Anna Rago

Dispersion of repolarization and beta-thalassemia major: the prognostic role of QT and JT dispersion for identifying the high-risk patients for sudden death

Background:  Patients with beta‐thalassemia major (β‐TM) are at increased risk for sudden cardiac death (SCD). Heterogeneity of ventricular repolarization is considered to provide an electrophysiological substrate for malignant arrhythmias. QT dispersion (QTc‐D) and JT dispersion (JTc‐D) are electrocardiographic parameters indicative of heterogeneity of ventricular repolarization. The aim of our study was to evaluate the heterogeneity of ventricular repolarization in patients with beta‐thalassemia and to test the hypothesis that an abnormal QTc and JTc dispersion may predict SCD in this population.

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

Although previous studies have documented a variety of electrocardiogram abnormalities in beta-thalassemia major (β-TM), little is known about P-wave dispersion (PD), an independent risk factor for development of atrial fibrillation. The aim of our study was to evaluate PD in β-TM patients with conserved systolic and diastolic functions. The study involved 40 β-TM patients (age 37.5 ± 10.2; 33 M) and 40 healthy subjects used as controls, matched for age and gender. PD was carefully measured using a 12-lead electrocardiogram. Cardiac iron levels were measured by cardiac magnetic resonance T2 star (CMR T2*) imaging. Comparing to the healthy control group, β-TM group presented increased values of the PD (40.1 ± 12.9 vs. 24 ± 7 ms; P < 0.004) and decreased CMR T2* imaging (29 ± 15 vs. 55 ± 13 ms; P = 0.03). We found a significant correlation between PD and CMR T2* values. Our study showed a significant increase of PD in β-TM patients with conserved systolic and diastolic cardiac functions. Our results indicate that PD is correlated to myocardial iron deposit, as assessed by CMR T2* imaging.

Does Bachmann's bundle pacing prevent atrial fibrillation in myotonic dystrophy type 1 patients? A 12 months follow-up study

AIMS Paroxysmal atrial arrhythmias occur in myotonic dystrophy type 1 (MD1) patients frequently. Pacemaker (PM) including detailed diagnostic functions may facilitate the diagnosis and management of frequent paroxysmal atrial tachyarrhythmias that may remain undetected during conventional clinical follow-up. Aim of our study was to evaluate the preventive effects of interatrial septum pacing in the Bachmanns Bundle region on atrial fibrillation (AF) in MD1 patients during 12 months follow up period. METHODS AND RESULTS Thirty MD1 patients (age 50.3 +/- 7.3; 11 F) who underwent dual chamber PM implantation were randomized at implantation to receive right atrial appendage pacing (16 patients) or Bachmanns bundle pacing (14 patients). No statistically significant difference in the electrical parameters (P wave amplitude, pacing threshold and lead impedance) was found between the two groups at implantation. Patients were followed at 1 month, 3 months, and every 6 months thereafter. They underwent clinical assessment, a standard 12-lead ECG and assessment of device performance at every visit. We counted the number of episodes of atrial arrhythmia occurred during the collection period and the duration of each episode. At 12 months of follow-up, no statistically significant differences in the number of AF episodes or in AF duration were found. Lead parameters remained stable over time and there were no displacements of the electrodes after implantation. CONCLUSION Implantation of an atrial-active fixation lead on the atrial septum is safe and feasible. However, this study showed no significant difference between septal pacing and high atrial pacing, using the endpoints of AF duration and number of AF episodes.

P-Wave Duration and Dispersion in Patients With Emery-Dreifuss Muscular Dystrophy

Background Paroxysmal episodes of atrial fibrillation frequently occur in Emery-Dreifuss muscular dystrophy (EDMD). Although previous studies have documented a variety of electrocardiographic abnormalities in EDMD, little is still known about P-wave dispersion (PD), an independent risk factor for the development of atrial fibrillation. The aim of our study was to evaluate the P-wave duration and PD in patients with EDMD with conserved systolic and diastolic cardiac function. Methods The study involved 36 patients with EDMD (age, 20 [SD, 12] years; 26 men) and 36 healthy subjects used as controls, matched for age and sex. P-wave dispersion was carefully measured using 12-lead electrocardiogram. Compared with the healthy control group, patients with EDMD presented increased maximum P-wave duration (108.2 [SD, 22.2] vs 97.8 [SD, 11] milliseconds, P = 0.04) and PD (51.4 [SD, 12.8] vs 39.3 [SD, 9.7] milliseconds, P = 0.004) values. No statistically significant differences in left atrium diameter (37.1 [SD, 2.9] vs 34.1 [SD, 4.2] mm, P = 0.3) and maximum left atrium volume (15.2 [SD, 3.8] vs 14.1 [SD, 4.2] mL/m2, P = 0.4) were found between the 2 groups. We divided our study population into 2 subgroups, according to the different genetic diagnosis, patients with laminopathy EDMD (n = 17) or with emerinopathy EDMD (n = 19). No statistically significant differences were found in PD between the 2 subgroups (54.6 [SD, 15.6] vs 50.2 [SD, 11.5] milliseconds, P = 0.4). Conclusions Our study showed a significant increase of maximum P-wave duration and PD in patients with EDMD with conserved systolic and diastolic cardiac function.

