Incidental and anticipated arrhythmic diagnoses in patients with an implantable cardiac monitor.

AIMS: In this study, we investigated a cohort of unselected patients with various indications for an implantable cardiac monitor (ICM). Our main objectives were to determine the incidence of arrhythmic diagnoses, both anticipated and incidental in relation to the ICM indication, and to assess their clinical relevance. METHODS: We examined remote monitoring transmissions from patients with an ICM at four Italian sites to identify occurrences of cardiac arrhythmias. Concurrently, we collected data on medical actions taken in response to arrhythmic findings. RESULTS: The study included 119 patients, with a median follow-up period of 371 days. ICM indications were syncope/presyncope (46.2%), atrial fibrillation management (31.1%), and cryptogenic stroke (22.7%). In the atrial fibrillation management group, atrial fibrillation was the most common finding, with an incidence of 36% [95% confidence interval (CI) 22-55%] at 18 months. Rates of atrial fibrillation were not significantly different between patients with cryptogenic stroke and syncope/presyncope [17% (95% CI 7-40%) vs. 8% (95% CI 3-19%), P  = 0.229].For patients with cryptogenic stroke, the incidence of asystole and bradyarrhythmias at 18 months was 23% (95% CI 11-45%) and 42% (95% CI 24-65%), respectively, similar to estimates obtained for patients implanted for syncope/presyncope ( P  = 0.277 vs. P  = 0.836).Overall, 30 patients (25.2%) required medical intervention following ICM-detected arrhythmias, predominantly involving atrial fibrillation ablation (10.9%) and medication therapy changes (10.1%). CONCLUSION: In a real-life population with heterogeneous insertion indications, approximately 25% of patients received ICM-guided medical interventions within a short timeframe, including treatments for incidental findings. Common incidental arrhythmic diagnoses were bradyarrhythmias in patients with cryptogenic stroke and atrial fibrillation in patients with unexplained syncope.

Multiparametric identification of subclinical atrial fibrillation after an embolic stroke of undetermined source.

BACKGROUND: Subclinical atrial fibrillation (SCAF) may represent a cause of embolic stroke of undetermined source (ESUS) and its detection has important implications for secondary prevention with anticoagulation. Indications to implantable cardiac monitors (ICM) include SCAF detection. The aims of this study were to (1) evaluate the frequency of ICM-detected SCAF; (2) determine predictors of SCAF; and (3) identify patients who would benefit most from ICM implantation. METHODS: Between February 2017 and November 2020, all consecutive patients referred for ICM implantation after a diagnosis of ESUS and without previous history of atrial fibrillation or atrial flutter were included in this study. SCAF was diagnosed if the ICM electrogram demonstrated an episode of irregularly irregular rhythm without distinct P waves lasting > 2 min. RESULTS: We enrolled 109 patients (age 66, SD = 13 years; 36% females). During a median follow-up of 19.2 (IQR 11.0-27.5) months, SCAF episodes were detected in 36 (33%) patients. Only abnormal P wave terminal force in lead V1, left atrial end-systolic indexed volume > 34 ml/m2, and BMI > 25 kg/m2 were independently associated with an increased risk of SCAF (HR 2.44, 95% CI 1.14-5.21, p = 0.021; HR 2.39, 95% CI 1.11-5.13, p = 0.026; and HR 2.64, 95% CI 1.06-6.49, p = 0.036 respectively). The ROC curve showed that the presence of all three parameters had the best accuracy (74%) to predict SCAF detection (sensitivity 39%, specificity 91%). CONCLUSION: A multiparametric evaluation has the best accuracy to predict SCAF in ESUS patients and may help identifying those who would benefit most from ICM.

Strategic reprogramming of implantable cardiac monitors reduces the false-positive remote alert burden in a nurse-led service.

