High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

BACKGROUND: The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. OBJECTIVE: To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. METHODS: Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. RESULTS: Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. CONCLUSION: Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

Asystole on loop recorder in patients with unexplained syncope and negative tilt testing: age distribution and clinical predictors.

BACKGROUND: Approximately 50% of patients with unexplained syncope and negative head-up tilt test (HUTT) who have an electrocardiogram (ECG) documentation of spontaneous syncope during implantable loop recorder (ILR) show an asystolic pause at the time of the event. OBJECTIVE: The aim of the study was to evaluate the age distribution and clinical predictors of asystolic syncope detected by ILR in patients with unexplained syncope and negative HUTT. METHODS: This research employed a retrospective, single-center study of consecutive patients. The ILR-documented spontaneous syncope was classified according to the International Study on Syncope of Uncertain Etiology (ISSUE) classification. RESULTS: Among 113 patients (54.0 ± 19.6 years; 46% male), 49 had an ECG-documented recurrence of syncope during the observation period and 28 of these later (24.8%, corresponding to 57.1% of the patients with a diagnostic event) had a diagnosis of asystolic syncope at ILR: type 1A was present in 24 (85.7%), type 1B in 1 (3.6%), and type 1C in 3 (10.7%) patients. The age distribution of asystolic syncope was bimodal, with a peak at age < 19 years and a second peak at the age of 60-79 years. At Cox multivariable analysis, syncope without prodromes (OR 3.7; p = 0.0008) and use of beta blockers (OR 3.2; p = 0.002) were independently associated to ILR-detected asystole. CONCLUSIONS: In patients with unexplained syncope and negative HUTT, the age distribution of asystolic syncope detected by ILR is bimodal, suggesting a different mechanism responsible for asystole in both younger and older patients. The absence of prodromes and the use of beta blockers are independent predictors of ILR-detected asystole.

Remote monitoring of implantable cardiac monitors in patients with unexplained syncope: Predictors of false-positive alert episodes.

BACKGROUND: Remote monitoring is recommended for patients with implantable cardiac monitors (ICMs), but compared to other cardiac implantable devices, ICMs are less accurate and transmit a higher number of alerts. OBJECTIVE: The aim of this study was to investigate the predictors of false-positive (FP) arrhythmic alerts in patients with unexplained syncope who were implanted with ICM and followed by an automatic remote monitoring system. METHODS: We retrospectively evaluated all consecutive patients who received a long-sensing vector ICM for unexplained syncope between January 2019 to September 2021 at our Syncope Unit. The primary endpoint was the incidence of the first FP episode. The secondary endpoints included assessing the incidence of FP episodes for all types of algorhythms and indentifying the reasons for the misdetection of these episodes. RESULTS: Among 105 patients (44.8% males, median age 51 years), 51 (48.6%) transmitted at least one FP alert during a median follow-up of 301 days. The presence of pre-ventricular complexes (PVCs) on the resting electrocardiogram was the only clinical characteristic associated with an increased risk of FP alerts (adjusted Hazard ratio [HR] 5.76 [2.66-12.4], p = 0.010). The other significant device-related variables were a low-frequency filter at 0.05 Hz versus the default 0.5 Hz (adjusted HR 3.82 [1.38-10.5], p = 0.010) and the R-wave amplitude (adjusted HR 0.35 [0.13-0.99], p = 0.049). CONCLUSION: Patients who have PVCs are at higher risk of inappropriate ICM activations. To reduce the occurrence of FP alerts, it may be beneficial to target a large R-wave amplitude during device insertion and avoid programming a low-frequency filter at 0.05 Hz.

Gender Differences in Atrial Fibrillation: From the Thromboembolic Risk to the Anticoagulant Treatment Response.

Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with an increased thromboembolic risk. The impact of the female sex as an independent risk factor for thromboembolic events in AF is still debated. Background and Objectives: The aim of this review is to evaluate the gender-related differences in cardioembolic risk and response to anticoagulants among AF patients. Materials and Methods: The PubMed database is used to review the reports about gender differences and thromboembolic risk in atrial fibrillation. Results: Non-vitamin K oral anticoagulants (NOACs) represent the gold standard for thromboembolic risk prevention in patients with non-valvular atrial fibrillation (NVAF). Despite a similar rate of stroke and systemic embolism (SE) among men and women in NOACs or vitamin K antagonists (VKAs) treatment, the use of NOACs in AF women is associated with a lower risk of intracranial bleeding, major bleeding, and all-cause mortality than in men. Conclusions: The female sex can be defined as a stroke risk modifier rather than a stroke risk factor since it mainly increases the thromboembolic risk in the presence of other risk factors. Further studies about the efficacy and safety profile of NOACs according to sex are needed to support clinicians in performing the most appropriate and tailored anticoagulant therapy, either in male or female AF patients.

Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) study: the predictive role of programmed ventricular stimulation.

AIMS: Myotonic dystrophy type 1 (DM1) predisposes to the development of life-threatening arrhythmias and sudden cardiac death. Our study aimed to evaluate the prognostic value of programmed ventricular stimulation (PVS) in DM1 patients with conduction system disease. METHODS AND RESULTS: Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) is a double-arm non-randomized interventional prospective study. Myotonic dystrophy type 1 patients with permanent cardiac pacing indication were eligible for the inclusion. The study population underwent to pacemaker (PM) or implantable cardioverter-defibrillator (ICD) implantation according to the inducibility of ventricular tachyarrhythmias at PVS. Primary endpoint of the study was a composite of appropriate ICD therapy and cardiac arrhythmic death. The secondary study endpoint was all-cause mortality. Seventy-two adult-onset DM1 patients (51 ± 12 years; 39 male) were enrolled in the study. A ventricular tachyarrhythmia was induced in 25 patients (34.7%) at PVS (PVS+) who underwent dual chambers ICD implantation. The remaining 47 patients (65.3%) without inducible ventricular tachyarrhythmia (PVS-) were treated with dual-chamber PM. During an average observation period of 44.7 ± 10.2 months, nine patients (12.5%) met the primary endpoint, four in the ICD group (16%) and five (10.6%) in the PM group. Thirteen patients died (18.5%), 2 in the ICD group (8%) and 11 in PM group (23.4%). The Kaplan-Meier analysis did not show a significantly different risk of both primary and secondary endpoint event rates between the two groups. CONCLUSIONS: The inducibility of ventricular tachyarrhythmias has shown a limited value in the arrhythmic risk stratification among DM1 patients.

Cardioinhibitory syncope with asystole during nitroglycerin potentiated head up tilt test: prevalence and clinical predictors.

AIMS: The aim of our study was to evaluate the prevalence and clinical predictors of cardioinhibitory (CI) responses with asystole at the nitroglycerin (NTG)-potentiated head-up tilt test (HUTT) in patients with a history of syncope admitted to a tertiary referral syncope unit. METHODS: We retrospectively evaluated all consecutive patients who underwent NTG-potentiated HUTT for suspected reflex syncope at our institution from March 1 2017 to May 1 2020. The prevalence of HUTT-induced CI syncope was assessed. Univariate and multivariate analyses were performed to test the association of asystolic response to HUTT with a set of clinical covariates. RESULTS: We enrolled 1285 patients (45 ± 19.1 years; 49.6% male); 368 (28.6%) showed HUTT-induced CI response with asystole. A multivariate analysis revealed that the following factors were independently associated with HUTT-induced CI syncope: male sex (OR 1.48; ConInt 1.14-1.92; P = 0.003), smoking (OR 2.22; ConInt 1.56-3.115; P < 0.001), traumatic syncope (OR: 2.81; ConInt 1.79-4.42; P < 0.001), situational syncope (OR 0.45; ConInt 0.27-0.73; P = 0.002), and the use of diuretics (OR 9.94; ConInt 3.83-25.76; P < 0.001). CONCLUSIONS: The cardioinhibitory syncope with asystole induced by NTG-potentiated HUTT is more frequent than previously reported. The male gender, smoking habit, history of traumatic syncope, and use of diuretics were independent predictors of HUTT-induced CI responses. Conversely, the history of situational syncope seems to reduce this probability.

Direct Current Cardioversion in Atrial Fibrillation Patients on Edoxaban Therapy Versus Vitamin K Antagonists: a Real-world Propensity Score-Matched Study.

