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Cardiac resynchronization therapy (CRT) with biventricular pacing is an established therapy for heart failure (HF) patients (P) with ventricular desynchronization and reduced left ventricular (LV) ejection fraction. The aim of this study was to evaluate electrical right atrial (RA), left atrial (LA), right ventricular (RV) and LV conduction delay with novel telemetric signal averaging electrocardiography (SAECG) in implantable cardioverter defibrillator (ICD) P to better select P for CRT and to improve hemodynamics in cardiac pacing.
Methods: ICD-P (n=8, age 70.8 ± 9.0 years; 2 females, 6 males) with VVI-ICD (n=4), DDD-ICD (n=3) and CRT-ICD (n=1) (Medtronic, Inc., Minneapolis, MN, USA) were analysed with telemetric ECG recording by Medronic programmer 2090, ECG cable 2090AB, PCSU1000 oscilloscope with Pc-Lab2000 software (Velleman®) and novel National Intruments LabView SAECG software.
Results: Electrical RA conduction delay (RACD) was measured between onset and offset of RA deflection in the RAECG. Interatrial conduction delay (IACD) was measured between onset of RA deflection and onset of far-field LA deflection in the RAECG. Interventricular conduction delay (IVCD) was measured between onset of RV deflection in the RVECG and onset of LV deflection in the LVECG. Telemetric SAECG recording was possible in all ICD-P with a mean of 11.7 ± 4.4 SAECG heart beats, 97.6 ± 33.7 ms QRS duration, 81.5 ± 44.6 ms RACD, 62.8 ± 28.4 ms RV conduction delay, 143.7 ± 71.4 ms right cardiac AV delay, 41.5 ms LA conduction delay, 101.6 ms LV conduction delay, 176.8 ms left cardiac AV delay, 53.6 ms IACD and 93 ms IVCD.
Conclusions: Determination of RA, LA, RV and LV conduction delay, IACD, IVCD, right and left cardiac AV delay by telemetric SAECG recording using LabView SAECG technique may be useful parameters of atrial and ventricular desynchronization to improve P selection for CRT and hemodynamics in cardiac pacing.
Cardiac resynchronization therapy (CRT) is an established therapy for heart failure patients and improves quality of life in patients with sinus rhythm, reduced left ventricular ejection fraction (LVEF), left bundle branch block and wide QRS duration. Since approximately sixty percent of heart failure patients have a normal QRS duration they do not benefit or respond to the CRT. Cardiac contractility modulation (CCM) releases nonexcitatoy impulses during the absolute refractory period in order to enhance the strength of the left ventricular contraction. The aim of the investigation was to evaluate differences in cardiac index between optimized and nonoptimized CRT and CCM devices versus standard values. Impedance cardiography, a noninvasive method was used to measure cardiac index (CI), a useful parameter which describes the blood volume during one minutes heart pumps related to the body surface. CRT patients indicate an increase of 39.74 percent and CCM patients an improvement of 21.89 percent more cardiac index with an optimized device.
Spectral analysis of signal averaging electrocardiography in atrial and ventricular tachyarrhythmias
(2017)
Background: Targeting complex fractionated atrial electrograms detected by automated algorithms during ablation of persistent atrial fibrillation has produced conflicting outcomes in previous electrophysiological studies. The aim of the investigation was to evaluate atrial and ventricular high frequency fractionated electrical signals with signal averaging technique.
Methods: Signal averaging electrocardiography (ECG) allows high resolution ECG technique to eliminate interference noise signals in the recorded ECG. The algorithm uses automatic ECG trigger function for signal averaged transthoracic, transesophageal and intracardiac ECG signals with novel LabVIEW software (National Instruments, Austin, Texas, USA). For spectral analysis we used fast fourier transformation in combination with spectro-temporal mapping and wavelet transformation for evaluation of detailed information about the frequency and intensity of high frequency atrial and ventricular signals.
Results: Spectral-temporal mapping and wavelet transformation of the signal averaged ECG allowed the evaluation of high frequency fractionated atrial signals in patients with atrial fibrillation and high frequency ventricular signals in patients with ventricular tachycardia. The analysis in the time domain evaluated fractionated atrial signals at the end of the signal averaged P-wave and fractionated ventricular signals at the end of the QRS complex. The analysis in the frequency domain evaluated high frequency fractionated atrial signals during the P-wave and high frequency fractionated ventricular signals during QRS complex. The combination of analysis in the time and frequency domain allowed the evaluation of fractionated signals during atrial and ventricular conduction.
