Grzegorz Opolski - Academia.edu (original) (raw)
Papers by Grzegorz Opolski
European Journal of Echocardiography, 2010
Subclinical impairment of LV function in patients with obstructive sleep apnoea HQ Pham, TG v. Lu... more Subclinical impairment of LV function in patients with obstructive sleep apnoea HQ Pham, TG v. Lueder, SK Namtvedt, H Røsjø T. Omland, K Steine Aims: Obstructive sleep apnea (OSA) is associated with obesity, hypertension and heart failure. The aim of the present study was to assess LV function in patients with OSA of mainly moderate severity and no previous diagnosis of heart disease. Methods: 40 consecutive patients with OSA verified by polysomnography (apneahypopnea-index) were compared with 41 voluntary healthy controls. OSA patients were divided into lean (BMI, body-mass-index ≤ 28; "OSA-lean", n ¼ 16) or obese (BMI .28; "OSA-fat", n ¼ 24). LV systolic function was determined using 2D echo including 2D longitudinal global strain recorded from three apical views. LV diastolic function was assessed by the ratio between early diastolic-transmitral Doppler velocity (E) and the septal mitral tissue Doppler imaging velocity (e'). All analyses were performed by one investigator blinded to the study groups. Results: Healthy controls and "OSA-lean" were identical for height and body weight, while "OSA-fat" had greater body weight. "OSA-fat" had lower minimal nocturnal oxygen saturation and greater apnea-hypopnea-index than "OSA-lean". While systolic blood pressure (mmHg) was similar in "OSA-lean" and controls (130+3 and 128+3), it was significantly elevated in "OSA-fat" (141+3). LV dimensions were similar in all three groups, while LV ejection fraction (Simpson) was slightly but significantly lower in both OSA groups. Septal, posterior, and relative wall thickness were all increased in "OSA-lean", and further augmented in "OSA-fat". Peak longitudinal global LV strain values were significantly and similarly reduced in "OSA-lean" (216.0+0.4%) and OSA-fat (215.5+0.5%) compared to controls (218.0+0.3%). Moreover, LV global strain was inversely correlated with apnea-hypopnea-index (R ¼ 0.55; P , 0.00001). E/é ratio was significantly increased in "OSA-fat" (10.1+0.8) as compared to "OSA-lean" (8.4+0.7) and controls (7.7+0.3). Conclusion: The present study demonstrates subclinical impairment of LV systolic and diastolic function in obese asymptomatic patients with OSA as compared to lean OSA patients and controls. Although increased blood pressure might have an impact on our findings, the strong association between systolic 2D strain and the apnoea-hypnoea index indicates decreased oxygen saturation to be of importance for the impairment of LV function in patients with OSA of moderate severity. P968 What is the real diagnostic accuracy of carotid intima-media thickness for the prediction of significant coronary artery disease?
Journal of Clinical Medicine
Background: Increased resting heart rate (RHR) after pulmonary vein isolation (PVI) for treatment... more Background: Increased resting heart rate (RHR) after pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF) is a common observation, possibly resulting from ganglionated plexus modification during ablation. Previous trials have suggested that an increase in RHR after ablation might be related to higher efficacy of the procedure. The aim of this study was to determine whether or not higher increase in RHR after radiofrequency (RF) PVI might predict better long-term outcome of the procedure in a real-life cohort of patients in whom index ablation for paroxysmal AF was performed. Material and methods: The health records of patients who underwent index point-by-point or drag lesion RF PVI for paroxysmal AF in our department between January 2014 and November 2018 were analyzed. Resting heart rate (RHR) was determined from 12-lead ECG recorded prior to the ablation and before discharge to evaluate changes in RHR after PVI. Only patients in sinus rhythm before the procedu...
