Sudden cardiac death ventricular arrhythmias
Conditions
Interventions
None listed
Sponsors
Universitair Medisch Centrum Utrecht
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
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
Exclusion criteria
Exclusion criteria: - Age
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 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 meth | — |
Secondary
| Measure | Time frame |
|---|---|
| - 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) | — |
Countries
Netherlands
Outcome results
None listed