PURPOSE: The purpose of the present study was to compare the long-term effectiveness and safety of newly initiated anticoagulation with edoxaban (EDO) versus uninterrupted vitamin K antagonist (VKA) therapy in patients with atrial fibrillation (AF) scheduled for transesophageal echocardiogram (TEE)-guided direct electrical current cardioversion (DCC). METHODS: A propensity score-matched cohort observational study was performed comparing the safety and effectiveness of edoxaban versus well-controlled VKA therapy among a cohort of consecutive non-valvular AF patients scheduled for DCC. The primary safety outcome was major bleeding. The primary efficacy outcome was the composite of stroke, transient ischemic attack (TIA), and systemic embolism (SE). FINDINGS: A total of 130 AF patients receiving edoxaban 60-mg (EDO) treatment were compared with the same number of VKA recipients. The cumulative incidence of major bleedings was 1.54% in the EDO group and 3.08% in the VKA group (P = 0.4). The cumulative incidence of thromboembolic events was 1.54% in the EDO group and 2.31% in the VKA group (P = 0.9). A non-significant trend in improved adherence was observed between the EDO and VKA groups with a total anticoagulant therapy discontinuation rate of 4.62% (6/130) vs 6.15% (8/130), respectively (P = 0.06). IMPLICATIONS: Our study provides the evidence of a safe and effective use of edoxaban in this clinical setting, justified by no significant difference in major bleedings and thromboembolic events between edoxaban and well-controlled VKA treatments.

Clinical Performance of Nonvitamin K Antagonist Oral Anticoagulants in Real-World Obese Patients with Atrial Fibrillation.

The prevalence of both atrial fibrillation (AF) and obesity has steadily increased. Nonvitamin K antagonist oral anticoagulants (NOACs) have been shown to be more effective and safer than vitamin K antagonists (VKAs) for long-term stroke prevention in patients with nonvalvular AF. There are still limited data in the literature regarding performance of NOACs in obese patients with AF in the "real world." The aim of our study was to compare the safety and effectiveness of NOACs versus well-controlled VKA therapy in obese AF patients in a "real-world" setting. Here, we have considered patients with AF and obesity (body mass index [BMI] > 30 kg/m2) on NOAC or VKA therapy included in the multicenter Atrial Fibrillation Research Database (NCT03760874). The occurrence of major bleedings (MBs) and thromboembolic events (composite of ischemic stroke, transient ischemic attack, and systemic embolism) was respectively considered primary safety and effectiveness outcomes. We identified 1,047 AF patients with obesity who received NOAC (n = 272) or VKA (n = 775) treatment. After propensity score matching analysis, 248 NOAC and 496 VKA recipients with similar clinical characteristics, including BMI (34.8 ± 3.4 in NOAC vs. 35.1 ± 3.8 in the VKA group; p = 0.50), were evaluated. The mean follow-up was 39 ± 7 months. The incidence rate of thromboembolic events was 1.10 per 100 person-years (0.67 in NOAC vs. 1.28 in the VKA group; hazard ratio [HR]: 0.52; 95% confidence interval [CI]: 0.22-1.22; p = 0.19). The incidence rate of MB was 1.9 per 100 person-years (1.1 in NOAC vs. 2.28 in the VKA group; HR: 0.46; 95% CI: 0.24-0.88; p = 0.04). The incidence rate of intracranial hemorrhage was 0.4 per 100 person-years (0.27 in NOAC vs. 0.47 in the VKA group; HR: 0.57; 95% CI: 0.12-2.73; p = 0.48). A positive net clinical benefit (NCB) of NOACs over VKAs was found (+0.91). Presence of anemia (HR: 1.75; p = 0.003) and concomitant use of antiplatelet drugs (HR: 2.41; p = 0.001) were found to be independent predictors of MB; moreover, age (HR: 1.65; p = 0.003) was an independent predictor of thromboembolic events. Our data support the hypothesis of safe and effective use of NOACs in patients with AF and obesity, justified by a statistically significant lower incidence of MB and a favorable NCB over VKAs.

Prevalence of Left Ventricular Systolic Dysfunction in Myotonic Dystrophy Type 1: A Systematic Review.

