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Zbigniew Kalarus

Publications and source records attributed to Zbigniew Kalarus.

At least 19 recordsLinked to original sources
PubMed2006

Current developments in microvolt T-wave alternans.

Microvolt T-wave alternans (MTWA), the beat-to-beat fluctuation in T wave amplitude and morphology, is closely linked to vulnerability to ventricular arrhythmias in various experimental and clinical conditions. Clinically, MTWA is most commonly measured using the spectral method, although non-spectral methods for its assessment from ambulatory electrocardiographical recordings also have been developed. Recent studies suggest that the quantitative assessment of TWA may also be clinically relevant. The standardisation of the criteria for abnormal MTWA test still needs to be completed. The expansion of indications for implantable cardioverter-defibrillator (ICD) therapy following the positive results of the MADIT-II and SCD-HeFT trials might have unacceptable economic and medical consequences, and therefore new tests are needed to better discriminate patients who will and will not benefit from ICD implantation. A recent meta-analysis of MTWA studies revealed an overall positive predictive value for arrhythmic events of 19.3%, negative predictive value of 97.2%, and 3.77% univariate relative risk of arrhythmic events. The negative predictive value of MTWA in MADIT-II type patients has been reported to be 97.5%. The predictive value of the test varied significantly in different patient population. Current data support the use of MTWA testing for evaluation of patients with low ejection fraction who are considered for ICD implantation. The independence of the prognostic value of MTWA from other clinical and electrophysiological variables needs further confirmation.

Journal Article↗
PubMed2006

Coronary sinus stenting for the stabilization of left ventricular lead during resynchronization therapy.

We report on two patients treated with cardiac resynchronization therapy, in whom early (intra-operatively, 64-year-old man) and late (4 months post-operatively, 57-year-old woman) instability of the left ventricular (LV) lead occurred. In order to stabilize the electrodes, stents were deployed in both patients within the coronary sinus, into the space between the lead and the wall of the vein effectively pinning the lead to the wall. During 3 and 5 months of follow-up, the electrodes remained stable and allowed for successful resynchronization in both cases. Stenting within the coronary sinus seems to be a safe method for LV lead stabilization, which can substantially increase the success rate of resynchronization therapy. This new approach, although promising, has to prove its safety and should not be practised routinely until long-term follow-up data are available.

Cardiac Pacing, Artificial↗
PubMed2006

Effect of percutaneous interventions within the coronary sinus on the success rate of the implantations of resynchronization pacemakers.

BACKGROUND: Cardiac resynchronization therapy (CRT) becomes a "gold standard" in therapy of selected patients with advanced heart failure. We set out to evaluate the feasibility and safety of percutaneous interventions within coronary sinus (CS) and their effect on the success rate of left ventricular (LV) lead implantation during CRT. METHODS: The study analyzed eight consecutive patients with the indications for CRT, who needed additional procedures within CS to overcome technical problems during left ventricular (LV) electrode implantation. The analyzed group consisted of three subgroups: patients in whom percutaneous balloon angioplasty within CS was needed (n = 4); patients with acute instability of the lead, requiring stenting of the vein to fix the electrode (n = 2); and patients with the stenting of CS due to late dislocation of the lead (n = 2). Success rate, procedure duration, fluoroscopy, complications, and electrical parameters of leads were analyzed. RESULTS: Success rate of the procedures was 87.5%; additional interventions increased overall efficacy of CRT implantation at our center from 88% to 98% (P < 0.05). Procedure duration (155.0 minute) and fluoroscopy time (42.5 minute) remained acceptable for the patient and operator; however, both were higher than in the procedures performed routinely in our hospital. Electrical properties of the LV leads were stable and within normal ranges during the observation period. We noted two local dissections of CS during the procedure, which remained clinically silent. CONCLUSION: Percutaneous interventions within CS seem to be feasible and safe treatment options, which can improve the short- and long-term success rates of CRT.

Adult↗
PubMed2006

Use of the LocaLisa mapping system during ablation procedures in patients with atrioventricular nodal reentrant tachycardia.

