INTRODUCTION: A variable proportion of non-responders to cardiac resynchronization therapy (CRT) warrants the search for new approaches to optimize the position of the left ventricular (LV) lead and the CRT device programming. CineECG is a novel ECG modality proposed for the spatial visualization and quantification of myocardial depolarization and repolarization sequences. OBJECTIVE: The present study aimed to evaluate CineECG-derived parameters in different pacing modes and to test their associations with acute hemodynamic responses in CRT patients. METHODS AND RESULTS: CineECG was used to construct the average electrical path within the cardiac anatomy from the 12-lead ECG. CineECG and LV dP/dt max were tested in 15 patients with nonischemic dilated cardiomyopathy and left bundle branch block (QRS: 170 ± 17 ms; LVEF: 26 ± 5.5%) under pacing protocols with different LV lead localizations. The CineECG-derived path directions were computed for the QRS and ST-T intervals for the anteroposterior (Xh), interventricular (Yh), and apicobasal (Zh) axes. In a multivariate linear regression analysis with adjustment for the pacing protocol type, the ST-T path direction Yh was independently associated with the increase in dP/dt max during CRT, [regression coefficient 639.4 (95% confidence interval: 187.9-1090.9), p = 0.006]. In ROC curve analysis, the ST-T path direction Yh was associated with the achievement of a 10% increase in dP/dt max (AUC: 0.779, p = 0.002) with the optimal cut-off > 0.084 (left-to-right direction) with sensitivity 0.67 and specificity 0.92. CONCLUSION: The acute hemodynamic response in CRT patients was associated with specific CineECG repolarization sequence parameters, warranting their further testing as potential predictors of clinical outcomes.

• MeSH
• akční potenciály MeSH
• blokáda Tawarova raménka * patofyziologie   terapie   diagnóza   MeSH
• časové faktory MeSH
• dilatační kardiomyopatie patofyziologie   terapie   diagnóza   MeSH
• elektrokardiografie * MeSH
• funkce levé komory srdeční * MeSH
• hemodynamika * MeSH
• lidé středního věku MeSH
• lidé MeSH
• prediktivní hodnota testů * MeSH
• prostředky srdeční resynchronizační terapie MeSH
• senioři MeSH
• srdeční frekvence MeSH
• srdeční resynchronizační terapie * MeSH
• srdeční selhání patofyziologie   terapie   diagnóza   MeSH
• tepový objem MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Diabetes mellitus (DM) causes myocardial electrical remodeling and promotes ventricular tachycardia and/or fibrillation (VT/VF). However, experimental studies have been frequently unsuccessful in developing a DM model with the expected high level of arrhythmic outcomes. The present study aims at evaluating cardiac electrophysiological properties in the rats with different Type 1 DM (T1DM) durations and identifying an electrophysiological phenotype associated with the high incidence of VT/VF. METHODS: The experiments were performed in 109 male Wistar rats (6-10 weeks old), subdivided into the groups of control, 4-weeks and 8-weeks T1DM (streptozotocin model). The animals were studied with epicardial electrophysiological mapping, whole-cell patch-clamp and histological examination. The VT/VF susceptibility was tested in ischemia/reperfusion induced in the anesthetized animals. RESULTS: In the 4-weeks T1DM group, we observed the increase in the incidence of reperfusion VT/VF, collagen deposition and dispersion of repolarization, slowed longitudinal and transverse conduction velocity, prolonged action potential duration, increased INa and ICaL currents, nonchanged Ito and IK1 currents. In the 8-weeks T1DM group, the VT/VF incidence, dispersion of repolarization, INa and Ito currents decreased. Other parameters persisted unchanged as compared to the 4-weeks T1DM group. CONCLUSIONS: Relatively early (4 weeks) diabetic electrical remodeling was proarrhythmic and included augmentation of sodium and calcium currents in the presence of fibrosis and slowed conduction and increased dispersion of repolarization. An unexpected finding was that diabetic arrhythmogenesis was associated with the increase in depolarizing transmembrane currents. Further research is warranted to elucidate molecular mechanisms and test the potential for the control of observed changes.

