Fakultät Elektrotechnik und Informationstechnik (E+I)
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- CST (7)
- HF-Ablation (7)
- CRT (5)
- Herzkrankheit (5)
- Synchronisierung (4)
- Kardiale Resynchronisationstherapie (3)
- Herzschrittmacher (2)
- IVD (2)
- cardiac resynchronization therapy (2)
- 3D modeling (1)
Die Erfindung betrifft eine Ösophaguselektrodensonde bzw. einen Ösophaguskatheter 10 zur Bioimpedanzmessung und/oder zur Neurostimulation, eine Vorrichtung 100 zur transösophagealen kardiologischen Behandlung und/oder kardiologischen Diagnose und ein Verfahren zum Steuern oder Regeln einer Ablationseinrichtung zum Durchführen einer Herzablation. Die Ösophaguselektrodensonde 10 umfasst eine Bioimpedanzmesseinrichtung zur Messung der Bioimpedanz von zumindest einem Teil des die Ösophaguselektrodensonde 10 umgebenden Gewebes. Die Bioimpedanzmesseinrichtung umfasst mindestens eine erste Elektrode 12A und mindestens eine zweite Elektrode 12B, wobei die mindestens eine erste Elektrode 12A auf einer dem Herzen zugewandten Seite 14 der Ösophaguselektrodensonde 10 angeordnet ist, und die mindestens eine zweite Elektrode 12B auf einer vom Herzen abgewandten Seite 16 der Ösophaguselektrodensonde 10 angeordnet ist.Die Vorrichtung 100 umfasst die Ösophaguselektrodensonde 10 und eine Steuer- und/oder Auswerteinrichtung 30. Die Steuer- und/oder Auswerteinrichtung 30 ist eingerichtet, ein erstes Bioimpedanzmesssignal von der mindestens einen ersten Elektrode 12A und ein zweites Bioimpedanzmesssignal von der mindestens einen zweiten Elektrode 12B zu empfangen und zu vergleichen, und ein Kontrollsignal auf Basis des Vergleichs zu generieren. Das Kontrollsignal kann ein Signal zum Steuern oder Regeln einer Ablationseinrichtung zum Durchführen einer Herzablation sein.
Hintergrund: Richtung und Stärke des elektrischen Feldes (E-Feld) der biventrikulären (BV) Stimulation und elektrische interventrikuläre Desynchronisation sind bei Patienten mit Herzinsuffizienz und verbreitertem QRS Komplex von Bedeutung für den Erfolg der kardialen Resynchronisationstherapie (CRT). Das 3D Herzrhythmusmodell (HRM) ermöglicht die
Simulation von CRT und Hochfrequenz (HF) Ablation. Das Ziel der Studie besteht in der Integration von Schrittmacher- und Ablationselektroden in das HRM zur E-Feld Simulation der BV Stimulation und thermischen Feld (T-Feld) Simulation der HF Ablation von Vorhofflimmern (AF).
Methoden: Es wurden fünf multipolare linksventrikuläre (LV) Elektroden, eine epikardiale LV Elektrode, vier bipolare rechtsatriale (RA) Elektroden, zwei rechtsventrikuläre (RV) Elektroden und ein HF Ablationskatheter mit CST (Computer Simulation Technology, Darmstadt) modelliert und das HRM (Schalk et al: Clin Res Cardiol 106, Suppl 1, April 2017, P1812) um den Koronarvenensinus (CS) erweitert (HRM-CS). E-Feld Simulationen bei vorhofsynchroner BV Stimulation und bei RA Stimulation mit RV und LV Ableitung erfolgten mit den Elektroden Select Secure 3830, Capsure VDD-2 5038 und Attain OTW 4194 im HRM+CS (Fig.). F-Feld Simulationen der HF Ablation von AF bei CRT wurden mit integriertem Ablationskatheter AlCath G FullCircle (Biotronik) simuliert.
Ergebnisse: HRM-CS ermöglichte 3D E-Feld Simulationen bei vorhofsynchroner bipolarer BV Stimulation und bei bipolarer RA Stimulation mit bipolarer RV und LV Ableitung. RV und LV Stimulation erfolgten zeitgleich bei einer Amplitude von 3 V an der LV Elektrode und 1 V an der RV Elektrode mit einer Impulsbreite von jeweils 0,5 ms. Die von der BV Stimulationen erzeugten Fernpotentiale konnten von der RA Elektrode wahrgenommen werden. Das Fernpotential an der RA Elektrodenspitze betrug 32,86 mV und in 1 mm Abstand von der RA Elektrodenspitze ergab sich ein Fernpotential von 185,97 mV. HRM-CS ermöglichte 3D T-Feld Simulationen der HF Ablation von AF bei CRT. Das T-Feld bei HF Ablation des AV-Knotens wurde mit einer anliegenden Leistung von 5 W bei 420 kHz an der distalen 8 mm Ablationselektrode simuliert. Die Temperatur an der Katheterspitze betrug nach 5 s Ablationsdauer 88,66 °C, in 1 mm Abstand von der Katheterspitze im Myokard 42,17 °C und in 2 mm Abstand 37,49 °C.