INTRODUCTION: LocaLisa is a novel system for anatomical mapping. It enables an assessment of the three-dimensional position of electrodes within cardiac chambers without fluoroscopy. With this technique it may be possible to reduce radiation exposure during catheter-based ablation procedures. AIM: To evaluate the efficacy and safety of ablation procedures performed using the LocaLisa mapping system in patients with atrioventricular nodal reentrant tachycardia (AVNRT). METHODOLOGY: This study evaluated the course of the first 26 ablations performed using the LocaLisa system (studied group). The control group involved 30 consecutive patients with AVNRT treated with the conventional ablation technique that was routinely used prior to the introduction of the novel system into clinical practice. RESULTS: In the studied group procedural duration was 72.4+/-24.9 minutes, in the control group 80.1+/-18.2 minutes (NS). However, radiation exposure was significantly lower in the examined group -- 74.4+/-109.2 mGy compared to 184.8+/-59.9 mGy in the control group (p <0.05). All procedures were successful. No complications related to the ablation were observed. CONCLUSIONS: Employment of the LocaLisa mapping system enables the reduction of fluoroscopic exposure without any decrease of efficacy or elevation of risk of any complications during AVNRT ablations.

Body Surface Potential Mapping↗
PubMed2006

Electrophysiologic parameters suggesting significant acute cellular rejection of the transplanted heart.

AIM OF THE STUDY: Was to estimate an influence of acute cellular rejection on electrophysiologic parameters of allograft and remnants of recipient's heart, in patients after orthotopic heart transplantation (OHT). PATIENTS AND METHODS: Analysis was performed in 25 OHT recipients (24M/1F, age 48.4 +/- 9 y., ischemic time 197 +/- 51 min., donor age 30 +/- 9 y.), who underwent electrophysiological study (EPS), along with elective endomyocardial biopsy (EMB), scheduled for the 1st month after the surgery. Results of EPS were correlated with a degree of rejection, assessed with the ISHLT grading system. Grades > or =3A were considered a significant cellular rejection. RESULTS: ISHLT grade 0 was observed in 8 patients, grade 1A or 1B in 12 patients, and 3A in 5 patients. Frequency of transplanted heart rhythm (TH-R) was 691.3+/- 37 ms in patients with ISHLT grade 0, 690.4 +/- 41 ms in patients with grade 1A or 1B, and 744.4 +/- 668 ms in individuals with 3A rejection (p < 0.04, for difference between 0 and 3A groups). Intraatrial conduction time (IntrtaCT) was significantly shorter in grade 3A group (20.4 +/- 1.6 ms), when compared with patients without rejection (36.2 +/- 4.9 ms, p < 0.03), or with 1A or 1B rejection (41.5 +/- 13 ms, p < 0.032). Also interatrial conduction time (InterCT) was the shortest in patients with 3A rejection (53.8 +/- 4.3 ms), when compared with ISHLT grade 0 group (78.5 +/- 7.6 ms, p < 0.02) and 1A/1B group (74.1 +/- 12 ms, p < 0.023). The other characteristics of atria, ventricles and AV-junction performance were comparable in all patients. CONCLUSIONS: TH-R, IntraCT and InterCT should be considered as the markers of significant cellular rejection in patients after OHT. Further analysis involving higher number of patients is warranted.

Acute Disease↗
PubMed2006

Radio-frequency ablation of arrhythmias following congenital heart surgery.

BACKGROUND: Cardiac arrhythmias as a late complication following congenital heart surgery are encountered more and more frequently in clinical practice. The use of new electrophysiological methods of visualisation and mapping improves the efficacy of radio-frequency (RF) ablation of these arrhythmias. AIM: To assess patterns of atrial arrhythmias following congenital heart surgery and to examine the efficacy of RF ablation using the electro-anatomical CARTO system. METHODS: Electrophysiological diagnostic study and RF ablation were performed in 24 consecutive patients (mean age 36+/-18 years) who had atrial arrhythmias following congenital heart surgery. The mechanism of arrhythmia (ectopic or reentrant) and strategy of RF ablation procedure were based on the results of the right atrial map performed during index arrhythmia. RESULTS: The patients were divided into five groups according to the type of congenital heart surgery. The ASD group consisted of 17 patients who had undergone in the past surgery due to atrial septal defect, four patients had a history of surgery due to ventricular septal defect (VSD group), and one patient each had undergone surgery due to corrected transposition of the great arteries (ccTGA), tetralogy of Fallot (TF) or dual-outflow right ventricle (DORV). During diagnostic electrophysiological study typical atrial flutter (AFL) was diagnosed in nine patients from the ASD group, atypical AFL in three ASD patients, and ectopic atrial tachycardia (EAT) in six ASD patients. In one patient EAT was induced after ablation of typical AFL. Of the VSD patients, three had atypical AFL, and one had typical AFL. The patient following surgery for ccTGA had atypical AFL and EAT, whereas in the two remaining patients (DORV and TF) atypical AFL was demonstrated. The efficacy of the first session of RF ablation was 83% and no complications were observed. The efficacy of RF ablation of typical AFL was 90%, atypical AFL 78%, and EAT 86% (NS). During the long-term follow-up (24+/-17 months) arrhythmia recurrences were noted in 2 (10%) out of 20 patients who were effectively treated during the first RF ablation session. CONCLUSIONS: Reentry is the most common electrophysiological mechanism of incisional tachycardias, followed by ectopic atrial tachycardia. RF ablation using the electro-anatomical CARTO system is effective and safe in this group of patients.

Adult↗
PubMed2006

[Isolated non-compaction of the left ventricular myocardium in a neonate--a case report].

We describe a case of a neonate who developed cardiogenic shock 24 days after birth. Echocardiography revealed congenital anomaly--isolated non-compaction of the left ventricular myocardium. Medical treatment was effective. The whole clinical presentation suggests the Barth syndrome. The diagnosis and treatment of this condition are discussed.

Antihypertensive Agents↗
PubMed2005

Methods of assessment and clinical relevance of QT dynamics.

The dependence on heart rate of the QT interval has been investigated for many years and several mathematical formulae have been proposed to describe the QT interval/heart rate (or QT interval/RR interval) relationship. While the most popular is Bazett's formula, it overcorrects the QT interval at high heart rates and under-corrects it at slow heart rates. This formulae and many others similar ones, do not accurately describe the natural behaviour of the QT interval. The QT interval/RR interval relationship is generally described as QT dynamics. In recent years, several methods of its assessment have been proposed, the most popular of which is linear regression. An increased steepness of the linear QT/RR slope correlates with the risk of arrhythmic death following myocardial infarction. It has also been demonstrated that the QT interval adapts to heart rate changes with a delay (QT hysteresis) and that QT dynamics parameters vary over time. New methods of QT dynamics assessment that take into account these phenomena have been proposed. Using these methods, changes in QT dynamics have been observed in patients with advanced heart failure, and during morning hours in patients with ischemic heart disease and history of cardiac arrest. The assessment of QT dynamics is a new and promising tool for identifying patients at increased risk of arrhythmic events and for studying the effect of drugs on ventricular repolarisation.

Journal Article↗
PubMed2005

Circadian and sex-dependent QT dynamics.

The dynamic QT relationship between the QT and RR intervals in normal individuals, including sex differences, has not been well examined. The aim of this Holter monitor-based study was to assess circadian and sex-related variations in QT dynamics in healthy subjects. The study population consisted of 50 healthy volunteers (mean age = 32 +/- 6 years, 25 men), in whom 24-hour digital Holter monitoring and QT interactive, beat-by-beat analyses were performed. The mean lengths of QT and RR intervals were measured from the 24-hour recordings. In order to assess QT dynamics, QT/RR linear regression was performed, and the slope was calculated over 24 hour and for day and night periods, and both genders separately. In the whole population, the mean QT interval was 356.5 +/- 19.2 ms and RR interval was 785.9 +/- 80.7 ms. The mean value of the slope over 24 hour was 0.17 +/- 0.03, though significantly steeper during the day (0.13 +/- 0.03) than at night (0.09 +/- 0.03, P < 0.001). The analysis of QT/RR dynamics over 24 hour revealed a significantly steeper slope in women (0.18 +/- 0.03) than in men (0.16 +/- 0.03, P = 0.006), as well as during daytime (0.14 +/- 0.03 vs 0.12 +/- 0.03, P = 0.04). Circadian variations and sex differences were observed in QT dynamics. The latter may explain the greater susceptibility of women to torsades de pointes during treatment with drugs that prolong repolarization.

Adolescent↗
PubMed2005

Effectiveness of radiofrequency catheter ablation of right ventricular outflow tract tachycardia using the CARTO system.

BACKGROUND: Ventricular ectopy or ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) are the most common forms of arrhythmias in patients with structurally normal heart. Pharmacological treatment is effective in no more than 50% of patients, whereas radio-frequency catheter ablation (RFCA) offers a much higher success rate. AIM: To assess early and late outcome in patients with RVOT arrhythmias treated with RFCA combined with electro-anatomical mapping system (CARTO). METHODS: The study group consisted of 34 consecutive patients (mean age 38.8+/-12.0 years, range 21-52 years, 11 males, 23 females) with symptomatic arrhythmias originating from RVOT, who underwent RFCA in our department between December 2001 to July 2003. RFCA was performed with the use of the CARTO system. The power of RF current was set at 40 Watts, duration -- 90 seconds, and maximal temperature -- 55 degrees C. In order to assess short- and long-term RFCA efficacy, a 24-hour Holter ECG monitoring was performed before RFCA and shortly after the procedure as well as one and three months afterwards. Effective RFCA was defined as the reduction of ventricular ectopy <1000 / 24 hours in Holter monitoring performed just after the procedure. RESULTS: Holter ECG monitoring performed after RFCA showed that the procedure was effective in 30 (88.2%) patients. In the remaining four patients no significant reduction in the frequency of ventricular ectopy was noted, however, no complex ventricular arrhythmias were present. In none of the patients neither early nor late complications were observed. The mean follow-up duration was 15.6 months (range 5-26 months). During Holter ECG monitoring performed one and three months after RFCA, a recurrence of frequent ventricular ectopy (7139 beats / 24 hours) was found in one patient, however, without complex arrhythmias. The remaining patients, in whom RFCA was found to be effective at Holter ECG monitoring performed just after the procedure, continue to be free from arrhythmia and do not require antiarrhythmic agents. CONCLUSIONS: RFCA with the use of the CARTO system is effective and safe in the treatment of arrhythmias originating from RVOT.

Adult↗
PubMed2005

Radiofrequency ablation of typical atrial flutter with the use of electro-anatomical mapping system CARTO.

BACKGROUND: Radiofrequency (RF) ablation of typical atrial flutter (AFL) is a well-established method of treatment. Although its efficacy is high, a search for new, more effective techniques is continuing. These new methods include modern systems for electro-anatomical mapping and new types of ablating electrodes such as cooled-tip or dual-sensor catheters. AIM: To assess the efficacy of RF ablation of typical AFL with the use of electro-anatomical mapping system CARTO and to compare the effectiveness of various ablating catheters. METHODS: The study group consisted of 60 consecutive patients who underwent RF ablation of typical AFL with the use of the CARTO system. In 35 patients standard ablating electrodes were used, in 15 -- cooled-tip catheters (Thermo-Cool), and in 10 -- Dual-Sensor catheters. RESULTS: Overall efficacy of RF ablation was 96.6%. In two procedures which occurred ineffective, standard ablating electrodes were used. In 4 (6.6%) patients a recurrence of AFL was noted -- also these patients had RF ablation performed with the use of standard ablating electrodes. None of the patients had procedure-related complications. CONCLUSIONS: RF ablation of typical AFL with the use of electro-anatomical system CARTO is effective, safe and associated with reduced fluoroscopy time. The use of cooled-tip or dual sensor ablating electrodes further enhances efficacy of the procedure.

Aged↗
PubMed2005

[Holter monitoring in the prognosis of sudden cardiac death--new experiences and possibilities].

Sudden cardiac death is a great problem of nowadays. Patients suffer from coronary artery disease, myocarditis, dilated and hypertrophic cardiomyopathy, congenital and acquired heart diseases have a higher risk of sudden cardiac death. Holter monitoring allows to estimate the sudden cardiac death risk by risk factors analysis. We estimate arrhythmias, presence of ischaemia, QT interval, heart rate variability. Moreover, the event Holter is a useful method of searching the cause of syndromes which do not appear every single day.

Death, Sudden, Cardiac↗
PubMed2005

[Femoral artery pseudoaneurysms: treatment with ultrasound guided thrombin injection in 28 patients].