• MeSH
• diabetes mellitus 1. typu * komplikace   patofyziologie   MeSH
• experimentální diabetes mellitus patofyziologie   komplikace   MeSH
• fibrilace komor patofyziologie   MeSH
• komorová tachykardie patofyziologie   etiologie   MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• potkani Wistar * MeSH
• remodelace komor MeSH
• srdeční arytmie patofyziologie   etiologie   MeSH
• srdeční komory patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Continuous deep septal pacing and signal recording during implantation of left bundle branch pacing (LBBP) lead enables to monitor beat-to-beat changes of electrocardiogram (ECG) and myocardial current of injury (COI) as the lead crosses the septum. OBJECTIVES: This study aimed to characterize patterns of continuous QRS, ST-T, and COI change for monitoring of the lead depth and instantaneous determination of the obtained capture type (LBBP vs left ventricular septal pacing [LVSP]). METHODS: The ECG and COI during lead implantation were scrutinized for sudden changes of V6 R-wave peak time, V1 initial and terminal R-wave amplitude, V3-V6 R-wave amplitude, repolarization pattern and S-wave amplitude in I, V5-V6, and COI drop. The sudden and gradual transition patterns were diagnosed depending on the presence or absence of the above beat-to-beat ECG phenomena, respectively. RESULTS: A total of 212 pacemaker recipients were analyzed; LBBP and LVSP were obtained in 77.4% and 22.6%, respectively. There were 4.7 ± 2.1 and 0.2 ± 0.6 beat-to-beat phenomena in LBBP and LVSP patients, respectively. The sudden transition pattern, recognized in 80.7%, had sensitivity and specificity for LBBP diagnosis of 98.8% and 81.2%, respectively. A sudden drop of COI (29.4 ± 8.5 mV to 12.8 ± 4.9 mV) was observed in 53.9% patients (LBBP was simultaneously obtained in 92.7%). CONCLUSIONS: Capture of left bundle branch during lead penetration is a beat-to-beat phenomenon. Two transseptal transition patterns were identified: 1) sudden, which is typical for obtaining LBBP; and 2) gradual, which is typical for obtaining LVSP. A sudden COI drop, a very observable phenomenon, also identified reaching the left subendocardial area.

• MeSH
• blokáda Tawarova raménka patofyziologie   terapie   MeSH
• elektrokardiografie * MeSH
• Hisův svazek patofyziologie   MeSH
• kardiostimulace umělá metody   MeSH
• kardiostimulátor MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční septum patofyziologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

V současné době nejsou známa rozmezí normálních hodnot QT intervalu pro konkrétní věkové skupiny v dětství a pubertě. V rámci tohoto projektu budou u dětí a adolescentů provedeny kontinuální 12-svodové elektrokardiografické záznamy v průběhu standardizovaných posturálních autonomních provokačních testů. V těchto záznamech bude provedena analýza již dříve ověřeného souboru ukazatelů a charakteristik morfologie a heterogenity repolarizace. Tak budou stanoveny věkově a pohlavně specifické normy pro QT/RR závislost a související korekční matematické vzorce s cílem zpřesnění časné diagnózy abnormalit QT intervalu a dalších souvisejících repolarizačních patologií.; Presently, sex-specific normality limits of QT interval are not known for different age-groups of children and adolescents. In this project continuous, 12-lead electrocardiographic monitoring will be performed in children and adolescents during standardised postural autonomic provocations. A previously verified battery of repolarization morphology indices and of repolarization heterogeneity characteristics will be investigated. The project will establish age- and sex-related normative QT/RR patterns and corresponding heart rate correction formulae to serve more accurate early diagnosis of QT interval abnormalities and of repolarization-related pathologies.

• Klíčová slova
• děti, children, adolescenti, adolescents, repolarizace, pohlavně závislé rozdíly, QT interval, repolarization, sex-related differences, QT interval,

• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Celosvětově se vyskytující zoonotická onemocnění jako brucelóza zvyšují mortalitu na onemocnění srdce i výskyt maligních arytmií. Variabilita srdeční frekvence (heart rate variability, HRV) se měří neinvazivně se spolehlivým výsledkem. Nižší hodnoty HRV ukazují na autonomní dysfunkci. K detekci komorových arytmií se používají poměry intervalu Tp-e/QT (QT) a korigovaného QT (QTc). Cíl: U pacientů s brucelózou jsme zkoumali vztah mezi autonomní dysfunkcí a repolarizací komor (ventricular repolarization, VR). Hodnocení se provádělo neinvazivně měřením parametrů HRV a VR. Metody: Do studie bylo zařazeno 100 pacientů s brucelózou; jejich průměrný věk byl 39,2 ± 1,1 roku. Kontrolní skupinu srovnatelného věku a poměru obou pohlaví tvořilo 100 zdravých dobrovolníků průměrného věku 44,3 roku. Vypočítávali a zaznamenávali jsme hodnoty Tp-e, QT a QTc i poměr Tp-e/QTc stejně jako hodnoty HRV. Výsledky: Pacienti s brucelózou měli značně vyšší hodnoty QTmax , QTcmax , QTmin a QTcmin než kontroly. Poměry rozptylu hodnot Tp-e, cTp-e, Tp-e/QTc a Tp-e byly statisticky významně vyšší u pacientů s brucelózou než u kontrolních jedinců (80,2 ± 4,4 a 73,8 ± 5,4; p < 0,001, resp. 87,5 ± 6,2 a 82,6 ± 7,8; p = 0,001, 0,20 ± 0,01 a 0,21 ± 0,01; p = 0,004 a 29,4 ± 11,9 a 21,7 ± 10,2). U pacientů s brucelózou byly nalezeny vyšší poměry LF/ HF během dne a během noci (p < 0,001). Poměry LF/HF během dne a během noci příznivě korelovaly s hodnotami Tpe_cQT (r = 0,700; p < 0,001, resp. r = 0,746; p < 0,001). Závěry: Při elektrokardiografickém vyšetření měli pacienti s brucelózou delší intervaly Tp-e a vyšší poměry QT i QTc. U pacientů s brucelózou byly zjištěny jisté známky zvýšené HRV včetně poměru LF/HF. Byla prokázána příznivá korelace hodnot LF/HF a Tp-e/QTc. Brucelóza může působit subklinické postižení srdce a autonomní dysfunkci. Tito pacienti vyžadují důslednější screening komorových arytmií.

Background: Global zoonotic diseases like brucellosis increase cardiac mortality and malignant arrhythmias. Heart rate variability (HRV) measures heart rate non-invasively and reliably. Lower HRV suggests autonomic dysfunction. The Tp-e/QT interval (QT) and corrected QT (QTc) ratios are used to detect ventricular arrhyth- mogenesis. Objective: In brucellosis, we examined the relationship between autonomic dysfunction and ventricular repolarization (VR). This was done noninvasively by assessing HRV and VR parameters. Methods: One hundred patients with brucellosis had a mean age of 39.2±1.1 years. One hundred healthy volunteers with a mean age of 44.3 years made up the control group, which was age and sex matched. We calculated and recorded Tp-e, QT, QTc, and Tp-e/QTc, as well as HRV values. Results: Brucellosis patients had considerably greater QTmax, QTcmax, QTmin, and QTcmin than controls. Tp-e, cTp-e, Tp-e/QTc, and Tp-e dispersion ratios were significantly greater in brucellosis patients compared to the control group (80.2±4.4 and 73.8±5.4, p <0.001; 87.5±6.2 and 82.6±7.8, p = 0.001; 0.20±0.01 and 0.21±0.01, p = 0.004; 29.4±11.9 and 21.7±10.2. Patients with brucellosis had greater LF/HF ratios during daylight and overnight (p <0.001). Daytime and nighttime LF/HF ratios were favourably linked with Tpe_cQT (r = 0.700, p <0.001, and r = 0.746, p <0.001, respectively). Conclusions: On electrocardiography, brucellosis patients had longer Tp-e intervals, QT ratios, and QTc ratios. Brucellosis patients had increased HRV traits, including the LF/HF ratio. LF/HF and Tp-e/QTc correlated favourably. Brucellosis may cause subclinical cardiac engagement and autonomic dysfunction. These pa- tients need more ventricular arrhythmia screening.

