Programming Optimization in Implantable Cardiac Monitors to Reduce False-Positive Arrhythmia Alerts: A Call for Research.

No studies have investigated whether optimizing implantable cardiac monitors (ICM) programming can reduce false-positive (FP) alerts. We identified patients implanted with an ICM (BIOMONITOR III) who had more than 10 FP alerts in a 1-month retrospective period. Uniform adjustments of settings were performed based on the mechanism of FP triggers and assessed at 1 month. Eight patients (mean age 57.5 ± 23.2 years; 37% female) were enrolled. In 4 patients, FPs were caused by undersensing of low-amplitude premature ventricular contractions (PVCs). No further false bradycardia was observed with a more aggressive decay of the dynamic sensing threshold. Furthermore, false atrial fibrillation (AF) alerts decreased in 2 of 3 patients. Two patients had undersensing of R waves after high-amplitude PVCs; false bradycardia episodes disappeared or were significantly reduced by limiting the initial value of the sensing threshold. Finally, the presence of atrial ectopic activity or irregular sinus rhythm generated false alerts of AF in 2 patients that were reduced by increasing the R-R variability limit and the confirmation time. In conclusion, adjustments to nominal settings can reduce the number of FP episodes in ICM patients. More research is needed to provide practical recommendations and assess the value of extended ICM programmability.

Role of Provocable Brugada ECG Pattern in The Correct Risk Stratification for Major Arrhythmic Events.

The so-called Brugada syndrome (BS), first called precordial early repolarization syndrome (PERS), is characterized by the association of a fascinating electrocardiographic pattern, namely an aspect resembling right bundle branch block with a coved and sometime upsloping ST segment elevation in the precordial leads, and major ventricular arrhythmic events that could rarely lead to sudden death. Its electrogenesis has been related to a conduction delay mostly, but not only, located on the right ventricular outflow tract (RVOT), probably due to a progressive fibrosis of the conduction system. Many tests have been proposed to identify people at risk of sudden death and, among all, ajmaline challenge, thanks to its ability to enhance latent conduction defects, became so popular, even if its role is still controversial as it is neither specific nor sensitive enough to guide further invasive investigations and managements. Interestingly, a type 1 pattern has also been induced in many other cardiac diseases or systemic diseases with a cardiac involvement, such as long QT syndrome (LQTS), arrhythmogenic right ventricular cardiomyopathy (ARVC), hypertrophic cardiomyopathy (HCM) and myotonic dystrophy, without any clear arrhythmic risk profile. Evidence-based studies clearly showed that a positive ajmaline test does not provide any additional information on the risk stratification for major ventricular arrhythmic events on asymptomatic individuals with a non-diagnostic Brugada ECG pattern.

Twiddler's Syndrome Combined With Subclavian Crush Syndrome: A Case of ICD Lead Failure and Potential Challenging Lead Extraction.

Our report demonstrates how Twiddler's syndrome associated with subclavian crush syndrome may result in a challenging transvenous lead extraction. Thus, it should be performed in centers with experience with the appropriate tools.

Multicenter experience with the Evolution RL mechanical sheath for lead extraction using a stepwise approach: Safety, effectiveness, and outcome.

BACKGROUND: In addition to the Evolution RL sheath, tools by Cook Medical (Bloomington, IN, USA), supporting lead extraction (LE), are available. Data on their use are not reported in detail in previous studies. Moreover, data regarding outcome are lacking. The aim was to evaluate the safety and effectiveness of the Evolution sheath (Evolution RL and Evolution Shortie, Cook Medical) by using a stepwise approach with the available extraction tools and the outcome. METHODS: A total of 393 leads in 198 consecutive patients were removed with the Evolution RL sheath and ancillary tools using a stepwise approach. RESULTS: The main indication for LE was infection in 125 (63.1%) cases. The mean implant duration was 95.4 ± 59.7 months. According to our stepwise approach, the Evolution Shortie RL sheath was used in all cases and complete LE was achieved in 24 (12.2%) cases. The Evolution RL was used in 174 (87.8%) cases and the SteadySheath Evolution tissue stabilization sheath (Cook Medical) in 87 (44%) because of tenacious fibrosis anchored targeted leads. Compression coil (OneTie, Cook Medical) was used in 141 (71%) cases. Complete procedural success rate, clinical success rate, and lead removal with clinical success rate were 97%, 99%, and 99.5%, respectively. One major complication (0.5%) and 10 (5%) minor complications were encountered. During a mean time follow-up of 12 ± 9 months, 14 (7%) patients died. Predictors of mortality included impaired renal function (HR 5.7; 95% CI 1.9-17.6; P = 0.002), extraction because of infection (hazard ratio [HR] 4.0; 95% confidence interval [CI] 1-18.1; P = 0.045), and diabetes (HR 3.2; 95% CI 1.1-9.8; P = 0.036). CONCLUSIONS: Lead extraction using the Evolution RL bidirectional rotational mechanical sheath and ancillary tools in a systematic stepwise approach was effective and safe.

First-degree atrioventricular block on basal electrocardiogram predicts future arrhythmic events in patients with Brugada syndrome: a long-term follow-up study from the Veneto region of Northeastern Italy.

