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8 záznamů v Medvik Filtry

Článek

Ventricular Electrical Delay Measured From Body Surface ECGs Is Associated With Cardiac Resynchronization Therapy Response in Left Bundle Branch Block Patients From the MADIT-CRT Trial (Multicenter Automatic Defibrillator Implantation-Cardiac Resynchronization Therapy)

Plesinger, Filip
Autor Plesinger, Filip The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.). fplesinger@isibrno.cz
Jurak, Pavel
Autor Jurak, Pavel The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.)
Halamek, Josef
Autor Halamek, Josef The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.)
Nejedly, Petr
Autor Nejedly, Petr The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.)
Leinveber, Pavel
Autor Leinveber, Pavel International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic (P.L.)
Viscor, Ivo
Autor Viscor, Ivo The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.)
Vondra, Vlastimil
Autor Vondra, Vlastimil The Czech Academy of Sciences, Institute of Scientific Instruments, Department of Medical Signals, Brno, (F.P., P.J., J.H., P.N., I.V., V.V.)
McNitt, Scott
Autor McNitt, Scott Heart Research Follow-up Program, University of Rochester Medical Center, NY (S.M., B.P., A.J.M., W.Z., J.-P.C.)
Polonsky, Bronislava
Autor Polonsky, Bronislava Heart Research Follow-up Program, University of Rochester Medical Center, NY (S.M., B.P., A.J.M., W.Z., J.-P.C.)
Moss, Arthur J
Autor Moss, Arthur J Heart Research Follow-up Program, University of Rochester Medical Center, NY (S.M., B.P., A.J.M., W.Z., J.-P.C.)

Circulation. Arrhythmia and electrophysiology. 2018 ; 11 (5) : e005719. [pub] 20180426

Circ Arrhythm Electrophysiol
ISSN 1941-3084
Medvik
Zdroj

BACKGROUND: Although cardiac resynchronization therapy (CRT) is beneficial in heart failure patients with left bundle branch block, 30% of these patients do not respond to the therapy. Identifying these patients before implantation of the device is one of the current challenges in clinical cardiology. METHODS: We verified the diagnostic contribution and an optimized computerized approach to measuring ventricular electrical activation delay (VED) from body surface 12-lead ECGs. We applied the method to ECGs acquired before implantation (baseline) in the MADIT-CRT trial (Multicenter Automatic Defibrillator Implantation-Cardiac Resynchronization Therapy). VED values were dichotomized using its quartiles, and we tested the association of VED values with the MADIT-CRT primary end point of heart failure or death. Multivariate Cox proportional models were used to estimate the risk of study end points. In addition, the association between VED values and hemodynamic changes after CRT-D implantation was examined using 1-year follow-up echocardiograms. RESULTS: Our results showed that left bundle branch block patients with baseline VED <31.2 ms had a 35% risk of MADIT-CRT end points, whereas patients with VED ≥31.2 ms had a 14% risk (P<0.001). The hazard ratio for predicting primary end points in patients with low VED was 2.34 (95% confidence interval, 1.53-3.57; P<0.001). Higher VED values were also associated with beneficial hemodynamic changes. These strong VED associations were not found in the right bundle branch block and intraventricular conduction delay cohorts of the MADIT-CRT trial. CONCLUSIONS: Left bundle branch block patients with a high baseline VED value benefited most from CRT, whereas left bundle branch block patients with low VED did not show CRT benefits.

Článek

The effect of ICD programming on inappropriate and appropriate ICD Therapies in ischemic and nonischemic cardiomyopathy: the MADIT-RIT trial

Journal of cardiovascular electrophysiology. 2015 ; 26 (4) : 424-33. [pub] 20150211

J Cardiovasc Electrophysiol
ISSN 1540-8167
Medvik
Zdroj

INTRODUCTION: The MADIT-RIT trial demonstrated reduction of inappropriate and appropriate ICD therapies and mortality by high-rate cut-off and 60-second-delayed VT therapy ICD programming in patients with a primary prophylactic ICD indication. The aim of this analysis was to study effects of MADIT-RIT ICD programming in patients with ischemic and nonischemic cardiomyopathy. METHODS AND RESULTS: First and total occurrences of both inappropriate and appropriate ICD therapies were analyzed by multivariate Cox models in 791 (53%) patients with ischemic and 707 (47%) patients with nonischemic cardiomyopathy. Patients with ischemic and nonischemic cardiomyopathy had similar incidence of first inappropriate (9% and 11%, P = 0.21) and first appropriate ICD therapy (11.6% and 14.1%, P = 0.15). Patients with ischemic cardiomyopathy had higher mortality rate (6.1% vs. 3.3%, P = 0.01). MADIT-RIT high-rate cut-off (arm B) and delayed VT therapy ICD programming (arm C) compared with conventional (arm A) ICD programming were associated with a significant risk reduction of first inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy (HR range 0.11-0.34, P < 0.001 for all comparisons). Occurrence of total inappropriate and appropriate ICD therapies was significantly reduced by high-rate cut-off ICD programming and delayed VT therapy ICD programming in both ischemic and nonischemic cardiomyopathy patients. CONCLUSION: High-rate cut-off and delayed VT therapy ICD programming are associated with significant reduction in first and total inappropriate and appropriate ICD therapy in patients with ischemic and nonischemic cardiomyopathy.

