INTRODUCTION: Left bundle branch area pacing (LBBAP) comprises pacing at the left ventricular septum (LVSP) or left bundle branch (LBBP). The aim of the present study was to investigate the differences in ventricular electrical heterogeneity between LVSP, LBBP, right ventricular pacing (RVP) and intrinsic conduction with different dyssynchrony measures using the ECG, vectorcardiograpy, ECG belt, and Ultrahigh frequency (UHF-)ECG. METHODS: Thirty-seven patients with a pacemaker indication for bradycardia or cardiac resynchronization therapy underwent LBBAP implantation. ECG, vectorcardiogram, ECG belt and UHF-ECG signals were recorded during RVP, LVSP and LBBP, and intrinsic activation. QRS duration (QRSd) was measured from the ECG, QRS area was calculated from the vectorcardiogram, LV activation time (LVAT) and standard deviation of activation time (SDAT) from ECG belt and electrical dyssynchrony (e-DYS16) from UHF-ECG. RESULTS: Both LVSP and LBBP significantly reduced ventricular electrical heterogeneity as compared to underlying LBBB and RV pacing in terms of QRS area (p < .001), SDAT (p < .001), LVAT (p < .001) and e-DYS16 (p < .001). QRSd was only reduced as compared to RV pacing(p < .001). QRS area was similar during LBBP and normal intrinsic conduction, e-DYS16 was similar during LVSP and normal intrinsic conduction, whereas SDAT was similar for LVSP, LBBP and normal intrinsic conduction. For all these variables there was no significant difference between LVSP and LBBP. CONCLUSION: Both LVSP and LBBP resulted in a more synchronous LV activation than LBBB and RVP. Especially LBBP resulted in levels of LV synchrony comparable to normal intrinsic conduction.

• MeSH
• akční potenciály * MeSH
• blokáda Tawarova raménka patofyziologie   terapie   diagnóza   MeSH
• bradykardie patofyziologie   terapie   diagnóza   MeSH
• časové faktory MeSH
• elektrofyziologické techniky kardiologické MeSH
• elektrokardiografie MeSH
• funkce levé komory srdeční * MeSH
• Hisův svazek * patofyziologie   MeSH
• kardiostimulace umělá * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezikomorová přepážka * patofyziologie   MeSH
• prediktivní hodnota testů * MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční frekvence * MeSH
• srdeční resynchronizační terapie MeSH
• vektorkardiografie * metody   MeSH
• výsledek terapie 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
• srovnávací studie MeSH

BACKGROUND: Although cardiac resynchronization therapy (CRT) is beneficial in heart failure patients with left bundle branch block, 30% of these patients do not respond to the therapy. Identifying these patients before implantation of the device is one of the current challenges in clinical cardiology. METHODS: We verified the diagnostic contribution and an optimized computerized approach to measuring ventricular electrical activation delay (VED) from body surface 12-lead ECGs. We applied the method to ECGs acquired before implantation (baseline) in the MADIT-CRT trial (Multicenter Automatic Defibrillator Implantation-Cardiac Resynchronization Therapy). VED values were dichotomized using its quartiles, and we tested the association of VED values with the MADIT-CRT primary end point of heart failure or death. Multivariate Cox proportional models were used to estimate the risk of study end points. In addition, the association between VED values and hemodynamic changes after CRT-D implantation was examined using 1-year follow-up echocardiograms. RESULTS: Our results showed that left bundle branch block patients with baseline VED <31.2 ms had a 35% risk of MADIT-CRT end points, whereas patients with VED ≥31.2 ms had a 14% risk (P<0.001). The hazard ratio for predicting primary end points in patients with low VED was 2.34 (95% confidence interval, 1.53-3.57; P<0.001). Higher VED values were also associated with beneficial hemodynamic changes. These strong VED associations were not found in the right bundle branch block and intraventricular conduction delay cohorts of the MADIT-CRT trial. CONCLUSIONS: Left bundle branch block patients with a high baseline VED value benefited most from CRT, whereas left bundle branch block patients with low VED did not show CRT benefits.