• MeSH
• brucelóza * komplikace   MeSH
• dospělí MeSH
• elektrokardiografie metody   MeSH
• kardiovaskulární nemoci etiologie   MeSH
• lidé MeSH
• nemoci autonomního nervového systému * etiologie   komplikace   MeSH
• srdeční arytmie etiologie   komplikace   MeSH
• srdeční frekvence * MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH

Rozdíl os komplexu QRS a vlny T (frontal QRS-T angle, fQRSTa) je elektrokardiografický parametr odrážející prostorový vztah mezi vektory depolarizace a repolarizace v srdci; určují jej úhly mezi vektory QRS a vlnou T ve frontální rovině. Širší fQRSTa je obecně spojován se zvýšenou komorovou ektopickou aktivitou, poruchou funkce levé komory a zvýšeným rizikem kardiovaskulárních onemocnění (KVO); podle několika studií je širší QRSTa spojen se zvýšeným rizikem rozvoje KVO včetně infarktu myokardu, srdečního selhání a náhlé srdeční smrti. Celkově lze z dostupných důkazů usuzovat, že fQRSTa je užitečný marker kardiovaskulárního rizika a může mít značný význam pro prevenci a léčbu KVO. Poznání vztahu mezi QRSTa a KVO si nicméně vyžádá další výzkum, který zároveň pomůže stanovit optimální využití tohoto ukazatele v klinické praxi.

The frontal QRS-T angle is an electrocardiographic measurement that reflects the spatial relationship between the depolarization and repolarization vectors in the heart. It is determined by the angles between the QRS and T wave vectors in the frontal plane. A wider QRS-T angle is associated with increased ventricular ectopic activity, impaired left ventricular function, and increased risk of cardiovascular diseases (CVDs). Several studies have suggested that a wider frontal QRS-T angle is associated with an increased risk of developing CVDs, including myocardial infarction, heart failure, and sudden cardiac death. Overall, the evidence suggests that the frontal QRS-T angle is a useful marker of CV risk and may have important clinical implications for the prevention and management of CVDs. However, further research is needed to fully understand the relationship between the QRS-T angle and CVD, and to determine the optimal use of this marker in clinical practice.

• Klíčová slova
• Úhel QRS-T,
• MeSH
• diagnostické techniky kardiovaskulární MeSH
• elektrokardiografie * metody   MeSH
• kardiovaskulární nemoci diagnostické zobrazování   etiologie   MeSH
• lidé MeSH
• náhlá srdeční smrt etiologie   prevence a kontrola   MeSH
• srdce patofyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

AIMS: Little is known about patients with right bundle branch block (RBBB)-ventricular tachycardia (VT) and arrhythmogenic cardiomyopathy (ACM). Our aims were: (i) to describe electrocardiogram (ECG) characteristics of sinus rhythm (SR) and VT; (ii) to correlate SR with RBBB-VT ECGs; and (iii) to compare VT ECGs with electro-anatomic mapping (EAM) data. METHODS AND RESULTS: From the European Survey on ACM, 70 patients with spontaneous RBBB-VT were included. Putative left ventricular (LV) sites of origin (SOOs) were estimated with a VT-axis-derived methodology and confirmed by EAM data when available. Overall, 49 (70%) patients met definite Task Force Criteria. Low QRS voltage predominated in lateral leads (n = 37, 55%), but QRS fragmentation was more frequent in inferior leads (n = 15, 23%). T-wave inversion (TWI) was equally frequent in inferior (n = 28, 42%) and lateral (n = 27, 40%) leads. TWI in inferior leads was associated with reduced LV ejection fraction (LVEF; 46 ± 10 vs. 53 ± 8, P = 0.02). Regarding SOOs, the inferior wall harboured 31 (46%) SOOs, followed by the lateral wall (n = 17, 25%), the anterior wall (n = 15, 22%), and the septum (n = 4, 6%). EAM data were available for 16 patients and showed good concordance with the putative SOOs. In all patients with superior-axis RBBB-VT who underwent endo-epicardial VT activation mapping, VT originated from the LV. CONCLUSIONS: In patients with ACM and RBBB-VT, RBBB-VTs originated mainly from the inferior and lateral LV walls. SR depolarization and repolarization abnormalities were frequent and associated with underlying variants.

