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Ethnic differences in electrocardiographic criteria for left ventricular hypertrophy: the LIFE study. Losartan
Peter M Okin1, Jackson T Wright, Markku S Nieminen
1Department of Medicine, Weill Medical College of Cornell University, New York, New York 10021, USA. pokin@med.cornell.edu
Insights
African Americans exhibit higher electrocardiogram (ECG) precordial QRS voltages, impacting left ventricular hypertrophy (LVH) detection. Tailoring ECG criteria by ethnicity can improve accuracy in identifying LVH in both African American and white hypertensive patients.
Area of Science:
- Cardiology
- Medical Diagnostics
- Health Disparities
Background:
- African Americans have higher ECG precordial QRS voltages than whites.
- This leads to higher prevalence of ECG-detected left ventricular hypertrophy (LVH) and lower specificity of criteria in African Americans.
- Accurate LVH detection is crucial due to high mortality in African American patients.
Purpose of the Study:
- To evaluate the performance of different ECG LVH criteria in African American versus white hypertensive patients.
- To determine if ethnicity-specific criteria improve LVH detection accuracy.
Main Methods:
- 120 African American and 751 white hypertensive patients from the LIFE study were analyzed.
- ECG LVH was assessed using Sokolow-Lyon, 12-lead sum, and Cornell voltage criteria.
- Echocardiographic LVH was defined by LV mass indexed to height(2.7).
Main Results:
- Sokolow-Lyon and 12-lead voltage criteria showed lower specificity but higher sensitivity in African Americans with standard thresholds.
- Cornell voltage criteria showed higher specificity but slightly lower sensitivity in African Americans.
- Receiver operating curve analyses revealed no ethnic differences in overall test accuracy when partition values were adjusted.
Conclusions:
- Standard ECG LVH criteria have differential performance between African Americans and whites.
- Apparent ethnic differences in ECG LVH detection disappear when considering ethnic variations in criterion distribution.
- Ethnicity-specific ECG criteria can equalize the detection of anatomic LVH across ethnic groups.
Background:
African Americans have greater precordial QRS voltages than whites, with concomitant higher prevalences of electrocardiographic (ECG) left ventricular hypertrophy (LVH) and lower specificity of ECG LVH criteria for the identification of anatomic hypertrophy. However, the high mortality associated with LVH in African American patients makes more accurate ECG detection of LVH in these patients a clinical priority.
Methods:
Electrocardiograms and echocardiograms were obtained at study baseline in 120 African American and 751 white hypertensive patients enrolled in the Losartan Intervention For Endpoint (LIFE) echocardiographic substudy. The ECG LVH was determined using Sokolow-Lyon, 12-lead sum, and Cornell voltage criteria. Echocardiographic LVH was defined by LV mass indexed to height(2.7) >46.7 g/m(2.7) in women and >49.1 g/m(2.7) in men.
Results:
After adjusting for ethnic differences in LV mass, body mass index, sex, and prevalence of diabetes, mean Sokolow-Lyon and 12-lead sum of voltage were significantly higher, but Cornell voltage was lower, in African Americans than in whites. As a consequence of these differences, when identical partition values were used in both ethnic groups, Sokolow-Lyon and 12-lead voltage criteria had lower specificity in African Americans than whites (44% v 69%, P = .007 and 44% v 59%, P = .10) but had greater sensitivity in African Americans (51% v 27%, P < .001 and 62% v 45%, P = .003). In contrast, Cornell voltage specificity was higher (78% v 62%, P = .09) but sensitivity was slightly lower (49% v 57%, P = 0.16) in African Americans. However, when overall test performance was compared using receiver operating curve analyses that were independent of partition value selection, ethnic differences in test performance disappeared, with no differences in accuracy of any of the ECG voltage criteria for the identification of LVH between African American and white hypertensive individuals.
Conclusions:
When standard, non-ethnicity-specific thresholds for the identification of LVH are used, Sokolow-Lyon and 12-lead voltage overestimate and Cornell voltage underestimates the presence and severity of LVH in African American relative to white individuals. However, these apparent ethnic differences in test performance disappear when ethnic differences in the distribution of ECG LVH criteria are taken into account. These findings demonstrate that ethnicity-specific ECG criteria can equalize detection of anatomic LVH in African American and white patients.