Holter ρυθμού:ποιους άλλους δείκτες

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Εμμ. Μ. Κανουπάκης MD PhD FESCΠανεπιστημιακό Νοσοκομείο Ηρακλείου

Norman J. Holter

…the original Holter monitor was a 75-lb backpack with areel-to-reel FM

tape recorder, analog patient interface electronics, and largebatteries

Η εξέλιξη

Indications for AECG to AssessSymptoms Possibly Related to Rhythm

Disturbances• Class I

• Patients with unexplained syncope, near syncope, orepisodic 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 AssessAntiarrhythmic Therapy

• Class I• To assess antiarrhythmic drug response in individuals

in whom baseline frequency of arrhythmia isreproducible and of sufficient frequency to permitanalysis

• 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 forIschemia Monitoring

• Class I• None

• Class IIa• Patients with suspected variant angina

• Class IIb• Evaluation of patients with chest pain who

cannot exercise• Preoperative evaluation for vascular surgery of

patients who cannot exerciseACC/AHA Guidelines for Ambulatory Electrocardiography JACC 1999;34:912–48

Indications for AECG Arrhythmia Detection toAssess Risk for Future Cardiac Events in Patients

Without Symptoms From Arrhythmia• Class I

• None• 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 δείκτηςπρογνωστικής ταξινόμησης

• The greatest number of SCD events occurs inpatients with a preserved or only moderatelyreduced LVEF

• LVEF has a limited "specificity" meaning that areduced LVEF is a risk factor not only for sudden butalso for non-sudden death– only a small portion will benefit from ICD

“Arrhythmic” risk stratification tools

• imbalance in autonomic tone– HRV, heart rate turbulence

• heterogeneities in ventricularrepolarization– QT interval, QT dispersion, T-wave alternans

• slowed conduction– QRS duration, late potentials

• ventricular ectopy– NSVT, EP study

• extent of myocardial damage and scarformation– CMR-LGE

Δείκτες από το Holter

• imbalance in autonomic tone– HRV, heart rate turbulence

• heterogeneities in ventricularrepolarization– QT interval, QT dispersion, T-wave alternans

• slowed conduction– QRS duration, late potentials

• ventricular ectopy– NSVT, EP study

• extent of myocardial damage and scarformation– CMR-LGE

Heart rate variability

MARKERS OF AUTONOMIC DYSFUNCTION

“A healthy heart is not ametronome”

Tachograms

Arsenos et al, Hellenic J Cardiol 2013; 54: 301-315

Η εξήγηση για την HRV

Time domain analysis

Arsenos et al, Hellenic J Cardiol 2013; 54: 301-315

...reduced values of SDNN <70msec predict increased risk for mortality aftermyocardial infarction

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 mortalityremains a difficult task and there is no agreementon which HRV parameter is more suitable toidentify high risk patients

Heart rate turbulence

MARKERS OF AUTONOMIC DYSFUNCTION

Heart rate turbulence

Heart rate turbulence physiologyΈκτακτη κοιλιακή συστολή

↓ όγκος παλμού

↓ αρτηριακής πίεσης

Ενεργοποίηση τασεοϋποδοχέων αορτικού τόξου/καρωτίδων

↑ καρδιακής συχνότητας ( βράχυνση RR διαστήματος – Τ.Ο.)

↑ όγκος παλμού

↑ αρτηριακής πίεσης

↓ καρδιακής συχνότητας(επιβράδυνση RR διαστήματος –T.S.)