• MeSH
• akční potenciály * MeSH
• blokáda Tawarova raménka diagnóza   mortalita   patofyziologie   terapie   MeSH
• časové faktory MeSH
• defibrilátory implantabilní * MeSH
• elektrická defibrilace škodlivé účinky   přístrojové vybavení   mortalita   MeSH
• elektrokardiografie * MeSH
• klinické rozhodování MeSH
• lidé středního věku MeSH
• lidé MeSH
• multicentrické studie jako téma MeSH
• obnova funkce MeSH
• prediktivní hodnota testů MeSH
• randomizované kontrolované studie jako téma MeSH
• retrospektivní studie MeSH
• senioři MeSH
• srdeční frekvence MeSH
• srdeční resynchronizační terapie * škodlivé účinky   mortalita   MeSH
• srdeční selhání diagnóza   mortalita   patofyziologie   terapie   MeSH
• výběr pacientů 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
• práce podpořená grantem MeSH

INTRODUCTION: Cardiac resynchronization therapy (CRT) is an effective treatment that reduces mortality and improves cardiac function in patients with left bundle branch block (LBBB). However, about 30% of patients passing the current criteria do not benefit or benefit only a little from CRT. Three predictors of benefit based on different ECG properties were compared: 1) "strict" left bundle branch block classification (SLBBB); 2) QRS area; 3) ventricular electrical delay (VED) which defines the septal-lateral conduction delay. These predictors have never been analyzed concurrently. We analyzed the relationship between them on a subset of 602 records from the MADIT-CRT trial. METHODS & RESULTS: SLBBB classification was performed by two experts; QRS area and VED were computed fully automatically. High-frequency QRS (HFQRS) maps were used to inspect conduction abnormalities. The correlation between SLBBB and other predictors was R = 0.613, 0.523 and 0.390 for VED, QRS area in Z lead, and QRS duration, respectively. Scatter plots were used to pick up disagreement between the predictors. The majority of SLBBB subjects- 295 of 330 (89%)-are supposed to respond positively to CRT according to the VED and QRS area, though 93 of 272 (34%) non-SLBBB should also benefit from CRT according to the VED and QRS area. CONCLUSION: SLBBB classification is limited by the proper setting of cut-off values. In addition, it is too "strict" and excludes patients that may benefit from CRT therapy. QRS area and VED are clearly defined parameters. They may be used to optimize biventricular stimulation. Detailed analysis of conduction irregularities with CRT optimization should be based on HFQRS maps.

• MeSH
• akční potenciály MeSH
• blokáda Tawarova raménka patofyziologie   terapie   MeSH
• elektrická defibrilace MeSH
• elektrokardiografie metody   normy   MeSH
• funkce levé komory srdeční MeSH
• lidé MeSH
• prediktivní hodnota testů MeSH
• prostředky srdeční resynchronizační terapie normy   MeSH
• srdeční frekvence MeSH
• srdeční resynchronizační terapie metody   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AIMS: The aim of this study was to characterize ventricular activation patterns in normal and connexin40-deficient mice in order to dissect the role of connexin40 in developing the conduction system. METHODS AND RESULTS: We performed optical mapping of epicardial activation between ED9.5-18.5 and analysed ventricular activation patterns and times of left ventricular activation. Mouse embryos deficient for connexin40 were compared with normal and heterozygous littermates. Morphology of the primary interventricular ring (PIR) was delineated with the help of T3-LacZ transgene. Four major types of ventricular activation patterns characterized by primary breakthrough in different parts of the heart were detected during development: PIR, left ventricular apex, right ventricular apex, and dual right and left ventricular apices. Activation through PIR was frequently present at the early stages until ED12.5. From ED14.5, the majority of hearts showed dual left and right apical breakthrough, suggesting functionality of both bundle branches. Connexin40-deficient embryos showed initially a delay in left bundle branch function, but the right bundle branch block, previously described in the adults, was not detected in ED14.5 embryos and appeared only gradually with 80% penetrance at ED18.5. CONCLUSION: The switch of function from the early PIR conduction pathway to the mature apex to base activation is dependent upon upregulation of connexin40 expression in the ventricular trabeculae. The early function of right bundle branch does not depend on connexin40. Quantitative analysis of normal mouse embryonic ventricular conduction patterns will be useful for interpretation of effects of mutations affecting the function of the cardiac conduction system.

• MeSH
• akční potenciály MeSH
• blokáda Tawarova raménka genetika   metabolismus   MeSH
• gestační stáří MeSH
• Hisův svazek embryologie   metabolismus   MeSH
• konexiny nedostatek   genetika   MeSH
• lac operon MeSH
• morfogeneze MeSH
• myši knockoutované MeSH
• myši transgenní MeSH
• myši MeSH
• penetrance MeSH
• převodní systém srdeční embryologie   metabolismus   MeSH
• srdeční komory embryologie   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zobrazování pomocí barviva citlivého na potenciál MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

