Related Experiment Videos
Clinical significance of left ventricular hypertrophy: insights from the Framingham Study
1Department of Health and Human Services, Framingham Heart Study, Massachusetts 01701.
Insights
Left ventricular hypertrophy (LVH) detected by electrocardiogram (ECG) indicates high mortality risk. Echocardiography reveals higher LVH prevalence and links it to arrhythmias and cardiovascular disease, warranting further study.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Preventive Medicine
Background:
- Left ventricular hypertrophy (LVH) is a cardiac response to pressure or volume overload.
- Electrocardiogram (ECG) has historically detected LVH, associated with increased coronary heart disease and mortality risks.
- Antihypertensive drug therapy has coincided with a decline in ECG-detected LVH prevalence.
Purpose of the Study:
- To compare LVH detection rates between ECG and echocardiography.
- To investigate the association of echocardiographic LVH with ventricular arrhythmias and cardiovascular disease risk.
- To evaluate the prognostic significance of echocardiographically defined LVH.
Main Methods:
- Utilized data from the Framingham Heart Study.
- Employed both electrocardiogram (ECG) and echocardiography for LVH detection.
- Incorporated ambulatory ECG monitoring to assess arrhythmias in relation to LVH.
Main Results:
- Echocardiography identified significantly more cases of LVH (174/1000) than ECG (24/1000).
- Ambulatory ECG monitoring linked echocardiographic LVH to an increased risk of ventricular arrhythmias.
- Echocardiographically defined LVH is a significant predictor of cardiovascular morbidity and mortality.
Conclusions:
- Echocardiography offers a more sensitive method for detecting LVH compared to ECG.
- Echocardiographic LVH is associated with heightened risks for arrhythmias and adverse cardiovascular outcomes.
- Further research is needed to determine if antihypertensive therapy can mitigate risks by preventing or regressing LVH.
Abstract:
Left ventricular hypertrophy (LVH) is a cardiac end-organ response to increased pressure or volume load. For the past 40 years the electrocardiogram (ECG) has been used in the Framingham Heart Study for the detection of LVH. There is an increased risk of developing coronary heart disease following the appearance of LVH on the ECG. ECG LVH also carries a high risk for mortality. The overall risk of mortality in subjects with ECG LVH exceeds that following myocardial infarction. Over the past three decades there has been a significant decline in prevalence of ECG LVH concomitant with increased utilization of antihypertensive drug therapy. The recent introduction of echocardiography into the Framingham Heart Study has resulted in the development of new echocardiographic criteria for LVH. Echocardiographic LVH is more prevalent than ECG LVH. Corresponding prevalence rates for these two methods (per 1,000) are 174 vs. 24, respectively. Ambulatory ECG monitoring documents an association of echocardiographic LVH with increased risk for ventricular arrhythmias. Data from Framingham and elsewhere suggest that echocardiographically defined LVH is an important predictor of risk for cardiovascular disease morbidity and mortality. The extent to which prevention or regression of LVH, in response to antihypertensive drug therapy will alter the substantial risks associated with this condition, awaits additional investigation.