ECG characteristics according to the presence of late gadolinium enhancement on cardiac MRI in hypertrophic cardiomyopathy

Abstract

BackgroundLate gadolinium enhancement (LGE) on cardiac MRI (CMR) has been described as an independent predictive factor of cardiovascular events among patients with hypertrophic cardiomyopathy (HCM). LGE and Q waves are considered as myocardial scar markers but their relation in the context of HCM is poorly established and has to be more supported. The objective of the study was to compare ECG findings in the presence or absence of LGE.Methods42 patients with HCM confirmed by CMR were included in the study. ECG abnormalities including abnormal Q waves and five ECG scores of left ventricular hypertrophy were assessed and compared according to LGE presence and its extension. Some CMR features, such as septal to posterior wall thickness ratio, were also studied according to the presence of LGE and the presence of abnormal Q waves.ResultsAbnormal Q waves were more prevalent in the LGE (+) group (60% vs 12%; p=0.002), but there was no correlation between location of Q waves on ECG and territory of LGE on CMR. Among patients with LGE, quantitative analysis of LGE was not different in the presence or absence of Q waves. In contrast to the LGE mass, septal to posterior wall thickness was higher in patients with abnormal Q waves (2.3±0.7 vs 1.6±0.5; p=0.012).ConclusionsAlthough abnormal Q waves were more prevalent in the presence of LGE, no correlation was found with the LGE location and extent. These data suggest that abnormal electrical activation of the hypertrophied ventricular septum represented by a high septal to posterior wall thickness ratio seems to be an important mechanism of abnormal Q waves in HCM.

Electro‐ and echocardiographic features of left ventricle hypertrophy in patients with hypertrophic cardiomyopathy

“…The main finding of this study is low sensitivity (14.3%–40.8%) of each respective ECG criteria of LVH. This may be surprising in presence of extensive hypertrophy confirmed in TTE; however, it is consistent with results of several studies (Dohy et al, 2020 ; Erice et al, 2009 ; Grall et al, 2014 ; Tangwiwat et al, 2019 ). Majority of those analyzes took into consideration only Sokolow‐Lyon Index and Cornell Voltage.…”

“…Dohy et al suggested that fibrosis of myocardium may be connected with lower QRS amplitude in corresponding leads (Dohy et al, 2020 ). Conversely, Grall et al did not find relation between LGE and QRS amplitude (Grall et al, 2014 ). We showed that combination of two or three criteria highly increases sensitivity.…”

Relationship between electrocardiographic findings and Cardiac Magnetic Resonance phenotypes in patients with Hypertrophic Cardiomyopathy

“…Others, by correlating ECG findings with echocardiogram first and LGE-CMR later suggested that lateral Q waves might be secondary to an abnormal activation of the hypertrophied septum rather than fibrosis [6], [13], [18]. This hypothesis was also recently supported by a French study of 42 patients [19]. Negative T waves have been correlated with a specific pattern of apical hypertrophy extremely common in Asia (25% of cases) called “Japanese variant” ascribing the pathogenesis of such ECG abnormalities to a chronic ischaemia and fibrosis replacement [20].…”

Unexpectedly low left ventricular voltage on ECG in hypertrophic cardiomyopathy

“…A previous study in an adult population study by Grall et al 23 described a correlation between Q waves on ECG and LGE presence. Unlike this and other previous adult studies,24 25 while pathological Q waves, T wave changes and ST segment changes were commonly found in patients with LGE, we found no significant difference in frequency compared with patients without LGE in this paediatric population.…”

“…In this population, we found that the presence of LGE was associated with significantly increased septal thickness yet paradoxically decreased precordial voltages on ECG. Previous studies have reported on the relationship between abnormal ECG findings and phenotypical expression of HCM22 and presence of LGE23 in adults. To our knowledge, this is the first report on the effect of LGE presence in HCM on LV precordial voltage on ECG in the paediatric population.…”