INTRODUCTION: The present study introduces a new ultra-high-frequency 14-lead electrocardiogram technique (UHF-ECG) for mapping ventricular depolarization patterns and calculation of novel dyssynchrony parameters that may improve the selection of patients and application of cardiac resynchronization therapy (CRT). METHODS: Components of the ECG in sixteen frequency bands within the 150 to 1000 Hz range were used to create ventricular depolarization maps. The maximum time difference between the UHF QRS complex centers of mass of leads V1 to V8 was defined as ventricular electrical dyssynchrony (e-DYS), and the duration at 50% of peak voltage amplitude in each lead was defined as the duration of local depolarization (Vd). Proof of principle measurements was performed in seven patients with left (left bundle branch block) and four patients with right bundle branch block (right bundle branch block) before and during CRT using biventricular and His-bundle pacing. RESULTS: The acquired activation maps reflect the activation sequence under the tested conditions. e-DYS decreased considerably more than QRS duration, during both biventricular pacing (-50% vs -8%) and His-bundle pacing (-77% vs -13%). While biventricular pacing slightly increased Vd, His-bundle pacing reduced Vd significantly (+11% vs -36%), indicating the contribution of the fast conduction system. Optimization of biventricular pacing by adjusting VV-interval showed a decrease of e-DYS from 102 to 36 ms with only a small Vd increase and QRS duration decrease. CONCLUSIONS: The UHF-ECG technique provides novel information about electrical activation of the ventricles from a standard ECG electrode setup, potentially improving the selection of patients for CRT and application of CRT.

• MeSH
• akční potenciály MeSH
• blokáda Tawarova raménka diagnóza   patofyziologie   terapie   MeSH
• časové faktory MeSH
• elektrokardiografie * MeSH
• funkce levé komory srdeční MeSH
• funkce pravé komory srdeční MeSH
• Hisův svazek patofyziologie   MeSH
• lidé MeSH
• ověření koncepční studie MeSH
• prediktivní hodnota testů MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• srdeční frekvence * MeSH
• srdeční resynchronizační terapie * MeSH
• srdeční selhání diagnóza   patofyziologie   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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: Inflorescences of wheat species, spikes, are characteristically unbranched and bear one sessile spikelet at a spike rachis node. Development of supernumerary spikelets (SSs) at rachis nodes or on the extended rachillas is abnormal. Various wheat morphotypes with altered spike morphology, associated with the development of SSs, present an important genetic resource for studies on genetic regulation of wheat inflorescence development. RESULTS: Here we characterized diploid and tetraploid wheat lines of various non-standard spike morphotypes, which allowed for identification of a new mutant allele of the WHEAT FRIZZY PANICLE (WFZP) gene that determines spike branching in diploid wheat Ttiticum monococcum L. Moreover, we found that the development of SSs and spike branching in wheat T. durum Desf. was a result of a wfzp-A/TtBH-A1 mutation that originated from spontaneous hybridization with T. turgidum convar. сompositum (L.f.) Filat. Detailed characterization of the false-true ramification phenotype controlled by the recessive sham ramification 2 (shr2) gene in tetraploid wheat T. turgidum L. allowed us to suggest putative functions of the SHR2 gene that may be involved in the regulation of spikelet meristem fate and in specification of floret meristems. The results of a gene interaction test suggested that genes WFZP and SHR2 function independently in different processes during spikelet development, whereas another spike ramification gene(s) interact(s) with SHR2 and share(s) common functions. CONCLUSIONS: SS mutants represent an important genetic tool for research on the development of the wheat spikelet and for identification of genes that control meristem activities. Further studies on different non-standard SS morphotypes and wheat lines with altered spike morphology will allow researchers to identify new genes that control meristem identity and determinacy, to elucidate the interaction between the genes, and to understand how these genes, acting in concert, regulate the development of the wheat spike.

• MeSH
• květy růst a vývoj   MeSH
• meristém růst a vývoj   MeSH
• pšenice genetika   růst a vývoj   MeSH
• regulace genové exprese u rostlin genetika   fyziologie   MeSH
• rostlinné geny genetika   fyziologie   MeSH
• vývojová regulace genové exprese genetika   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Conduction system pacing (CSP) is being increasingly adopted as a more physiological alternative to right ventricular and biventricular pacing. Since the 2021 European Society of Cardiology pacing guidelines, there has been growing evidence that this therapy is safe and effective. Furthermore, left bundle branch area pacing was not covered in these guidelines due to limited evidence at that time. This Clinical Consensus Statement provides advice on indications for CSP, taking into account the significant evolution in this domain.

• MeSH
• akční potenciály MeSH
• kardiologie * normy   MeSH
• kardiostimulace umělá * normy   škodlivé účinky   metody   MeSH
• konsensus MeSH
• lidé MeSH
• převodní systém srdeční * patofyziologie   MeSH
• společnosti lékařské MeSH
• srdeční arytmie * terapie   patofyziologie   diagnóza   MeSH
• srdeční frekvence MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• směrnice pro lékařskou praxi MeSH
• Geografické názvy
• Evropa MeSH

Syndrom vlny J je soubor klinických znaků charakterizovaných časnou repolarizací, elevací úseků ST a zobrazením vlny J na EKG, což je způsobeno přechodnou akcentací draslíkového kanálu Ito. Rizika náhlé smrti se u těchto syndromů liší s ohledem na velikost a lokalizaci vlny J i na výraznost elevace úseku ST. Vrozené formy syndromu vlny J zahrnují syndrom časné repolarizace, který lze rozdělit na tři podtypy podle lokalizace vlny J a rizika arytmogeneze a na syndrom Brugadových. Syndrom vlny J se může objevit za určitých patologických podmínek, např. při hypotermii nebo při akutním infarktu myokardu s elevacemi úseků ST. V článku je podán přehled klinických, iontových a elektrokardiografi ckých pohledů na syndrom vlny J.

J wave syndrome is a complex of clinical features characterized by early repolarization, ST segment elevation and J wave – mediated by transient accentuation of the potassium outward current Ito. The risks of sudden cardiac death of these syndromes diff er with respect to the magnitude and location of abnormal J wave manifestation and ST segment elevation. The congenital forms of J wave syndromes include early repolarization, which can be divided into three subtypes according to J wave location and the risk of arrhythmogenesis, and the Brugada syndrome. Acquired forms of J wave syndrome can occur due to some pathological conditions like hypothermia or acute myocardial infarction with ST segment elevation. The article presents the review of clinical, ionic and ECG aspects of J wave syndromes.

• Klíčová slova
• draslíkový kanál Ito, časná repolarizace, elevace úseků ST, akutní infarkt myokardu, syndrom vlny J, Osbornova vlna,
• MeSH
• akční potenciály genetika   účinky léků   MeSH
• akutní nemoc MeSH
• antiarytmika MeSH
• Brugadův syndrom MeSH
• diferenciální diagnóza MeSH
• draslíkové kanály MeSH
• echokardiografie MeSH
• fibrilace komor MeSH
• hypotermie MeSH
• infarkt myokardu MeSH
• lidé MeSH
• náhlá srdeční smrt MeSH
• převodní systém srdeční abnormality   účinky léků   MeSH
• srdeční arytmie klasifikace   patofyziologie   MeSH
• syndrom MeSH
• Check Tag
• lidé MeSH

The present study proposed procedure for predicting an optimal left and right ventricular pacing interval delay (V-V interval). In 16 patients (heart failure, left bundle branch block, biventricular pacing) two methods (A and B) identifying optimal V-V interval were tested. Method A: predicted optimal V-V interval A (POVVA) = electromechanical delay of the segment paced by left ventricle lead minus electromechanical delay of the segment paced by right ventricle lead. Method B: predicted optimal V-V interval B (POVV-B) = difference in the onset of aortic and pulmonary flows. Both methods were validated using echocardiography and right-sided heart catheterization. Cardiac output during POVV-A (4.6 l.min-1) was significantly better than that during POVV-A minus 20 ms (4.3 l.min-1, p<0.01) and POVVA plus 20 ms (4.3 l.min-1, p<0.01), and than that during POVV-B (4.4 l.min-1, p<0.05). LV dP/dt during POVV-A (818 mm Hg.s-1) exceeded that during POVV-A plus 20 ms (717 mm Hg.s-1, p<0.05) and POVV-A minus 20 ms (681 mm Hg.s-1, p<0.05), and that during POVV-B (727 mm Hg.s-1, p<0.01). The time difference in onsets of myocardial deformation of left ventricle segment paced by the left ventricle and right ventricle lead allows identifying the optimal V-V interval and improves left ventricle performance.

• Klíčová slova
• Biventricular pacing, Inter-ventricular asynchrony, Intraventricular asynchrony, V-V interval, Cardiac resynchronization therapy,
• MeSH
• akční potenciály MeSH
• časové faktory MeSH
• dospělí MeSH
• financování organizované MeSH
• funkce levé komory srdeční MeSH
• kardiostimulace umělá metody   MeSH
• komorový tlak (srdce) MeSH
• lidé středního věku MeSH
• lidé MeSH
• minutový srdeční výdej MeSH
• převodní systém srdeční patofyziologie   MeSH
• pulzní dopplerovská echokardiografie MeSH
• reprodukovatelnost výsledků MeSH
• senioři MeSH
• srdeční katetrizace MeSH
• srdeční selhání patofyziologie   terapie   ultrasonografie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH