Upgrade of right ventricular pacing to cardiac resynchronization therapy in heart failure: a randomized trial.

BACKGROUND AND AIMS: De novo implanted cardiac resynchronization therapy with defibrillator (CRT-D) reduces the risk of morbidity and mortality in patients with left bundle branch block, heart failure and reduced ejection fraction (HFrEF). However, among HFrEF patients with right ventricular pacing (RVP), the efficacy of CRT-D upgrade is uncertain. METHODS: In this multicentre, randomized, controlled trial, 360 symptomatic (New York Heart Association Classes II-IVa) HFrEF patients with a pacemaker or implantable cardioverter defibrillator (ICD), high RVP burden ≥ 20%, and a wide paced QRS complex duration ≥ 150 ms were randomly assigned to receive CRT-D upgrade (n = 215) or ICD (n = 145) in a 3:2 ratio. The primary outcome was the composite of all-cause mortality, heart failure hospitalization, or <15% reduction of left ventricular end-systolic volume assessed at 12 months. Secondary outcomes included all-cause mortality or heart failure hospitalization. RESULTS: Over a median follow-up of 12.4 months, the primary outcome occurred in 58/179 (32.4%) in the CRT-D arm vs. 101/128 (78.9%) in the ICD arm (odds ratio 0.11; 95% confidence interval 0.06-0.19; P < .001). All-cause mortality or heart failure hospitalization occurred in 22/215 (10%) in the CRT-D arm vs. 46/145 (32%) in the ICD arm (hazard ratio 0.27; 95% confidence interval 0.16-0.47; P < .001). The incidence of procedure- or device-related complications was similar between the two arms [CRT-D group 25/211 (12.3%) vs. ICD group 11/142 (7.8%)]. CONCLUSIONS: In pacemaker or ICD patients with significant RVP burden and reduced ejection fraction, upgrade to CRT-D compared with ICD therapy reduced the combined risk of all-cause mortality, heart failure hospitalization, or absence of reverse remodelling.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole.

AIMS: To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD. METHODS AND RESULTS: In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF. CONCLUSION: A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Clinical valuation of ST changes in a group of patients with ventricular arrhythmias: The inSighT Study.

BACKGROUND: The inSighT study was designed to determine the prevalence of ischemic changes as recorded by implantable cardioverter-defibrillator (ICD) ST deviations in intracardiac electrocardiograms (EGM) over the 24 h preceding malignant ventricular arrhythmias (VT/VF). METHODS: The study enrolled patients with known coronary artery disease (CAD) or high risk of future development of CAD implanted with an ICD equipped with an ST monitoring feature (Ellipse™/Fortify Assura™, St. Jude Medical). Device session records were collected at each in-clinic follow-up. EGM ST levels of the beats over the 15 minutes prior to VT/VF events were compared using a t test with those from a baseline period of 23-24 h prior to the VT/VF event. All events with p < .05 were visually inspected to confirm they were evaluable; additional criteria for exclusion from further analysis included inappropriate therapy, aberrant conduction, and occurrence of VT/VF within 24h prior to the current event. RESULTS: The study enrolled 481 ICD patients (64 ± 11 years, 83% male) in 14 countries and followed them for 15±5 months. A total of 165 confirmed VT/VF episodes were observed, of which 71 events (in 56 patients, 34% of all patients with VT/VF) were preceded by significant (p < .05) ST-segment changes unrelated to known non-ischemic causes. None of the analyzed demographic and clinical factors proved to be associated with greater odds of presenting with ST-segment changes prior to VT/VF episode. CONCLUSION: In this exploratory study, characteristic ST-segment changes, likely representative of ischemic events, were observed in 34% of all patients with VT/VF episodes.

Effect of empagliflozin on exercise ability and symptoms in heart failure patients with reduced and preserved ejection fraction, with and without type 2 diabetes.

AIMS: The EMPERIAL (Effect of EMPagliflozin on ExeRcise ability and HF symptoms In patients with chronic heArt faiLure) trials evaluated the effects of empagliflozin on exercise ability and patient-reported outcomes in heart failure (HF) with reduced and preserved ejection fraction (EF), with and without type 2 diabetes (T2D), reporting, for the first time, the effects of sodium-glucose co-transporter-2 inhibition in HF with preserved EF (HFpEF). METHODS AND RESULTS: HF patients with reduced EF (HFrEF) (≤40%, N = 312, EMPERIAL-Reduced) or preserved EF (>40%, N = 315, EMPERIAL-Preserved), with and without T2D, were randomized to empagliflozin 10 mg or placebo for 12 weeks. The primary endpoint was 6-minute walk test distance (6MWTD) change to Week 12. Key secondary endpoints included Kansas City Cardiomyopathy Questionnaire Total Symptom Score (KCCQ-TSS) and Chronic Heart Failure Questionnaire Self-Administered Standardized format (CHQ-SAS) dyspnoea score. 6MWTD median (95% confidence interval) differences, empagliflozin vs. placebo, at Week 12 were -4.0 m (-16.0, 6.0; P = 0.42) and 4.0 m (-5.0, 13.0; P = 0.37) in EMPERIAL-Reduced and EMPERIAL-Preserved, respectively. As the primary endpoint was non-significant, all secondary endpoints were considered exploratory. Changes in KCCQ-TSS and CHQ-SAS dyspnoea score were non-significant. Improvements with empagliflozin in exploratory pre-specified analyses of KCCQ-TSS responder rates, congestion score, and diuretic use in EMPERIAL-Reduced are hypothesis generating. Empagliflozin adverse events were consistent with those previously reported. CONCLUSION: The primary outcome for both trials was neutral. Empagliflozin was well tolerated in HF patients, with and without T2D, with a safety profile consistent with that previously reported in T2D. Hypothesis-generating improvements in exploratory analyses of secondary endpoints with empagliflozin in HFrEF were observed.

[Wartosc prognostyczna wskazników elektrokardiograficznych zawalu prawej komory w ocenie wewnatrzszpitalnego przebiegu klinicznego u chorych z rozpoznanym zawalem sciany dolnej leczonych interwencyjnie]. / Wartosc prognostyczna wskazników elektrokardiograficznych zawalu prawej komory w ocenie wewnatrzszpitalnego przebiegu klinicznego u chorych z rozpoznanym zawalem sciany dolnej leczonych interwencyjnie.

Myocardial infarction (MI) of the right ventricle (RV) coexists in 20- 60% of patients with inferior MI. There are electrocardiographic indicators which are connected with RV MI, which may also predict unfavorable clinical outcome of in-hospital follow-up. AIM: The aim of the study was determination a value of seven electrocardiographic predictors of RV MI in prognosis of in-hospital complications in patients with inferior MI. MATERIALS AND METHODS: The analysis of hospital files of patients admitted with diagnosis of inferior MI with persistent ST elevation (STEMI) was retrospectively performed. A set of seven RV MI predictors (RVMIP) was assessed from the electrocardiographic tracings (ECG). Finally in group of 167 patients relation between each RVMIP and in-hospital complications was statistically evaluated. RESULTS: The most often RVMIP was an elevation of ST higher in III lead then in II and aVF (RVMIP-2; recorded in 61,7% patients). In total any RVMIP was found in ECG of 142 patients (85%). Patients who had more RVMIP were more prone for combined adverse cardiac event (CACE, which included artificial respirotherapy, lungs edema and cardiogenic shock) (p=0,012); ventricular arrhythmias (p<0,001) and second/third grade atrioventricular blocks (p=0,028). Advanced atrioventricular blocks were more often observed in patient with ST elevation in V1 and ST depression in aVL (OR=4,91, p=0,005; OR=4,67, p=0,006; respectively). On the other hand second/third grade atrioventricular blocks were also related to higher incidence of CACE, ventricular arrhythmias and atrial fibrillation (AF), respectively: OR=8,1, p<0,001; OR=7,19, p=0,001; OR=5,75, p=0,001). CONCLUSIONS: The more RVMIPs the higher risk of in-hospital complication in patients with inferior MI. The second/third grade atrioventricular blocks were recorded more often in patients with ST elevation in V1 and ST depression in aVL. Advanced atrioventricular conduction blocks were related to worse outcome of in-hospital followup. A detailed ECG analysis in admission still adds important contribution in determination of in-hospital risk of complications.