AIMS: Implantable cardiac monitors (ICMs) can generate false-positive (FP) alerts. Although these devices have an extended programmability, there are no recommendations on their optimization to reduce not-relevant activations.We tested a strategic programming optimization guide based on the type of FP and investigated the safety and feasibility of the nurse-led insertion of ICMs with a long-sensing vector. METHODS AND RESULTS: Consecutive patients implanted by trained nurses with long-sensing vector ICM were enrolled in a 1-month observational stage (Phase A). Patients who had ≥10 FP episodes underwent ICM reprogramming based on the predefined guide and were followed for an additional month (Phase B). A total of 78 patients had successful ICM insertion by nurses with a mean R wave amplitude of 0.96 ± 0.43 mV and an 86% P wave visibility. Only one patient reported a significant device-related issue, and nurse-delivered ICM was generally well accepted by the patients. During Phase A, 11 patients (14%) generated most of FP (3,627/3,849; 94%) and underwent ICM reprogramming. In the following month (Phase B), five patients (45%) were free from FP and six (55%) transmitted 57 FP alerts (98% reduction compared with Phase A). The median number of FP per patient was significantly reduced after reprogramming [195 (interquartile range, 50-311) vs. one (0-10), P = 0.0002]. CONCLUSION: A strategic reprogramming of ICM in those patients with a high FP alert burden reduces the volume of erroneous activations with potential benefits for the remote monitoring service. No concerns were raised regarding nurse-led insertion of ICMs with a long-sensing vector.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Scheduled versus alert transmissions for remote follow-up of cardiac implantable electronic devices: Clinical relevance and resource consumption.

BACKGROUND: The remote follow-up of pacemakers and implantable cardiac defibrillators (ICDs) usually includes scheduled checks and alert transmissions. However, this results in a high volume of remote data reviews to be managed. We measured the relative contribution of scheduled and alert transmissions to the detection of relevant conditions, and the workload generated by their management. METHODS: At our center, the frequency of remote scheduled transmissions is 4/year. Moreover, all system-integrity and clinical alerts are turned on for wireless notification. We calculated the number of transmissions received from January to December 2020, and identified transmissions that necessitated in-hospital access for further assessment and transmissions that required clinical discussion with the physician. For all alert transmissions, we identified whether the alert was clinically meaningful (i.e. center was not previously aware of the condition and no action had yet been taken to treat it). RESULTS: Of 8545 transmissions received from 1697 pacemakers and ICDs, 5766 (67%) were scheduled and 2779 (33%) were alert transmissions received from 764 patients (45%); 499 (9%) scheduled transmissions required clinical discussion with the physician, but only 2 of these necessitated in-hospital visits for further assessment. Of the alert transmissions, 664 (24%) required clinical discussion, and 75 (3%) necessitated in-hospital visits. The proportion of alerts judged clinically meaningful was 7%. CONCLUSION: Scheduled transmissions generate 67% of remote data reviews for pacemakers and ICDs, but their ability to detect clinically relevant events is very low. A strategy that relies exclusively on alert transmissions could ensure continuity of patient monitoring while reducing the workload at the center.

Implementation of remote follow-up of cardiac implantable electronic devices in clinical practice: organizational implications and resource consumption.

AIMS: Current guidelines recommend remote follow-up for all patients with cardiac implantable electronic devices. However, the introduction of a remote follow-up service requires specifically dedicated organization. We evaluated the impact of adopting remote follow-up on the organization of a clinic and we measured healthcare resource utilization. METHODS: In 2016, we started the implementation of the remote follow-up service. Each patient was assigned to an experienced nurse and a doctor in charge with preestablished tasks and responsibilities. During 2016 and 2017, all patients on active follow-up at our center were included in the service; since 2018, the service has been fully operational for all patients following postimplantation hospital discharge. RESULTS: As of December 2018, 2024 patients were on active follow-up at the center. Of these, 93% of patients were remotely monitored according to the established protocol. The transmission rates were: 5.3/patient-year for pacemakers, 6.0/patient-year for defibrillators, and 14.1/patient-year for loop recorders. Only 21% of transmissions were submitted to the physician for further clinical evaluation, and 3% of transmissions necessitated an unplanned in-hospital visit for further assessment. Clinical events of any type were detected in 39% of transmissions. Overall, the nurses' total workload was 3596 h per year, that is, 1.95 full-time equivalent, which resulted in 1038 patients/nurse. The total workload for physicians was 526 h per year, that is, 0.29 full-time equivalent. After 1 year on follow-up, most patients judged the service positively and expressed their preference for the new follow-up approach. CONCLUSION: A remote follow-up service can be implemented and efficiently managed by nursing staff with minimal physician support. Patients are followed up with greater continuity and seem to appreciate the service.

