[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.

[Parameters of cardiac pacing and effectiveness of defibrillation during implantable cardioverter-defibrillator lead implantation to right ventricle outflow tract]. / Parametry stymulacji elektrycznej oraz skutecznosc defibrylacji podczas implantacji elektrody kardiowertera-defibrylatora w drodze odplywu prawej komory serca.

UNLABELLED: Traditional implantation site for implantable cardioverter-defibrillator (ICD) is right ventricular apex (RVA). According to many data, this location ensures low enough defibrillation threshold. ICDs are more often implanted in patients with impaired left ventricle function, in whom, along with disease progression, the need for permanent stimulation develops. Right ventricle outflow tract (RVOT) is considered to be a better site for permanent stimulation. The aim of the study was to assess acute parameters of an ICD lead implantation to RVOT. These are: electrical parameters measured during implantation, defibrillation safety margin (DSM) and some acute complications requiring reoperation. MATERIAL AND METHODS: The study was retrospective. 113 consecutive patients were included in the study (including 19 women, mean age was 60,08 years), who had a single coil ICD lead implanted in the clinic from 2008 to 2012. The implantation site was left to the physicians' discretion, which resulted in majority of RVOT implantations. Among indications to implantation in both groups ischaemic cardiomiopathy with low ejection fraction was a main indication. Excluding criteria were: using dual coil lead, lack of DSM, device of resynchronization implantation. During implantation procedure the following parameters were assessed: R wave amplitude, lead impedance, ventricular pacing threshold. DSM was performed according to the attached scheme. Analysis included: implantation criteria (primary or secondary prevention), demographic and clinical factors, administered anti-arrhythmic medications. RESULTS: In 91 patients (80.53% of the population) the lead was primarily positioned in RVOT while in 22 patients (19.47%) in RVA. In the primarily RVOT group, 50% of ICDs were dual chamber, while in RVA group it was 36%. There were no statistically significant differences between the groups in relation to pacing threshold, lead impedance or R wave amplitude. In 20 patients the lead was repositioned from RVOT to RVA and in 3 from RVA to RVOT due to inappropriate pacing parameters. DSM was satisfying in all of the patients. However, in patients implanted in primary prevention 20% of leads needed repositioning. In patients implanted in secondary prevention 25% of leads needed repositioning. Due to small patient groups, statistical calculations were not feasible in this matter. Complications demanding reoperation were the following: 1 case of right ventricle perforation, 2 cases of atrial lead dislodgement, 3 pocket haematomas, 1 ventricular exit block and 1 infection. CONCLUSIONS: Acute ventricular pacing parameters of single coil defibrillator leads do not differ significantly between RVA and RVOT. Surgical complications in both groups are similar, while permanent RVOT stimulation seems to be clinically better. Further observation in order to determine long term consequences of implantation in different sites seems reasonable.

[QTc duration in the long QT syndrome type 2 - diagnostic dilemma]. / Czas trwania skorygowanego odstepu QT w zespole dlugiego QT typu 2 - problemy diagnostyczne.

We present a case of a 43-year old woman with a long QT syndrome (LQTS). Despite her family history of several sudden deaths in close relatives the patient was misdiagnosed, being treated many years for epilepsy. Finally, after another series of syncopal spells she was diagnosed with LQTS. Although QTc interval was normal on surface ECG, the presence of notched T-waves and QT prolongation up to 543 ms on Holter recording were helpful in establishing the correct diagnosis, which was later confirmed by genotyping revealing G601S mutation in the HERG gene. The patient refused an ICD and despite beta-blocker treatment died suddenly several months later.

[Long-term results of radiofrequency (RF) catheter ablation of cardiac arrhythmias]. / Odlegla skutecznosc zabiegów przezskórnej ablacji RF w leczeniu zaburzen rytmu serca--doswiadczenia wlasne.

BACKGROUND: Although the short-term results after radiofrequency (RF) catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT), accessorry pathway (AP), atrioventricular junction (AVJ) and common atrial flutter (Aflu) have been widely reported, there is insufficient data on long-term outcome. AIM: To evaluate the long-term efficacy of RF ablation of cardiac arrhythmias in a single center. METHODS: The study population consisted of 349 consecutive patients (mean age 49.5 years) who underwent RF ablation of AP (136 patients), AVNRT (105 patients), AVJ (86 patients) or Aflu (15 patients). In 4 patients two AP and in 3 patients AP and AVNRT were ablated during the same session. The patients were subsequently followed-up for an average of 44.3 months (12-76 months). RESULTS: Ablation was successful in 341 patients (97.7%). Major complications occurred in 8 patients (2.3%) and included av block (6 patients), ventricular fibrillation (1 patient) and cardiac tamponade (1 patient). Tachycardia recurrences were observed in 21 patients (6.2%) after successful ablation. All the recurrences occurred within 10 months (mean 2.3 months) after ablation. The recurrence rate was 5.8% (6 patients) in the AVNRT group, 9.2% (12 patients) in the AP group, 1.2% in the AVJ group (1 patient) and 13% (2 patients) in the Aflu group. The differences between groups were insignifficant. CONCLUSIONS: (1) The immediate success rate of RF ablation of AVNRT, AP, AVJ or Aflu was high and there was a low incidence of complications. (2) The recurrence rate during long-term observation is low. (3). All the recurrences occurred within 10 months after successful ablation.

[7 years retrospective analysis of implantation and reimplantation of cardioverter-defibrillators]. / Analiza wszczepien oraz wymian implantowanych kardiowerterów-defibrylatorów serca w 7-letniej wlasnej retrospekcji.

AIM: The aim of the study was to clinical analyse patients with cardioverter-defibrillator (ICD) treated in Cracow Department of Electrocardiology IK CMUJ between 1997-2004. METHODS: Data from 199 patients, aged 10 to 82, mean 56.9 year, in whom 198 implantations (31 of dual-chamber) and replacements were analyzed. CONCLUSIONS: (1) Number of ICD implantation as primary prevention is insufficient in this Dept. (2) Simultaneous presence of pacemaker and ICD is acceptable. (3) Careful sudden cardiac death risk stratification, even in non-classic indicative diseases should be undertaken. (4) Subcutaneous ICD implantation, even in slim people can be done without danger of skin erosion and parameters deterioration. 5. Devices implanted in the past presented longevity shorter than expected. (6) Cooperation with house-officers and pathologists is insufficient.

[Acute pacing parameters of endocardial ventricular leads: comparison of two electrode designs]. / Porównanie "ostrych" parametrów stymulacji dwóch typów endokawitarnych elektrod komorowych.

BACKGROUND: Active-fixation pacemaker leads seem to have advantages over passive-fixation ones, such as the possibility of pacing at various sites, low dislodgement rate, and they are easier to extract. Unexpectedly their popularity in European countries is not high. AIM: The comparative estimation of acute electrical parameters between high-impedance fractal passive-fixation and traditional active-fixation leads. Second aim of the study was the evaluation of commonly used active- and passive-fixation leads in order to find the best solution for ambulatory implantation. METHODS: 35 patients received passive-fixation Biotronik Synox SX60BP pacemaker leads and 35 patients received active-fixation Biotronik YP60BP pacemaker leads. Intraoperative measurement of pacing threshold, impedance, R amplitude, and slew-rate were performed. RESULTS: The pacing threshold was statistically significant lower (p = 0.1) in passive-fixation "tined-tip" SX60BP group (0.45 vs. 0.63). In 3 active-fixation cases "exit block" with ineffective pacing occured in early post-operative period. CONCLUSION: Active-fixation YP60BP electrodes should not be used for ambulatory implantation course.

[Passive-fixation ventricular lead of DDD pacing system implantation through left superior vena cava]. / Implantacja komorowej elektrody o biernej fiksacji systemu DDD przez lewa zyle glówna górna.

Passive-fixation of ventricular lead was implanted through left superior vena cava (LSVC) and DDD pacing system replaced AAI in a young patient with II degree A-V block. Good mechanical stability and proper bioelectrical parameters obtained in short-lasting, uncomplicated procedure does not stay in line with world-wide approach. It is preferential for active fixation of leads in the right ventricle through the LSVC.

[Patients history following artificial aortic valve and pacemaker implantation]. / Losy chorych po implantacji sztucznej zastawki aortalnej i rozrusznika serca.

UNLABELLED: The follow-up of 22 patients (out of 31 patients after artificial aortic valve and pacemaker implantation between 1982 and 2001) have been evaluated. There were 15 men aged 30-76 (x=55) and 7 women aged 43-69 (x=59). Aortic valve replacement (AVR) was subsequently followed by pacemaker implantation (PI) after approximately 16 days. Indication for permanent stimulation were: atrio-ventricular complete block in 18 patients and atrial fibrillation with slow ventricular response in the remaining 4. There were implanted 15 devices of VVI type and 7 of VDD type. The duration of follow up was 9-196 (x=56) months. All these patients remained in good general state (II degree--19 patients or II/III degree--3 patients acc. to NYHA classification). In 21 out of 22 patients, atrioventricular conduction disturbances and bradyarrhythmia remained for the entire follow-up duration with permanent stimulation (VVI or VAT). In one patient the postoperative complete atrio-ventricular block disappeared during follow up, 24 months after AVR. CONCLUSIONS: 1. The main indication for PI after AVR was complete atrio-ventricular block, persisting 2-3 weeks after surgery, without accompanying atrial fibrillation. 2. In long term follow up after AVR and PI (VVI or VDD) the dominance of 100% capture ventricular pacing have been recorded in almost all cases, which holds the decision of early postoperative PI.

[Pacemaking in Cracow in years 1966-1980]. / Elektrostymulacja serca w Krakowie w latach 1966-1980.

Permanent pacemaking, a new and effective bradycardia--treatment method, has appeared in the sixties. In Cracow the first emergency temporary stimulation by means of transvenously inserted intracardiac electrode was performed in 1966. Permanent technique of artificial pacing was introduced soon after. The number of pacemaker implantations grew successfully, obtaining 750 of the end of the seventies when the Institute of Cardiology of Nicolaus Copernicus Medical Academy was established. Assortment of implantable devices also became wider, including such rare constructions like nuclear pacemakers and an inductive coupled pacemaker.