Biology, 2021
Background, the mechanisms underlying left ventricular remodelling (LVR) after acute myocardial i... more Background, the mechanisms underlying left ventricular remodelling (LVR) after acute myocardial infarction (AMI) remain obscure. In the course of AMI, blood cells and endothelial cells release extracellular vesicles (EVs). We hypothesized that changes in EV concentrations after AMI may underlie LVR. Methods, plasma concentrations of EVs from endothelial cells (CD146+), erythrocytes (CD235a+), leukocytes (CD45+), platelets (CD61+), activated platelets (P-selectin+), and EVs exposing phosphatidylserine after AMI were determined by flow cytometry in 55 patients with the first AMI. LVR was defined as an increase in left ventricular end-diastolic volume by 20% at 6 months after AMI, compared to baseline. Results, baseline concentrations of EVs from endothelial cells, erythrocytes and platelets were lower in patients who developed LVR (p ≤ 0.02 for all). Concentrations of EVs from endothelial cells and erythrocytes were independent LVR predictors (OR 8.2, CI 1.3–54.2 and OR 17.8, CI 2.3–1...
Journal of Clinical Medicine, 2022
Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioven... more Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioventricular accessory pathway (AP). Electroanatomical mapping (EAM) systems are useful during CA of AP, especially for reducing fluoroscopy. There are limited data about the feasibility of CA procedures performed with the use of the EAM system entirely without fluoroscopy in adults with AP. The aim of the study is to assess the feasibility, efficacy and safety of CA with the use of EAM without fluoroscopy, compared to CA with EAM and fluoroscopy in patients with AP. Methods: The study included 83 consecutive patients (age 38.25 ± 15.8 years), who were subjected to CA for AP. In 40 patients CA was performed with the use of EAM without fluoroscopy (EAM group), and in 43 patients CA was performed with EAM and fluoroscopy (control group). Baseline characteristics, procedure parameters and complications were obtained from the medical records. Data on permanent success rate was obtained after the...
Journal of Clinical Medicine, 2021
The epidemiology of myocarditis is unknown and based mainly on small single-centre studies. The s... more The epidemiology of myocarditis is unknown and based mainly on small single-centre studies. The study aimed to evaluate the current incidence, clinical characteristics, management and outcomes of patients hospitalized due to myocarditis in a general population. The study was registered in ClinicalTrials.gov (NCT04827706). The nationwide MYO-PL (the occurrence, trends, management and outcomes of patients with myocarditis in Poland) database (years 2009–2020) was created to identify hospitalization records with a primary diagnosis of myocarditis according to the International Classification of Diseases and Related Health Problems, 10th Revision (ICD 10), derived from the database of the national healthcare insurer. We identified 19,978 patients who were hospitalized with suspected myocarditis for the first time, of whom 74% were male. The standardized incidence rate of myocarditis ranged from 1.15 to 14 per 100,000 people depending on the age group and was the highest in patients aged...
Annals of Biomedical Engineering, 2019
Journal of the American College of Cardiology, Jan 21, 2018
Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Ad... more Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Additionally, the effect of the triggering factors remains elusive. This study compared prognosis between TTS and acute coronary syndrome (ACS) patients and investigated short- and long-term outcomes in TTS based on different triggers. Patients with TTS were enrolled from the International Takotsubo Registry. Long-term mortality of patients with TTS was compared to an age- and sex-matched cohort of patients with ACS. In addition, short- and long-term outcomes were compared between different groups according to triggering conditions. Overall, TTS patients had a comparable long-term mortality risk with ACS patients. Of 1,613 TTS patients, an emotional trigger was detected in 485 patients (30%). Of 630 patients (39%) related to physical triggers, 98 patients (6%) had acute neurologic disorders, while in the other 532 patients (33%), physical activities, medical conditions, or procedures were ...
Postepy w kardiologii interwencyjnej = Advances in interventional cardiology, 2017
Left ventricular hypertrophy (LVH) is a common compensating process in the pressure overload mech... more Left ventricular hypertrophy (LVH) is a common compensating process in the pressure overload mechanism of aortic stenosis (AS). To identify a group of patients with a LVH pattern which may alter periprocedural and 1-year outcomes after transcatheter aortic valve implantation (TAVI). Echocardiographic examinations of 226 patients with severe AS treated with TAVI between March 2010 and February 2016 were retrospectively analysed and correlated with echocardiographic parameters and clinical outcomes in the study group. Ultimately 208 patients were enrolled in the study. Based on left ventricular mass index (LVMI) and relative wall thickness (RWT) patients were divided into three categories: concentric remodelling (CR), concentric hypertrophy (CH) and eccentric hypertrophy (EH). Most of the patients with severe AS referred for TAVI were found to have CH (n = 150, 72.8%), then EH (n = 33, 16%) and CR (n = 16, 7.8%). There were no significant differences between groups in terms of peripro...
