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
• Action Potentials MeSH
• Bundle-Branch Block diagnosis   physiopathology   therapy   MeSH
• Time Factors MeSH
• Electrocardiography * MeSH
• Ventricular Function, Left MeSH
• Ventricular Function, Right MeSH
• Bundle of His physiopathology   MeSH
• Humans MeSH
• Proof of Concept Study MeSH
• Predictive Value of Tests MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Heart Rate * MeSH
• Cardiac Resynchronization Therapy * MeSH
• Heart Failure diagnosis   physiopathology   therapy   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

AIMS: To assess the influence of gender on the course of rocuronium-induced neuromuscular block following a single bolus dose of 2 x ED(95) (0.6 mg kg(-1)). METHODS: Following the ethics committee approval and informed consent, 245 patients (121 men, 124 women) scheduled for elective general surgery under TIVA with muscle relaxation were studied. After rocuronium 0.6 mg kg(-1), the onset time for maximal depression of T(1), clinical duration until 25 % recovery and recovery index (T(1) from 25 to 75 %) were determined with TOF-Watch SX accelerometric monitor. The data for male and female groups were compared with appropriate statistical tests (Student's unpaired t-test, Mann-Whitney Rank Sum Test and Fisher's exact test). RESULTS: Men were significantly larger (p < 0.001) and heavier (p < 0.05) than women, but the body mass index was comparable (ns). The onset time was shorter in females [92.5 (SD 14.2) vs. 104.7 (12.2) s, p < 0.0001]. Clinical duration was increased in females [43.1 (7.9) vs. 31.3 (5.5) min; p < 0.0001], while the recovery index was identical in both groups [14.7 (5.0) min in females and 14.8 (4.0) min in males; ns]. CONCLUSIONS: Women are more sensitive than men to the dose 0.6 mg kg(-1) of rocuronium. Under the study conditions described, the onset time was shortened and the clinical duration increased in female patients. This suggests that the routine dose of rocuronium should be reduced in women.

• MeSH
• Androstanols pharmacology   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Neuromuscular Nondepolarizing Agents pharmacology   MeSH
• Neuromuscular Blockade MeSH
• Neuromuscular Junction physiology   MeSH
• Synaptic Transmission drug effects   MeSH
• Sex Characteristics MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Compared to the natural electrical activation of the myocardium through the His-Purkinje system, right ventricular pacing is associated with prolonged QRS complex duration, thereby impeding the synchronicity of contractions. In left ventricular pacing, a higher pacing voltage decreases the QRS complex duration. The aim of our study was to describe the relation between the right ventricular pacing voltage and the QRS complex duration. Fourteen patients (73.6 +/- 7.6 years) with AV block and implanted pacemakers were paced at a frequency of 100 bpm with various pacing voltages. A signal-averaged QRS vector length was calculated at each degree of pacing voltage. The changes in the QRS complex duration were measured as a relative shift of the terminal region of the vectorcardiographic QRS complex (end-shift) and its most prominent peak (peak-shift) using the cross-correlation method. The nonlinear relationship between stimulation voltage and QRS duration was observed with the highest impact of stimulation voltage changes near the threshold value. The fourfold increase in the stimulation voltage above the threshold caused QRS complex shortening by 3.7 +/- 2.1 ms (range 0.19-7.76 ms). Similar peak- and end-shift responses to altered stimulation energy demonstrated that the acceleration of depolarization occurred in the initial portion of the QRS complex. Older electrodes exhibited smaller and more linear changes in the QRS complex duration.