The effect of dual-chamber closed-loop stimulation on syncope recurrence in healthy patients with tilt-induced vasovagal cardioinhibitory syncope: a prospective, randomised, single-blind, crossover study

Background The closed-loop stimulation (CLS) pacemaker algorithm is a system that permanently monitors the contractile state of the myocardium and converts the intrinsic information into rate regulation. The role that the CLS algorithm plays in the prevention of syncope recurrences still remains unclear. The aim of our prospective, randomised, single-blind, crossover study was to evaluate the effect of dual-chamber CLS in the prevention of syncope recurrence in patients with refractory vasovagal syncope (VVS) and a cardioinhibitory response to head-up tilt test (HUT) during a 36 months follow-up. Method sand results We studied 50 patients (mean age 53±5.1; 33 male) with the indication for permanent dual-chamber cardiac pacing for HUT-induced vasovagal cardioinhibitory syncope. They were randomised after 1 month of stabilisation period to CLS algorithm features programmed OFF or ON for 18 months each, using a crossover design. The number of syncopal and presyncopal episodes during active treatment was lower than those registered during no treatment (n syncopal episodes: 2 vs 15; p=0.007; n presincopal episodes: 5 vs 30; p = 0.004). Lead parameters remained stable over time, and there were no lead-related complications. Conclusions Based on these 36 months follow-up data, it is concluded that dual-chamber CLS is an effective algorithm for preventing syncope recurrences in healthy patients with tilt-induced vasovagal cardioinhibitory syncope.

The effect of atrial preference pacing on paroxysmal atrial fibrillation incidence in myotonic dystrophy type 1 patients: a prospective, randomized, single-bind cross-over study

AIMS Atrial Preference Pacing (APP) is a pacemaker (PM) algorithm that supports a continuous atrial stimulation instead of a spontaneous atrial rhythm to prevent supraventricular tachyarrhythmias. The role of the APP in the prevention of atrial fibrillation (AF) is still controversial. The aim of our study was to evaluate the effect of preventive atrial pacing on AF incidence in myotonic dystrophy type I patients during a 12-month follow-up period. METHODS AND RESULTS We studied 40 patients with myotonic dystrophy type 1 (MD1) who underwent dual-chamber PM implantation for first- and second-degree atrioventricular block. After a 1-month stabilization period, they were randomized to APP algorithm programmed OFF or ON for 6 months each, using a cross-over design. The number of AF episodes during active treatment (APP ON phases) was lower than those registered during no treatment (APP OFF phases). No statistically significant difference was found in AF episodes duration between the two phases. During the APP OFF phases and APP ON phases, the atrial pacing percentage was 0 and 98%, respectively, while the ventricular pacing percentage did not show statistically significant difference (10 vs. 8%, P =0.2). Atrial premature beats count was significantly greater during APP OFF phases than during APP ON phases. Lead parameters remained stable over time and there were no lead-related complications. CONCLUSIONS Based on these 12-month follow-up data, it is concluded that APP is an efficacy algorithm for preventing paroxysmal AF in MD1 patients who underwent dual-chamber PM implantation for atrioventricular conduction disorders.

Does left atrial appendage closure with a cardiac plug system reduce the stroke risk in nonvalvular atrial fibrillation patients? A single-center case series.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and it is associated with an increased stroke risk, due mainly to cardiac embolism from the left atrial appendage (LAA). Percutaneous LAA closure is a method to reduce stroke risk in AF without using anticoagulant agents. In this study we report data from an Italian experience with the LAA occluder Amplatzer Cardiac Plug (ACP) device (Aga Medical Corporation, Plymouth, MN, USA).

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 (β-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 β-TM patients with conserved systolic or diastolic cardiac function during a twelve-months follow-up. Materials and Methods 50 β-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 β-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, β-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 β-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 β-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 β-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 β-TM patients at risk for AF. Conclusion Our results indicate that P-max and PD are useful electrocardiographic markers for identifying the β-TM-high-risk patients for AF onset, even when the cardiac function is conserved.

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

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.

Does a high percentage of right ventricular pacing influence the incidence of paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients

BACKGROUND Paroxysmal atrial tachyarrhythmias occur frequently in myotonic dystrophy type 1 (MD1) patients. Pacemakers, implanted for the treatment of bradyarrhythmias and including detailed diagnostic functions, may facilitate the diagnosis and management of frequent paroxysmal atrial fibrillation (AF) that may remain undetected during a conventional clinical follow-up. The effect of right ventricular pacing on AF incidence is still controversial. AIM To evaluate the influence of a high percentage of right ventricular pacing on AF in MD1 patients during a 12-month follow-up period. METHODS We enrolled in the present study 70 MD1 patients (age 51.3 ± 5 years; 32 females) who underwent dual chamber pacemaker implantation. At 12 months of follow-up, the study population was divided into three groups according to the percentage of atrial and ventricular stimulation: Group 1, the atrial sensing ventricular sensing group (ASVS; n = 22; age 52 ± 7.7; eight female) with a percentage of atrial and ventricular stimulation lower than 50%; Group 2, the atrial sensing ventricular pacing group (ASVP; n = 24; age 50.5 ± 7.6; 13 female) with a percentage of atrial stimulation lower than 50% and percentage of ventricular stimulation higher than 80%; and Group 3, the atrial pacing ventricular pacing group (APVP; n = 24; age 56 ± 4.3; 11 female) with a percentage of atrial and ventricular stimulation higher than 80%. We counted the number of episodes of atrial arrhythmia that occurred during the observation period and the duration of each episode. RESULTS We found a statistically significant difference in the number and duration of AF episodes between the three groups at the 12-month follow-up. In particular, there were more episodes (253 ± 30 vs. 80 ± 27 vs. 53 ± 32; p < 0.03) and longer durations of AF (8,700 ± 630 vs. 4,480 ± 975 vs. 3,853 ± 870 min; p < 0.03) in the ASVP group than in the ASVS group and the APVP group. Lead parameters remained stable over time and there were no displacements of the electrodes after implantation. CONCLUSIONS In a 12-month follow-up comparison, we showed a statistically significant increase in paroxysmal AF episodes in MD1 patients with a high percentage of right ventricular pacing and a lower percentage of atrial stimulation.