Publications by authors named "Ondrej Toman"

Introduction: The reduction of fluoroscopic exposure during catheter ablation of supraventricular arrhythmias is widely adopted by experienced electrophysiology physicians with a relatively short learning curve and is becoming the standard of care in many parts of the world. While observational studies in the United States and some parts of Western Europe have evaluated the minimal fluoroscopic approach, there are scarce real-world data for this technique and the generalizability of outcomes in other economic regions.

Method: The AALARA study is a prospective, observational, multicenter, and multinational open-label study.

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Purpose: Variations in the anatomy of pulmonary veins can influence selection of approaches of atrial fibrillation catheter ablation. Therefore, preprocedural evaluation and knowledge of pulmonary veins anatomy is crucial for proper mapping and the successful ablation of atrial fibrillation. The aim of this observational study was to assess CT angiography scans and perform detailed analysis of pulmonary veins morphology in patients scheduled for catheter ablation of atrial fibrillation.

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Three-dimensional angle between the QRS complex and T wave vectors is a known powerful cardiovascular risk predictor. Nevertheless, several physiological properties of the angle are unknown or poorly understood. These include, among others, intra-subject profiles and stability of the angle relationship to heart rate, characteristics of angle/heart-rate hysteresis, and the changes of these characteristics with different modes of QRS-T angle calculation.

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Increases in beat-to-beat variability of electrocardiographic QT interval duration have repeatedly been associated with increased risk of cardiovascular events and complications. The measurements of QT variability are frequently normalized for the underlying RR interval variability. Such normalization supports the concept of the so-called immediate RR effect which relates each QT interval to the preceding RR interval.

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While it is now well-understood that the extent of QT interval changes due to underlying heart rate differences (i.e., the QT/RR adaptation) needs to be distinguished from the speed with which the QT interval reacts to heart rate changes (i.

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Monitoring of QTc interval is mandated in different clinical conditions. Nevertheless, intra-subject variability of QTc intervals reduces the clinical utility of QTc monitoring strategies. Since this variability is partly related to QT heart rate correction, 10 different heart rate corrections (Bazett, Fridericia, Dmitrienko, Framingham, Schlamowitz, Hodges, Ashman, Rautaharju, Sarma, and Rabkin) were applied to 452,440 ECG measurements made in 539 healthy volunteers (259 females, mean age 33.

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Objectives: This first-in-human feasibility study was undertaken to translate the novel low-voltage MultiPulse Therapy (MPT) (Cardialen, Inc., Minneapolis, Minnesota), which was previously been shown to be effective in preclinical studies in terminating atrial fibrillation (AF), into clinical use.

Background: Current treatment options for AF, the most common arrhythmia in clinical practice, have limited success.

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The normal physiologic range of QRS complex duration spans between 80 and 125 ms with known differences between females and males which cannot be explained by the anatomical variations of heart sizes. To investigate the reasons for the sex differences as well as for the wide range of normal values, a technology is proposed based on the singular value decomposition and on the separation of different orthogonal components of the QRS complex. This allows classification of the proportions of different components representing the 3-dimensional representation of the electrocardiographic signal as well as classification of components that go beyond the 3-dimensional representation and that correspond to the degree of intricate convolutions of the depolarisation sequence.

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Chronic myeloid leukemia (CML) is a malignant hematopoietic disorder distinguished by the presence of a BCR‑ABL1 fused oncogene with constitutive kinase activity. Targeted CML therapy by specific tyrosine kinase inhibitors (TKIs) leads to a marked improvement in the survival of the patients and their quality of life. However, the development of resistance to TKIs remains a critical issue for a subset of patients.

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The electrocardiographic (ECG) assessment of the T peak-T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.

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QT interval variability, mostly expressed by QT variability index (QTVi), has repeatedly been used in risk diagnostics. Physiologic correlates of QT variability expressions have been little researched especially when measured in short 10-second electrocardiograms (ECGs). This study investigated different QT variability indices, including QTVi and the standard deviation of QT interval durations (SDQT) in 657,287 10-second ECGs recorded in 523 healthy subjects (259 females).

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On standard electrocardiogram (ECG) PQ interval is known to be moderately heart rate dependent, but no physiologic details of this dependency have been established. At the same time, PQ dynamics is a clear candidate for non-invasive assessment of atrial abnormalities including the risk of atrial fibrillation. We studied PQ heart rate dependency in 599 healthy subjects (aged 33.

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To facilitate the precision of clinical electrocardiographic studies of J-to-Tpeak (JTp) and Tpeak-to-Tend (Tpe) intervals, the study investigated their differences between healthy females and males, and between subjects of African and Caucasian origin. In 523 healthy subjects (254 females; 236 subjects of African origin), repeated Holter recordings were used to measure QT, JT, JTp, and Tpe intervals preceded by both stable and variable heart rates. Subject-specific curvilinear regression models were used to obtain individual QTc, JTc, JTpc and Tpec intervals.

