Reader‐ and Instrument‐Dependent Variability in the Electrocardiographic Assessment of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy
Variability in ECG Assessment in ARVD/C. Introduction: Despite the use of standardized definitions, widely varying prevalence estimates of electrocardiographic (ECG) features related to arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) have been reported in different cohorts. This study was aimed at examining the variability in the ECG interpretation resulting from the same reader, different readers, and using different ECG-resolutions.
Methods and Results: Blinded to other clinical data, 2 readers examined quantitative and qualitative ECG features of 20 (10 ARVD/C) randomly selected individuals. ECGs were recorded at standard-speed (SS) and double-speed-double-amplitude (DS) settings. The SS ECGs were scanned, magnified 4×, and evaluated using electronic calipers (EL). One reader repeated all measurements. For both readers, the intraclass correlation coefficient (ICC) for the measurement of QRS duration was good between conventional and electronic evaluation [DS vs EL: Reader 1—0.64 (0.52–0.73); Reader 2—0.67 (0.55–0.76)][SS vs EL: Reader 1—0.60 (0.47–0.70); Reader 2—0.60 (0.47–0.70)]. Using the same resolution, the intrareader ICC was good for SS [0.70 (0.59–0.78)], DS [0.85 (0.80–0.90)], and EL [0.70 (0.69–0.83)] resolutions, but deteriorated for interreader comparisons [0.50 (0.36–0.62), 0.75 (0.66–0.82), and 0.75 (0.66–0.82), respectively]. For qualitative parameters, the intra- and interreader agreement was inconsistent for all but 2 parameters. Both readers were in perfect agreement while interpreting right precordial T-wave inversion [κ= 1] and right bundle branch block morphology (RBBB) [κ= 0.83 (0.5–1.0)] even when using SS resolution.
Conclusions: Right precordial t-wave inversion and RBBB are the only ECG parameters that can be detected consistently even using the conventionally used ECG-resolution. The substantial variability in evaluation of other parameters is not improved even with the use of higher resolutions. (J Cardiovasc Electrophysiol, Vol. 22, pp. 561-568 May 2011)
Available from: Larisa Tereshchenko
- "Terminal activation duration (TAD) of QRS (distance from the S-wave nadir to the end of QRS) ≥ 55ms in V1, V2 or V3 in the absence of complete RBBB was identified as a minor criterion. However, a previous study has demonstrated that manual measurements of many quantitative ECG parameters relevant to ARVD/C diagnosis, particularly QRS duration, can vary greatly between readers . "
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Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by delay in depolarization of the right ventricle, detected by prolonged terminal activation duration (TAD) in V1-V3. However, manual ECG measurements have shown moderate-to-low intra- and inter-reader agreement. The goal of this study was to assess reproducibility of automated ECG measurements in the right precordial leads.
Pairs of ECGs recorded in the same day from Johns Hopkins ARVD/C Registry participants [n=247, mean age 35.2±15.6 y, 58% men, 92% whites, 11(4.5%) with definite ARVD/C] were retrospectively analyzed. QRS duration, intrinsicoid deflection, TAD, and T-wave amplitude in the right precordial leads, as well as averaged across all leads QRS duration, QRS axis, T axis, QTc interval, and heart rate was measured automatically, using 12SL TM algorithm (GE Healthcare, Wauwatosa, WI, USA). Intrinsicoid deflection was measured as the time from QRS complex onset to the alignment point of the QRS complex. TAD was calculated as the difference between QRS duration and intrinsicoid in V1, V2, V3. Reproducibility was quantified by Bland-Altman analysis (bias with 95% limits of agreement), Lin's concordance coefficient, and Bradley-Blackwood procedure.
Bland-Altman analysis revealed satisfactory reproducibility of tested parameters. V1 QRS duration bias was -0.10ms [95% limits of agreement -12.77 to 12.56ms], V2 QRS duration bias -0.09ms [-11.13 to 10.96ms]; V1 TAD bias 0.14ms [-13.23 to 13.51ms], V2 TAD bias 0.008ms [-12.42 to 12.44ms].