Coronary sinus and great cardiac vein electroanatomic mapping predicts the activation delay of the coronary sinus branches.

BACKGROUND: Implantation of left ventricular (LV) lead in segments with delayed electrical activation may improve response to cardiac resynchronization therapy (CRT). The search for the latest LV electrical delay (LVED) site can be time-consuming. OBJECTIVE: To assess if electrical mapping of coronary sinus (CS) and magna cardiac vein can help to identify the latest activated CS branch. METHODS: We retrospectively evaluated 48 consecutive patients who underwent electroanatomic mapping system-guided (EAMS)-CRT device implantation with ≥2 mapped CS branches. The activation mapping of the CS and relative branches were performed using an insulated guide wire. LVED was defined as the interval between the beginning of the QRS complex on the surface electrocardiogram and the local electrogram and expressed in milliseconds (ms). RESULTS: Thirty-two (67%) patients showed left bundle branch block (LBBB) and 16 (33%) non-LBBB electrocardiographic patterns. A total of 116 CS branches (mean, 2.4/patient; range, 2-5) were mapped. In the left oblique view, most patients (N = 39, 81%) showed the latest CS-LVED in lateral segments while nine (19%) showed the latest CS-LVED in anterior or posterior segments. Specifically, 94% of patients with LBBB showed the latest CS-LVED in lateral segments while CS activation among non-LBBB patients was heterogeneous. In all patients, the CS branch that demonstrated the highest LVED originated from the latest activated segment of the CS. CONCLUSION: Electrical mapping of CS allows identifying the latest activated branches. This finding may contribute to simplify CRT device implantation compared to activation mapping of all the branches.

Ventricular Arrhythmias in Young Competitive Athletes: Prevalence, Determinants, and Underlying Substrate.

BACKGROUND: Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes. METHOD AND RESULTS: We studied 288 competitive athletes (age range, 16-35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12-lead 24-hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty-eight athletes (10%) and 13 sedentary individuals (11%) showed >10 isolated premature ventricular beats (PVBs) or ≥1 complex VA (P=0.81). Athletes with >10 isolated PVBs or ≥1 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with >10 isolated PVBs or ≥1 complex VA had a normal echocardiographic examination; 17 of them showing >500 isolated PVBs, exercise-induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features. CONCLUSIONS: The prevalence of >10 isolated PVBs or ≥1 complex VA at 24-hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features.

Use of impedance-based catheter tip-to-tissue contact assessment (electroanatomic coupling index, ECI) in typical right atrial flutter ablation.

PURPOSE: The electrical coupling index (ECI) (Abbott, USA) is a marker of tissue contact and ablation depth developed particularly for atrial fibrillation treatment. We sought to evaluate if these measures can be also a marker of lesion efficacy during cavotricuspid isthmus (CTI) ablation for typical right atrial flutter. METHODS: We assessed the ECI values in patients undergoing typical right atrial flutter point-by-point ablation guided by the Ensite Velocity Contact™ (St. Jude Medical, now Abbott St. Paul, MN, USA) electroanatomic mapping system. ECI values were collected before, during (at the plateau), and after radiofrequency (RF) delivery. The physician was blinded to ECI and judged ablation efficacy according to standard parameters (impedance drop, local potential reduction, and/or split in two separate potentials). Patients were followed up at 3 and 12 months. RESULTS: Fifteen consecutive patients (11 males, mean age 69.2 ± 10.6 years) with a history of typical right atrial flutter were included in this study. A total of 158 RF applications were assessed (mean 10.5 ± 6.6 per patient, range 6-28). The absolute and percentage ECI variations (pre-/post-ablation) were significantly greater when applications were effective (p < 0.001). A 12% drop in the ECI after ablation was identified by the ROC curve as the best cutoff value to discriminate between effective and ineffective ablation (sensitivity 94%, specificity 100%). Acute success was achieved in all patients with no complications and no recurrences during follow-up. CONCLUSION: The ECI appeared a reliable index to guide CTI ablation. A 12% drop of ECI during radiofrequency energy delivery was highly accurate in identifying effective lesion.

