[Arrhythmia, device interventions and mortality analysis in patients with implanted cardioverter-defibrillator with/without resynchronisation therapy in dilative cardiomyopathy in primary prevention of sudden cardiac death]. / Analiza arytmii, interwencji urzadzenia oraz umieralnosci w populacji chorych z implantowanym kardiowerterem-defibrylatorem i/lub z funkcja resynchronizacji z powodu kardiomiopatii rozstrzeniowej w prewencji pierwotnej naglego zgonu sercowego.

UNLABELLED: Ambulatory follow-up of patients with implanted cardioverter-defibrillator (ICD) with/without resynchronisation therapy (CRTD) requires regular visits to assess arrhythmias, device interventions and mortality. AIM: The aim of the study was to examine arrhythmia prevalence, device interventions and mortality in patients with dilative cardiomyopathy with ICD/CRTD implanted in primary sudden cardiac death (SCD) prevention. MATERIALS AND METHODS: The study consisted of patients with ICD and/or CRTD implanted between 2010-2011. The inclusion criteria were: left ventricle ejection fraction (LVEF) ≤ 35%, NYHA class ≥ II, implantation in primary SCD prevention and in case of CRTD additionally LBBB with wide QRS ≥ 120ms. All of patients' visits in outpatient clinic were analysed. The following data were assessed: age, gender, presence of coronary artery disease (CAD), diabetes, thyroid gland diseases, chronic kidney failure, atrial fibrillation (AF), LVEF, NYHA class, device interventions, number of arrhythmias, changes in pharmacotherapy, device parameters and mortality. RESULTS: The study analysed 360 patients (302 M, mean age 64±12 years) with cardiac implantable devices (127 with CRTD, 233 with ICD). During observation, which lasted the mean of 768±491 days, 258 patients had ventricular arrhythmias and 118 patients had adequate device interventions. 10 patients died because of the progression of heart failure. Ventricular arrhythmia was more frequent in patients with CRTD, who died, with low cholesterol level, high NYHA class, low LVEF, diabetes and kidney failure. Device interventions occurred in the above described groups and additionally in patients with AF. After step exclusion of characteristics with highest p value in Wald test, it was confirmed that the factors influencing ventricular arrhythmia and death were low LVEF (HR=0,944, p<0,002 and HR=0,813, p<0,013) and diabetes (HR=7,043, p<0,009 and HR=29,931, p<0,002). CONCLUSIONS: Ventricular arrhythmia is more often in patients with CRTD, who died, with low cholesterol level, high NYHA class, low LVEF, diabetes and kidney failure. Adequate interventions are more often in patients who died, with low cholesterol level, high NYHA class, low LVEF, diabetes, kidney failure and AF. Patients who died, compared to those who survived, had significantly more often lipid level anomalies, high NYHA class, low LVEF, advanced age, diabetes, kidney failure, atrial fibrillation, arterial hypertension, device interventions and pharmacotherapy changes. Diabetes and low LVEF are predictors of ventricular arrhythmias and death.

[Some aspects of energy-saving pacing in the light of the author's studies]. / Niektóre aspekty kardiostymulacji energooszczednej w swietle badan wlasnych.

UNLABELLED: Pacemaker working time, which was in the beginning not more than one year, reached the maximum in the first half of the 70s, then shortened to between a few to several years. Aim of the study was investigated the electrical properties of the endocavitary pacemaker leads, considered the possibility of manufacturing a longlasting pacemaker ("lifetime pacemaker") and examined the preference of patients in relation to dimensions of the implanted device. MATERIALS AND METHODS: The investigation included 190 electrodes with cathodes coated with titanium nitride (TIJ and TIR), 244--coated with iridium (SXA and SXV) and 90--coated with black platinum (DXA and DXV). A formula was developed to calculate the estimated pacemaker longevity: Longevity (years)=Qog (Ah)x10(6)/8760x[Isp (µA)+Ist (µA)], where Qog is the capacity of the electric cell, Ist--current stimulation, Isp--quiescent current of the generator. The survey was performed in a group of 145 patients with pacemakers, using an original questionnaire. RESULTS: All the tested electrodes manifested a good acute and distant pacing threshold and the small intra-electrode differences were not clinically significant. In distant measurement, the average rheobasis of the steroid platinum electrode was 0.59 V and the chronaxie was 0.23 ms. These parameters have direct impact on modern pacemaker programming methods. It was proven that increasing the electric cell capacity in the DDD pacemaker by every one-tenth of ampere-hours caused a significant increase in the working time (p=0.000). Thus, the increase of the electric cell capacity allows for returning to the concept of a "lifetime pacemaker". The results of the survey showed that patients were willing to accept larger, but longlasting pacemakers (p=0.000). CONCLUSIONS: The tested passive and active electrode with a fractalcoated cathode ensured good electrical parameters within several months of observation. The electrode equipped with dexamethasone deposit showed no advantage in terms of the stimulation threshold when compared to the passive electrode coated with titanium nitride. Significant differences in the pacing threshold, which were detected between the leads with different cathode coatings, had little effect on pacemaker longevity. The most extensive impact on the generator longevity was exerted by the capacity of the electrical cell and pacemaker quiescent current. Patients were able to accept a much larger device than currently produced providing a long working time was ensured.