• MeSH
• Ventricular Function, Right MeSH
• Cardiac Pacing, Artificial MeSH
• Middle Aged MeSH
• Humans MeSH
• Models, Cardiovascular MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Vectorcardiography MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Nonselective His-bundle pacing (nsHBp), nonselective left bundle branch pacing (nsLBBp), and left ventricular septal myocardial pacing (LVSP) are recognized as physiological pacing techniques. OBJECTIVE: The purpose of this study was to compare differences in ventricular depolarization between these techniques using ultra-high-frequency electrocardiography (UHF-ECG). METHODS: In patients with bradycardia, nsHBp, nsLBBp (confirmed concomitant left bundle branch [LBB] and myocardial capture), and LVSP (pacing in left ventricular [LV] septal position without proven LBB capture) were performed. Timings of ventricular activations in precordial leads were displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Duration of local depolarization (Vd) was determined as width of the UHF-QRS complex at 50% of its amplitude. RESULTS: In 68 patients, data were collected during nsLBBp (35), LVSP (96), and nsHBp (55). nsLBBp resulted in larger e-DYS than did LVSP and nsHBp [- 24 ms (-28;-19) vs -12 ms (-16;-9) vs 10 ms (7;14), respectively; P <.001]. nsLBBp produced similar values of Vd in leads V5-V8 (36-43 ms vs 38-43 ms; P = NS in all leads) but longer Vd in leads V1-V4 (47-59 ms vs 41-44 ms; P <.05) as nsHBp. LVSP caused prolonged Vd in leads V1-V8 compared to nsHBp and longer Vd in leads V5-V8 compared to nsLBBp (44-51 ms vs 36-43 ms; P <.05) regardless of R-wave peak time in lead V5 or QRS morphology in lead V1 present during LVSP. CONCLUSION: nslbbp preserves physiological LV depolarization but increases interventricular electrical dyssynchrony. LV lateral wall depolarization during LVSP is prolonged, but interventricular synchrony is preserved.

• MeSH
• Bundle-Branch Block physiopathology   therapy   MeSH
• Electrocardiography methods   MeSH
• Ventricular Function, Left physiology   MeSH
• Bundle of His physiopathology   MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Humans MeSH
• Ventricular Septum physiopathology   MeSH
• Follow-Up Studies MeSH
• Prospective Studies MeSH
• Aged MeSH
• Heart Ventricles physiopathology   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

Background: Three different ventricular capture types are observed during left bundle branch pacing (LBBp). They are selective LBB pacing (sLBBp), non-selective LBB pacing (nsLBBp), and myocardial left septal pacing transiting from nsLBBp while decreasing the pacing output (LVSP). Study aimed to compare differences in ventricular depolarization between these captures using ultra-high-frequency electrocardiography (UHF-ECG). Methods: Using decremental pacing voltage output, we identified and studied nsLBBp, sLBBp, and LVSP in patients with bradycardia. Timing of ventricular activations in precordial leads was displayed using UHF-ECGs, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. The durations of local depolarizations (Vd) were determined as the width of the UHF-QRS complex at 50% of its amplitude. Results: In 57 consecutive patients, data were collected during nsLBBp (n = 57), LVSP (n = 34), and sLBBp (n = 23). Interventricular dyssynchrony (e-DYS) was significantly lower during LVSP -16 ms (-21; -11), than nsLBBp -24 ms (-28; -20) and sLBBp -31 ms (-36; -25). LVSP had the same V1d-V8d as nsLBBp and sLBBp except for V3d, which during LVSP was shorter than sLBBp; the mean difference -9 ms (-16; -1), p = 0.01. LVSP caused less interventricular dyssynchrony and the same or better local depolarization durations than nsLBBp and sLBBp irrespective of QRS morphology during spontaneous rhythm or paced QRS axis. Conclusions: In patients with bradycardia, LVSP in close proximity to LBB resulted in better interventricular synchrony than nsLBBp and sLBBp and did not significantly prolong depolarization of the left ventricular lateral wall.