Wearable Cardioverter-Defibrillator after Myocardial Infarction.

BACKGROUND: Despite the high rate of sudden death after myocardial infarction among patients with a low ejection fraction, implantable cardioverter-defibrillators are contraindicated until 40 to 90 days after myocardial infarction. Whether a wearable cardioverter-defibrillator would reduce the incidence of sudden death during this high-risk period is unclear. METHODS: We randomly assigned (in a 2:1 ratio) patients with acute myocardial infarction and an ejection fraction of 35% or less to receive a wearable cardioverter-defibrillator plus guideline-directed therapy (the device group) or to receive only guideline-directed therapy (the control group). The primary outcome was the composite of sudden death or death from ventricular tachyarrhythmia at 90 days (arrhythmic death). Secondary outcomes included death from any cause and nonarrhythmic death. RESULTS: Of 2302 participants, 1524 were randomly assigned to the device group and 778 to the control group. Participants in the device group wore the device for a median of 18.0 hours per day (interquartile range, 3.8 to 22.7). Arrhythmic death occurred in 1.6% of the participants in the device group and in 2.4% of those in the control group (relative risk, 0.67; 95% confidence interval [CI], 0.37 to 1.21; P=0.18). Death from any cause occurred in 3.1% of the participants in the device group and in 4.9% of those in the control group (relative risk, 0.64; 95% CI, 0.43 to 0.98; uncorrected P=0.04), and nonarrhythmic death in 1.4% and 2.2%, respectively (relative risk, 0.63; 95% CI, 0.33 to 1.19; uncorrected P=0.15). Of the 48 participants in the device group who died, 12 were wearing the device at the time of death. A total of 20 participants in the device group (1.3%) received an appropriate shock, and 9 (0.6%) received an inappropriate shock. CONCLUSIONS: Among patients with a recent myocardial infarction and an ejection fraction of 35% or less, the wearable cardioverter-defibrillator did not lead to a significantly lower rate of the primary outcome of arrhythmic death than control. (Funded by the National Institutes of Health and Zoll Medical; VEST ClinicalTrials.gov number, NCT01446965 .).

Baseline intrinsic heart rate and response to ivabradine treatment in patients with inappropriate sinus tachycardia.

BACKGROUND: Treatment with ivabradine became a new therapeutic alternative for patients with inappropriate sinus tachycardia (IST). The aim was to determine a relation between intrinsic heart rate (IHR) and response to ivabradine treatment. METHODS: Twenty-seven patients (mean age 37 ± 11; 23 women) with symptomatic IST despite medical treatment were recruited into the study. Resting ECG, 24-hr ECG monitoring (24hECG), exercise treadmill test, and symptoms evaluation were performed initially and after 60 days on ivabradine. IHR was acquired at baseline after pharmacological autonomic blockade. RESULTS: Nineteen patients (70%) were classified as abnormal IHR group (AIHR) while eight showed normal IHR (NIHR). No significant differences in ECG parameters were found between NIHR and AIHR subgroups, while baseline exercise capacity was higher in AIHR patients (10.9 vs. 9.5 METs, p < .05). Ivabradine treatment resulted in significant reduction in resting heart rate, average 24hECG heart rate, improvement in exercise capacity and reduction of symptoms in both subgroups. Nevertheless, favorable influence of ivabradine was significantly more exaggerated in AIHR subgroup (HR 116 vs. 90 bpm, av. HR 98 vs. 79 bpm, 10.9 vs. 13.6 METS, EHRA score 3.1 vs. 1.1, p < .001 for all) than in NIHR patients (HR 112 vs. 98 bpm, av. HR 97 vs. 88 bpm, 9.5 vs. 11.1 METs, EHRA score 3.1 vs. 1.9; p < .05 for all). CONCLUSIONS: Intrinsic heart rate may be useful in predicting response to ivabradine in patients with IST. More intense response to ivabradine in patients with AIHR may be attributed to different pathophysiological mechanisms underlying IST in AIHR and NIHR groups.

Conventional and alternative preimplantation ECG screening for subcutaneous ICD in high risk hypertrophic cardiomyopathy patients.

INTRODUCTION: Patients with hypertrophic cardiomyopathy (HCM) relatively often fail preimplantation ECG screening for subcutaneous implantable cardioverter-defibrillator (S-ICD). We aimed to evaluate impact of conventional and alternative ECG electrodes placement on eligibility for S-ICD implantation in HCM patients at high risk of sudden cardiac death (SCD). We hypothesized that modified electrodes placement will influence QRS-T morphology and thus it will increase S-ICD eligibility in the screening process. MATERIAL AND METHODS: This study enrolled 17 HCM patients at high risk of SCD (5-year SCD risk above 5%) referred for an ICD implantation. ECG screening for S-ICD eligibility in horizontal and vertical position was performed in each patient, in two different screening electrodes configuration: conventional (recommended by manufacturer) and alternative (precordial electrodes shifted rightwards and lateral electrodes dorsally). We evaluated QRS and T waves amplitude as well as T wave index. Primary, secondary and alternate sensing vectors were assessed. RESULTS: Preimplantation ECG screening with alternative electrodes placement resulted in more sensing vectors that were screened successfully (77 vs. 88, p = 0.05). Modified screening combined with a standard one allowed more patients to qualify for S-ICD implantation (17/17 vs. 12/17, p = 0.04). Electrocardiographically, the alternative positioning of ECG electrodes resulted in significant decrease in absolute values of QRS complex and T waves amplitudes in almost all sensing vectors, which was responsible for successful screening. CONCLUSIONS: The use of alternative placement of screening electrodes may be a valuable method to increase eligibility for S-ICD implantation in HCM patients at high risk of SCD.

Impact of admission glycaemia on the annual risk of major cardiovascular events and development of type 2 diabetes mellitus in patients with non-ST-elevation acute coronary syndrome undergoing percutaneous coronary intervention.

Elevated admission glycaemia (ABG) in a patient with or without type 2 diabetes (T2DM) is associated with adverse consequences. There is still a lack of accurate data on the adverse effects of ABG on the risk of major cardiovascular events and the development of T2DM in patients hospitalized for unstable angina (UA) or non-ST elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention. AIM: The main aim of this study was to evaluate the effect of ABG to the risk of major cardiovascular events and the development of T2DM during one year follow-up in patients with UA and NSTEMI. MATERIALS AND METHODS: 100 consecutive patients (68% men, mean age 64.2±10.5 years) hospitalized due to non-ST-elevation acute coronary syndrome (NSTE-ACS) were included in observational study. In each patient, medical history was taken and physical examination, standard diagnostics procedures, including venous glucose deterioration and coronarography were performed. Patients were assigned to two groups: UA or NSTEMI and observed during hospitalization and one year after discharge. RESULTS: 74 patients were diagnosed with NSTEMI and 26 with UA. 41 patients were treated for T2DM and 28 were diagnosed with impaired fasting glucose (IFG) prior to hospitalization. Both carbohydrate disorders occurred with a similar frequency in the compared groups of patients, and its incidence was comparable in both groups. During observation, T2DM was diagnosed only in 8 patients with IFG. Out of the 8 patients whose ABG was >250mg/dl, 7 died during one year, including three during hospitalization, and two during the first month after discharge. These patients were diagnosed with T2DM before hospitalization. CONCLUSIONS: Different degrees of impaired glucose homeostasis are present before or develop after occurrence NSTE-ACS. ABG >250mg/ dl in this group of patients is associated with the highest risk of death, regardless of the diagnosis of UA or NSTEMI.