Comprehensive statistical evaluation of reproducibility of automated ECG measurements is important for appropriate interpretation of ECG. Automated ECG measurements are reproducible to within 25%.
Available from: Loizos Antoniades
- "Although ARVC/D due to desmosome mutations represents more than 50% of ARVC/D probands and the majority of familial cases, other genetic or acquired causes might exist. A standard and accurate protocol was followed for measurement of QRS complex duration; however, in other studies, this electronic method has not been proved to be of higher reproducibility.15 In addition, since CMR was not achievable for all patients, functional/structural alterations were evaluated by two-dimensional echocardiography. "
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ABSTRACT: To evaluate arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) in affected families with desmosome mutations on the basis of the recently revised Task Force Criteria (TFC).
One hundred and three consecutive carriers of pathogenic desmosome mutations and 102 mutation-negative relatives belonging to 22 families with dominant and 14 families with recessive ARVC/D were evaluated according to the original and revised TFC. Serial cardiac assessment with 12-lead, signal-averaged, and 24 h ambulatory ECG and two-dimensional echocardiography was performed. Clinical events and outcome were prospectively analysed up to 24 years (median 4 years). With the revised criteria, 16 carriers were newly diagnosed on the basis of ECG abnormalities in 100%, ventricular arrhythmias in 79%, and functional/structural alterations in 31%, increasing diagnostic sensitivity from 57 to 71% (P = 0.001). Task Force Criteria specificity improved from 92 to 99% (P = 0.016). In dominant mutation carriers, penetrance changed significantly (61 vs. 42%, P = 0.001); no changes were observed in recessive homozygous carriers (97 vs. 97%, P = 1.00). Affected carriers according to the revised TFC (n = 73) had 12-lead ECG abnormalities in 96%, ventricular arrhythmias in 91%, and functional/structural alterations fulfilling echocardiographic criteria in 76%. Cumulative and event-free survival did not differ significantly between dominant and recessive affected carriers, being at 78.6 vs. 76 and 51.7 vs. 55.4%, respectively, by the age of 40 years.
Revised TFC increased diagnostic sensitivity particularly in dominant ARVC/D. Serial family evaluation may rely on electrocardiography which seems to have the best diagnostic utility particularly in early disease that is not detectable by two-dimensional echocardiography.
Available from: Andrew Krahn
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ABSTRACT: BACKGROUND: Ventricular arrhythmias in ARVD/C and idiopathicVT patients can share a left bundle branch block/inferior axis morphology. We previously reported ECG characteristics during outflow tract ventricular arrhythmias that helped distinguish VT related to ARVD/C from idiopathicVT. OBJECTIVE: The purpose of this study was to prospectively validate these criteria. METHODS: We created a risk score using a derivation cohort. Two experienced electrophysiologists blinded to the diagnosis prospectively scored patients with VT/PVCs with LBBB/inferior axis pattern in a validation cohort of 37 ARVD/C tracings and 49idiopathicVT tracings. All ARVD/C patients had their diagnosis confirmed based on the revised Task Force criteria. IdiopathicVT patients were selected based on structurally normal hearts with documented RV outflow tract VT successfully treated with ablation. The scoring system provides 3 points for sinus rhythm anterior T wave inversions in leads V1 through V3, and during ventricular arrhythmia: 2 points for QRS duration in lead I ≥120msec, 2 points for QRS notching, and 1 point for precordial transition at lead V5 or later. RESULTS: A score of 5 or greater was able to correctly distinguish ARVD/C from idiopathicVT 93% of the time, with a sensitivity of 84%, specificity of 100%, positive predictive value 100%, and negative predictive value 91%. CONCLUSIONS: We describe a simple scoring algorithm that uses 12 lead ECG characteristics to effectively distinguish right ventricular outflow tract arrhythmias originating from ARVD/C versus idiopathicVT patients.
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