Cardiac involvement is recorded in about 80% of patients affected by myotonic dystrophy type 1 (DM1). The prevalence of cardiac conduction abnormalities and arrhythmias has been well described. Data regarding the prevalence of left ventricle systolic dysfunction (LVSD) and heart failure (HF) are still conflicting. The primary objective of this review was to assess the prevalence of LVSD and HF in DM1. The secondary aim was to examine the association of clinical features with LVSD and to detect predisposing and influencing prognosis factors. A systematic search was developed in MEDLINE, EMBASE, Cochrane Register of Controlled Trials, and Web of Science databases to identify original reports between January 1, 2009, and September 30, 2017, assessing the prevalence of LVSD and HF in populations with DM1. Retrospective and prospective cohort studies and case series describing the prevalence of LVSD, as evaluated by echocardiography, and HF in patients with DM1 were included. Case reports, simple reviews, commentaries and editorials were excluded. Seven studies were identified as eligible, of which 1 was a retrospective population-based cohort study, and 6 were retrospective single-center-based cohort studies. Echocardiographic data concerning LV function were available for 647 of the 876 patients with DM1 who were included in the analysis. The prevalence of LVSD in patients with DM1, defined as LVEF < 55%, was 13.8%, 4.5-fold higher than in general population. Patients with DM1 and LVSD were older, were more likely to be male, had longer baseline atrioventricular and intraventricular conduction-time durations, had higher incidences of atrial arrhythmias, and were more likely to have undergone device implantation. Also, symptomatic HF is more prevalent in patients with DM1 despite their limited levels of physical activity. Further studies are needed to evaluate the prevalence of LVSD and HF in patients with DM1 and to investigate electrocardiographic abnormalities and other clinical features associated with this condition.

SERUM cardiac-specific biomarkers and atrial fibrillation in myotonic dystrophy type I.

INTRODUCTION: The aim of the present study was to evaluate the role of high-sensitivity cardiac troponin I, N terminal pro-B-type natriuretic peptide (NT-proBNP), creatine kinase-MB mass concentration (CK-MB mass) and copeptin (CP) in predicting incident atrial fibrillation (AF) in myotonic dystrophy type 1 (DM1) patients. MATERIALS AND METHODS: The study enrolled 60 consecutive DM1 patients (age 50.3 ± 7.3 years, 34 male) who underwent pacemaker (PM) implantation for cardiac rhythm abnormalities and 60 PM recipients whose age and sex matched served as control group. All DM1 patients underwent a 12-lead electrocardiogram, 2D color Doppler echocardiogram, biomarkers measurements and device interrogation at implantation, 1 month after and every 6 months thereafter for a minimum of 2-year follow-up. RESULTS: The study population was divided into two groups according to the presence of AF (AF group vs non-AF group). The AF group was older (47.3 ± 8 vs 38.6 ± 7 years, P = .03) and showed higher serum levels of NT-proBNP (151 ± 38.4 vs 107.3 ± 24.2 pg/mL, P < .001) and CP (18.9 ± 4.5 vs 7 ± 2.3 P < .001) than non-AF Group. NT-proBNP (P < .001) and CP (P < .001) were found to be an independent predictor of AF. Based on the receiver-operating characteristics curve analysis, the cut-off value for NT-proBNP that best predicted AF event in DM1 patients was 123 pg/ml (sensitivity of 83.3% and specificity of 86.5%); the cut-off value for CP that best predicted AF event in DM1 patients was 9 pmol/L (sensitivity of 89% and specificity of 87%). CONCLUSION: NT-proBNP and CP represent two independent predictors of AF onset in DM1 population with conduction disturbances underwent PM implantation.

Use of Non-Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients with Malignancy: Clinical Practice Experience in a Single Institution and Literature Review.

This observational study aimed to investigate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF) patients with malignancy. A total of 76 patients (mean age: 73.2 ± 8.9; 28 females) with AF and malignancy treated with NOAC were included in the analysis. The mean CHA2DS2-VASc and HAS-BLED scores were 3.2 ± 1.2 and 2.2 ± 0.9, respectively. The study population was taking dabigatran 150 mg (25%) twice daily (BID), apixaban 5 mg BID (25%), dabigatran 110 mg BID (24%), rivaroxaban 20 mg (18%) once a day (OD), rivaroxaban 15 mg OD (5%), or apixaban 2.5 mg OD (3%). NOAC therapy began, on average, 248 ± 238 days before malignancy diagnosis for an average duration of 1,000 ± 289 days. Stroke, transient ischemic attack, major and minor bleeding events, other adverse effects, and major cardiovascular complications during the follow-up period were collected. In our study population, no patients experienced thromboembolic events during therapy with any NOAC. We recorded a low global incidence of major bleeding (3.9%) with a mean annual incidence of 1.4%. No hemorrhagic stroke or subarachnoid hemorrhage was observed. Only nine patients (11.8%) experienced minor bleeding. According to our data, anticoagulation therapy with NOACs seems to be an effective and safe treatment strategy for nonvalvular AF patients with malignancy.