Self-terminating ventricular fibrillation recorded by an implantable loop recorder as a cause of syncope - A case report.

Ventricular fibrillation (VF) is the most common arrhythmia leading to sudden cardiac death, but in rare cases VF can manifest as a syncope, provided that it will self-terminate. We present a case of a 45-year old female with a history of unexplained syncopal episodes despite exhaustive diagnostics. Implantable loop recorder documented an episode of idiopathic, self-terminating VF as a cause of syncope.

Rationale and design of the BUDAPEST-CRT Upgrade Study: a prospective, randomized, multicentre clinical trial.

AIMS: There is lack of conclusive evidence from randomized clinical trials on the efficacy and safety of upgrade to cardiac resynchronization therapy (CRT) in patients with implanted pacemakers (PM) or defibrillators (ICD) with reduced left ventricular ejection fraction (LVEF) and chronic heart failure (HF). The BUDAPEST-CRT Upgrade Study was designed to compare the efficacy and safety of CRT upgrade from conventional PM or ICD therapy in patients with intermittent or permanent right ventricular (RV) septal/apical pacing, reduced LVEF, and symptomatic HF. METHODS AND RESULTS: The BUDAPEST-CRT study is a prospective, randomized, multicentre, investigator-sponsored clinical trial. A total of 360 subjects will be enrolled with LVEF ≤ 35%, NYHA functional classes II-IVa, paced QRS ≥ 150 ms, and a RV pacing ≥ 20%. Patients will be followed for 12 months. Randomization is performed in a 3:2 ratio (CRT-D vs. ICD). The primary composite endpoint is all-cause mortality, a first HF event, or less than 15% reduction in left ventricular (LV) end-systolic volume at 12 months. Secondary endpoints are all-cause mortality, all-cause mortality or HF event, and LV volume reduction at 12 months. Tertiary endpoints include changes in quality of life, NYHA functional class, 6 min walk test, natriuretic peptides, and safety outcomes. CONCLUSION: The results of our prospective, randomized, multicentre clinical trial will provide important information on the role of cardiac resynchronization therapy with defibrillator (CRT-D) upgrade in patients with symptomatic HF, reduced LVEF, and wide-paced QRS with intermittent or permanent RV pacing. CLINICAL TRIALS.GOV IDENTIFIER: NCT02270840.

Risk score to assess mortality risk in patients undergoing transvenous lead extraction.

AIMS: The main aim of this study was to assess 1-year mortality and its predictors in a cohort of patients who underwent transvenous lead extraction (TLE) procedure. METHODS: Retrospective analysis of clinical characteristics and 1-year follow-up of patients referred for a TLE procedure in a single, high-volume center between June 2006 and October 2014 was performed. RESULTS: The studied population included 130 patients (82 males; mean age 64 ± 15 years) implanted with pacemakers (74%), implantable cardioverter defibrillators (15%), or cardiac resynchronization therapy defibrillator (11%). Indications for the extraction included infective endocarditis (40.5%), pocket infection (18.5%), and lead fault or failure (41%). Total radiological success rate was 90% while clinical success rate was 93.5%. The cumulative 1-year mortality was 28%. Mortality was higher in a group of older patients (94.4% vs 68%, P = 0.001) and those with chronic kidney disease (33.3% vs 4.3 %, P = 0.0002) as well as in patients after removal of high voltage lead (88.9% vs 26.3%, P = 0.01). Higher mortality was also related to infection as an indication for TLE (37.2% vs 13.5%, P = 0.002). Following these findings a new risk score model named IKAR (I = infective indications; K = kidney dysfunction; A = age ≥ 56; R = removal of high voltage lead) was constructed. Patients with IKAR score ≥3 points were characterized by 79% mortality as compared to 16% in those with a score 1-2 points. CONCLUSIONS: One-year mortality of patients undergoing TLE procedure can be predicted by using IKAR risk score.

