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ECG characteristics of dilated cardiomyopathy
Y Momiyama1, H Mitamura, M Kimura
1Department of Cardiology, Tokyo Saiseikai Central Hospital, and Keio University, Japan.
Insights
Electrocardiograms (ECGs) reveal distinct patterns in dilated cardiomyopathy (DCM). High voltage ratios, particularly RV6/Rmax, are characteristic of DCM and correlate with left ventricular (LV) dilatation, aiding diagnosis.
Area of Science:
- Cardiology
- Medical Diagnostics
- Electrophysiology
Background:
- Dilated cardiomyopathy (DCM) is a significant cause of heart failure.
- Electrocardiography (ECG) is a non-invasive tool for cardiac assessment.
- Distinguishing DCM from other conditions causing left ventricular (LV) enlargement is clinically important.
Purpose of the Study:
- To identify specific ECG characteristics of dilated cardiomyopathy (DCM).
- To compare ECG findings in DCM with LV dilatation due to valvular heart disease (VHD) and hypertensive LV hypertrophy.
- To assess the utility of ECG voltage ratios in diagnosing DCM.
Main Methods:
- Analysis of 12-lead ECGs and echocardiograms in 45 DCM patients, 54 VHD patients, 101 hypertensive patients, and 63 controls.
- Evaluation of serial ECG and echocardiographic changes in DCM patients over a mean follow-up of 1.6 years.
- Calculation and comparison of ECG voltage criteria, including Sokolow's criterion and RV6/Rmax ratio.
Main Results:
- Sokolow's criterion was common across DCM, VHD, and hypertension groups.
- The RV6 amplitude was highest in DCM and correlated with LV dilatation.
- Voltage ratios, specifically RV6/Rmax, were significantly higher in DCM (67% > or = 3) compared to VHD (4%), hypertension (1%), and controls (0%), correlating with LV dilatation and inversely with ejection fraction.
Conclusions:
- DCM frequently exhibits ECG signs of LV hypertrophy.
- High voltage ratios, particularly RV6/Rmax, are characteristic of DCM.
- These specific ECG voltage ratios can aid in differentiating DCM from other causes of LV enlargement.
Abstract:
To elucidate the electrocardiographic (ECG) characteristics of dilated cardiomyopathy (DCM), the authors analyzed the 12-lead ECGs and echocardiograms in 45 patients with DCM, 54 patients with left ventricular (LV) dilatation secondary to valvular heart disease (VHD), 101 hypertensive patients with LV hypertrophy, and 63 normal control subjects. In addition, serial ECG and echocardiographic changes in DCM during a mean follow-up period of 1.6 years were evaluated. Sokolow's criterion (S wave in lead V1 [SV1] + R wave in lead V5 or V6 [RV5 or RV6] > 35 mm) was met comparably in patients with DCM (69%), VHD (61%), and hypertension (74%) (P = NS). Notably, RV6 in DCM was the highest among the four groups and correlated with the degree of LV dilatation. In contrast, the R waves in leads I, II, and III (RI, RII, RIII) in DCM were the lowest and were not affected by the degree of LV dilatation, although RII and RIII in VHD and RI in hypertension correlated with the degree of LV dilatation and hypertrophy, respectively. As a result, all voltage ratios of RV6/RI, RII, RIII in DCM were not only the highest, but also increased linearly as the LV dilated progressively during the follow-up period. In particular, RV6 over the maximum R wave in leads I, II, and III (RV6/Rmax) in DCM correlated with the degree of LV dilatation and inversely correlated with ejection fraction. Subjects with DCM had a significantly higher RV6/Rmax than did patients with VHD, hypertension, and normal subjects (3.4 vs 1.7, 1.4, 1.2, respectively; P < .001), and this ratio of > or = 3 was seen in 67% of the DCM patients versus 4% of the VHD patients, 1% of the hypertensive patients, and 0% of the normal subjects. Thus, DCM commonly shows the ECG signs of LV hypertrophy, but characteristically has the high voltage ratios of RV6/RI, RII, RIII.