; P < 0.001), cardiogenic shock (AOR: 1.08; CI: 1.01-1.15; P < 0.022), and cardiac arrest (AOR: 1.11; CI: 1.03-1.18; P < 0.002). Women were less likely to receive an implantable cardioverter-defibrillator (ICD) (AOR: 0.57; CI: 0.47-0.68; P < 0.001) or undergo catheter ablation (AOR: 0.51; CI: 0.27-0.98; P < 0.001) during the index admission. Conclusions: We found important sex differences in the incidence and outcomes of VAs among patients with AMI. Women had lower odds of VAs but worse hospital outcomes overall. In addition, women were less likely to receive ICD. Further studies to address these sex disparities are needed.

Characteristics and Outcome of Patients with or without Previous Implantable Cardioverter Defibrillator Interventions Undergoing Ablation for Ventricular Tachycardia.

Background: Catheter ablation (CA) is a well-established treatment in patients with ventricular tachycardia and appropriate implantable cardioverter defibrillator (ICD) therapies. Methods: We enrolled 57 consecutive carriers of ICD undergoing CA for electrical storm (ES). Our aim was to investigate differences in clinical, device-related, and electroanatomic features among patients who had history of appropriate ICD interventions before the ES compared to those who had not. The primary endpoint was a composite of death from any cause and recurrences of sustained VT, ventricular fibrillation, appropriate ICD therapy, or ES. Results: During a median follow up of 39 months, 28 patients (49%) met the primary endpoint. Those with previous ICD interventions had a higher prevalence of late potentials and a greater unipolar low-voltage area at electroanatomic mapping. Patients who met the primary endpoint had a higher prevalence of ATP/shock episodes preceding the ES event. At Cox regression analysis, non-ischemic dilated cardiomyopathy (NIDCM), QRS duration, and previous ATP and/or shock before the ES were associated with arrhythmic recurrences and/or death. At multivariate analysis, NIDCM and previous shock were associated with arrhythmic recurrences and/or death. Conclusions: A history of recurrent ICD therapies predicts worse outcomes when CA is needed because of ES. Although more studies are needed to definitively address this question, our data speak in support of an early referral for CA of ES.

Electrocardiographic abnormalities are associated with seropositive Trypanosoma cruzi infection status using a simplified cardiac diagnostic evaluation in dogs.

OBJECTIVE: To describe associations between cardiac abnormalities and Trypanosoma cruzi serostatus by use of a simplified diagnostic evaluation in dogs at risk for T cruzi infection. METHODS: A prospective, cross-sectional study was performed using a simplified diagnostic evaluation including high-sensitivity cardiac troponin I, 30-second ECG, and echocardiogram with 7 variables in 46 client-owned dogs from high-risk environments. Dogs were categorized as serologically positive (SP), negative (SN), or discordant (SD) by use of 2 antibody tests. Functional evaluation of cardiac health scores and blood PCR were obtained. RESULTS: Dogs were SP (n = 19), SN (17), and SD (10), with 9 PCR positive (7 SP, 1 SN, 1 SD). Troponin was above reference range in 6 of 46 (4 SP, 1 SN, 1 SD), and functional evaluation of cardiac health scores were 0 in all dogs. Conduction system abnormalities (prolonged interval durations, second-degree atrioventricular block, splintered QRS complex) and ventricular arrhythmias were documented in 8 (7 SP, 0 SN, 1 SD). Twenty-six (12 SP, 8 SN, 6 SD) had echocardiographic abnormalities, most often myxomatous mitral valve disease (MMVD) and left ventricular enlargement. Seropositive dogs were significantly older and had a higher likelihood of MMVD. Conduction system abnormalities were associated with positive serostatus. CONCLUSIONS: Echocardiographic abnormalities were complicated by MMVD and did not distinguish between serostatus. An ECG with assessment and detailed measurement of complexes and cardiac troponin I are simple tests to perform with abnormalities detected in seroreactive dogs. CLINICAL RELEVANCE: Electrocardiographic abnormalities in high-risk or seroreactive dogs should prompt further evaluation and monitoring of T cruzi infection.