Απόσυρσηπαρασυμπαθητικού

Ενεργοποίησηπαρασυμπαθητικού

Turbulence Onset

…is the percentage difference between the average value ofthe first two normal intervals following the PVC and of the lasttwo normal intervals preceding the PVC

Turbulence Slope

…μέγιστη θετική κλίση της γραμμικής παλινδρόμησης μιαςχρονοσειράς από 5 διαστήματα RR σε σύνολο 15 RRδιαστημάτων

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-MIProspective studies

…HRT was a strong and independent predictor of adverseevents independent from other risk factors tested

Zuern et al, Frontiers in Physiology 2011

HRT after MI

…an attenuated improvement ofHRT slope in the initial weeks afterMI is independently associated witha high risk of fatal or near-fatalarrhythmic 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 whomight benefit from prophylactic ICD

implantation, HRT should be combinedwith other independent predictors

Deceleration capacity

MARKERS OF AUTONOMIC DYSFUNCTION

Deceleration capacity

• Εκφράζει την επίδραση τουπαρασυμπαθητικού στο φλεβόκομβο καιτην ικανότητα του να επιβραδύνει τονκαρδιακό ρυθμό από beat to beat

Deceleration capacity

Bauer et al, Lancet 2006; 367: 1674–81

• …computation of heartbeatintervals longer than thepreceding 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

Mortality according to DC

Bauer et al, Lancet 2006; 367: 1674–81

Sensitivity & specificity of DCcompared 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)

Bauer et al, European Heart Journal 2009;30:576–583

from ISAR-RISK

SAF & risk stratification

Bauer et al, European Heart Journal 2009;30:576–583

from ISAR-RISK

…in post-MI patients with LVEF>30%, SAF identifies a high-risk group equivalentin size and mortality risk to patients with LVEF<30%

Prolongation of qt interval

MARKERS OF ABNORMAL REPOLARIZATION

QT interval

…the mean 24-h QTc interval with a cutoff point of >450 ms performed wellas an independent arrhythmia predictor.

...the QTc interval that was derived from the 24-h HM succeeded, while theQTc interval that was derived from 12-lead ECG failed as an arrhythmia riskstratifier in multivariate analysis.

T-WAVE ALTERNANS

MARKERS OF ABNORMAL REPOLARIZATION

T-wave alternans

results from heterogeneity of repolarization and abnormalities inintracellular calcium handling

a beat-to-beat fluctuation in ST-segment or T-wave morphology

Time-domain method(Modified Moving Average)

• A TWA level of ≥47 μV isconsidered abnormal and≥60 μV severely abnormalfor elevated risk for SCDand/or cardiovascularmortality

Exercise test, Holter

Abnormal AECG-TWA

AECG-TWA in different diseases

Verrier et al, Prog Cardiovasc Dis 2013;56:172-185

AECG-TWA & fatal cardiac events

Quan et al. BMC Cardiovascular Disorders 2014, 14:198

…in a meta-analysis of more than 1,500 subjects, thepositive TWA result predicted a nearly six-fold risk of a

cardiac event compared with the negative result

Late potentials

MARKERS OF ABNORMAL SUBSTRATE

Criteria for LP

• a filtered QRS complex>114 ms (fQRS>114 ms)

• a low-amplitude signalvoltage <40 μV in theterminal QRS complex thatlasts >38 ms (LAS>38 ms)

• a signal <20 μV in the last40 ms of the filtered QRScomplex (RMS<20 μV)

Holter derived LP

2/3 positive criteriathrough the 45-min high-resolution digital ECGrecording

•

Η κριτική…

• High negative but low positive predictivevalue

• Low “specificity” for sudden cardiac death

Future research

Should focus on:

• optimal timing of measurements

• evolution of these parameters on anindividual basis

REFINE-ICD

• Post –MI pts with LVEF 36%-49% are randomly assignedto usual care or to usual care plus an ICD if they haveabnormal HRT and TWA test results

• 1400 subjects to be followed for the primary end point ofall 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-infarctionscreening method for use in the earlyidentification of low-risk patients inwhom further diagnostic workout isnot warranted

Bauer et al, Lancet 2006; 367: 1674–81

Late Potentials

• Abnormal electric activitydue to depolarization delaymay develop in areas offibrosis and scars aroundthe infarcted myocardialzones

• These scar areas may form the electrical substrate formonomorphic VT

Spectral method

Exercise test (treadmill), heart rate 105-110 bpm