ΣΥΝΔΡΟΜΟ ΜΑΚΡΟΥ QT Eπεµβατική και µη επεµβατική διαστρωµάτωση κινδύνου Ελένη Χατζηνικολάου-Κοτσάκου Επεµβατική Καρδιολόγος-Ηλεκτροφυσιολόγος ΚΛΙΝΙΚΗ ΑΓΙΟΣ ΛΟΥΚΑ Σ
Σύνδροµο Long QT µια κληρονοµούµενη διαταραχή (καναλοπάθεια) που χαρακτηρίζεται από παράταση της κοιλιακής επαναπόλωσης στο ΗΚΓ φηµα και προδιαθέτει στην εµφάνιση συγκοπής και αιφνιδίου θανάτου µέσω πρόκλησης πολύµορφης κοιλιακής ταχυκαρδίας TdP
Modified Swartz criteria ( 1985) Σύνδροµο Long QT
Σύνδροµο Long QT
Σύνδροµο Long QT ΜΕΤΡΗΣΗ QT HKΓ-φηµα 12 απαγωγών, µε ταχύτητα 25 mm/s και 10 mm/mv amplitude στις απαγωγές ΙΙ, V5, V6 Μέση τιµή 3-5 συστολών
Σύνδροµο Long QT
βάσει αυτού η αποτελεσµατική θεραπευτική αντιµετώπιση και πρόληψη.. 1/3000-5000
A patient symptomatic or asymptomatic, with or without family history with this ECG Is he or she in high risk for SCD????? II V2 V5
Σύνδροµο Long QT
Risk stratification by clinical parameters Ø Length of the QT/QTc interval on serial resting ECG Ø QTc Variability Ø Gender
Risk stratification by clinical parameters
Risk stratification by clinical parameters
Risk stratification by clinical parameters
Risk stratification by clinical parameters
Risk stratification by clinical parameters q The presence of overt T wave alternans, especially when evident despite proper therapy q Patients with syncope or cardiac arrest before age 7 q Patients who have syncope or cardiac arrest in the first year of life, may not fully protected by traditional therapies q Patients who suffer arrhythmic events despite being on full medical therapy
Risk stratification by genotype
Risk stratification by genotype Risk Stratification
Risk stratification by genotype
Risk stratification by genotype
Σύνδροµο Long QT ΗΚΓ-φικά Χαρακτηριστικά Συνδρόμου LQT
Which is the genotype of the patient with this ECG??? Ασυµπτωµατικός άρρεν 25 ετών µε ιστορικό οικογενούς ΑΘ Ποιός είναι ο γονότυπος του συνδρόµου; QTc 560 msec
Risk stratification by genotype
Risk stratification by genotype
Risk stratification by combined parameters
3 Risk stratification by genotype
Risk stratification by genotype
Identification and Genotype Prediction in Long-QT Syndrome 1}Postural change in QTc was obtained by taking the QTc difference between rest and standing ECGs. 2}Absolute QT shortening refers to the difference between the rest and peak exercise QT intervals (QTpeak QTrest). 3 }The QTc prolongation was calculated by taking the difference between the peak exercise and rest QTc intervals (QTcpeak QTcrest). 4}QT hysteresis was determined by calculating the QT interval difference between exercise and 2-minute into the recovery phase at similar heart rates (within 10 bpm). Patients with LQTS exhibited a greater prolongation in QTc on standing than LQTS-negative, P=0.029 During exercise, patients with LQT1 mutations had an attenuated QT shortening compared with LQTS-negative and LQT2 patients B, P<0.0001 In addition, LQT1 patients had a marked QTc prolongation during exercise, whereas only a modest change in the QTc interval was observed in LQT2 and LQT-negative patients, P<0.0001. Burst bike and gradual bike testing showed similar results, with LQT1 patients demonstrating significantly impaired shortening of their QT interval and pronounced QTc lengthening with exercise). In contrast, LQT2 patients had greater QT hysteresis than LQT1 and LQTS-negative patients, P<0.0022. The area under the ROC curve for identifying LQT2 by hysteresis was 0.825 (95% CI, 0.721 to 0.930; P<0.0001), for LQT1 by peak exercise prolongation was 0.775 (95% CI, 0.654 to 0.896; P=0.0002), and for LQTS from postural QTc change was 0.666 (95% CI, 0.544 to 0.789; P=0.0095; In the patients with concealed LQTS (resting QTc 460 ms in men, 480 ms in women), postural QTc increase was >30 ms in 68%. Exercise QTc prolongation was >60 ms in 94% of concealed LQT1 patients. Hysteresis was >25 ms in 67% of concealed LQT2 patients. But the value of exercise test or adrenaline stimulation is still under control studies.. Jorg A Wong et al, Circulation:Arrhythmia and Electrophysiology, 2010;3:120-125
Risk stratification by genotype
Risk stratification by genotype
Risk stratification by genotype
GENETIC SCREENING GENETIC SCREENING
RISK STRATIFICATION BY INVASIVE TESTS RISK STRATIFICATION THE ROLE OF INVASIVE TEST ELECTROPHYSIOLOGY STUDY
ELECTROPHYSIOLOGY STUDY v There is little role for diagnostic EP testing in LQTS. v Studies have shown v that programmed ventricular stimulation v QT interval response to pacing v and infusion of β-blocking medication in LQTS are of limited value v Monophasic action potential studies demonstrated afterdepolarizations but were not prognostic v and proarrhythmia can occur with ventricular stimulation.
RISK STRATIFICATION BY ALL PARAMETERS
Avoidance of strenous exercise especially swimming without supervison in LQT1 patients Reduction in exposure to abrupt loud noises in LQT2patients
Acquired LQT usually results from drug therapy. hypokalemia or hypomagnesemia ischemia and bradycardia can increase the risk of druginduced LQTS. Polymorphism of gene MiRP-1 (T8A),is present in 1.6% of general population and is associated with antibiotic bactrimel proarrhytmic effect
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