Efficacy and safety of dabigatran in patients with atrial fibrillation scheduled for transoesophageal echocardiogram-guided direct electrical current cardioversion: a prospective propensity score-matched cohort study.

Patients with atrial fibrillation (AF) are predisposed to a hypercoagulable state and are at an increased risk for thromboembolic events when undergoing procedures. This study investigated the long-term efficacy and safety of newly initiated anticoagulation with dabigatran versus uninterrupted vitamin K antagonist (VKA) therapy in patients with AF scheduled for transesophageal echocardiogram (TEE)-guided direct electrical current cardioversion (DCC). Consecutive adult patients with persistent AF scheduled to undergo DCC were included in the study. Patients received dabigatran 110 mg or 150 mg twice daily (bid) or VKA at therapeutic doses for at least 3 weeks before and 4 weeks after DCC. All patients underwent anamnestic, clinical, electrocardiographic and echocardiographic evaluation at each follow-up visit, and were followed up for a total period of 2 years. The primary efficacy outcome was the composite of stroke/transient ischaemic attack and systemic embolism. The primary safety outcome was major bleeding. 176 patients receiving dabigatran (77% dabigatran 150 mg bid) were propensity score-matched to 176 patients on VKA therapy. A low incidence of atrial thrombus (0.6%) at TEE was found in both groups (0.6%). The acute cardioversion success rate was 85.1% in the dabigatran group (149/175) and 83.4% in the VKA group (146/175). During the follow-up period, a similar low incidence of thromboembolic events (0.6%) was reported in both groups; the bleeding safety profile tended to favour dabigatran over VKA (1.1% vs 1.7%; P = 0.3). Newly initiated anticoagulation with dabigatran in patients with nonvalvular AF scheduled for TEE-guided DCC seems to be as effective and safe as uninterrupted VKA therapy, during long-term follow up.

Electrocardiographic Presentation, Cardiac Arrhythmias, and Their Management in ß-Thalassemia Major Patients.

Beta-thalassemia major (ß-TM) is a genetic hemoglobin disorder characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Clinical management of thalassemia major consists in regular long-life red blood cell transfusions and iron chelation therapy to remove iron introduced in excess with transfusions. Iron deposition in combination with inflammatory and immunogenic factors is involved in the pathophysiology of cardiac dysfunction in these patients. Heart failure and arrhythmias, caused by myocardial siderosis, are the most important life-limiting complications of iron overload in beta-thalassemia patients. Cardiac complications are responsible for 71% of global death in the beta-thalassemia major patients. The aim of this review was to describe the most frequent electrocardiographic abnormalities and arrhythmias observed in ß-TM patients, analyzing their prognostic impact and current treatment strategies.

Which hemodynamic parameter predicts nitroglycerin-potentiated head-up tilt test response?

BACKGROUND: The aim of our study was to identify the early hemodynamic predictors of head-up tilt test (HUTT) outcome in healthy patients with recurrent unexplained syncope. METHODS AND RESULTS: The study involved 95 patients (mean age 38 ± 15; 42 male) who were referred for the evaluation of the syncopal episodes from October 2012 to May 2013. According to the nitroglycerin-potentiated diagnostic tilt test response, the study population was divided into two groups: HUTT+ Group (61 patients, mean age 37 ± 10; 27 male) and HUTT- Group (34 patients, mean age 38 ± 11; 15 male) with no tilt-induced syncope. Finger arterial blood pressure (BP) was recorded during tilt testing. Left ventricular stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were computed from the pressure pulsations. After nitroglycerin administration, the HUTT+ Group showed a significant increase in heart rate (92.0 ± 7.3 beats/min vs 68.9 ± 8.7 beats/min, P < 0.0001), with well-maintained systolic BP (111.6 ± 14.1 mm Hg vs 108.8 ± 11.5 mm Hg; P = 0.332) and diastolic BP (66.1 ± 8.5 mm Hg vs 63.1 ± 6.9 mm Hg; P = 0.0913); a significant decrease in SV (53.9 ± 8.0 mL vs 78.6 ± 8.2 mL; P < 0.0001) and CO (4.0 ± 0.5 L/min vs 5.8 ± 1.0 L/min; P < 0.001), and a significant increase in TPR (1.3 ± 0.3 U vs 0.9 ± 0.2 U, P < 0.0011). We tested three hemodynamic parameters (SV, CO, and TPR) as predictors of positive tilt test response with receiver-operating characteristic curve analysis. CONCLUSIONS: Our results show that, 2 minutes after nitroglycerin administration, a statistically significant decrease of SV values (<67 mL) strongly predicts (area under the curve, 0.985; P < 0.0001) the HUTT-positive response in healthy patients with recurrent unexplained syncope.

