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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.

Introduction: Our study was designed to analyze dynamic changes in autonomic tone before the onset of typical sustained atrioventricular nodal reentry tachycardia (AVNRT) in a large group of patients without structural heart disease. Materials and Methods: Twenty-four-hour Holter tapes from 42 consecutive patients (27 men and 15 women; aged 30 ± 21 years) with several episodes of sustained typical AVNRT were analyzed. The diagnosis was validated by transesophageal electrophysiological study. The time-domain calculated parameters were SDNN, SDANN, rMSSD, pNN50; the frequency-domain parameters were low-frequency power (LF, 0.04–0.15 Hz), high-frequency power (HF, 0.15–0.40 Hz), very low-frequency power (VLF, 0.008 to 0.04 Hz) and LF/HF. The mean values in the hour before the onset of sustained AVNRT were compared with the mean values of 2 hours before and 1 hour after the onset of sustained AVNRT. Results: The mean SDNN, rMSSD, pNN50, HF were significantly decreased during the hour preceding the onset of AVNRT, when compared to the mean values observed during the time periods selected. Instead, the LF values and LF/HF were increased before the onset of sustained AVNRT. No significant change in the VLF and atrial ectopic beats were observed. Conclusion: This study suggests that sustained typical AVNRT episodes are preceded by increase in adrenergic drive. Ann Noninvasive Electrocardiol 2010;15(1):49–55

Aim: We performed a two-year follow-up comparative study of long-term electrical parameters between the right atrial appendage (RAA) and Bachmann’s Bundle (BB) stimulation in myotonic dystrophy type 1 (MD1) patients. Methods: Twenty-five MD1 patients (18 men; age: 54 ± 13 years) with no difference in the electrical parameters between the RAA site and the BB region at implantation were randomized into two groups: in group I (13 patients; age: 52 ± 14 years; four women) the atrial lead was placed in the RAA and in group II (12 patients, age: 56 ± 12 years, three women) the lead was placed in the BB region. Measurements of electrical parameters were recorded at follow-up intervals of 6 weeks and then 12 and 24 months postimplant. Results: There was no statistically significant different in P-wave amplitude, pacing threshold, and impedance values between the two groups at 6 weeks. At 24 months follow-up, the intrinsic P-wave amplitude was 2.05 ± 1.45 mV in the RAA group versus 3.28 ± 1.09 mV in the BB group (P < 0.05); the pacing threshold was 1.85 ± 1.8 V in the RAA group versus 0.50 ± 0.39 V in the BB group (P = 0.03); there were no differences in the atrial impedance between the two groups during the follow-up period. Conclusions: In a direct two-year follow-up comparison between the RAA and BB atrial pacing sites, we showed a statistically significant increased pacing threshold and decreased intrinsic P-wave amplitude during RAA stimulation in MD1 patients. (PACE 2009; 32:1191–1196) Bachmann’s bundle, myotonic dystrophy, pacemaker, arrhythmias, heart block, fibrosis, sensing,pacing, impedance, atrial lead

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.

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. © Springer Science+Business Media, LLC 2011.

We report the case of 14-year-old boy with X-linked Emery-Dreifuss muscular dystrophy who developed sick sinus syndrome and required placement of an implantable intracardiac cardioverter-defibrillator (ICD) to prevent sudden death. He demonstrated no significant risk factors for sudden death such as depressed left ventricular ejection fraction, or spontaneous or inducible ventricular tachycardia. One month after implantation, the patient experienced one appropriate ICD discharge.