• MeSH
• blokáda Tawarova raménka MeSH
• elektrokardiografie MeSH
• kardiomyopatie * komplikace   diagnóza   MeSH
• komorová tachykardie * etiologie   komplikace   MeSH
• lidé MeSH
• srdeční komory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: Antiviral drugs are considered as potentially cardiotoxic, due to prolongation of QT interval which may affect incidence of severe ventricular arrhythmias. The main aim of this retrospective study was to assess the influence of treatment by three antiviral drugs on QT interval and to find patients who are at an increased risk of developing malignant ventricular arrhythmias. METHODS: The study included 23 patients (14 men, 9 women) who were treated with a combination of interferon alpha, ribavirin, and an NS3/4A protease inhibitor. The parameters from the 12 leads electrocardiograms were evaluated before treatment, and then 3 ± 1 and 6 ± 1 months after treatment. RESULTS: Heart rate (HR) 69 ± 12 / min and corrected QT interval (QTc) 412 ± 35 ms were obtained before the treatment and there was not observed a significant prolongation of intervals after 3 months (HR 72 ± 11 / min, QTc 412 ± 33 ms) and after 6 months (HR 64 ± 12 / min, QTc 405 ± 28 ms) respectively. In total QTc interval was prolonged from the baseline in 53% and in 43% of the patients 3 months respectively 6 months after treatment. A QTc prolongation over of 450 ms and new treatment-related repolarization change was noted in 1 (4%) patient. CONCLUSION: The study demonstrates that a combination therapy of 3 antiviral drugs does not significantly prolong the QTc interval and does not cause severe pathological changes on the ECG. Patients undergoing this treatment are not at risk of developing heart disease as an undesirable side effect.

• MeSH
• antivirové látky škodlivé účinky   MeSH
• chronická hepatitida C * farmakoterapie   MeSH
• elektrokardiografie MeSH
• hepatitida C * farmakoterapie   MeSH
• lidé MeSH
• retrospektivní studie MeSH
• srdeční arytmie MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: Antiviral drugs are considered as potentially cardiotoxic, due to prolongation of QT interval which may affect incidence of severe ventricular arrhythmias. The main aim of this retrospective study was to assess the influence of treatment by three antiviral drugs on QT interval and to find patients who are at an increased risk of developing malignant ventricular arrhythmias. METHODS: The study included 23 patients (14 men, 9 women) who were treated with a combination of interferon alpha, ribavirin, and an NS3/4A protease inhibitor. The parameters from the 12 leads electrocardiograms were evaluated before treatment, and then 3 ± 1 and 6 ± 1 months after treatment. RESULTS: Heart rate (HR) 69 ± 12 / min and corrected QT interval (QTc) 412 ± 35 ms were obtained before the treatment and there was not observed a significant prolongation of intervals after 3 months (HR 72 ± 11 / min, QTc 412 ± 33 ms) and after 6 months (HR 64 ± 12 / min, QTc 405 ± 28 ms) respectively. In total QTc interval was prolonged from the baseline in 53% and in 43% of the patients 3 months respectively 6 months after treatment. A QTc prolongation over of 450 ms and new treatment-related repolarization change was noted in 1 (4%) patient. CONCLUSION: The study demonstrates that a combination therapy of 3 antiviral drugs does not significantly prolong the QTc interval and does not cause severe pathological changes on the ECG. Patients undergoing this treatment are not at risk of developing heart disease as an undesirable side effect.

• MeSH
• antivirové látky škodlivé účinky   MeSH
• chronická hepatitida C * farmakoterapie   MeSH
• elektrokardiografie MeSH
• hepatitida C * farmakoterapie   MeSH
• lidé MeSH
• retrospektivní studie MeSH
• srdeční arytmie MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. METHODS AND RESULTS: Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7. CONCLUSION: In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

• MeSH
• elektrokardiografie metody   MeSH
• fenotyp MeSH
• hodnocení rizik MeSH
• hypertrofická kardiomyopatie * komplikace   diagnóza   MeSH
• lidé MeSH
• náhlá srdeční smrt * epidemiologie   etiologie   MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH