Πώς διαγιγνώσκω τα ηλεκτρικά νοσήματα; Ι. Σκιαδάς Ιπποκράτειο Αθήνων
Sudden cardiac death (SCD) is predominantly related to coronary artery disease and its sequelae, cardiomyopathy, and congenital or valvular heart disease. No structural abnormalities are detectable in 5 8% of SCDs. Identified ion channelopathies such as Brugada syndrome, long-qt syndrome(lqts), and catecholaminergic polymorphic ventricular tachycardia (CPVT) contribute to this incidence. McGorrian C, et al. Europace 2013;15:1050-1058.
Σημαντικές θεωρίες με αποδείξεις Άτομο DNA Σύναψη (δίαυλοι) Δημόκριτος Jean-Pierre Changeux:, L homme neuronal, 1998
1998, MacKinnon: Πρώτη απεικόνηση
αλλιώς διαυλοπάθειες
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The diagnosis of an inheritable arrhythmogenic disorder is established in up to 50% of families with a SADS victim, especially channelopathies [e.g. LQTS, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT)] and occasionally subtle forms of cardiomyopathy [HCM and arrhythmogenic right ventricular cardiomyopathy (ARVC) in particular] or familial hypercholesterolaemia.
Recommendations with low level of evidence The most obvious differenceen countered for inherited diseases is that randomized and/or blinded studies do not exist in this field. Therefore most of the available data derive from registries that have followed patients and recorded outcome information. As a consequence, all consensus recommendations are level of evidence (LOE) C (i.e.,based on experts opinions).
Ομάδες νοσημάτων Long QT Syndrome (LQTS) Brugada Syndrome (BrS) Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) Short QT Syndrome (SQTS) Early Repolarization (ER) Progressive Cardiac Conduction Disease (PCCD) Unexplained Cardiac Arrest: Idiopathic VF Unexplained Cardiac Arrest: Sudden Unexplained Death Syndrome (SUDS) and Sudden Unexplained Death in Infancy (SUDI)
Επιπολασμός στο γενικό πληθυσμό LQT Brugada CPVT 1 / 2.500 1 / 1.-10.000 1 / 10.000
Στις οικογένειες
ΗΚΓ στο γενικό πληθυσμό fighting new wars with old weapons 4 / 12.000
Definitions of special terms Syncope (exlusion of vasovagal) Symptomatic individuals Arrhythmic events Concealed mutation-positive patients
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ECG in LGTs
Προτεινόμενος αλγόριθμος διερεύνησης LQT Syndrome Obeyesekere M N et al. Circ Arrhythm Electrophysiol. 2011;4:958-964
Δοκιμασίες πρόκλησης ηλεκτρικών νοσημάτων Obeyesekere M N et al. Circ Arrhythm Electrophysiol. 2011;4:958-964
Exercise testing in LQTS Exercise stress testing has also been used for differentiating LQT1, LQT2, and unaffected individuals. End-of-recovery QTc may have clinical use in distinguishing patients with LQTS from healthy individuals a QTc >445 ms at the end of recovery (4 minutes after cessation of exercise) had a sensitivity of 92% and specificity of 88% at identifying LQT1 and LQT2 individuals. Furthermore, early-recovery QTc may be used to distinguish LQT1 from LQT2 patients: early recovery QTc > 460 ms had a sensitivity of 79% and specificity of 92% at identifying LQT2 patients (from LQT1). Chattha IS, et al. Heart Rhythm. 2010 Sy RW, et al. J Cardiovasc Electrophysiol. 2010
Brugada Syndrome (BrS) The diagnosis of BrS requires the signature type 1 Brugada ECG pattern. Genetic testing is not involved in the diagnosis, but the identification of a causative mutation may help confirm a clinically uncertain diagnosis. The involvement of loss-of-function sodium channel mutations, the predominant genetic cause of BrS, may be recognized by more or less discrete conduction disorders at different levels of the heart. Fever, excessive alcohol intake and large meals are triggers that unmask a type I ECG pattern and predispose to VF
Σύνδρομο Brugada Symptoms associated with BrS include: 1. VF or aborted SCD (more often at night than during the day) 2. Syncope 3. Nocturnal agonal respiration 4. Palpitations 5. Chest discomfort
Επιδημιολογικά σύνδρομου Brugada VF occurs at a mean age of 41±15 years but it may manifest at any age, usually during rest or sleep incidence of arrhythmic events 13.5% per year in patients with a history of sudden cardiac arrest, 3.2% per year in patients with syncope 1% per year in asymptomatic patients
Υποστηρικτικά σημεία
1st-2nd decade of life Low heart rate Holter monitoring, exercise stress test or implantable loop recorders Drug challenge with epinephr-ine or isoproterenol may elicit arrhythmias (sensitivity not defined)
CPVT an exercise stress test that elicits atrial arrhythmias and VA (bidirectional or polymorphic VT) is recommended to establish the diagnosis Obeyesekere M N et al. Circ Arrhythm Electrophysiol. 2011;4:958-964
Five genes have been linked to SQTS (KCNH2, KCNQ1, KCNJ2, CACNA1C and CACNB2b), but the yield of genetic screening remains low (20% overall).
highly lethal in all age groups, including children in their first months of life the probability of a first cardiac arrest by the age of 40 years is >40%. Given the small size of the populations reported so far, the high lethality may partially reflect a reporting bias related to the underdetection of SQTS in asymptomatic patients SQT syndrome
Early Repolarization Syndrome
1% 13% of the general population 15% 70% of idiopathic VF cases
Συνοψίζοντας Η διαγνωση των ηλεκτρικών νοσημάτων θέλει πρώτα απ όλα υψηλή κλινική υποψία και εγρήγορση από μέρους του κλινικού ιατρού, καθώς το ΗΚΓ ηρεμίας μπορεί να είναι φυσιολογικό, μεθοριακό ή μη ειδικό!!! Ιδιαίτερη προσοχή και αντιμετώπιση χρήζουν οι ψυχικές κι κοινωνικές επιπτώσεις της ανακοίνωσης ενός τέτοιου απειλητικού νοσήματος. Στο LQTs το όριο είναι 480msec, και ο γενετικός έλεγχος έχει σημασία, στο Brugada το ΗΚΓ τύπου 1 είναι από μόνο του αρκετό για την διάγνωση, ενώ στην CPVT η παρουσία της αρρυθμίας ή ο γενετικός έλεγχος (δύο θέσεις γονιδίων) θέτει διάγνωση. Συχνά δοκιμασίες πρόκλησης φαρμακολογικές ή με άσκηση μπορεί να χρειαστούν για να αποκαλυφθεί η λανθάνουσα παθολογία. Η πολύπλευρη από ειδικότητες και δοκιμασίες προσέγγιση και διαστρωμάτωση είναι η δέουσα προσέγγιση.