AIMS: This study was designed to assess the prognostic value of clinical and electrocardiographic parameters in Brugada syndrome (BrS). METHODS AND RESULTS: The study population included 272 consecutive patients (82% males; mean age 43 ± 12 years), with either a spontaneous (n = 137, 50%) or drug-induced (n = 135, 50%) Type 1 Brugada electrocardiogram (ECG) pattern. The study combined endpoint included sudden cardiac death (SCD), cardiac arrest, and appropriate intervention of implantable cardioverter-defibrillator (ICD). A first-degree atrioventricular (AV) block (PR = 219 ± 17 ms) was documented at basal ECG in 45 patients (16.5%); 27 of these underwent an electrophysiological study with recording in 21 (78%) of an HV interval ≥55 ms (mean 61 ± 3 ms). Patients with first-degree AV block had a wider QRS complex (median 110 ms vs. 95 ms; P = 0.04) and more often showed a left anterior hemiblock pattern (n = 13, 29% vs. n = 35, 16%; P = 0.056). During a mean follow-up of 85 ± 55 months, 17 patients (6.3%) experienced ≥1 major arrhythmic events (appropriate ICD intervention, n = 13 and SCD, n = 4). At univariate analysis, the occurrence of major arrhythmic events was significantly associated with a history of syncope or cardiac arrest (P < 0.001), Type 1 ECG pattern (P = 0.04), and first-degree AV block (P < 0.001). Univariate and multivariable predictors of events included a history of syncope or cardiac arrest [hazard ratio (HR) 5.8, 95% confidence interval (95% CI) 2.04-16.5; P < 0.001; and HR 6.68, 95% CI 2.34-19.1; P < 0.001; respectively], a spontaneous Type 1 ECG pattern (HR 1.56, 95% CI 1.03-4.24; P = 0.033; and HR 1.84, 95% CI 1.01-4.29; P = 0.044; respectively) and a first-degree AV block at baseline ECG (HR 3.84, 95% CI 1.47-9.99; P = 0.006; and HR 4.65, 95% CI 2.34-19.1; P = 0.002; respectively). CONCLUSION: Besides a history of cardiac arrest or syncope, first-degree AV block on basal ECG is an independent predictor of malignant arrhythmic events and a stronger marker of arrhythmic risk than a spontaneous 'coved-type' ECG pattern in patients with BrS.

Hybrid minimally invasive technique with the bidirectional rotational Evolution® mechanical sheath for transvenous lead extraction: A collaboration between electrophysiologists and cardiac surgeons.

We report a case of a 63-year-old man referred for lead extraction with the bidirectional rotational Evolution ® RL mechanical sheath because of systemic infection. As it was judged a "high-risk" procedure, we opted for a "hybrid," minimally invasive approach consisting in a minithoracotomic access. This technique is a feasible approach, and it might be a potential safer alternative in the most challenging transvenous lead extraction procedures.

[Endomyocardial biopsy should be performed in every patient with suspected myocarditis]. / La biopsia endomiocardica nella miocardite acuta: per tutti i pazienti.

The diagnosis of myocarditis is difficult because there is no pathognomonic clinical presentation and the disease may mimic other non-inflammatory diseases. Thus, current classifications on cardiomyopathies (e.g., the World Health Organization and the International Society and Federation of Cardiology [WHO/ISFC], the European Society of Cardiology [ESC], and the 2013 Expert Myocarditis ESC Task Force) define myocarditis as an inflammatory disease of the myocardium, which is diagnosed on endomyocardial biopsy (EMB) based upon histological, immunological, immunohistochemical and molecular tools. This will identify etiology, and differentiate between infectious, mainly viral, and non-infectious, immune-mediated forms. The term "inflammatory cardiomyopathy" may be applied in biopsy-proven myocarditis with associated left, right or biventricular dysfunction. Myocarditis may resolve spontaneously, relapse or become chronic progressing to dilated cardiomyopathy, death or heart transplantation. The 2013 Myocarditis ESC Task Force consensus document recommends consideration of EMB and selective coronary angiography in all patients with clinically suspected myocarditis according to the Task Force criteria. It is recommended that EMB analysis includes not only histology (Dallas criteria), but also immunohistology and detection of the genome of infectious agents by molecular tools. EMB should be performed by expert teams. The rationale for this diagnostic effort is the availability of a wide range of immunosuppressive or immunomodulatory agents that, as shown in systemic extracardiac autoimmune disease and in many clinical studies, can be used in infection-negative myocarditis patients to stop or at least stabilize chronic cardiac tissue damage mediated by the immune system, and thus prevent fibrosis and progression to irreversible end-stage dilated cardiomyopathy.

Passive transfer of affinity-purified anti-heart autoantibodies (AHA) from sera of patients with myocarditis induces experimental myocarditis in mice.

BACKGROUND: Human autoimmune myocarditis is characterized by an increased frequency of serum organ and disease-specific anti-heart autoantibodies (AHA) in affected patients. To assess whether AHA are directly pathogenic, we used the passive transfer technique of AHA from patients to normal Balb/c mice to induce an experimental myocarditis. METHODS: In keeping with a classical passive transfer experiment, sera from 5 AHA positive myocarditis patients (3 male, mean age 30 ± 11 years, 3 with giant cell and 2 with lymphocytic myocarditis) were affinity purified and injected into 25 Balb/c mice. As controls, affinity purified sera from 5 healthy donors were passively transferred to 25 Balb/c mice. Further 15 control mice were injected with phosphate-buffered saline and 9 mice did not receive any injection. In all patients cardiac-specific AHA of IgG class had been previously detected by an indirect immunofluorescence (IFL) technique on cryostat sections of O blood group human heart. The animals were sacrificed after 4 weeks and the hearts were blindly examined for histological evidence of myocarditis by an expert cardiac pathologist. RESULTS: Myocarditis was present in 13/25 (52%) of the mice which received affinity-purified IgG from patients. The findings of severe, moderate or mild myocarditis were more common in the mice which received affinity-purified IgG from patients (20%; 20% and 12%) than in control animals (2%, p=0.01; 0%, p=0.003; and 0%, p=0.04 respectively). CONCLUSIONS: These findings provide a new evidence for AHA-mediated pathogenicity in human myocarditis, according to Rose-Witebsky criteria.