The point on the treatment of arrhythmic storm.

Arrhythmic storm is a clinical emergency associated with high mortality, which requires multi-disciplinary management. Reprogramming of the implantable cardiac defibrillator (ICD) aimed at reducing shocks, adrenergic blockade using beta-blockers, sedation/anxiolysis, and blockade of the stellate ganglion represent the first simple and effective manoeuvres, but further suppression of arrhythmias with antiarrhythmics is often required. A low-risk patient (e.g. monomorphic ventricular tachycardia, functioning ICD, and haemodynamically stable) should be managed with a beta-blocker (possibly non-selective) plus amiodarone, in addition to sedation with a benzodiazepine or dexmedetomidine; in patients at greater risk (high burden and haemodynamic instability), autonomic modulation with blockade of the stellate ganglion and the addition of a second antiarrhythmic (lidocaine) should be considered. In patients refractory to these measures, with advanced heart failure, general anaesthesia with intubation and the establishment of a haemodynamic circulatory support should be considered. Ablation, performed early, appears to be superior in terms of mortality and reduction of future shocks compared with titration of antiarrhythmics.

Impact of Continuous Positive Airway Pressure Therapy on Atrial Electromechanical Delay in Obesity-Hypoventilation Syndrome Patients.

BACKGROUND: Obesity-hypoventilation syndrome (OHS) is defined as daytime hypercapnia and hypoxemia in obese patients with sleep-disordered breathing. We evaluated the electrocardiographic P-wave duration and dispersion (PD) and echocardiographic noninvasive indicators of atrial conduction heterogeneity in OHS patients and the impact of CPAP on atrial conduction and atrial fibrillation incidence. METHODS AND RESULTS: We enrolled 50 OHS patients and 50 sex- and age-matched obese subjects as control. Study population underwent cardiologic evaluation and polysomnography before enrollment, at 1- and 6-month follow-ups after CPAP therapy. The OHS group showed a significant increase in inter-atrial (35.2 ± 8 milliseconds vs. 20.1 ± 2.7 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 16.5 ± 2 milliseconds, P < 0.0001), and intra-right atrial electromechanical delays (AEMD)(24.8 ± 10 milliseconds vs. 15 ± 2.6 milliseconds, P < 0.0001) as well as in Pmax (130 ± 7.4 milliseconds vs. 97 ± 7.2 milliseconds, P = 0.002) and PD (56.5 ± 8.5 milliseconds vs. 31 ± 7.2 milliseconds, P = 0.002) compared to the control group. Significant improvement was noted after 6 months of CPAP therapy in inter-atrial (35.2 ± 8 milliseconds vs. 24.5 ± 6.3 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 20.6 ± 5 milliseconds, P = 0.003), and intra-right AEMD (24.8 ± 10 milliseconds vs. 17 ± 7.5 milliseconds, P < 0.0001), as well as in Pmax (130 ± 7.4 milliseconds vs. 95 ± 10 milliseconds, P < 0.0001) and in PD (56.5 ± 8.5 milliseconds vs. 32.5 ± 6 milliseconds, P < 0.0001) in the OHS group. External loop recorder monitoring detected paroxysmal AF in 19 OHS patients (38%) with significant reduction in paroxysmal AF episodes (12 ± 6 vs. 47 ± 12, P < 0.0001) after 6-month CPAP therapy. CONCLUSION: Our findings showed a significant increase of electrocardiographic and echocardiographic indexes of atrial conduction heterogeneity in OHS patients. The CPAP therapy, having a positive impact on atrial conduction time, seems to reduce AF incidence in OHS patients.

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.

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.

Far field R-wave sensing in Myotonic Dystrophy type 1: right atrial appendage versus Bachmann's bundle region lead placement.

