A b s t r a c tBackground: Emery-Dreifuss muscular dystrophy (EDMD) is a genetic condition associated with cardiac arrhythmias. The patients typically develop early, asymptomatic bradyarrhythmia, which may lead to sudden death, preventable with a cardiac implantable electronic device (CIED). EDMD may be characterised by atrial electrical silence. Intra-operative electrophysiological evaluation of the myocardium helps ultimately determine the true nature of the disorder and select an appropriate CIED. Aim:To analyse permanent electrotherapy procedures in EDMD patients: atrial pacing limitations that stem from the electrophysiological properties of the myocardium and long-term follow-up of implanted devices.Methods: A total of 21 EDMD patients (mean age 29 ± 9 years) with a CIED implanted due to bradyarrhythmia were included in the study. The implantation procedures and factors determining the CIED type selection were analysed.Results: CIEDs were implanted in five women and in 16 men with EDMD types 1 and 2 (mean follow-up: 11 ± 8 years). Intra-operatively assessed atrial electrophysiology resulted in changing the planned CIED type during the procedure in three men with EDMD type 1. Eventually, we implanted: eight DDD, one VDD, 11 VVI, and one CD-DR device, with four of the patients' devices switched later from DDD to VVI mode in response to electrophysiological changes in the atria. Conclusions:Intra-operative assessment of atrial electrophysiological properties resulted in changing the planned DDD mode for VVI in 19% of patients with EDMD type 1. Progression of the underlying disease over a 39-year follow-up resulted in a later change of the initially selected pacing mode from DDD to VVI in 40% of cases.

We present a case of a 35 year-old male patient with Emery-Dreifuss muscular dystrophy diagnosed in the age of 12 who was assigned to dual chamber pacing system due to bradycardia primarily recognised as sinus node insufficiency with the atrio-ventricular nodal rhythm. During the procedure permanent electrical atrial stand-still without atrial capture were detected and the mode of stimulation was change to VVIR.

Short-term coronary ischemia was produced in dogs anesthetized with pentothal by ligating the left anterior descending coronary artery. The resulting changes in representative hemodynamic parameters and the patterns of segmental contraction within and outside the ischemic area were recorded. Two types of reaction to coronary ligation were obtained: in some animals the contractility of the ischemic area rapidly decreased, leading to ballooning of the cardiac wall, inversion of the segmental contraction trace, marked reduction in stroke volume, pronounced increase in ventricular end-diastolic volume, and significant reduction in rate of intra-ventricular pressure rise (dP/dt). In other animals there were no signs of functional ventricular aneurysm, the changes in ventricular end-diastolic volume were less marked, and dP/dt was not altered to a significant extent. These observations suggest that in these cases characterized by the development of a functional aneurysm, the decrease in stroke volume does not result solely from dilation of the entire left ventricle, but also from the increased requirement for systolic fiber shortening in the viable myocardium, which must compensate for the extra stretch in the aneurysmal portion of the ventricular wall. It is suggested that diminution of stroke volume is due not only to the increase in wall stress in the whole left ventricle; it owes also to the expending of contractile elements in the viable portion of the muscle to compensate for additional elasticity in the functional left ventricular aneurysm.

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