The value of different electrocardiographic depolarization criteria in the diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy.

BACKGROUND: The use of electrocardiographic (ECG) depolarization and repolarization criteria plays a large role in the diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Different ECG algorithms should be analyzed in making the diagnosis of ARVD/C with the use of normal and modified recording techniques. METHODS: In a cohort of 343 patients (210 men and 133 women; mean age, 46.0 +/- 13.7 years) meeting the Task Force of the Working Group on Myocardial and Pericardial Diseases of the European Society of Cardiology and the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology diagnostic criteria for ARVD/C, the value of different ECG criteria (eg, localized right precordial QRS prolongation defined as QRS duration in (V1+V2+V3)/(V4+V5+V6) of 1.2 or higher, right precordial QRS prolongation with QRS in V1-3 of 110 milliseconds or higher, epsilon potentials in the right precordial leads, S-wave upstroke in V1-3 of 55 milliseconds or higher, and right precordial T-wave inversions) was analyzed with the use of a normal recording technique and a highly amplified and modified recording technique (n = 207) at a paper speed of 50 mm/s. Fifty-two phenotypically and genotypically unaffected individuals identified by systematic screening in 24 families (30 men; mean age, 42.4 +/- 8.3 years) were treated as control subjects. RESULTS: In the normal as well as highly amplified and modified recording techniques, the incidence of localized right precordial QRS prolongation was 98% (100%), that of QRS in V1-3 of 110 milliseconds or higher was 75% (80%), that of prolonged right precordial S-wave upstroke was 84% (60%), that of epsilon potentials was 23% (77%), and that of right precordial T-wave inversions was 55%. Four of 6 patients without the phenomenon of localized right precordial QRS prolongation with the use of the normal recording technique had a prolonged S-wave upstroke of 55 milliseconds or higher. In the control group, localized right precordial QRS prolongation, QRS in V1-3 of 110 milliseconds or higher, and epsilon potentials could not be identified. An S-wave upstroke of 55 milliseconds or higher was present in 2 of 3 cases, and T-wave inversions were found in 3. CONCLUSIONS: Electrocardiographic depolarization criteria for ARVD/C analyzed in this large cohort of patients meeting the International Society and Federation of Cardiology/European Society of Cardiology criteria presented with high sensitivity and specificity in comparison with those in the control group of phenotypically and genotypically unaffected individuals defined by systematic screening in 24 families with ARVD/C. The incidence of right precordial T-wave inversions was much lower, indicating that not only patients with overt right ventricular dilatation and dysfunction were included. Electrocardiographic algorithms, including localized right precordial QRS prolongation, prolonged S-wave upstroke, and epsilon potentials, with the use of the normal recording technique and the amplified and modified recording technique at a paper speed of 50 mm/s contribute significantly to the noninvasive diagnosis of ARVD/C.

Mechanisms of syncopes in arrhythmogenic right ventricular dysplasia-cardiomyopathy beyond monomorphic ventricular tachycardia.

Syncopes appear in 10-20% in arrhythmogenic right ventricular dysplasia-cardiomyopathy (ARVD/C). In the majority of cases sustained or non-sustained monomorphic ventricular tachycardias represent the underlying mechanism of syncope. In other cases the mechanism remains unclear. In 37 patients (23 females, mean age 43.6+/-12.8 years) without detectable and inducible monomorphic ventricular tachycardia, a diagnostic algorithm including repeat ECG, holter monitoring, telemetry, electrophysiological examination, ajmaline challenge, tilt table testing and neurological work-up (EEG, cranial computer tomography) was used in order to identify the mechanism of syncopes. Constant AV block 3 degrees could be found in 3 patients (2 males). Intermittant AV block 2 degrees or 3 degrees could be identified in 3 females. Four males had abnormal Wenckebach point during rapid atrial stimulation, 3 males demonstrate isolated HV interval prolongation. Rapid polymorphic VT and VF could be induced in a young female with ARVD/C. Eight patients (7 females) presented with recurrent syncopes and provocable right precordial ST elevation and right bundle branch block during ajmaline challenge. Three patients had abnormal tilt table testing as the only pathological finding. In one female with intermittent AV block 2 degrees tilt table testing and ajmaline challenge was positive. One female had the diagnosis of focal epilepsia after neurological work-up. In 11 cases the mechanism of syncopes remained unclear. In patients with ARVD/C and syncopes beyond detectable or inducible monomorphic VT, several mechanisms of syncopes could be identified with conduction disease as the predominant finding. These results may help in identifying rare mechanisms of syncopes in ARVD/C.