Článek

Mortality reduction in relation to implantable cardioverter defibrillator programming in the Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT)

Circulation. Arrhythmia and electrophysiology. 2014 ; 7 (5) : 785-92. (Arrhythmia and electrophysiology)

Circ Arrhythm Electrophysiol
ISSN 1941-3084
Medvik
Zdroj

BACKGROUND: The benefit of novel implantable cardioverter defibrillator (ICD) programming in reducing inappropriate ICD therapy and mortality was demonstrated in Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT). However, the cause of mortality reduction remains incompletely evaluated. We aimed to identify factors associated with mortality, with focus on ICD therapy and programming in the MADIT-RIT population. METHODS AND RESULTS: In MADIT-RIT, 1500 patients with a primary prophylactic indication for ICD or cardiac resynchronization therapy with defibrillator were randomized to 1 of 3 different ICD programming arms: conventional programming (ventricular tachycardia zone ≥170 beats per minute), high-rate programming (ventricular tachycardia zone ≥200 beats per minute), and delayed programming (60-second delay before therapy ≥170 beats per minute). Multivariate Cox models were used to assess the influence of time-dependent appropriate and inappropriate ICD therapy (shock and antitachycardia pacing) and randomized programming arm on all-cause mortality. During an average follow-up of 1.4±0.6 years, 71 of 1500 (5%) patients died: cardiac in 40 patients (56.3%), noncardiac in 23 patients (32.4%), and unknown in 8 patients (11.3%). Appropriate shocks (hazard ratio, 6.32; 95% confidence interval, 3.13-12.75; P<0.001) and inappropriate therapy (hazard ratio, 2.61; 95% confidence interval, 1.28-5.31; P=0.01) were significantly associated with an increased mortality risk. There was no evidence of increased mortality risk in patients who experienced appropriate antitachycardia pacing only (hazard ratio, 1.02; 95% confidence interval, 0.36-2.88; P=0.98). Randomization to conventional programming was identified as an independent predictor of death when compared with patients randomized to high-rate programming (hazard ratio, 2.0; 95% confidence interval, 1.06-3.71; P=0.03). CONCLUSIONS: In MADIT-RIT, appropriate shocks, inappropriate ICD therapy, and randomization to conventional ICD programming were independently associated with an increased mortality risk. Appropriate antitachycardia pacing was not related to an adverse outcome. CLINICAL TRIAL REGISTRATION URL: clinicaltrials.gov Unique identifier: NCT00947310.

MeSH
časové faktory MeSH
defibrilátory implantabilní * MeSH
elektrická defibrilace škodlivé účinky přístrojové vybavení mortalita MeSH
Kaplanův-Meierův odhad MeSH
komorová tachykardie diagnóza mortalita patofyziologie terapie MeSH
lidé středního věku MeSH
lidé MeSH
multivariační analýza MeSH
proporcionální rizikové modely MeSH
protézy - design * MeSH
rizikové faktory MeSH
rozdělení chí kvadrát MeSH
selhání protézy * MeSH
senioři nad 80 let MeSH
senioři MeSH
srdeční frekvence MeSH
výsledek terapie MeSH
Check Tag
lidé středního věku MeSH
lidé MeSH
mužské pohlaví MeSH
senioři nad 80 let MeSH
senioři MeSH
Publikační typ
časopisecké články MeSH
multicentrická studie MeSH
práce podpořená grantem MeSH
randomizované kontrolované studie MeSH
Geografické názvy
Evropa MeSH
Izrael MeSH
Japonsko MeSH
Kanada MeSH
Spojené státy americké MeSH

Článek

Measure of the QT-RR dynamic coupling in patients with the long QT syndrome

Annals of noninvasive electrocardiology. 2012 ; 17 (4) : 323-30.

Ann Noninvasive Electrocardiol
ISSN 1542-474X
Medvik
Zdroj

BACKGROUND: The patients with the long QT syndrome type-1 (LQT-1) have an impaired adaptation of the QT interval to heart rate changes. Yet, the description of the dynamic QT-RR coupling in genotyped LQT-1 has never been thoroughly investigated. METHOD: We propose a method to model the dynamic QT-RR coupling by defining a transfer function characterizing the relationship between a QT interval and its previous RR intervals measured from ambulatory Holter recordings. Three parameters are used to characterize the QT-RR coupling: a fast gain (Gain(F) ), a slow gain (Gain(L) ), and a time constant (τ). We investigated the values of these parameters across genders, and in genotyped LQT-1 patients with normal QTc interval duration (QTc < 470 ms). RESULTS: The QT-RR dynamic profiles are significantly different between LQT-1 patients (97) and controls (154): LQT-1 have longer QTc interval (453 ± 35 vs. 384 ± 26 ms, P < 0.0001), and an increased dependency of the QT interval to previous RR changes revealed by a larger Gain(L) (0.22 ± 0.06 vs. 0.18 ± 0.07, P < 0.0001) and Gain(F) (0.05 ± 0.02 vs. 0.03 ± 0.01, P < 0.0001). Importantly, LQT-1 patients have a faster QT dynamic response to previous RR changes described by τ: 122 ± 44 vs. 172 ± 92 beats (P < 0.0001). This faster QT dynamic response of the QT-RR dynamic coupling remained in LQT-1 patients with QTc in a normal range (<430 ms). CONCLUSIONS: The measurement of QT-RR dynamic coupling could be used in patients suspected to carry a concealed form of the LQT-1 syndrome, or to provide insights into the types of arrhythmogenic triggers a patient may be prone to.