Primary objective: to explore the application of automatic STV measurements by the ICD (STV-ARI,automatic), by correlating the STV-ARI,automatic values to the STV-values derived from our clinical gold standard, i.e. STV-QT (STV values derived from…
ID
Source
Brief title
Condition
- Cardiac arrhythmias
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Short-term variability of repolarization (STV) of 30 consecutive beats is
measured from different recording sites (ECG, RV EGM; unipolar & bipolar
signals). STV is calculated with the formula * !n+1 * !n /30× 2, where *D*
represents the repolarization duration and *n* the number of complexes, in this
case 30 complexes. The repolarization duration is defined and measured
differently per recording site. All intracardiac and ECG leads can be recorded
simultaneously.
The following parameters are measured:
- STV-QT: QT-interval is defined as the interval from the beginning of the
Q-wave until the end of the T-wave. Since the end of T-wave is hard to define,
the method of fiducial segment averaging is used to calculate STV. All
complexes are aligned around the R-wave as trigger point. Next, each fiducial
point (QRS-onset, end of T- wave) was aligned separately by cross correlating
the individual complex to the average of the other complexes till maximal
correlation was achieved. After alignment, Q-onset and T-end were determined
all at once. However, the individual intervals of every beat are preserved. the
QT-interval of every complex was calculated by summation of the intervals of
the QRS-onset to trigger point and trigger point to the T-wave, respectively.
- STV-ARI,automatic: intracardiac EGM signals will be opened in a Matlab
environment containing the algorithm to automatically determine STV-values.
First, the QRS complex will be blanked to avoid interference in the T-wave end
detection. Next, the first derivative of the resultant signal is calculated
over time to detect changes in the slope. This gradient signal was then squared
in order to make all data points positive and to emphasize slope changes in the
signal. Finally, the T-wave end was defined as the point at 60% of the area
under the curve of the resultant signal. The ARI is defined from the moment of
ventricular sensing of the QRS-complex to the T-wave end, derived with this
method.
The main endpoint is the p-value of the correlation coefficient between
STV-EGM,automatic and STV-QT values in sinus rhythm.
Secondary outcome
- Explore the modulation of STV by pacing through different pacing modalities
(atrial pacing (AAI) and dual pacing (DDD)) and different pacing frequencies
(80 beats per minute and [SR+20] beats per minute). We will perform a repeated
measure ANOVA, comparing the four pacing possibilities with SR, with post-hoc
Tukey correction. We will do the repeated ANOVA for the STV-QT and
STV-EGMautomatic values separately.
- Find the optimal ICD vector for each individual at each pacing modality,
based on quality indicators of the signal, i.e. minimal amplitude-noise ratio
and maximal variation of the T-wave during the recording. We will determine the
threshold of these quality indicators based on correlations between STV-QT and
STV-ARIautomatic.
Furthermore we'll recording the following clinical characteristics:
- Age
- Sex;
- Left ventricular ejection fraction (LVEF) measured by MRI, nuclear imaging or
echocardiography;
- NYHA class ( II, III, ambulatory IV);
- Underlying cardiac disease (ischemic cardiomyopathy, dilated
cardiomyopathy, other);
- Cardiovascular risk factors (smoking, hypertension, diabetes mellitus,
peripheral artery disease)
- Relevant comorbidities (COPD, chronic kidney disease, malignancy)
- Medications (beta blockers, ACE-inhibitors/AT2-antagonists, aldosterone
antagonists, diuretics, calcium blockers, digoxin, class I or III
anti-arrhythmic drugs)
- ECG parameters (RR-interval, PQ-interval, QRS-duration, heart axis)
Background summary
Implantation of an Implantable Cardioverter-Defibrillator (ICD) is the mainstay
of treatment in the prevention of Sudden Cardiac Death (SCD). While an ICD is
highly effective in termination of sustained ventricular arrhythmias, it does
not prevent arrhythmias from occurring. Prediction of imminent arrhythmias that
could trigger preventive treatment by the ICD would substantially increase its
functionality. Short-term variability (STV) of repolarization has shown to be
associated with a high risk of ventricular arrhythmias and SCD. Furthermore, it
has been demonstrated that STV derived from the activation-recovery interval
(ARI) of intracardiac electrograms (EGM) increases abruptly prior to the
occurrence of arrhythmias in an arrhythmic animal model. Moreover, in this
animal model it has been demonstrated that automatic STV-ARI measurements by an
ICD can guide high-rate pacing to prevent imminent ventricular arrhythmias. To
translate these findings to human application, we want to research if there is
a correlation between the STV-ARIautomatic values and the STV values derived
from our gold standard in humans, STV-QT. Furthermore, it is not known which
intracardiac electrogram (unipolar/bipolar) should be used for STV analysis.