Atrial Septal Aneurysms and Supraventricular Arrhythmias: The Role of Atrial Electromechanical Delay.

BACKGROUND: Paroxysmal supraventricular arrhythmias (SVAs) frequently occur in patients with atrial septal aneurysm (ASA). The aim of the current study was to evaluate the electrocardiographic (P-wave duration and dispersion) and echocardiographic (atrial electromechanical delay, AEMD) noninvasive indicators of atrial conduction heterogeneity in healthy ASA subjects without interatrial shunt and to assess the AEMD role in predicting the SVAs onset in this population. MATERIALS AND METHODS: One hundered ASA patients (41 males, mean age of 32.5 ± 8 years) and 100 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of SVAs during a 4-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 3 months. ASAs were diagnosed by transthoracic echocardiography based on the criteria of a minimal aneurismal base of ≥15 mm and an excursion of ≥10 mm. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram (ECG). RESULTS: Compared to the healthy control group, the ASA group showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the ASA group into 2 subgroups (patients with or without SVAs), the inter-AEMD, intra-left AEMD, P max, and PD were significantly higher in the subgroup with SVAs compared to the subgroup without SVAs. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cutoff value of 40.1 msec for intra-left AEMD had a sensitivity of 82% and a specificity of 83% in identifying ASA patients at risk for SVA. CONCLUSION: Our results showed that the echocardiographic AEMD indices (intra-left and inter-AEMD) and the PD were significantly increased in healthy ASA subjects without interatrial shunt. PD and AEMD represent noninvasive, inexpensive, useful, and simple parameters to assess the SVAs' risk in ASA patients.

Adenosine-induced sinus tachycardia in a patient with Myotonic Dystrophy type 1.

We report the case of a 32-year-old man with Myotonic Dystrophy type 1 showing adenosine-induced sinus tachycardia during transesophageal electrophysiological evaluation.

The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population.

P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the possible correlation between atrial preference pacing algorithm, P-wave dispersion and AF burden in DM1 patients with normal cardiac function underwent permanent dual-chamber pacemaker implantation. We enrolled 50 patients with DM1 (age 50.3 ± 7.3; 11 F) underwent dual-chamber pacemaker implantation for various degree of atrioventricula block. The study population was randomized following 1 months stabilization period to APP algorithm features programmed OFF or ON. Patients were assessed every 3 months for the first year, and every 6 months thereafter up to 3 years. At each follow-up visit, we counted: the number of premature atrial beats, the number and the mean duration of AF episodes, AF burden and the percentage of atrial and ventricular pacing. APP ON Group showed lower number of AF episodes (117 ± 25 vs. 143 ± 37; p = 0.03) and AF burden (3059 ± 275 vs. 9010 ± 630 min; p < 0.04) than APP OFF Group. Atrial premature beats count (44903 ± 30689 vs. 13720 ± 7717 beats; p = 0.005) and Pwave dispersion values (42,1 ± 11 ms vs. 29,1 ± 4,2 ms, p = 0,003) were decreased in APP ON Group. We found a significant positive correlation between PD and AF burden (R = 0,8, p = 0.007). Atrial preference pacing algorithm, decreasing the number of atrial premature beats and the P-wave dispersion, reduces the onset and perpetuator factors of AF episodes and decreases the AF burden in DM1 patients underwent dual chamber pacemaker implantation for various degree of atrioventricular blocks and documented atrial fibrillation.

