No value of the ECG in congenital left ventricular aneurysms and diverticula?

In this issue of the journal, Ohlow et al.1 present their experience regarding the value of the electrocardiogram (ECG) in diagnosing congenital left ventricular diverticulum or aneurysm. Both are rare disorders of the left ventricular wall; the former being a finger- or a hook-like appendix emerging from the wall of the left ventricle, contracting in synchrony with the left ventricle and with a narrow connection to the left ventricular cavity. 2 In contrast, congenital aneurysms have a wide connection to the left ventricle and look similar to acquired aneurysms of the ventricular wall. Their size may vary from 0.5 to 9 cm and they are located most frequently in the apex or the perivalvular area. There is a frequent association with other congenital cardiac malformations, most frequently ventricular and atrial septal defect, patent foramen ovale and tricuspid atresia, and vascular or non-vascular extracardiac abnormalities. The clinical course of isolated congenital aneurysms and diverticula is usually benign, but ventricular arrhythmias and sudden cardiac death, systemic emboli, rupture with cardiac tamponade, mitral regurgitation, or compression of the left coronary artery in case of perivalvular localization have been reported. Recent data from the same authors 3 suggest a 20-fold higher prevalence than reported in the literature and a male preponderance for aneurysms; women were more likely to have diverticula. Embolic events were more frequent in patients with diverticula. Arrhythmias occurred more frequently in both conditions than in the control group. In this study, the ECG abnormalities in congenital aneurysms and diverticula are described. For this purpose, standard 12-lead ECGs of 125 patients were studied and compared with ECGs of age- and gender-matched controls. In this relatively old population (the mean age was 66 years), ECG abnormalities were found in 56.8% of cases. More specifically, inverted T waves >2 mm in ≥2 leads, abnormal Q waves, slow R progression in the precordial leads, (in)complete right bundle branch block, an early repolarization pattern, a prolonged PR-interval, and atrial fibrillation were more prevalent in the study group. More frequently, abnormalities were found in diverticula (38.2 vs. 15.8%) and in the apical localization of the aneurysm (32 vs. 16%), and there was a trend for more abnormal ECGs at older age. This study, reporting on the ECG in congenital left ventricular aneurysms and diverticula, is important, being the largest one until now and based on an impressive, single centre, coronary angiography database. Although ECG findings were abnormal in the majority of cases, the sensitivity, specificity, and positive and negative predictive value were disappointing. The authors conclude that the ECG has little value as a screening tool to diagnose congenital aneurysms or diverticula. These findings, however, are not unexpected: although an ECG is an excellent tool to diagnose arrhythmias, ischaemia, and electrical disease (such as long QT syndrome and Brugada syndrome), it is much less appropriate to diagnose structural changes of the heart. This does not mean, however, an ECG is not useful for identifying structural or prognostic features. Unfortunately, in the present study, no detailed information on electrocardiographic and structural or clinical associations was provided. Other study limitations, some acknowledged by the authors, are partly due to the retrospective study design. The study population has been retrieved from the coronary angiography database, leading to inclusion bias because individuals with anginal or arrhythmia complaints were more likely to be included. It is, therefore, unclear how representative the results are for both anomalies in the general population. Abnormal ECGs might have further contributed to the selection of patients for coronary angiography, influencing the results obtained in the study. The study population consists of adults with a mean age of 66 years; therefore, children are not represented. Because more pronounced manifestations of both conditions exist in children, including those that could result in more frequent and possibly more specific ECG abnormalities than described in the present study. Inherent to the patient selection is the underrepresentation of patients with associated congenital cardiac abnormalities, which could be considered an advantage, allowing the aneurysms and diverticula to be studied in the absence of other abnormalities. The ECG findings were related to age and gender, and also to the type and localization of the abnormality. Interestingly, in specific subgroups, such as female gender, the diverticula population, the setting of an apical location, and possibly also in the older age group, more distinct ECG abnormalities were present. It is not clear, however, whether and how these variables are mutually related. The authors did not report on the possible relationship between the different ECG abnormalities and other clinical variables such as the extent of the aneurysmatic process, the size of the diverticula, or the type of the underlying clinical problem (i.e. an arrhythmia, syncope, or chest pain). In this regard, several hypotheses would have been worthwhile testing: for instance, whether an abnormal ECG could be related to more extensive disease, whether the leads showing Q waves, slow R progression, or negative T waves 4 are related to the site and extent of the lesion, and whether the early repolarization pattern was related to ventricular arrhythmias and syncope, based on recent publications on the association between the early repolarization pattern and sudden cardiac death. 5 , 6 Also more clinical and angiographic details about the patients with atrial fibrillation and conduction disturbances would have been instructive. The authors made an important first step to unravel the clinical and prognostic features of these rare, but relevant entities. The next step should be a prospective study design using a more structured diagnostic work up, also including information from other electrocardiographic and imaging modalities. Conflict of interest: none declared.