(Circulation. 2005;112:e68-e69.)
© 2005 American Heart Association, Inc.
Correspondence |
Division of Cardiology, University of Padua Medical School, Padua, Italy
Institute of Pathology, University of Padua Medical School, Padua, Italy
We read with interest the article by Nasir et al1 that emphasizes the role of 12-lead ECG in the diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). The authors examined the ECG parameters in 50 affected patients, finding that almost all presented abnormal features and proposed as a new diagnostic ECG marker of ARVC a prolonged S-wave upstroke in V1 through V3. However, in a series of 132 patients belonging to 37 families with ARVC/D, we found an abnormal ECG in only 47% of cases, even though among 19 probands who died suddenly, the test was within normal limits only once.2 Although these data are in accordance with those of Nasir et al, confirming that the severity of the disease correlates well with the ECG features, the statement that the 12-lead ECG is almost always abnormal can be misleading for the reader. The different prevalence of abnormal 12-lead ECG features of ARVC/D in our series versus that of Nasir et al is clearly the result of different patient selection. In our paper, selection was made on the basis of familiarity. Therefore, subjects with different extents of the disease were examined, and we found that the majority of them (64%) presented a mild form of the disease in terms of right ventricular dilation and kinetic abnormalities. Nevertheless, 23% of this group had ventricular arrhythmias. Thus, the clinician must be aware that an in vivo diagnosis of ARVC/D can be achieved even in a subject with a normal 12-lead ECG, and that the more diffuse the disease, the more likely an abnormal 12-lead ECG will be found.
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2. Nava A, Bauce B, Basso C, Muriago M, Rampazzo A, Villanova C, Daliento L, Buja G, Corrado D, Danieli GA, Thiene G. Clinical profile and long-term follow-up of 37 families with arrhythmogenic right ventricular cardiomyopathy. J Am Coll Cardiol. 2000; 36: 22262233.
Department of Cardiology, St. Jans Hospital, Brugge, Belgium
To the Editor:
We read the article by Nasir et al1 with great interest. We learned that 95% of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (AVRD/C) without right bundle-branch block (RBBB) pattern on ECG had a prolonged S wave upstroke in V1 through V3 (S wave
The ECGs of 7 of our most recent cases with ARVD/C were reviewed. Diagnosis was made on the criteria proposed by the European Society of Cardiology.2 Each of the 7 patients fulfilled at least 2 major criteria, 1 major and 2 minor criteria, or 4 minor criteria.2 All patients had multiple ventricular tachycardia morphologies and had undergone an implantable cardioverter-defibrillator implantation.
The ECGs were reviewed by 3 independent cardiologists. We found that 2 patients had an LBBB and that of the 5 other patients only 1 (20%) had the prolonged upstroke S wave in V1 through V3 compared with the 87% that the Nasir group found. T inversion was seen in 4 of 5 patients (80%; without LBBB or RBBB) as the most important criterion; this number was almost identical to what Nasir et al (87%) found. The term ARVD/C encompasses a large spectrum of diseases with similar clinical presentations and histological features.3 This could be an explanation for the different prolonged upstroke S waves.
Recently, Chimenti et al4 published histological findings in patients with clinical and instrumental diagnoses of sporadic ARVD. They concluded that 50% of the cases of AVRD/C are sporadic and in the absence of a family history, they could be affected primarily by a myocarditis of the RV; myocarditis of the RV can mimic AVRD/C. However, only 22% of Nasirs patients had a known family history of ARVD/C. The prolonged upstroke S wave may thus be the result of other concurrent phenomena such as myocarditis. Among our patients, 57% (4/7) have a family history of ARVD/C.
Thus, after a retrospective analysis of our latest cases of ARVD/C, we conclude that this new ECG criterion is not as useful as stated by Nasir et al.
Letters Regarding Article by Nasir et al, "Electrocardiographic Features of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy According to Disease Severity: A Need to Broaden Diagnostic Criteria"
55 ms). Nasir et al state that this is the most prevalent ECG feature and propose it as a diagnostic ECG marker.
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2. McKenna WJ, Thiene G, Nava A, Fontaliran F, Blomstrom-Lundqvist C, Fontaine G, Camerini F. Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy. Task Force of the Working Group Myocardial and Pericardial Disease of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology. Br Heart J. 1994; 71: 215218.
3. Fontaine G, Prost-Squarcioni C. Implantable cardioverter defibrillator in arrhythmogenic right ventricular cardiomyopahties. Circulation. 2004; 109: 14451447.
4. Chimenti C, Pieroni M, Maseri A, Frustaci A. Histologic findings in patients with clinical and instrumental diagnosis of sporadic arrhythmogenic right ventricular dysplasia. J Am Coll Cardiol. 2004; 43: 23052313.
Department of Cardiology, Johns Hopkins University, Baltimore, Md
Sarver Heart Disease, University of Arizona Health Sciences Center, Tucson, Ariz
We are thankful to Nava et al and Dewilde et al for their interest in our study.1 Nava et al previously reported ECG abnormalities in only 47% of 132 patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients with a known family history of ARVD/C.2 There are several possible reasons for these observed differences between our study and that of Nava et al. Individuals with a known family history of ARVD/C tend to be diagnosed relatively early in the course of their disease when compared with ARVD/C patients without a family history of the disease who may be asymptomatic. The results of our study that differ from that of Nava et al can likely be explained by the facts that that only 22% of our study patients had a family history of the disease and almost all were symptomatic. In contrast, the study by Nava et al was based on familial cases of ARVD/C. Therefore, similar individuals with early forms of ARVD/C were not likely to be included in our study. We think that the increased duration of the S wave is another (and possibly a sensitive) indicator of parietal block caused by slowed conduction in the right ventricle. This measurement may reflect the extent of the abnormality of right ventricular involvement by ARVD/C.
It is difficult to understand the lower prevalence of S-wave upstroke >55 ms in V1 through V3, as reported by Dewilde et al in their small series of 5 patients. Dewilde et al did not state whether they followed the technique that we used to measure the S-wave upstroke. We measured the ECG intervals using digital calipers capable of measuring to within 1 ms (horizontal axis) after enlarging the ECG 2 times. This was assessed blindly by 2 independent observers. The cutoff of >55 ms was based on the best predictive value that differentiated ARVD/C from patients with idiopathic VT and normal controls. However, a lower cutoff value could be used with little loss of specificity.
This S-wave feature has been investigated as a potential diagnostic and prognostic marker by our group. We observed an increase in the S-wave upstroke of >10 ms in V1 through V3 in 24/35 (69%) of patients with ARVD/C who had repeat ECGs (median time between tracings of 43 months).3 We cannot comment on the issue of myocarditis because only 14 of the 50 ARVD/C patients in our series had an endomyocardial biopsy.
The reproducibility of our findings and correlation with the extent of the disease process should be the subject of future studies. Data from the ongoing US and European ARVD/C studies should answer these important questions.
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2. Nava A, Bauce B, Basso C, Muriago M, Rampazzo A, Villanova C, Daliento L, Buja G, Corrado D, Danieli GA, Thiene G. Clinical profile and long-term follow-up of 37 families with arrhythmogenic right ventricular cardiomyopathy. J Am Coll Cardiol. 2000; 36: 22262233.
3. Piccini J, Nasir K, Bomma C, Tandri H, Dalal D, Tichnell C, James C, Crosson J, Calkins H. Electrocardiographic findings over time in arrhythmogenic right ventricular dysplasia/cardiomyopathy. Am J Cardiol. 2005; 96: 122126.[Medline] [Order article via Infotrieve]
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