Ventricular fibrillation induced by coagulating mode bipolar electrocautery during pacemaker implantation in Myotonic Dystrophy type 1 patient.

The occurrence of ventricular fibrillation, induced by bipolar electrocautery during elective dual chamber pacemaker implantation, is reported in a patient affected by Myotonic Distrophy type 1 with normal left ventricular ejection fraction.

Atrial Fibrillation and Beta Thalassemia Major: The Predictive Role of the 12-lead Electrocardiogram Analysis.

BACKGROUND: Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (ß-TM) patients.The aim of our study was to investigate the role of maximum P-wave duration (P max) and dispersion (PD), calculated trough a new manually performed measurement with the use of computer software from all 12-ECG-leads,as predictors of atrial-fibrillation (AF) in ß-TM patients with conserved systolic or diastolic cardiac function during a twelve-months follow-up. MATERIALS AND METHODS: 50 ß-TM-patients (age38.4±10.1; 38M) and 50-healthy subjects used as controls, matched for age and gender, were studied for the occurrence of atrial arrhythmias during a 1-year follow-up, through ECG-Holter-monitoring performed every three months. The ß-TM-patients were divided into two groups according to number and complexity of premature-supraventricular-complexes at the Holter-Monitoring (Group1: <30/h and no repetitive forms, n:35; Group2: >30/h or couplets, or run of supraventricular tachycardia and AF, n:15). RESULTS: Compared to the healthy control-group, ß-TM patients presented increased P-max (107.5± 21.2 vs 92.1±11ms, P=0.03) and PD-values (41.2±13 vs 25.1±5 ms,P=0.03). In the ß-TM population, the Group2 showed a statistically significant increase in PD (42.8±8.6 vs 33.2±6.5ms, P<0.001) and P-max (118.1±8.7 vs 103.1±7.5ms, P<0.001) compared to the Group1. Seven ß-TM patients who showed paroxysmal AF during this study had significantly increased P-max and PD than the other patients of the Group2. Moreover, P-max (OR:2.01; CI:1.12-3.59; P=0.01) and PD (OR=2.06;CI:1.17-3.64;P=0.01) demonstrated a statistically significant association with the occurrence of paroxysmal AF,P min was not associated with AF-risk (OR=0.99; CI:0.25-3.40; P=0.9) in ß-TM-patients. A cut-off value of 111ms for P-max had a sensitivity of 80% and a specificity of 87%, a cut-off value of 35.5ms for PD had a sensitivity of 90% and a specificity of 85% in identifying ß-TM patients at risk for AF. CONCLUSION: Our results indicate that P-max and PD are useful electrocardiographic markers for identifying the ß-TM-high-risk patients for AF onset, even when the cardiac function is conserved.

Remote monitoring of implantable loop recorders reduces time to diagnosis in patients with unexplained syncope: a multicenter propensity score-matched study.

Background: There are little data on remote monitoring (RM) of implantable loop recorders (ILRs) in patients with unexplained syncope and whether it confers enhanced diagnostic power. Objective: To evaluate the effect of RM in ILR recipients for unexplained syncope for early detection of clinically relevant arrhythmias by comparison with a historical cohort with no RM. Methods: SyncRM is a propensity score (PS)-matched study prospectively including 133 consecutive patients with unexplained syncope and ILR followed up by RM (RM-ON group). A historical cohort of 108 consecutive ILR patients with biannual in-hospital follow-up visits was used as control group (RM-OFF group). The primary endpoint was the time to the clinician's evaluation of clinically relevant arrhythmias (types 1, 2, and 4 of the ISSUE classification). Results: The primary endpoint of arrhythmia evaluation was reached in 38 patients (28.6%) of the RM-ON group after a median time of 46 days (interquartile range, 13-106) and in 22 patients (20.4%) of the RM-OFF group after 92 days (25-368). The PS-matched adjusted ratio of rates of arrhythmia evaluation was 2.53 (95% confidence interval, 1.32-4.86) in the RM-ON vs. RM-OFF group (p = 0.005). Conclusion: In our PS-matched comparison with a historical cohort, RM of ILR patients with unexplained syncope was associated with a 2.5-fold higher chance of evaluations of clinically relevant arrhythmias as compared with biannual in-office follow-up visits.