Conclusions: Spectral analysis of signal averaging electrocardiography with novel LabVIEW software can utilized to evaluate atrial and ventricular conduction delays in patients with atrial fibrillation and ventricular tachycardia. Complex fractionated atrial electrograms may be useful parameters to evaluate electrical cardiac arrhythmogenic signals in atrial fibrillation ablation.
Transcatheter aortic valve implantation is a therapy for patients with reduced left ventricular ejection fraction and symptomatic aortic stenosis. The aim of the study was to compare the pre-and post- transcatheter aortic valve implantation procedures to determine the QRS and QT ventricular conduction times as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortic valve implantation. QRS and QT ventricular conduction times were prolonged after transcatheter aortic valve implantation in heart failure patients with permanent dual chamber pacemaker therapy after transcatheter aortic valve implantation. QRS and QT ventricular conduction times may be useful parameters to evaluate the risk of post-procedural ventricular conduction block and permanent pacemaker therapy in transcatheter aortic valve implantation.
In contrast to conventional aortic valve replacement, the Transcatheter Aortic Valve Implantation (TAVI) is a new highly specialist alternative to surgical valve replacement for patients with symptomatic severe aortic stenosis and high operative risk. The procedure was performed in a minimally invasive way and was introduced at the university heart centre, Freiburg – Bad Krozingen in 2008. The results have been getting better and better over the years. The aim of the investigation is the analysis of electrocardiogram conduction time and the electrocardiography changes recorded hours and days after the procedure depending on artificial heart valve models, which may lead to pacemaker implantation, even the analysis of the effectiveness of treatment.
Transcatheter aortiv valve implantation is a new safe strategy treatment for patients with symptomatic severe aortic stenosis and high operative risk. The aim of the study was to compare the pre-and post- muiscatheter aortiv valve implantation procedures to determine the atrioventricuktr conduction time as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortiv valve implantation. The transcatheter aortiv valve implantation patients were divided into groups without pacemaker and with dual or single chamber pacemEtker with diffent atrioventrieular conduction time disturbance before and after transcatheter aortiv valve implantation. In heart failure, patients without permanent pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was prolonged after transcatheter aortiv valve implantation. In patients with permanent dual chamber pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was normalised with dual chaniber atrioventrieuku pacing mode. Atrioventricular conduction time may be a useful parameter to evaluate the risk of post-procedural atrioventricular conduction block and permanent pacemaker therapy in transcatheter north, valve implantation patients.
Transthoracic impedance cardiography (ICG) is a non-invasive method for determination of hemodynamic parameters. The basic principle of transthoracic ICG is the measurement of electrical conductivity of the thorax over the time. The aim of the study was the analysis of hemodynamic parameters from healthy individuals and the evaluation of various hemodynamic monitoring devices. Fourteen men (mean age 25 ± 4.59 years) and twelve women (mean age 24 ± 3.5 years) were measured during the cardiovascular engineering laboratory at Offenburg University of Applied Sciences, Offenburg, Germany. The ICG recordings were measured with the devices CardioScreen 1000, CardioScreen 2000 and TensoScreen with the corresponding Software Cardiovascular Lab 2.5 (Medis Medizinische Messtechnik GmbH, Illmenau, Germany). In order to create identical frame conditions, all measurements were recorded in the same position and for the same duration. Various positions were simulated from horizontal lying position to vertical standing position. Altogether, more than 30 hemodynamic parameters were measured.
Heart rhythm model and simulation of electrophysiological studies and high-frequency ablations
(2017)
Background: Target of the study was to create an accurate anatomic CAD heart rhythm model, and to show its usefulness for cardiac electrophysiological studies and high-frequency ablations. The method is more careful for the patients’ health and has the potential to replace clinical studies due to its high efficiency regarding time and costs.
Methods: All natural heart components of the new HRM were based on MRI records, which guaranteed electronic functionality. The software CST was used for the construction, while CST’s material library assured genuine tissue properties. It should be applicable to simulate different heart rhythm diseases as well as various diffusions of electromagnetic fields, caused by electrophysiological conduction, inside the heart tissue.