Schlussfolgerungen: HRM-CS und Elektrodenmodelle ermöglichen die 3D Simulationen von E-Feldern bei vorhofsynchroner BV Stimulation, RA Stimulation mit RV und LV Wahrnehmung und von T-Feldern bei HF Ablation. E-Feld Simulationen von RA, RV und LV Stimulation und Sensing können möglicherweise zur Vorhersage von CRT Respondern genutzt werden.
The high frequency (HF) catheter ablation is the gold standard for the therapy of many cardiac tachyarrhythmias, such as atrioventricular node re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT) or atrial flutter (AFL). The aim of the study was to simulate the HF ablation of AVNRT, AVRT, AFL and its heat propagation in reference to the supplied power with different electrode material and electrode size. The modeling and simulation were performed with the thermal and electromagnetic simulation software CST® (Computer Simulation Technology, Darmstadt). The modeling and simulation were carried out using ablation catheters with 4 mm tip electrode and 8 mm tip electrode with different electrode materials. Both electrode types were made of platinum and gold respectively. For the measurement of the heat propagation in the heart tissue, the catheters were integrated in the Offenburg heart rhythm model. The HF ablation procedures were performed with the 4 mm platinum tip electrode, with an application duration of 45 seconds and a power output of 40 watts. The HF ablation of the atrioventricular node slow pathway produced a maximum temperature of 66.33 °C. The Kent bundle HF ablation in the left atrium achieved a maximum temperature of 67.14 °C. The HF ablation of the right atrial isthmus resulted 65.96 °C. The 8 mm distal platinum tip electrode and a power output of 60 watts reached 72.85 °C. The 8 mm distal gold tip electrode and a power output of 60 watt reached 64.66 °C, due to the improved thermal conductivity of gold. Virtual heart and ablation electrode models allow the static and dynamic simulation of HF ablation with different electrode material and electrode size. The 3D simulation of the temperature profile may be used to optimize the AVNRT, AVRT and AFL HF ablation.
Cardiac resynchronization therapy (CRT) with hemodynamic
optimized biventricular pacing is an established
therapy for heart failure patients with sinus rhythm,
reduced left ventricular ejection fraction and wide QRS
complex. The aim of the study was to evaluate electrical
right and left cardiac atrioventricular delay and left atrial
delay in CRT responder and non-responder with sinus
rhythm. Methods: Heart failure patients with New York
Heart Association class 3.0 ± 0.3, sinus rhythm and
27.7 ± 6.1% left ventricular ejection fraction were measured
by surface ECG and transesophageal bipolar left
atrial and left ventricular ECG before implantation of
CRT devices. Electrical right cardiac atrioventricular
delay was measured between onset of P wave and onset
of QRS complex in the surface ECG, left cardiac
atrioventricular delay between onset of left atrial signal
and onset of left ventricular signal in the transesophageal
ECG and left atrial delay between onset and offset of left
atrial signal in the transesophageal ECG. Results: Electrical
atrioventricular and left atrial delay were
196.9 ± 38.7 ms right and 194.5 ± 44.9 ms left cardiac
atrioventricular delay, and 47.7 ± 13.9 ms left atrial
delay. There were positive correlation between right and
left cardiac atrioventricular delay (r = 0.803 P < 0.001)
and negative correlation between left atrial delay and left
ventricular ejection fraction (r = −0.694 P = 0.026) with
67% CRT responder. Conclusions: Transesophageal
electrical left cardiac atrioventricular delay and left atrial
delay may be useful preoperative atrial desynchronization
parameters to improve CRT optimization.
Targeting complex fractionated atrial electrocardiograms
detected by automated algorithms during ablation of
persistent atrial fibrillation has produced conflicting
outcomes in previous electrophysiological studies and
catheter ablation of atrial fibrillation and ventricular
tachycardia. The aim of the investigation was to evaluate
atrial and ventricular high frequency fractionated electrical
signals with signal averaging technique. Methods:
Signal averaging electrocardigraphy allows high resolution
ECG technique to eliminate interference noise signals
in the recorded ECG. The algorithm use automatic ECG
trigger function for signal averaged transthoracic, transesophageal
and intra-cardiac ECG signals with novel
LabVIEW software. Results: 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. We evaluated
atrial flutter in the time domain with two-to-one atrioventricular
conduction, 212.0 ± 4.1 ms atrial cycle length,
426.0 ± 8.2 ms ventricular cycle length, 58.2 ± 1.8 ms
P-wave duration, 119.6 ± 6.4 ms PQ duration,
103.0 ± 2.4 ms QRS duration and 296.4 ± 6.8 ms QT
duration. 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. Conclusions: Spectral
analysis of signal averaging electrocardiography with
novel LabVIEW software can be utilized to evaluate atrial
and ventricular conduction delays in patients with atrial
fibrillation and ventricular tachycardia. Complex fractionated
atrial and ventricular electrocardiograms may be
useful parameters to evaluate electrical cardiac bradycardia
and tachycardia signals in atrial fibrillation and
ventricular tachycardia ablation.