Aim of the present study was to investigate far field R-wave sensing (FFRS) timing and characteristics in 34 Myotonic Dystrophy type 1 (DM1) patients undergoing dual chamber pacemaker implantation, comparing Bachmann's bundle (BB) stimulation (16 patients) site with the conventional right atrial appendage (RAA) pacing site (18 patients). All measurements were done during sinus rhythm and in supine position, with unipolar (UP) and bipolar (BP) sensing configuration. The presence, amplitude threshold (FFRS trsh) and FFRS timing were determined. There were no differences between both atrial sites in the Pmin and Pmean values of sensed P-wave amplitudes, as well as between UP and BP sensing configurations. The FFRS trsh was lower at the BB region in comparison to the RAA site. The mean BP FFRS trsh was significantly lower than UP configuration in both atrial locations. There were no significant differences in atrial pacing threshold, sensing threshold and atrial lead impedances at the implant time and at FFRS measurements. Bachmann's bundle area is an optimal atrial lead position for signal sensing as well as conventional RAA, but it offers the advantage of reducing the oversensing of R-wave on the atrial lead, thus improving functioning of standard dual chamber pacemakers in DM1 patients.

A Case Report of an Unusual Acute Intramural Hematoma Disguise as Pulmonary Embolism.

Aortic intramural hematoma (IMH) is characterized by an aortic wall hematoma without intimal flap and it is a variant of acute aortic syndromes (AAS). This entity may represent 10%-25% of the AAS involving the ascending aorta and aortic arch (Stanford Type A) in 10%-30% of cases and the descending thoracic aorta (Stanford Type B) in 60%-70% of cases. IMH impairs the aortic wall and may progress to either inward disruption of the intima, which finally induces typical dissection or outward rupture of the aorta. The literature describes some clinical reports where Type A aortic dissection mimics a pulmonary embolism but is not described as a case provoked by IMH with outward rupture of the aorta.

Increased dispersion of ventricular repolarization in Emery Dreifuss muscular dystrophy patients.

BACKGROUND: Sudden cardiac death (SCD) is common in patients with Emery-Dreifuss muscular dystrophy (EDMD) and is attributed to the development of life-threatening arrhythmias that occur in the presence of normal left ventricular systolic function. Heterogeneity of ventricular repolarization is considered to provide an electrophysiological substrate for malignant arrhythmias. QTc dispersion (QTc-D) and JTc 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 Emery-Dreifuss muscular dystrophy with preserved systolic and diastolic cardiac function. MATERIAL/METHODS: The study involved 36 EDMD patients (age 20 ± 12, 26 M) and 36 healthy subjects used as controls, matched for age and sex. Heart rate, QRS duration, maximum and minimum QT and JT interval, QTc-D and JTc-D measurements were performed. RESULTS: Compared to the healthy control group, the EDMD group presented increased values of QTc-D (82.7 ± 44.2 vs. 53.1 ± 13.7; P=0,003) and JTc-D (73.6 ± 32.3 vs. 60.4 ± 11.1 ms; P=0.001). No correlation between QTc dispersion and ejection fraction (R=0.2, P=0.3) was found. CONCLUSIONS: Our study showed a significant increase of QTc-D and JTc-D in Emery-Dreifuss muscular dystrophy patients with preserved systolic and diastolic cardiac function.

Heterogeneity of ventricular repolarization in newborns with severe aortic coarctation.

Sudden death is a possible occurrence for newborns younger than 1 year with severe aortic coarctation (CoA) before surgical correction. Basic research and animal experiments have shown electrophysiologic changes during mechanical ventricular pressure overload. The current study aimed to evaluate the effect of severe CoA on the heterogeneity of ventricular repolarization by examining corrected QT and JT interval dispersion (respectively, QTc-D and JTc-D) and electrocardiographic parameters of spatial heterogeneity of ventricular repolarization in newborns with no associated congenital cardiac malformations. The study enrolled 30 isolated severe CoA neonates (age, 45 ± 15 days; 17 males) with normal size and wall thickness of the left ventricle before surgical correction and 30 age- and sex-matched healthy newborns used as control subjects. Heart rate, QRS duration, maximum and minimum QT and JT intervals, and QTc-D and JTc-D measurements were performed. The healthy control group did not significantly differ from the CoA group in terms of heart rate, weight, height, and echocardiographic parameters. Compared with the healthy control group, the CoA group presented significantly increased values of QTc-D (109.7 ± 43.4 vs. 23 ± 15 ms; P = 0.03) and JTc-D (99.1 ± 43.3 vs. 65.8 ± 24.1 ms; P = 0.04). A statistically significant correlation was found between the Doppler peak pressure gradient across the coarctation site and the values of QTc-D (r = 0.48; P = 0.03) and JTc-D (r = 0.42; P = 0.04). Our study showed significantly increased QTc-D and JTc-D in isolated CoA newborns with normal left ventricular geometry.