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Sex differences are known in several facets of cardiac electrophysiology, mostly concerning myocardial repolarisation. In this study, heart rate and heart rate variability (HRV) responses to postural provocations were compared in 175 and 176 healthy females and males, respectively (aged 33.1 ± 9.

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Aims: Optimal ECG monitoring in detecting recurrences of atrial fibrillation (AF) or atrial tachycardia (AT) after catheter ablation has not been well established. The purpose of this prospective study was to compare the utility of daily ECG monitoring with episodic card recorder (ECR) vs. periodic monitoring with episodic loop recorder (ELR) for the detection of post-blanking AF/AT recurrences during early (Months 4-6) and late (Months 7-12) periods after catheter ablation for paroxysmal AF.

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Aims: Identifying patients who benefit from restored sinus rhythm (SR) would optimize the selection of candidates for ablation of long-standing persistent atrial fibrillation (LSPAF). This prospective study sought to identify the hitherto unknown factors associated with global functional improvement after successful radiofrequency catheter ablation of LSPAF.

Methods And Results: In 171 LSPAF patients (84% of the total consecutive 203 patients) who were examined in SR 12 months after ablation, the individual per cent change from baseline value in maximum oxygen consumption at exercise test (VO2 max), left ventricular ejection fraction (LVEF), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five-dimensional descriptive system (EQ-5D) of quality-of-life questionnaire were classified in quartiles by 0 (worse) to 3 (best) grades.

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Aims: The study investigated healthy subjects to study sex and race differences in QRS durations and the dependency of QRS durations on heart rates and other physiologic correlates.

Methods And Results: QRS duration and its heart rate dependency were evaluated in 420 615 electrocardiograms obtained in 523 healthy subjects including 111 females of African origin, 130 Caucasian females, 125 males of African origin, and 129 Caucasian males. The distributions of QRS/RR slopes and QRS durations at RR intervals of 1 and 0.

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Objectives: Neutrophil gelatinase-associated lipocalin (NGAL) from a pathophysiological perspective connects various pathways that affect the prognosis after myocardial infarction. The objective was to evaluate the benefits of measuring NGAL for prognostic stratification in addition to the Thrombolysis in Myocardial Infarction (TIMI) score, and to compare it with the prognostic value of B-type natriuretic peptide (BNP).

Design: Prospective observational cohort study.

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Aim: To compare the prognostic accuracy of six scoring models for up to three-year mortality and rates of hospitalisation due to acute decompensated heart failure (ADHF) in STEMI patients.

Methods And Results: A total of 593 patients treated with primary PCI were evaluated. Prospective follow-up of patients was ≥3 years.

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Background: The impact of restoring sinus rhythm (SR) by initial ablation in patients with long-standing persistent atrial fibrillation (LSPAF) is not fully established.

Objective: The purpose of this study was to investigate the prognostic value of SR restoration at the initial procedure and arrhythmia noninducibility at the final repeat procedure for long-term outcome.

Methods: A total of 203 patients (22% female; age 59 ± 9 years) underwent stepwise catheter ablation for LSPAF.

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Background: Pre-infarction unstable angina pectoris (UAP) can be considered ischemic preconditioning. The aim of this study was to compare short and long term outcomes in patients with or without pre-infarction UAP and ST elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

Methods: 593 patients with STEMI (388 without and 205 with UAP) were evaluated.

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Aims: Clinical benefit from ablation for long-standing persistent atrial fibrillation has remained unknown. We hypothesized that successful ablation of long-standing persistent atrial fibrillation would improve haemodynamics, functional status, and quality of life.

Methods And Results: A total of 160 patients (aged 59 ± 9 years, 23% females) undergoing ablation of long-standing (median of 28 months) persistent atrial were enrolled in this prospective study.

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Aims: Tissue inhibitors of metalloproteinase (TIMPs) bind to active matrix metalloproteinase (MMPs), and thereby inhibit their proteolytic activity. We investigated the role of polymorphisms in the gene for TIMP-1 and serum levels of TIMP-1 in association with postmyocardial infarction (MI), left ventricular (LV) dysfunction, and symptoms of acute heart failure (AHF) in patients treated with primary percutaneous coronary intervention.

Methods: In total, 556 patients with STEMI were evaluated.

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Background: Antiarrhythmic properties of statins were suggested as a part of their pleiotropic effects. The aim of the present study was to evaluate the effects of atorvastatin on myocardial repolarization as manifested on surface electrocardiograms (ECGs) in healthy subjects.

Methods And Results: Forty young healthy volunteers (20 men, 20 women) underwent a single-dose double-blind 3-way crossover study of 20 and 80 mg of atorvastatin and placebo.

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Background: We evaluated the associations among angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism, ACE activity and post-myocardial infarction (MI) left ventricular dysfunction and acute heart failure (AHF) early after presentation with MI with ST-segment elevation (STEMI).

Methods: A total of 556 patients with STEMI treated by primary PCI (421 patients without AHF and 135 patients with AHF) were the study population. The activity of BNP, NT-ProBNP and ACE were measured at hospital admission and 24 h after MI onset.

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