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Electrical axis and voltage criteria on left ventricular hypertrophy
Insights
This study found that the R wave in lead aVL is a sensitive indicator of left ventricular hypertrophy in hypertensive patients. Treating hypertension improved left anterior hemiblock in most patients, suggesting reversibility.
Area of Science:
- Cardiology
- Medical Diagnostics
- Hypertension Research
Background:
- Left ventricular hypertrophy (LVH) is a common complication of hypertension.
- Accurate diagnosis of LVH is crucial for timely intervention and management.
- Existing voltage criteria for LVH diagnosis have varying sensitivity and specificity.
Purpose of the Study:
- To evaluate the diagnostic performance of different voltage criteria for left ventricular hypertrophy in hypertensive patients.
- To investigate the association between specific voltage criteria and radiographic evidence of cardiomegaly.
- To assess the impact of hypertension treatment on left anterior hemiblock.
Main Methods:
- Retrospective analysis of electrocardiogram (ECG) and radiographic data from 229 treated and 62 untreated hypertensive patients.
- Comparison of limb-lead (R aVL) and precordial (V-lead) voltage criteria for LVH.
- Assessment of left anterior hemiblock prevalence and its changes over a 4-year follow-up period.
Main Results:
- The R wave in lead aVL (≥11 mm) was more frequent in patients with cardiomegaly than other voltage criteria.
- A more negative electrical axis in patients with cardiomegaly may explain the increased sensitivity of limb-lead criteria.
- Left anterior hemiblock resolved in 10 of 16 treated patients but persisted in all 5 untreated patients over 4 years.
Conclusions:
- The R wave in lead aVL is a valuable criterion for detecting LVH in hypertensive patients, potentially due to altered cardiac axis in cardiomegaly.
- Hypertension treatment can lead to the resolution of left anterior hemiblock, indicating its reversibility.
- Long-term management of hypertension is essential for preventing or reversing cardiac complications like LVH and hemiblock.
Abstract:
The voltage criteria of left ventricular hypertrophy were studied in 229 hypertensive patients undergoing treatment and 62 patients who were not treated. The limb-lead voltage criterion (R Lead aVL greater than or equal 11 mm.) was found more frequently in patients with radiographic evidence of cardiomegaly than other voltage criteria. This may have been due to a more negative axis in patients with cardiomegaly than in patients without cardiomegaly. It is possible that dilatation of the left ventricle to the left and posteriorly accentuates limb-lead criteria at the expense of V-lead criteria. Left anterior hemiblock occured in less than 10 per cent of the hypertensive patients. In 10 out of 16 patients with left anterior hemiblock, the hemiblock disappeared after treatment of the hypertension for 4 years whereas all five hemiblocks in untreated hypertensives persisted. Development of left anterior hemiblock subsequently occurred in only one patient with treatment and one without treatment over a 4-year period.