Safety and efficacy of the new bidirectional rotational Evolution® mechanical lead extraction sheath: results from a multicentre Italian registry.

Aims: The aim of this prospective multicentre study is to evaluate safety and efficacy of the new bidirectional rotational mechanical lead extraction (LE) sheath (Evolution RL, Cook Medical, USA) in chronically implanted leads (>1-year-old leads). Methods and results: Between September 2013 and June 2016, a total of 238 leads in 124 consecutive patients were removed by using the new Evolution RL rotational mechanical sheath. Indications for LE were cardiac device infection in 63 (50.8%) cases, lead malfunction in 41 (33.1%), upgrade in 1 (0.8%) case and for other reasons in the remaining 19 cases (15.3%). Ninety-one leads (38.2%) were implantable cardioverter defibrillator leads (81 dual coil vs. 10 single coil), 38 (16%) right ventricular leads, 86 (36.1%) right atrial leads, and 23 (9.7%) coronary sinus leads. The mean implant duration was 92.2 ± 52.9 months (range 12-336). 91.6% of the leads (218/238) were extracted completely with the Evolution RL alone, with the complete success rate rising to 98.7% (235/238 leads) with combined use of a snare. Overall clinical success rate was 100%. No Evolution sheath-related complications were noted. There were no deaths or major complications. Five minor complications (4%) were encountered. In cases of companion leads no wrapping or lead damage were observed. Conclusion: On the basis of our prospective multicentre study, the new hand-powered bidirectional rotational mechanical LE sheath is an effective and safe tool for the extraction of chronically implanted leads without major complications and lead wrapping or lead damage.

NOACs and atrial fibrillation: Incidence and predictors of left atrial thrombus in the real world.

AIMS: Despite optimal oral anticoagulation with vitamin K antagonist, left atrial (LA) thrombus could be detected in the left appendage (LAA) in >2% of patients with atrial fibrillation (AF) and CHA2DS2-VASc score≥1 but few data are available for patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). We evaluated the occurrence and predictors of LA thrombi by means of transesophageal echocardiography (TOE) in consecutive patients with non-valvular AF who received for at least 3weeks Apixaban, Dabigatran, or Rivaroxaban. METHODS: This study included 414 consecutive patients (male 252, 60.6%, mean age 67.3years) referred to our Centers for catheter ablation of AF (n=220, 53.1%) or scheduled electrical cardioversion (n=194, 46.9%). Patients were on Dabigatran (n=160), Rivaroxaban (n=150) or Apixaban (n=104). TOE was performed in all cases within 12h prior to ablation or cardioversion. RESULTS: Preprocedural TOE revealed LA thrombus in 15/414 patients (3.6%), all located in the LAA (Apixaban 3/104 2.9%, Dabigatran 5/160 3.1%, and Rivaroxaban 7/150 4.7%, p=0.69). Of these, 14 patients had persistent AF. Patients with LAA thrombus had a mean CHA2DS2-VASc score of 3 (3-4). Higher CHA2DS2-VASc score (p=0.02), but not the type of NOAC, significantly predicted the presence of LA thrombus. CONCLUSION: The incidence of LAA thrombus in a cohort of patients anticoagulated with NOACs is low but not negligible, in any case similar among the 3 drugs. Preprocedural TOE should be considered in patients with a CHA2DS2-VASc score>3.

Life-threatening ventricular tachyarrhythmias in the cardiology department: Implications for appropriate prescription of telemetry monitoring.