With this study (STV-ARI 2.0 study) we continue the STV-ARI clinical study,
registered under number 17-732. The aim of the original STV-ARI study was
similar to the aim of the STV-ARI 2.0 study, i.e. look into the possibility to
automatically measure STV on human EGM signals by the ICD by demonstrating a
correlation between STV-ARI,automatic and STV-QT. Unfortunately, due to
significant injury current on the recordings obtained during de novo
implantations, this goal was not achieved during the first STV-ARI study. STV
analyses are not reliable on signals with such significant injury current.
Based on the five recordings obtained during a replacement/upgrade procedure,
we were however able to calculate a sample size estimation of how many study
subjects we expect are needed to demonstrate a significant correlation
coefficient.
The ultimate goal is to incorporate the STV-ARI,automatic technique in the ICD,
in order for the ICD to start preventive therapy (temporary accelerated pacing)
when the STV surpasses a certain arrhythmic threshold, in order to prevent
imminent ventricular arrhythmias from occurring.
Study objective
Primary objective: to explore the application of automatic STV measurements by
the ICD (STV-ARI,automatic), by correlating the STV-ARI,automatic values to the
STV-values derived from our clinical gold standard, i.e. STV-QT (STV values
derived from the ECG using the fiducial segment averaging technique) in sinus
rhythm. Hence, our aim is to find out whether there is a statistically
significant correlation between STV-ARI,automatic and STV-QT.
Secondary objectives:
- Explore the modulation of STV by pacing at different frequencies (80 beats
per minute and [rate during sinus rhythm + 20 beats per minute]) and pacing
modalities (AAI and DDD pacing), captured by both STV techniques
(STV-ARIautomatic and STV-QT).
- Find the optimal ICD vector for each individual at each pacing modality,
based on quality indicators of the signal, i.e. minimal amplitude-noise ratio
and maximal variation of the T-wave during the recording. We will determine the
threshold of these quality indicators based on correlations between STV-QT and
STV-ARIautomatic.
Study design
This study will be a cross-sectional, single center observational study with
one time point of observation. The study will be performed in patients that are
scheduled for true/integrated bipolar dual chamber ICD replacement/upgrade in
the UMC Utrecht. During the replacement/upgrade procedure, additional
measurements will be performed. No extra follow-up or test needs to be
scheduled.
Study burden and risks
The study can only be done in these patients since they are the only patients
with an RV lead in situ and a Right Atrium lead. The risks and burden for the
patient will be minimal, since replacement procedure of the device will follow
standard practice. The measurement of the intracardiac signals will increase
the replacement procedure by approximately 30 minutes. No additional visits,
blood samples, tests or administration of drugs are needed. The patients will
not have a direct benefit from study participation. However, the results of the
study might have benefit for future patients with an ICD, leading to prevention
of ventricular arrhythmias.
Yalelaan 50
UTRECHT 3584 CL
NL
Yalelaan 50
UTRECHT 3584 CL
NL
Listed location countries
Age
Inclusion criteria
- Carrying a dual chamber ICD with a true/integrated bipolar ICD lead scheduled
for a generator replacement OR
- Carrying a single chamber ICD with a true/integrated bipolar lead, with an
indication for a dual
chamber upgrade according to current guidelines
AND
- Sinus rhythm at upgrade/replacement with intrinsic AV conduction
- QRS <130 ms
Exclusion criteria
- Age <18 years old
- Permanent atrial fibrillation
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL80446.041.22 |