BJSM Figure 12. ECG from a patient with arrhythmogenic right ventricular cardiomyopathy. Note multiple premature ventricular complexes with a left bundle branch pattern and superior axis (negative QRS vector in inferior leads). Figure 13. (A) Normal variant repolarisation changes in a black/African athlete characterised by domed ST segment elevation and T wave inversion in V1–V4. (B) Pathological T wave inversion in V1–V3. Note the isoelectric ST segment. The absence of ST segment elevation prior to T wave inversion makes this ECG abnormal. Additional testing is required to rule out arrhythmogenic right ventricular cardiomyopathy. In patients with diagnosed ARVC (‘overt stage’) or known desmosome mutation positive subjects, 95% have an abnormal ECG marked by abnormal TWI, a prolonged S wave upstroke in the anterior precordial leads (V1–V3), and/or an epsilon wave.50–52 However, in cardiac screening, physicians may encounter asymptomatic athletes in the early ‘concealed stage’ of the disease, showing less pronounced ECG changes. The extent of evaluation is dependent on the specific ECG findings suggestive of ARVC and will be more extensive in the presence of warning symptoms or significant family history. A combination of tests is needed to effectively make the diagnosis or to rule out ARVC. Echocardiography, ambulatory ECG (Holter) monitoring, signal-averaged ECG (SAECG), and ventricular angiography provided optimal evaluation, while cardiac MRI (falsepositives) and biopsy (low-sensitivity) were considered less useful for diagnosis in suspected ARVC.53 54 The evaluation of major diagnostic ECG findings according to the 2010 Task Force criteria of TWI in the right precordial leads (V1– V3) or beyond in ages >14 years (in the absence of complete RBBB) should be extensive. In addition to a comprehensive symptom history, family history and physical examination, evaluation of TWI in V1–V3 or beyond should include echocardiography, Holter monitoring, SAECG, maximal exercise-ECG test and possibly a cardiac MRI.49 Isolated epsilon waves in the right precordial leads, a less specific major ECG criteria, still require an echocardiography and ECG monitoring for an arrhythmia (Holter or exercise-ECG test).49 Evaluation of minor diagnostic ECG-findings according to the Task Force criteria (without accompanying positive family history or alarming symptoms), may be less extensive.49 TWI in right ventricular outflow tract consistent with idiopathic right ventricular outflow tract arrhythmia which is a benign condition, non-familial and not associated with structural ventricular abnormalities. PVCs with an LBBB morphology and superior axis (negative in the inferior leads) originate from the right ventricular free wall or apex and are more suggestive of ARVC (figure 12). Evaluation of suspected ARVC Disease expression in ARVC is variable, and clinical manifestations vary with age and stage of disease.49 Similarly, the extent of ECG abnormalities are associated with the severity of disease.51 32 Sport & Geneeskunde | september 2013 | nummer 4 V1–V2 may require simply a careful personal and family history and physical examination. Repolarisation variants in the anterior precordial leads in black/ African athletes must be distinguished from pathological repolarisation changes found in ARVC. In ARVC, the ST segment is usually isoelectric prior to TWI, in contrast to the ‘domed’ ST segment elevation which is the hallmark feature of the normal repolarisation variant in black/African athletes (figure 13). TWI involving at least two consecutive precordial leads from V2 to V6 with an isoelectric ST segment, regardless of ethnicity, requires additional investigation. Dilated cardiomyopathy DCM is a heart muscle disorder characterised by weakened myocardial contraction, which over time leads to cavity enlargement and eccentric heart muscle hypertrophy. It is a common cause of heart failure, the inability of the heart to meet the demands of the body. DCM can be caused by a Pagina 31
Pagina 33Interactieve web catalogus, deze presentatie of gids is levensecht online geplaatst met Online Touch en bied het digitaal uitgeven van digi onderzoeksrapporten.
Sport & Geneeskunde nummer 4 | September 2013 Lees publicatie 25Home