RT-137
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Changes in ventricular repolarization following balloon valvuloplasty and angioplasty for aortic stenosis and coartaction of aorta: evidence for mechano-electrical feedback in humans
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Berardo Sarubbi*°, Giuseppe Pacileo*, Valentino Ducceschi*°, Maria Giovanna Russo*, Carlo Pisacane*, Raimondo Calvanese*, Giuseppe Santoro*, Maurizio Cotrufo°, Raffaele Calabro*°.
*Division of Paediatric Cardiology, Second University of Naples, Monaldi Hospital, °Second University of Naples, Italy, Research Doctorate in “Cardiological and Cardiosurgical Sciences”
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Abstract
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BACKGROUND. Basic research and animal experiments have shown
the development of electrophysiological changes during or after changes in mechanical loading. Electrical
instability, following mechanical stretch, has been experimentally observed both in terms of development of
afterdepolarization and in terms of increased dispersion of refractoriness and repolarization. The aim of the
present study was to evaluate ventricular repolarization time indexes following acute changes in left ventricular
pressure in humans.
METHODS. The study group comprised 24 consecutive patients (16 M and 8 F, aged 2 days-19 years) affected by
severe congenital aortic stenosis and 14 patients (7 M and 7 F, aged 9 months–11 years) affected by severe
coartaction of aorta who underwent respectively successful balloon valvuloplasty and angioplasty. Ventricular
repolarization was evaluated before and after the interventional procedures both in terms of absolute measures
(JT, JTc, QT, QTc) and in terms of dispersion across the myocardium: QT and QTc dispersion (QTD and QTcD), JT
e JTc dispersion (JTD and JTcD) and T-peak to T-end interval (Tp-Te).
RESULTS. Patients with severe aortic stenosis and patients with aortic coartaction showed following balloon
valvuloplasty and angioplasty a significant decrease in ventricular repolarization indexes (JTc and QTc) and
dispersion of ventricular repolarization indexes (QTD, QTcD, JTD, JTcD and Tp-Te).
CONCLUSIONS. Changes in haemodynamic loading can produce electrophysiological effects in humans. Acute
reduction in left ventricular pressure overload, following balloon valvuloplasty and angioplasty, decreases
electrical instability, as expressed by ventricular repolarization time shortening both in terms of absolute
measures and in terms of depolarization across the myocardium.
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Key Words
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