Results: It was achievable to simulate sinus rhythm and fourteen different heart rhythm disturbance with different atrial and ventricular conduction delays. The simulated biological excitation of healthy and sick HRM were plotted by simulated electrodes of four polar right atrial catheter, six polar His bundle catheter, ten polar coronary sinus catheter, four polar ablation catheter and eight polar transesophageal left cardiac catheter. Accordingly, six variables were rebuilt and inserted into the anatomic HRM in order to establish heart catheters for ECG monitoring and HF ablation. The HF ablation catheters made it possible to simulate various types of heart rhythm disturbance ablations with different HF ablation catheters and also showed a functional visualisation of tissue heating. The use of tetrahedral meshing HRM made it attainable to store the results faster accompanied by a higher degree of space saving. The smart meshing function reduced unnecessary high resolutions for coarse structures.
Conclusions: The new HRM for EPS simulation may be additional useful for simulation of heart rhythm disturbance, cardiac pacing, HF ablation and for locating and identification of complex fractioned signals within the atrium during atrial fibrillation HF ablation.
Heart rhythm model and simulation of electrophysiological studies and high-frequency ablations
(2017)
Background: The simulation of complex cardiologic structures has the potential to replace clinical studies due to its high efficiency regarding time and costs. Furthermore, the method is more careful for the patients’ health than the conventional ways. The aim of the study was to create an anatomic CAD heart rhythm model (HRM) as accurate as possible, and to show its usefulness for cardiac electrophysiological studies (EPS) and high-frequency (HF) ablations.
Methods: All natural heart components of the new HRM were based on MRI records, which guaranteed electronic functionality. The software CST (Computer Simulation Technology, Darmstadt) was used for the construction, while CST’s material library assured genuine tissue properties. It should be applicable to simulate different heart rhythm diseases as well as various diffusions of electromagnetic fields, caused by electrophysiological conduction, inside the heart tissue.
Results: It was achievable to simulate normal sinus rhythm and fourteen different heart rhythm disturbance with different atrial and ventricular conduction delays. The simulated biological excitation of healthy and sick HRM were plotted by simulated electrodes of four polar right atrial catheter, six polar His bundle catheter, ten polar coronary sinus catheter, four polar ablation catheter and eight polar transesophageal left cardiac catheter (Fig.). Accordingly, six variables were rebuilt and inserted into the anatomic HRM in order to establish heart catheters for ECG monitoring and HF ablation. The HF ablation catheters made it possible to simulate various types of heart rhythm disturbance ablations with different HF ablation catheters and also showed a functional visualisation of tissue heating. The use of tetrahedral meshing HRM made it attainable to store the results faster accompanied by a higher degree of space saving. The smart meshing function reduced unnecessary high resolutions for coarse structures.
Conclusions: The new HRM for EPS simulation may be additional useful for simulation of heart rhythm disturbance, cardiac pacing, HF ablation and for locating and identification of complex fractioned signals within the atrium during atrial fibrillation HF ablation.
Heart rhythm model and simulation of electrophysiological studies and high-frequency ablations
(2017)
Background: The simulation of complex cardiologic structures has the potential to replace clinical studies due to its high efficiency regarding time and costs. Furthermore, the method is more careful for the patients’ health than the conventional ways. The aim of the study was to create an anatomic CAD heart rhythm model (HRM) as accurate as possible, and to show its usefulness for cardiac electrophysiological studies (EPS) and high-frequency (HF) ablations.
Methods: All natural heart components of the new HRM were based on MRI records, which guaranteed electronic functionality. The software CST (Computer Simulation Technology, Darmstadt) was used for the construction, while CST’s material library assured genuine tissue properties. It should be applicable to simulate different heart rhythm diseases as well as various diffusions of electromagnetic fields, caused by electrophysiological conduction, inside the heart tissue.
Results: It was achievable to simulate normal sinus rhythm and fourteen different heart rhythm disturbance with different atrial and ventricular conduction delays. The simulated biological excitation of healthy and sick HRM were plotted by simulated electrodes of four polar right atrial catheter, six polar His bundle catheter, ten polar coronary sinus catheter, four polar ablation catheter and eight polar transesophageal left cardiac catheter (Fig.). Accordingly, six variables were rebuilt and inserted into the anatomic HRM in order to establish heart catheters for ECG monitoring and HF ablation. The HF ablation catheters made it possible to simulate various types of heart rhythm disturbance ablations with different HF ablation catheters and also showed a functional visualisation of tissue heating. The use of tetrahedral meshing HRM made it attainable to store the results faster accompanied by a higher degree of space saving. The smart meshing function reduced unnecessary high resolutions for coarse structures.
Conclusions: The new HRM for EPS simulation may be additional useful for simulation of heart rhythm disturbance, cardiac pacing, HF ablation and for locating and identification of complex fractioned signals within the atrium during atrial fibrillation HF ablation.