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Hypertensive concentric left ventricular hypertrophy: when is ventricular ectopic activity increased?
C J Lavie1, B D Nunez, G E Garavaglia
1Department of Internal Medicine, Ochsner Clinic, New Orleans, La. 70121.
Insights
Left ventricular hypertrophy (LVH) increases cardiovascular risk. Early echocardiographic LVH in hypertension does not elevate ventricular ectopy, unlike ECG-detected LVH.
Area of Science:
- Cardiology
- Hypertension Research
- Cardiac Electrophysiology
Background:
- Left ventricular hypertrophy (LVH) is linked to increased cardiovascular risk and sudden death.
- Previous studies showed higher ventricular ectopy in hypertensive patients with ECG-defined LVH.
- The role of early, echocardiography-detected LVH without ECG changes in ventricular dysrhythmias is unclear.
Purpose of the Study:
- To investigate ventricular dysrhythmias in hypertensive patients with early concentric LVH detected by echocardiography but not ECG.
- To compare the prevalence and complexity of ventricular ectopy across different LVH classifications.
Main Methods:
- 24-hour ambulatory ECG monitoring was performed on 94 essential hypertension patients.
- Patients were categorized into three groups: no LVH, LVH by echocardiography only, and LVH by both echocardiography and ECG.
- Ventricular ectopy was quantified by premature ventricular contractions and Lown's class.
Main Results:
- Patients with ECG-defined LVH exhibited significantly more premature ventricular contractions and complex ventricular ectopy (P < .001).
- Mild to moderate concentric cardiac hypertrophy detected solely by echocardiography did not affect the prevalence or complexity of ventricular ectopic activity.
- No significant difference in ventricular dysrhythmias was found between patients without LVH and those with LVH by echocardiography only.
Conclusions:
- Early concentric LVH detected by echocardiography in hypertensive patients is not associated with increased myocardial electrical irritability.
- ECG criteria remain a stronger indicator of electrical instability in hypertensive patients with LVH.
- Echocardiographic detection of early LVH may not necessitate immediate concern for heightened ventricular dysrhythmia risk.
Abstract:
The Framingham Study has indicated that patients with left ventricular hypertrophy (LVH) have a greater risk of cardiovascular complications and sudden death than subjects with a normal heart. We have previously demonstrated that ventricular ectopy was more prevalent and complex in hypertensive patients with LVH by electrocardiographic (ECG) criteria than in those without ECG evidence of LVH. The present study was designed to detect and quantify ventricular dysrhythmias in hypertensive patients with early concentric LVH by echocardiography but without LVH by ECG criteria. Continuous ambulatory ECG tracings were recorded for 24 hours in 94 patients with essential hypertension: 37 without LVH, 26 with concentric LVH by echocardiographic but not ECG criteria, and 31 with LVH on both echocardiography and ECG. Patients with LVH by ECG criteria had significantly more premature ventricular contractions (P less than .001) and more complex (higher Lown's class) ventricular ectopy (P less than .001) than hypertensives without LVH or with LVH only by echocardiographic criteria. Prevalence and complexity of ventricular ectopic activity, however, was not affected by mild to moderate concentric cardiac hypertrophy detected echocardiographically. We conclude that unlike LVH shown by ECG, early hypertensive concentric LVH detected echocardiographically is not associated with increased electrical irritability of the myocardium.