• Publication type
• Journal Article MeSH

BACKGROUND: Left bundle branch pacing (LBBP) produces delayed, unphysiological activation of the right ventricle. Using ultra-high-frequency electrocardiography (UHF-ECG), we explored how bipolar anodal septal pacing with direct LBB capture (aLBBP) affects the resultant ventricular depolarization pattern. METHODS: In patients with bradycardia, His bundle pacing (HBP), unipolar nonselective LBBP (nsLBBP), aLBBP, and right ventricular septal pacing (RVSP) were performed. Timing of local ventricular activation, in leads V1-V8, was displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Durations of local depolarizations were determined as the width of the UHF-QRS complex at 50% of its amplitude. RESULTS: aLBBP was feasible in 63 of 75 consecutive patients with successful nsLBBP. aLBBP significantly improved ventricular dyssynchrony (mean -9 ms; 95% CI (-12;-6) vs. -24 ms (-27;-21), ), p < 0.001) and shortened local depolarization durations in V1-V4 (mean differences -7 ms to -5 ms (-11;-1), p < 0.05) compared to nsLBBP. aLBBP resulted in e-DYS -9 ms (-12; -6) vs. e-DYS 10 ms (7;14), p < 0.001 during HBP. Local depolarization durations in V1-V2 during aLBBP were longer than HBP (differences 5-9 ms (1;14), p < 0.05, with local depolarization duration in V1 during aLBBP being the same as during RVSP (difference 2 ms (-2;6), p = 0.52). CONCLUSION: Although aLBBP improved ventricular synchrony and depolarization duration of the septum and RV compared to unipolar nsLBBP, the resultant ventricular depolarization was still less physiological than during HBP.

• Publication type
• Journal Article MeSH

• MeSH
• Diagnostic Techniques, Cardiovascular MeSH
• Electrodiagnosis MeSH
• Electrocardiography methods   instrumentation   MeSH
• Heart Diseases diagnosis   MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• kardiologie
• NML Publication type
• kolektivní monografie

BACKGROUND: Right ventricular myocardial pacing leads to nonphysiological activation of heart ventricles. Contrary to this, His bundle pacing preserves their fast activation. Ultra-high-frequency electrocardiography (UHF-ECG) is a novel tool for ventricular depolarization assessment. OBJECTIVE: The purpose of this study was to describe UHF-ECG depolarization patterns during myocardial and His bundle pacing. METHODS: Forty-six patients undergoing His bundle pacing to treat bradycardia and spontaneous QRS complexes without bundle branch block were included. UHF-ECG recordings were performed during spontaneous rhythm, pure myocardial para-Hisian capture, and His bundle capture. QRS duration, QRS area, depolarization time in specific leads, and the UHF-ECG-derived ventricular dyssynchrony index were calculated. RESULTS: One hundred thirty-three UHF-ECG recordings were performed in 46 patients (44 spontaneous rhythm, 28 selective His bundle, 43 nonselective His bundle, and 18 myocardial capture). The mean QRS duration was 117 ms for spontaneous rhythm, 118 ms for selective, 135 ms for nonselective, and 166 ms for myocardial capture (P < .001 for nonselective and myocardial capture compared to each of the other types of ventricular activation). The calculated dyssynchrony index was shortest during spontaneous rhythm (12 ms; P = .02 compared to selective and P = .09 compared to nonselective), and it did not differ between selective and nonselective His bundle capture (16 vs 15 ms; P > .99) and was longest during myocardial capture of the para-Hisian area (37 ms; P < .001 compared to each of the other types of ventricular activation). CONCLUSION: In patients without bundle branch block, both types of His bundle, but not myocardial, capture preserve ventricular electrical synchrony as measured using UHF-ECG.

• MeSH
• Bundle-Branch Block physiopathology   therapy   MeSH
• Electrocardiography methods   MeSH
• Ventricular Function, Left physiology   MeSH
• Ventricular Function, Right physiology   MeSH
• Bundle of His physiopathology   MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Humans MeSH
• Aged MeSH
• Heart Rate physiology   MeSH
• Heart Ventricles physiopathology   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Aims. To compare the pharmacodynamics of 0.6 mg kg-1 rocuronium in young and older patients of both genders during total intravenous anesthesia. Methods. Following local ethics committee approval and informed consent, patients scheduled for surgery under total intravenous anesthesia (propofol/sufentanil) were divided into 4 study groups: 37 males aged 20-40, 40 males aged 60-75 yrs, 43 females aged 20-40 and 38 females aged 60-75 yrs. Neuromuscular block following rocuronium (0.6 mg kg-1) was monitored: train-of-four [TOF] stimulation of the ulnar nerve at 15-s intervals, EMG of the adductor pollicis muscle. The onset time (from application of rocuronium to maximum depression of T1), clinical duration (from application to 25% recovery of T1), and time to full spontaneous recovery (from application to TOF-ratio ≥ 0.9) were determined for each patient. The Kruskal-Wallis test was used to compare differences between groups; P<0.05 was considered statistically significant. Results. The onset time (median [interquartile range]) in the respective groups was 90 [80-110]BCD, 135 [116-165]AC, 75 [60-90]ABD, and 120 [90-146]AC seconds. The clinical duration was 30 [25-42]BCD, 58 [53-67]AD, 50 [40-65]AD, and 85 [70-90]ABC min. Interval to full spontaneous recovery was 59 [51-67]BCD, 102 [75-106]A, 76 [66-91]AD, and 128 [94- 137]AC min. (AP<0.05 vs. young males, BP<0.05 vs. elderly males, CP<0.05 vs. young females, DP<0.05 vs. elderly females). Conclusion. Females and older patients were more sensitive to rocuronium.

• MeSH
• Androstanols administration & dosage   pharmacokinetics   MeSH
• Adult MeSH
• Anesthesia, Intravenous MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Neuromuscular Nondepolarizing Agents administration & dosage   pharmacokinetics   MeSH
• Neuromuscular Blockade MeSH
• Sex Characteristics MeSH
• Aged MeSH
• Aging metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

Diabetes mellitus is a risk factor of cardiovascular diseases. ECG of patients with diabetes mellitus type 1 (DM 1) shows tachycardia (block of parasympathetic innervation) and abnormal repolarization (increased QT interval and QT dispersion (QTd)) indicating a risk of ventricular tachycardia and sudden death in young people with DM 1. The aim of the present report was to measure 145 parameters of the heart electric field in 22 patients (14 men, 8 women) with DM 1 without complications (mean age 32.8±11.4 years) and in 22 controls (11 men, 11 women, mean age 30.1±3.4 years). The duration of diabetes was 13.9±7.8 years. The parameters were registered by the diagnostic system Cardiag 112.2 and statistically evaluated by the Student and Mann-Whitney test. Tachycardia (86.3±2.7 beats.min-1), shortening of both QRS (79.9±1.6 ms) and QT (349.0±5.9 ms) and increased QT dispersion (115±36 ms) were observed in DM 1 when compared with the controls (75.0±2.1 beats. min.-1, QRS 89.9±2.7 ms, QT 374.0±4.4 ms, QTd 34.0±12.0 ms, p<0.01). The QTc was 415.2±4.1 ms in DM 1 and 401.4±6.6 ms in controls (NS). Other significant findings in DM 1 were: higher maximum of depolarization isopotential maps (DIPMmax) in the initial phase of QRS and less positive in the terminal phase, more negative minimum (DIPMmin) during QRS similarly as the minimum in depolarization isointegral maps (DIIMmin) and the minimum in isointegral map of the Q wave (Q-IIMmin), lower maximum in repolarization isopotential maps (RIPMmax) and less negative minimum (RIPMmin), more negative amplitude of Q wave (Q-IPMAM) and more pronounced spread of depolarization (activation time). Our results confirmed a decreased parasympathetic to sympathetic tone ratio (tachycardia, shortening of the activation time) and revealed different depolarization and repolarization patterns in DM 1. The differences in heart electric field parameters measured by the BSPM method in DM 1 and in the controls indicate the importance of ECG examination of diabetic patients type 1 in the prevention of cardiovascular diseases.

• MeSH
• Diabetes Mellitus MeSH
• Electrocardiography methods   utilization   MeSH
• Financing, Organized utilization   MeSH
• Data Interpretation, Statistical MeSH
• Insulin therapeutic use   MeSH
• Cardiovascular Diseases diagnosis   complications   MeSH
• Body Surface Potential Mapping methods   utilization   MeSH
• Vectorcardiography methods   utilization   MeSH