Polish Archives of Internal Medicine, 2017
Polish Archives of Internal Medicine, 2012
INTROduCTION Severe functional ischemic mitral regurgitation (FIMR) considerably worsens the prog... more INTROduCTION Severe functional ischemic mitral regurgitation (FIMR) considerably worsens the prognosis of patients after myocardial infarction. The complex pathomechanism of FIMR and its dynamic nature make it difficult to develop effective therapeutic methods. ObjECTIvEs The aim of the study was to prospectively assess a diagnostic strategy based on stress echocardiography in referring patients with severe FIMR for appropriate surgical procedure: coronary artery bypass grafting alone (CABGa) or CABG with mitral annuloplasty (CABGma) or replacement (CABGmr). PATIENTs ANd mEThOds A prospective analysis included 42 patients (23 women, 19 men) aged 67 ±12 years with severe FIMR after myocardial infarction, scheduled for CABG. In each patient, mitral valve morphology, left ventricular function, FIMR degree as assessed by the effective regurgitation orifice area (severe ≥20 mm²), myocardial viability, and mitral deformation indexes were assessed prior to surgery. Based on clinical assessment and rest and stress echocardiography parameters, patients were referred for CABGa (group 1; n = 6), CABGma (group 2; n = 27), or CABGmr (group 3; n = 9). REsuLTs In all study groups, no differences in clinical and echocardiographic results were observed during a 12-month follow-up. A significant improvement was reported in the majority of patients regardless of the surgical procedure. Early (30-day) mortality in the whole study population was 11.9% (n = 5). Survival at 12 months was 100%, 81.5%, and 77.8% for groups 1, 2, and 3, respectively (P = 0.3). In all study groups, a statistically significant FIMR reduction was observed in a 12-month follow-up: small, moderate, and severe FIMR was observed in 29 (83%), 5 (14%), and 1 (3%) surviving patient, respectively. Reverse left ventricular remodeling was observed in 83% of the patients in group 1, 63.7% in group 2, and 100% in group 3 (statistically nonsignificant difference). CONCLusIONs The presented diagnostic strategy, based on stress echocardiography, may facilitate the process of choosing a suitable cardiac surgical procedure for patients with severe FIMR.
Trials, Jan 23, 2017
Approximately 50% of heart failure patients are readmitted to hospital within 6 months, owing to ... more Approximately 50% of heart failure patients are readmitted to hospital within 6 months, owing to deterioration of their condition. Thus, symptomatic treatment of heart failure requires significant improvement. The aim of this study is to compare the effects of torasemide and furosemide on biochemical parameters of haemodynamic and neurohormonal compensation, myocardial remodelling, clinical outcomes and quality of life in patients with chronic heart failure. This is a multicentre, randomized, open, blinded endpoint phase-IV trial. The study includes 120 heart failure patients in NYHA (New York Heart Association) functional class II-IV, treated with optimal heart failure therapy, with indications for use of loop diuretics. At enrolment, patients are stable, with a fixed dose of loop diuretics. Patients are randomized to treatment with furosemide or torasemide (randomization 1:1). After randomization, the current fixed dose of furosemide is continued or is replaced by an equipotential...
Advances in Interventional Cardiology, 2016
Journal of the American College of Cardiology, 2016
nos: 647 760
Cardiology Journal, 1997
W pracy przedstawiono trzy przypadki infekcji i przebicia skory przez zewnątrznaczyniowy odcinek ... more W pracy przedstawiono trzy przypadki infekcji i przebicia skory przez zewnątrznaczyniowy odcinek elektrody do przewleklej stymulacji serca. Wszyscy chorzy byli skutecznie leczeni przez wyciecie zmienionych martwiczo i zapalnie tkanek otaczających elektrode. Postepowanie to bylo poprzedzone kilkudniowym miejscowym i ogolnym leczeniem antybiotykami. Przedstawiony sposob postepowania pozwolil na pozostawienie dotychczasowych ukladow stymulujących bez konieczności ich wymiany.