Pulmonary vein isolation (PVI) is a common
therapy in atrial fibrillation (AF). The cryoballoon was
invented to isolate the pulmonary vein in one step and in a
shorter time than a point-by-point radiofrequency (RF)
ablation. The aim of the study was to model two cryoballoon
catheters, one RF catheter and to integrate them into a heart
rhythm model for the static and dynamic simulation of PVI
by cryoablation and RF ablation in AF. The modeling and
simulation were carried out using the electromagnetic and
thermal simulation software CST (CST, Darmstadt). Two
cryoballons and one RF ablation catheter were modeled
based on the technical manuals of the manufacturers
Medtronic and Osypka. The PVI especially the isolation of
the left inferior pulmonary vein using a cryoballoon catheter
was performed with a -50 °C heatsource and an exponential
signal. The temperature at the balloon surface was -50 °C
after 20 s ablation time, -24 °C from the balloon 0,5 mm in
the myocardium, at a distance of 1 mm -3 °C, at 2 mm 18 °C
and at a distance of 3mm 29 °C. PVI with RF energy was
simulated with an applied power of 5 W at 420 kHz at the
distal 8 mm ablation electrode. The temperature at the tip
electrode was 110 °C after 15 s ablation time, 75 °C from the
balloon at 0,5 mm in the myocardium, at a distance of 1 mm
58 °C, at 2 mm 45 °C and at a distance of 3 mm 38 °C.
Virtual heart rhythm and catheter models as well as the
simulation of the temperature allow the simulation of PVI in
AF by cryo ablation and RF ablation. The 3D simulation of
the temperature profile may be used to optimize RF and cryo
ablation.
Cardiac contractility modulation (CCM) is a
device-
based therapy for the treatment of systolic left
ventricular chronic heart failure. Unlike other device
-
based therapies for heart failure, CCM delivers non
-
excitatory pacing signals to the myocardium. This leads to
an extension of the action potential and to an improved
contractility of the heart. The modeling and simulation
was done with the electromagnetic simulation software
CST. Three CCM electrodes were inserted into the
Offenburg heart rhythm model an
d subsequently
simulated the electric field propagation in CCM therapy.
In addition, simulations of CCM have been performed
with electrodes from other device
-based therapies, such as
cardiac resynchronization therapy (CRT) and implantable
cardioverter.
/. defi
brillator (ICD) therapy.
At the same
distance to the simulation electrode, the electric field is
slightly stronger in CCM therapy than in CCM therapy
with additionally implanted CRT or ICD electrodes. In
addition, there is a change in the electric field pr
opagation
at the electrodes of the CRT and the shock electrode of the
ICD.
By simulating several different therapy procedures
on the heart, it is possible to check how they affect their
behavior during normal operation. CCM heart rhythm
model simulation al
lows the evaluation the individual
electrical pacing and sensing field during CCM.
Abstract: Electric field of biventricular (BV) pacing, left ventricular (LV) electrode position and electrical interventricular desynchronization are important parameters for successful cardiac resynchronization therapy (CRT) in patients with heart failure, sinus rhythm and reduced LV ejection fraction. The aim of the study was to evaluate electric pacing field of transesophageal left atrial (LA) pacing and BV pacing with 3D heart rhythm simulation. Bipolar right atrial (RA), right ventricular (RV), LV electrodes and multipolar hemispherical esophageal LA electrodes were modeled with CST (Computer Simulation Technology, Darmstadt). Electric pacing field were simulated with bipolar RA and RV pacing with Solid S (Biotronik) electrode, bipolar LV pacing with Attain 4194 (Medtronic) electrode and bipolar LA pacing with TO8 (Osypka) esophageal electrode. 3D heart rhythm model with esophagus allowed electric pacing field simulation of 4-chamber pacing with bipolar intracardiac RA, RV, LV pacing and bipolar transesophageal LA pacing. The pacing amplitudes were 3V RA pacing amplitude, 50V LA pacing amplitude, 1.5V RV pacing amplitude and 3V LV pacing amplitude with 0.5ms pacing pulse duration. The atrioventricular delay between RA pacing and BV pacing was 140ms atrioventricular pacing delay and simultaneous RV and LV pacing. Electric pacing fields were simulated during the different pacing modes AAI, VVI, DDD and DDD0V. The intracardiac far-field pacing potentials were evaluated with intracardiac electrodes and a distance of 1mm from the electrodes with RA electrode 1.104V, RV electrode 0.703V and LV electrode 1.32V. The transesophageal far-field pacing potential was evaluated with transesophageal electrode and a distance of 10mm from the elelctrode with LA electrode 6.076V. Heart rhythm model simulation with esophagus allows evaluation of electric pacing fields in AAI, VVI, DDD, DDD0V and DDD0D pacing modes. Electric pacing field of RA, RV and LV pacing in combination with LA pacing may additional useful pacing mode in CRT non-responders.