Potential benefit of optimizing atrioventricular & interventricular delays in patients with cardiac resynchronization therapy.

BACKGROUND & OBJECTIVES: The clinical benefit of optimization (OPT) of atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) remains debatable. This study was aimed to determine the influence of AVD and VVD OPT on selected parameters in patients early after CRT implantation and at mid-term follow up (FU). METHODS: Fifty two patients (61±10 yr, 23 males) with left bundle branch block, left ventricular ejection fraction (LVEF) ≤35 per cent and heart failure were selected for CRT implantation. Early on the second day (2DFU) after CRT implantation, the patients were assigned to the OPT or the factory setting (FS) group. Haemodynamic and electrical parameters were evaluated at baseline, on 2DFU after CRT and mid-term FU [three-month FU (3MFU)]. Echocardiographic measures were assessed before implantation and at 3MFU. The AVD/VVD was deemed optimal for the highest cardiac output (CO) with impedance cardiography (ICG) monitoring. RESULTS: On 2DFU, the AVD was shorter in the OPT group, LV was paced earlier than in FS group and CO was insignificantly higher in OPT group. At 3MFU, improvement of CO was observed only in OPT patients, but the intergroup difference was not significant. At 3MFU in OPT group, reduction of LV in terms of LV end-diastolic diameter (LVeDD), LV end-systolic diameter, LV end-diastolic and systolic volume with the improvement in LVEF was observed. In FS group, only a reduction in LVeDD was present. In OPT group, the paced QRS duration was shorter than in FS group patients. INTERPRETATION & CONCLUSIONS: CRT OPT of AVD and VVD with ICG was associated with a higher CO and better reverse LV remodelling. CO monitoring with ICG is a simple, non-invasive tool to optimize CRT devices.

Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy.

BACKGROUND The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). MATERIAL AND METHODS Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. RESULTS Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. CONCLUSIONS During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead.

[The role of reactive oxygen species (ROS) in arrhythmogenesis]. / Rola wolnych rodników tlenowych w patogenezie zaburzen rytmu serca.

Reactive oxygen species (ROS) are the molecular oxygen derivatives that have at least one unpaired electron. Thus, ROS easily react with a number of cell structures causing a change in their functions. ROS produced in small quantities positively affect many cellular mechanisms, but in excess are responsible for the formation of oxidative stress. Oxidative stress is considered a major cause of many diseases, including cardiovascular disease. Abolition of the adverse effects of ROS on organisms in order to maintain redox homeostasis is possible thanks to antioxidants. The research conducted mainly in recent years shows that the formation of arrhythmias may also be related to the phenomenon of oxidative stress. Oxidative damage to cell membranes in particular are causing changes in ion channel activity, which proper functioning is the basis for the formation of normal heart rhythm. Antioxidants seem to play a protective role against the formation of arrhythmias.

[Technical options of electrotherapy in patients with vasovagal syncope]. / Techniczne mozliwosci elektroterapii u osób z omdleniami wazowagalnymi.

Syncope is a symptom of the disease with diverse etiology and can be evidence of both benign and very serious life-threatening conditions. Vasovagal syncope(VVS), with prevalence about 35% of the general population, is most frequent causes of transient loss of consciousness (T-LOC). Most cases of vasovagal syncope requires conservative treatment. Although cardioinhibitory type of VVS characterized by a significant bradycardia or pause of the heart rate and can be treated with continuous electrotherapy. This article discuss cardiac pacing and technical solutions for the treatment of VVS. Available cardiac pacing methods used to detect and break VVS such as Rate Drop Response (RDR), Closed Loop Stimulation (CLS) and rate response driven by variations of myocardial contractility like Peak Endocardial Acceleration (PEA), has been presented.