European Journal of Echocardiography, 2010
Subclinical impairment of LV function in patients with obstructive sleep apnoea HQ Pham, TG v. Lu... more Subclinical impairment of LV function in patients with obstructive sleep apnoea HQ Pham, TG v. Lueder, SK Namtvedt, H Røsjø T. Omland, K Steine Aims: Obstructive sleep apnea (OSA) is associated with obesity, hypertension and heart failure. The aim of the present study was to assess LV function in patients with OSA of mainly moderate severity and no previous diagnosis of heart disease. Methods: 40 consecutive patients with OSA verified by polysomnography (apneahypopnea-index) were compared with 41 voluntary healthy controls. OSA patients were divided into lean (BMI, body-mass-index ≤ 28; "OSA-lean", n ¼ 16) or obese (BMI .28; "OSA-fat", n ¼ 24). LV systolic function was determined using 2D echo including 2D longitudinal global strain recorded from three apical views. LV diastolic function was assessed by the ratio between early diastolic-transmitral Doppler velocity (E) and the septal mitral tissue Doppler imaging velocity (e'). All analyses were performed by one investigator blinded to the study groups. Results: Healthy controls and "OSA-lean" were identical for height and body weight, while "OSA-fat" had greater body weight. "OSA-fat" had lower minimal nocturnal oxygen saturation and greater apnea-hypopnea-index than "OSA-lean". While systolic blood pressure (mmHg) was similar in "OSA-lean" and controls (130+3 and 128+3), it was significantly elevated in "OSA-fat" (141+3). LV dimensions were similar in all three groups, while LV ejection fraction (Simpson) was slightly but significantly lower in both OSA groups. Septal, posterior, and relative wall thickness were all increased in "OSA-lean", and further augmented in "OSA-fat". Peak longitudinal global LV strain values were significantly and similarly reduced in "OSA-lean" (216.0+0.4%) and OSA-fat (215.5+0.5%) compared to controls (218.0+0.3%). Moreover, LV global strain was inversely correlated with apnea-hypopnea-index (R ¼ 0.55; P , 0.00001). E/é ratio was significantly increased in "OSA-fat" (10.1+0.8) as compared to "OSA-lean" (8.4+0.7) and controls (7.7+0.3). Conclusion: The present study demonstrates subclinical impairment of LV systolic and diastolic function in obese asymptomatic patients with OSA as compared to lean OSA patients and controls. Although increased blood pressure might have an impact on our findings, the strong association between systolic 2D strain and the apnoea-hypnoea index indicates decreased oxygen saturation to be of importance for the impairment of LV function in patients with OSA of moderate severity. P968 What is the real diagnostic accuracy of carotid intima-media thickness for the prediction of significant coronary artery disease?
Journal of Clinical Medicine
Background: Increased resting heart rate (RHR) after pulmonary vein isolation (PVI) for treatment... more Background: Increased resting heart rate (RHR) after pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF) is a common observation, possibly resulting from ganglionated plexus modification during ablation. Previous trials have suggested that an increase in RHR after ablation might be related to higher efficacy of the procedure. The aim of this study was to determine whether or not higher increase in RHR after radiofrequency (RF) PVI might predict better long-term outcome of the procedure in a real-life cohort of patients in whom index ablation for paroxysmal AF was performed. Material and methods: The health records of patients who underwent index point-by-point or drag lesion RF PVI for paroxysmal AF in our department between January 2014 and November 2018 were analyzed. Resting heart rate (RHR) was determined from 12-lead ECG recorded prior to the ablation and before discharge to evaluate changes in RHR after PVI. Only patients in sinus rhythm before the procedu...
Biology, 2021
Background, the mechanisms underlying left ventricular remodelling (LVR) after acute myocardial i... more Background, the mechanisms underlying left ventricular remodelling (LVR) after acute myocardial infarction (AMI) remain obscure. In the course of AMI, blood cells and endothelial cells release extracellular vesicles (EVs). We hypothesized that changes in EV concentrations after AMI may underlie LVR. Methods, plasma concentrations of EVs from endothelial cells (CD146+), erythrocytes (CD235a+), leukocytes (CD45+), platelets (CD61+), activated platelets (P-selectin+), and EVs exposing phosphatidylserine after AMI were determined by flow cytometry in 55 patients with the first AMI. LVR was defined as an increase in left ventricular end-diastolic volume by 20% at 6 months after AMI, compared to baseline. Results, baseline concentrations of EVs from endothelial cells, erythrocytes and platelets were lower in patients who developed LVR (p ≤ 0.02 for all). Concentrations of EVs from endothelial cells and erythrocytes were independent LVR predictors (OR 8.2, CI 1.3–54.2 and OR 17.8, CI 2.3–1...
Journal of Clinical Medicine, 2022
Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioven... more Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioventricular accessory pathway (AP). Electroanatomical mapping (EAM) systems are useful during CA of AP, especially for reducing fluoroscopy. There are limited data about the feasibility of CA procedures performed with the use of the EAM system entirely without fluoroscopy in adults with AP. The aim of the study is to assess the feasibility, efficacy and safety of CA with the use of EAM without fluoroscopy, compared to CA with EAM and fluoroscopy in patients with AP. Methods: The study included 83 consecutive patients (age 38.25 ± 15.8 years), who were subjected to CA for AP. In 40 patients CA was performed with the use of EAM without fluoroscopy (EAM group), and in 43 patients CA was performed with EAM and fluoroscopy (control group). Baseline characteristics, procedure parameters and complications were obtained from the medical records. Data on permanent success rate was obtained after the...
Journal of Clinical Medicine, 2021
The epidemiology of myocarditis is unknown and based mainly on small single-centre studies. The s... more The epidemiology of myocarditis is unknown and based mainly on small single-centre studies. The study aimed to evaluate the current incidence, clinical characteristics, management and outcomes of patients hospitalized due to myocarditis in a general population. The study was registered in ClinicalTrials.gov (NCT04827706). The nationwide MYO-PL (the occurrence, trends, management and outcomes of patients with myocarditis in Poland) database (years 2009–2020) was created to identify hospitalization records with a primary diagnosis of myocarditis according to the International Classification of Diseases and Related Health Problems, 10th Revision (ICD 10), derived from the database of the national healthcare insurer. We identified 19,978 patients who were hospitalized with suspected myocarditis for the first time, of whom 74% were male. The standardized incidence rate of myocarditis ranged from 1.15 to 14 per 100,000 people depending on the age group and was the highest in patients aged...
Annals of Biomedical Engineering, 2019
Journal of the American College of Cardiology, Jan 21, 2018
Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Ad... more Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Additionally, the effect of the triggering factors remains elusive. This study compared prognosis between TTS and acute coronary syndrome (ACS) patients and investigated short- and long-term outcomes in TTS based on different triggers. Patients with TTS were enrolled from the International Takotsubo Registry. Long-term mortality of patients with TTS was compared to an age- and sex-matched cohort of patients with ACS. In addition, short- and long-term outcomes were compared between different groups according to triggering conditions. Overall, TTS patients had a comparable long-term mortality risk with ACS patients. Of 1,613 TTS patients, an emotional trigger was detected in 485 patients (30%). Of 630 patients (39%) related to physical triggers, 98 patients (6%) had acute neurologic disorders, while in the other 532 patients (33%), physical activities, medical conditions, or procedures were ...
Postepy w kardiologii interwencyjnej = Advances in interventional cardiology, 2017
Left ventricular hypertrophy (LVH) is a common compensating process in the pressure overload mech... more Left ventricular hypertrophy (LVH) is a common compensating process in the pressure overload mechanism of aortic stenosis (AS). To identify a group of patients with a LVH pattern which may alter periprocedural and 1-year outcomes after transcatheter aortic valve implantation (TAVI). Echocardiographic examinations of 226 patients with severe AS treated with TAVI between March 2010 and February 2016 were retrospectively analysed and correlated with echocardiographic parameters and clinical outcomes in the study group. Ultimately 208 patients were enrolled in the study. Based on left ventricular mass index (LVMI) and relative wall thickness (RWT) patients were divided into three categories: concentric remodelling (CR), concentric hypertrophy (CH) and eccentric hypertrophy (EH). Most of the patients with severe AS referred for TAVI were found to have CH (n = 150, 72.8%), then EH (n = 33, 16%) and CR (n = 16, 7.8%). There were no significant differences between groups in terms of peripro...
Polish Archives of Internal Medicine, 2017
Polish Archives of Internal Medicine, 2012
INTROduCTION Severe functional ischemic mitral regurgitation (FIMR) considerably worsens the prog... more INTROduCTION Severe functional ischemic mitral regurgitation (FIMR) considerably worsens the prognosis of patients after myocardial infarction. The complex pathomechanism of FIMR and its dynamic nature make it difficult to develop effective therapeutic methods. ObjECTIvEs The aim of the study was to prospectively assess a diagnostic strategy based on stress echocardiography in referring patients with severe FIMR for appropriate surgical procedure: coronary artery bypass grafting alone (CABGa) or CABG with mitral annuloplasty (CABGma) or replacement (CABGmr). PATIENTs ANd mEThOds A prospective analysis included 42 patients (23 women, 19 men) aged 67 ±12 years with severe FIMR after myocardial infarction, scheduled for CABG. In each patient, mitral valve morphology, left ventricular function, FIMR degree as assessed by the effective regurgitation orifice area (severe ≥20 mm²), myocardial viability, and mitral deformation indexes were assessed prior to surgery. Based on clinical assessment and rest and stress echocardiography parameters, patients were referred for CABGa (group 1; n = 6), CABGma (group 2; n = 27), or CABGmr (group 3; n = 9). REsuLTs In all study groups, no differences in clinical and echocardiographic results were observed during a 12-month follow-up. A significant improvement was reported in the majority of patients regardless of the surgical procedure. Early (30-day) mortality in the whole study population was 11.9% (n = 5). Survival at 12 months was 100%, 81.5%, and 77.8% for groups 1, 2, and 3, respectively (P = 0.3). In all study groups, a statistically significant FIMR reduction was observed in a 12-month follow-up: small, moderate, and severe FIMR was observed in 29 (83%), 5 (14%), and 1 (3%) surviving patient, respectively. Reverse left ventricular remodeling was observed in 83% of the patients in group 1, 63.7% in group 2, and 100% in group 3 (statistically nonsignificant difference). CONCLusIONs The presented diagnostic strategy, based on stress echocardiography, may facilitate the process of choosing a suitable cardiac surgical procedure for patients with severe FIMR.
Trials, Jan 23, 2017
Approximately 50% of heart failure patients are readmitted to hospital within 6 months, owing to ... more Approximately 50% of heart failure patients are readmitted to hospital within 6 months, owing to deterioration of their condition. Thus, symptomatic treatment of heart failure requires significant improvement. The aim of this study is to compare the effects of torasemide and furosemide on biochemical parameters of haemodynamic and neurohormonal compensation, myocardial remodelling, clinical outcomes and quality of life in patients with chronic heart failure. This is a multicentre, randomized, open, blinded endpoint phase-IV trial. The study includes 120 heart failure patients in NYHA (New York Heart Association) functional class II-IV, treated with optimal heart failure therapy, with indications for use of loop diuretics. At enrolment, patients are stable, with a fixed dose of loop diuretics. Patients are randomized to treatment with furosemide or torasemide (randomization 1:1). After randomization, the current fixed dose of furosemide is continued or is replaced by an equipotential...
Advances in Interventional Cardiology, 2016
Journal of the American College of Cardiology, 2016
nos: 647 760
Cardiology Journal, 1997
W pracy przedstawiono trzy przypadki infekcji i przebicia skory przez zewnątrznaczyniowy odcinek ... more W pracy przedstawiono trzy przypadki infekcji i przebicia skory przez zewnątrznaczyniowy odcinek elektrody do przewleklej stymulacji serca. Wszyscy chorzy byli skutecznie leczeni przez wyciecie zmienionych martwiczo i zapalnie tkanek otaczających elektrode. Postepowanie to bylo poprzedzone kilkudniowym miejscowym i ogolnym leczeniem antybiotykami. Przedstawiony sposob postepowania pozwolil na pozostawienie dotychczasowych ukladow stymulujących bez konieczności ich wymiany.