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 (ß-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. MATERIALS AND METHODS: The study involved 51 patients with ß-TM (age 33.9±8.4; 33M) and 51 healthy subjects used as controls, matched for age, gender, and body mass index (BMI). Among the ß-TM group, 14 patients with ß-TM (age 27±6.64; 11M) died from SCD during follow-up. For each patient, QTD and JTD intervals were calculated. RESULTS: Compared to the healthy control group, ß-TM group presented increased values of the QTc-D (65.36±33.95 vs. 37, 62±17.65; P<0.003) and JTc-D (74.64±33.27 vs. 40.32±12.45; P<0.001). In the ß-TM sudden death group, QTc-D and JTc-D were significantly greater than in survived ß-TM group (92.70±44.24 vs. 56.14±23.80, P=0.0001; 101.54±47.93 vs. 64.47±17.90, P=0.0001). A cutoff value of 70ms for QTc-D had a sensitivity and specificity of 77% in identifying patients at risk for SCD. A cutoff value of 100ms for JTc-D had a sensitivity of 65% and a specificity of 94% in identifying this category of patients. CONCLUSION: ß-TM is associated with significant changes in heterogeneity of ventricular repolarization. QTc and JTc dispersion are useful markers of risk of SCD in patients with ß-TM.

Efficacy and safety of the target-specific oral anticoagulants for stroke prevention in atrial fibrillation: the real-life evidence.

The aim of our article is to provide a concise review for clinicians entailing the main studies that evaluated the efficacy and safety of target-specific oral anticoagulants (TSOAs) for thromboembolic stroke prevention in the real-world setting. Atrial fibrillation (AF) is one of the most common supraventricular arrhythmias that requires anticoagulation therapy to prevent stroke and systemic embolism. TSOAs, dabigatran, apixaban and rivaroxaban have become available as an alternative to warfarin anticoagulation in nonvalvular atrial fibrillation (NVAF). Randomized clinical trials showed non-inferior or superior results in efficacy and safety of the TSOAs compared with warfarin for stroke prevention in NVAF patients. For this reason, the 2012 update to the European Society of Cardiology guidelines for the management of AF recommends TSOAs as broadly preferable to vitamin K antagonists (VKAs) in the vast majority of patients with NVAF [Camm et al. 2012]. Although the clinical trial results and the guideline's indications, there is a need for safety and efficacy data from unselected patients in everyday clinical practice. Recently, a large number of studies testing the efficacy and the safety of TSOAs in clinical practice have been published. The aim of our article is to provide a concise review for clinicians, outlining the main studies that evaluated the efficacy and safety of TSOAs for thromboembolic stroke prevention in the real-world setting.

Voltage-directed cavo-tricuspid isthmus ablation using a novel ablation catheter mapping technology in a myotonic dystrophy type I patient.

A successful case of maximum voltage-directed cavo-tricuspid isthmus (CTI) ablation using a novel ablation catheter mapping technology in a myotonic dystrophy type I (DM1) patient is reported. The patient complained recurrent episodes of atrial flutter, revealed by the atrio-ventricular electrograms analysis during the routine pacemaker controls.

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 (ß-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 ß-TM patients with conserved systolic and diastolic functions. The study involved 40 ß-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, ß-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 ß-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.

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.