BACKGROUND: in-hospital life-threatening ventricular arrhythmias (LT-VA) may complicate the course of cardiovascular patients. We aimed to assess the incidence, circumstances, determinants, and outcome of in-hospital LT-VA in order to help clinicians in prescribing appropriate levels of monitoring. METHODS: the study population consisted of all 10,741 consecutive patients (65 ± 15 years, 67.7% males) admitted to a cardiology department in 2009-2014. Terminally ill patients and those with primary arrhythmia diagnosis were excluded. The composite end-point included sudden arrhythmic death, ventricular fibrillation, unstable ventricular tachycardia and appropriate ICD shock unrelated to invasive interventions. RESULTS: the incidence of LT-VA was 0.6%, with no differences regarding age, gender and primary diagnosis of coronary artery disease between patients with and without LT-VA. The incidence of LT-VA was significantly higher (1.2% versus 0.1%, p<0.001) among urgent compared with elective admissions and among patients with left ventricular ejection fraction (LV-EF) <45% (1.7% versus 0.2%, p<0.001). At multivariable analysis, urgent admission and LV-EF <45%, but not primary diagnosis of coronary artery disease, remained independent predictors of LT-VA. At the time of the event, 97.1% fulfilled either class I or class II indications for telemetry monitoring according to the American Heart Association guidelines. Survival to discharge with good neurological status was 70.6%. CONCLUSIONS: acutely ill patients with heart failure and LV systolic dysfunction showed the highest rate of LT-VAs, regardless of the underlying cardiac disease (ischemic or non-ischemic). Current guidelines demonstrated high sensitivity in identifying patients at risk. These findings may favor proper utilization of telemetry monitoring resources.

At-admission risk stratification for in-hospital life-threatening ventricular arrhythmias and death in non-ST elevation myocardial infarction patients.

AIMS: Identification of patients with non-ST elevation acute myocardial infarction (NSTEMI) at higher risk of in-hospital life-threatening ventricular arrhythmias (LT-VA) and death is crucial for determining appropriate levels of care/monitoring during hospitalisation. We assessed predictors of in-hospital LT-VA and all-cause mortality in a consecutive series of NSTEMI patients. METHODS AND RESULTS: We prospectively studied 1325 consecutive patients (69.7% males, median age 70 (61-79) years) presenting with NSTEMI and undergoing continuous electrocardiographic monitoring. The primary study end-point was the occurrence of spontaneous (unrelated to coronary interventions) in-hospital LT-VA, including sustained ventricular tachycardia and ventricular fibrillation; the secondary end-point was in-hospital mortality from all causes. Of 1325 patients, 21 (1.5%) experienced LT-VA and 62 (4.7%) died from either arrhythmias (n=1) or other causes (n=61). Seven of the 20 patients who survived LT-VA subsequently died of heart failure. Independent predictors of in-hospital LT-VA were the Global Registry of Acute Coronary Events (GRACE) score >140 (odds ratio (OR)=7.5; 95% confidence interval (CI) 1.7-33.3; p=0.008) and left ventricular ejection fraction (LV-EF)<35% (OR=4.1; 95% CI 1.7-10.3; p=0.002). GRACE score >140 (OR=14.6; 95% CI 3.4-62) and LV-EF <35% (OR=4.4; 95% CI 1.9-10) also predicted in-hospital all-cause death. The cumulative probability of in-hospital LT-VA and death was respectively 9.2% and 23% in the 98 (7.4%) patients with GRACE score >140 and LV-EF<35%, while it was respectively 0.2% and 0% among the 627 (47.3%) with GRACE score ≤140 and LV-EF ≥35%. CONCLUSIONS: Simple risk stratification at admission based on GRACE score and echocardiographic LV-EF allows early identification of NSTEMI patients at higher risk of both in-hospital LT-VA and all-cause mortality.

Brugada ECG disclosed by acute malaria: is it all about fever and propofol?

Brugada syndrome is an electrical cardiac disease predisposing to ventricular arrhythmias in which typical electrocardiographic (ECG) features consist of nonischemic repolarization abnormalities in the right precordial leads V1-V3. The appearance of a Brugada-ECG pattern is increasingly observed in critically ill patients and is traditionally attributed to the effect of body temperature and/or drug modulation on cardiac ion channels ("acquired Brugada syndrome"). A patient with complicated malaria in whom Brugada-ECG abnormalities appeared in concomitance with fever and propofol administration is presented. The repolarization changes did not disappear until the patient's clinical course improved.