Holter ρυθμού: ποιους άλλους δείκτες μπορούμε και πρέπει να μετράμε Εμμ. Μ. Κανουπάκης MD PhD FESC Πανεπιστημιακό Νοσοκομείο Ηρακλείου
Norman J. Holter the original Holter monitor was a 75-lb backpack with a reel-to-reel FM tape recorder, analog patient interface electronics, and large batteries
Η εξέλιξη
Indications for AECG to Assess Symptoms Possibly Related to Rhythm Disturbances Class I Patients with unexplained syncope, near syncope, or episodic dizziness in whom the cause is not obvious Patients with unexplained recurrent palpitation ACC/AHA Guidelines for Ambulatory Electrocardiography JACC 1999;34:912 48
Indications for AECG to Assess Antiarrhythmic Therapy To assess antiarrhythmic drug response in individuals in whom baseline frequency of arrhythmia is reproducible and of sufficient frequency to permit analysis Class I Class IIa To detect proarrhythmic responses to antiarrhythmic therapy in high-risk patients ACC/AHA Guidelines for Ambulatory Electrocardiography JACC 1999;34:912 48
Indications for AECG for Ischemia Monitoring None Class IIa Patients with suspected variant angina Class I Class IIb Evaluation of patients with chest pain who cannot exercise Preoperative evaluation for vascular surgery of patients who cannot exercise ACC/AHA Guidelines for Ambulatory Electrocardiography JACC 1999;34:912 48
Indications for AECG Arrhythmia Detection to Assess Risk for Future Cardiac Events in Patients Without Symptoms From Arrhythmia None Class I Class IIb Post-MI patients with LV dysfunction Patients with CHF Patients with HCM ACC/AHA Guidelines for Ambulatory Electrocardiography JACC 1999;34:912 48
Ο φόβος
Μειονεκτήματα του ΚΕ ως δείκτης προγνωστικής ταξινόμησης The greatest number of SCD events occurs in patients with a preserved or only moderately reduced LVEF LVEF has a limited "specificity" meaning that a reduced LVEF is a risk factor not only for sudden but also for non-sudden death only a small portion will benefit from ICD
Arrhythmic risk stratification tools imbalance in autonomic tone heterogeneities in ventricular repolarization QRS duration, late potentials ventricular ectopy QT interval, QT dispersion, T-wave alternans slowed conduction HRV, heart rate turbulence NSVT, EP study extent of myocardial damage and scar
Δείκτες από το Holter imbalance in autonomic tone heterogeneities in ventricular repolarization QRS duration, late potentials ventricular ectopy QT interval, QT dispersion, T-wave alternans slowed conduction HRV, heart rate turbulence NSVT, EP study extent of myocardial damage and scar
MARKERS OF AUTONOMIC DYSFUNCTION Heart rate variability
A healthy heart is not a metronome
Tachograms Arsenos et al, Hellenic J Cardiol 2013; 54: 301-315
Η εξήγηση για την HRV
Time domain analysis...reduced values of SDNN <70msec predict increased risk for mortality after myocardial infarction Arsenos et al, Hellenic J Cardiol 2013; 54: 301-315
Frequency domain analysis
Frequency domain analysis Arsenos et al, Hellenic J Cardiol 2013; 54: 301-315
Prognostic significance of HRV after MI
HRV as a risk marker for SCD Negative predictive value is high Positive predictive accuracy and sensitivity of abnormal HRV for adverse outcomes is low Unfortunately, prediction of arrhythmic mortality remains a difficult task and there is no agreement on which HRV parameter is more suitable to identify high risk patients
MARKERS OF AUTONOMIC DYSFUNCTION Heart rate turbulence
Heart rate turbulence
Heart rate turbulence physiology Έκτακτη κοιλιακή συστολή όγκος παλμού αρτηριακής πίεσης Ενεργοποίηση τασεοϋποδοχέων αορτικού τόξου/καρωτίδων καρδιακής συχνότητας ( βράχυνση RR διαστήματος Τ.Ο.) Απόσυρση παρασυμπαθητικού όγκος παλμού αρτηριακής πίεσης καρδιακής συχνότητας (επιβράδυνση RR διαστήματος T.S.) Ενεργοποίηση παρασυμπαθητικού
Turbulence Onset is the percentage difference between the average value of the first two normal intervals following the PVC and of the last two normal intervals preceding the PVC
Turbulence Slope μέγιστη θετική κλίση της γραμμικής παλινδρόμησης μιας χρονοσειράς από 5 διαστήματα RR σε σύνολο 15 RR διαστημάτων
HRT classification 1. HRT 0 (T.O. 0%, T.S. > 2.5 msec/rr) 2. HRT 1 (abnormal T.O or T.S.) 3. HRT 2 (abnormal Τ.Ο. and Τ.S.)
HRT as a risk marker post-mi Prospective studies HRT was a strong and independent predictor of adverse events independent from other risk factors tested Zuern et al, Frontiers in Physiology 2011
HRT after MI an attenuated improvement of HRT slope in the initial weeks after MI is independently associated with a high risk of fatal or near-fatal arrhythmic events CARISMA & REFINE Investigators Huikuri et al, Heart Rhythm 2010;7:229 235
HRT in post-mi with preserved EF Bauer et al, European Heart Journal 2009;30:576 583
For identifying high risk individuals who might benefit from prophylactic ICD implantation, HRT should be combined with other independent predictors
MARKERS OF AUTONOMIC DYSFUNCTION Deceleration capacity
Deceleration capacity Εκφράζει την επίδραση του παρασυμπαθητικού στο φλεβόκομβο και την ικανότητα του να επιβραδύνει τον καρδιακό ρυθμό από beat to beat
Deceleration capacity computation of heartbeat intervals longer than the preceding interval Step 1. Definition of anchors Step 2. Definition of segments Step 3. Phase rectification Step 4. Signal averaging Step 5. Quantification of DC and AC παθολογικές τιμές 4.5 ms Bauer et al, Lancet 2006; 367: 1674 81
Mortality according to DC Bauer et al, Lancet 2006; 367: 1674 81
Sensitivity & specificity of DC compared to EF and HRV Bauer et al, Lancet 2006; 367: 1674 81
Severe Autonomic Failure (SAF) Patients with both abnormal HRT (slope 2.5 ms/rr and onset 0%) and abnormal DC ( 4.5 ms) from ISAR-RISK Bauer et al, European Heart Journal 2009;30:576 583
SAF & risk stratification from ISAR-RISK in post-mi patients with LVEF>30%, SAF identifies a high-risk group equivalent in size and mortality risk to patients with LVEF<30% Bauer et al, European Heart Journal 2009;30:576 583
MARKERS OF ABNORMAL REPOLARIZATION Prolongation of qt interval
QT interval
the mean 24-h QTc interval with a cutoff point of >450 ms performed well as an independent arrhythmia predictor....the QTc interval that was derived from the 24-h HM succeeded, while the QTc interval that was derived from 12-lead ECG failed as an arrhythmia risk stratifier in multivariate analysis.
MARKERS OF ABNORMAL REPOLARIZATION T-WAVE ALTERNANS
T-wave alternans a beat-to-beat fluctuation in ST-segment or T-wave morphology results from heterogeneity of repolarization and abnormalities in intracellular calcium handling
Time-domain method (Modified Moving Average) Exercise test, Holter A TWA level of 47 μv is considered abnormal and 60 μv severely abnormal for elevated risk for SCD and/or cardiovascular mortality
Abnormal AECG-TWA
AECG-TWA in different diseases Verrier et al, Prog Cardiovasc Dis 2013;56:172-185
AECG-TWA & fatal cardiac events in a meta-analysis of more than 1,500 subjects, the positive TWA result predicted a nearly six-fold risk of a cardiac event compared with the negative result Quan et al. BMC Cardiovascular Disorders 2014, 14:198
MARKERS OF ABNORMAL SUBSTRATE Late potentials
Criteria for LP a filtered QRS complex >114 ms (fqrs>114 ms) a low-amplitude signal voltage <40 μv in the terminal QRS complex that lasts >38 ms (LAS>38 ms) a signal <20 μv in the last 40 ms of the filtered QRS complex (RMS<20 μv)
Holter derived LP 2/3 positive criteria through the 45-min highresolution digital ECG recording
Η κριτική High negative but low positive predictive value Low specificity for sudden cardiac death
Future research Should focus on: optimal timing of measurements evolution of these parameters on an individual basis
REFINE-ICD Post MI pts with LVEF 36%-49% are randomly assigned to usual care or to usual care plus an ICD if they have abnormal HRT and TWA test results 1400 subjects to be followed for the primary end point of all cause mortality Trial results are expected to be available in 2017
PRESERVE-EF
DC in post-mi with preserved EF an inexpensive, easily obtainable, and noninvasive post-infarction screening method for use in the early identification of low-risk patients in whom further diagnostic workout is not warranted Bauer et al, Lancet 2006; 367: 1674 81
Late Potentials Abnormal electric activity due to depolarization delay may develop in areas of fibrosis and scars around the infarcted myocardial zones These scar areas may form the electrical substrate for monomorphic VT
Spectral method Exercise test (treadmill), heart rate 105-110 bpm