[Long-term prognosis in patients with vasovagal syncope after pacemaker implantation]. / Rokowanie odlegle u pacjentów z omdleniami wazowagalnymi po implantacji kardiostymulatora.

Patients with syncope, without presence of a structural or primary electrical disease, have a very good prognosis. On the other hand, recurring syncope has a negative impact on quality of life and involves a real risk of physical injuries. Vasovagal syncope usually requires no medical therapy and the most commonly recommended instruction include avoidance of fainting triggers, exercise that mainly provoke leg muscles tension, increase salt consumption and drink indicated amount of fluids. In the case cardioinhibitory type of vasovagal syncope the pacemaker implantation can consider. Unfortunately, not all patients benefit from this treatment. Medical society clearly highlights that proper qualification of VVS patients is the most important factor for cardiostimulator implantation. This article aims to summarize the most important research and guidelines concerning cardiac pacing for patients with vasovagal syncope.

[Clinical procedure in amiodarone-induced thyroid dysfunction]. / Postepowanie kliniczne w poamiodaronowych zaburzeniach czynnosci gruczolu tarczowego.

Amiodarone is an antiarrhythmic drug frequently used in everyday clinical practice. Its mechanism of action involves the interaction with many receptors, including those in the cardiac conduction system. Amiodarone usefulness is protect in the treatment of a variety of tachyarrhythmias, both benign and life-threatening. In contrast to other antiarrhythmic drugs, amiodarone is characterized by high therapeutic efficacy, both in patients with normal and impaired left ventricular systolic function. A significant limitation of its is associated with side effects including thyroid gland dysfunction. Disturbances of this organ associated with amiodarone are an important diagnostic and therapeutic problem. They may contribute to the occurrence of both Amiodarone- Induced Thyrotoxicosis (AIT) and Amiodarone-Induced Hypothyroidism (AIH). The risk of such complications should be considered for each patient individually, taking into account thyroid function at the beginning of pharmacotherapy. Appropriate procedure, both before and after treatment allows a rapid diagnosis and treatment of thyroid disturbances. It seems that the best parameter used to assess the hormonal imbalance during amiodarone therapy is the concentration of the free triiodothyronine (fT3). The evaluation of thyroid function should be performed before starting pharmacotherapy, and then repeated every six months. In the case of a thyroid dysfunction, assessment must be performed immediately according to standard diagnostic and therapeutic regimens. Despite abnormal thyroid function, high efficiency of amiodarone and relatively small risk of thyroid damage allows continuation therapy. Amiodarone therapy requires a care from both cardiologist and endocrinologist. The aim of this paper is to present the state of art of evaluation of the thyroid function and procedures implemented in care of thyroid dysfunction before and during treatment with amiodarone.

[Atrial fibrillation in patients with heart failure].

The most common arrhythmia is atrial fibrillation, which is very often associated with heart failure. Treatment of both clinical entries are difficult and became a clinical, social and economic challenge in last decades. The authors present clinical aspects connected with a coexistence of HF and AF. They discuss systematic review of research studies regarding medical therapy and invasive electrotherapy.

[Prophylaxis of sudden cardiac death in patients with chronic kidney disease]. / Profilaktyka naglego zgonu sercowego u pacjentów z przewlekla choroba nerek.

In everyday practice, more commonly can we meet patients suffering from chronic kidney disease at different stages. Such patients are more susceptible to new risk factors, that can impair their health, along with the development of the disease. Sudden cardiac death (SCD) is the most common cause of death, that occurs in such group of patients. This article reviews the most important risk factors of SCD. They can be divided into two groups: heart dependent risk factors, such as: ischemic heart disease, cardiomyopathy, electrophysiology disturbances and dializo-therapy dependent risk factors, such as: type of dialysis, composition of dialysate, ions and hormonal disturbances. Also, prophylactic options, decreasing the risk of SCD, will be introduced, such as: pharmacotherapy, type of dializo-therapy and implantation of cardioverter-defibrillator.