INTRODUCTION: Femoral artery pseudoaneurysms (PSA) develop in 0.2-8% patients undergoing procedures that require femoral artery cannulation. Ultrasound guided thrombin injection has been described as successful and safe alternative to ultrasound guided compression and surgical treatment. AIM OF THE STUDY: Assessment of efficacy and safety of PSA treatment with USGTI. METHODS: 28 patients (pts) (18 female, mean age 64.6 +/- 11.4) with femoral pseudoaneurysms developed due to coronary angiogram or percutaneous coronary angioplasty were treated with ultrasound guided thrombin injection. 24 PSAs arose from right common femoral artery, 3 from right superficial femoral artery, and 1 from left common femoral artery. 24 patients were receiving antiplatelet and 4 anticoagulation therapy at the time of the procedure. With ultrasound guidance, a 21Gx11/2 needle was placed into pseudoaneurysm lumen followed by thrombin injection (1074 +/- 473 U). No complications of the procedure were observed. In 24-hour observation USGTI was successful in 28 (100%) patients. However, in 7-day follow-up resolution of 1 PSA was found, which reduced efficacy rate to 96.3%. CONCLUSIONS: Ultrasound guided thrombin injection is a successful, safe and well tolerated method of pseudoaneurysms treatment. Neither antiplatelet nor anticoagulation therapy affects success rate of the method.

Aged↗
PubMed2004

[Cost-effectiveness of coronary angioplasty procedures in Poland].

BACKGROUND: Restenosis following percutaneous coronary interventions (PCI) increases re-hospitalisation rate and may lead to new myocardial infarction (MI) or death. Besides medical aspects, it may also reduce cost-effectiveness of the procedure. AIM: To analyse the medical and economical outcome of patients treated with PCI during a one year period. METHODS: Medical outcome, cost of PCI and total cost of treatment during one year after PCI were assessed in 188 consecutive patients who underwent PCI during the first three months of 2002. Patients with acute MI treated with PCI were not included in the analysis. RESULTS: The rate of major adverse cardiac events (MACE) which included death, new MI or repeated revascularisation, was 1.6% during hospital stay and 14.4% during one-year follow-up. Re-hospitalisation rate was 28.2%. The mean number of outpatient visits during one year was 9.8. The costs of initial hospitalisation and procedures performed during this hospital stay were 7,839 Polish zlotys (PLN) per patient whereas the costs during one-year follow-up were 3,490 PLN (re-hospitalisations and repeated procedures 3,091 PLN, outpatient visits 238 PLN, and pharmacotherapy costs 161 PLN). In the group of patients with MACE, the costs of treatment during one-year follow-up were 13,398 PLN whereas in patients without complications 1,349 PLN per patient. CONCLUSIONS: Patients who develop complications after PCI generate costs exceeding ten times that of patients with a favourable outcome. Thus, from the economical and medical point of view, there is a need to identify high-risk patients before the decision is made as to which type of treatment is used. Because the health service in Poland is under-funded, patients at risk should be treated with the most effective methods (antiproliferative stents or surgical revascularisation) as an initial treatment, which may decrease total costs during a long-term period.

Aged↗
PubMed2004

Percutaneous coronary interventions in patients with transplanted heart coronary artery disease. Effects of intracoronary stent implantation on long-term results.

BACKGROUND: Transplanted heart coronary artery disease (TxCAD) is the most frequent casue of death occuring > or =5 years after orthotopic heart transplantation (OHT). Considering three basic therapeutic approaches - percutaneous coronary intervention (PCI), surgical revascularisation and retransplantation - PCI seems to be the superior method due to its safety and good short-term results, however, the long-term efficacy of PCI has been less well established. AIM: To evaluate long-term results of PCI in the treatment of OHT recipients with TxCAD. METHODS: The study group consisted of 20 patients (19 males, aged 24-63, median 45.5 years; 14 (70%) had before OHT), who underwent single or multiple PCI of significant coronary lesions, revealed by elective (n=17) or urgent (n=3) coronary angiography (CAG). The overall number of PCI procedures was 26, including 8 with stent implantation. procedures were performed 9-151 (median 61.5) months after OHT. Analysis of PCI results was based on the follow-up CAGs or autopsy in case of death. RESULTS: Follow-up time was 3-90 (median 28) months. At least one CAG was performed in 17 (85%) patients - the overall number of follow-up CAGs was 53. Progression of TxCAD was revealed by 33 (62%) CAGs - the decision to perform subsequent single or multiple PCI was undertaken in 22 (42%) patients. The overall number of re-PCI procedures was 38 (with stent implantation in 11 cases). Out of 38 PCI procedures without stent implantation, significant restenosis was found on control CAG in 16 (42%) patients, and out of 16 PCI with stents -- in 11 (69%) patients, including 8 haemodynamically significant lesions. TxCAD was the cause of 5 out of 9 deaths that occurred during follow-up. CONCLUSIONS: PCI is unable to stop TxCAD development in the majority of patients. Stent implantation does not improve long-term results of TxCAD treatment.

Adult↗