DISCUSSION
In spite of the absence of symptoms, but in view of the remarkably abnormal findings on the ECG, echocardiography, a stress test, a Holter monitor test, and 64-slice CT angiography were performed; all results were unremarkable except for concentric left ventricular hypertrophy (LVH). Both the patient and his primary care physician were reassured that he just has an abnormal looking ECG but were instructed to be aware of this to avoid the extra tests in the future. The ST-segment depression, T-wave inversion in the inferolateral leads (leads II, III, aVF and V4-V6), and voltage criteria for LVH were thought to be secondary to his LVH/bradycardia.
Comment Although LVH occurs as a natural reaction to aerobic exercise and strength training, it is most frequently referred to as a pathologic reaction to cardiovascular disease or hypertension. LVH itself is not a disease; it is usually a marker for disease involving the heart.1
The principal diagnostic method for LVH is echocardiography. ECG results often show signs of increased voltage from the heart in persons with LVH; therefore, it is often used as a screening test to determine who should undergo further testing.
Normal thickness of the left ventricular myocardium, seen on twodimensional echocardiography, is 0.6 to 1.1 cm (measured at the end of diastole). A myocardial thickness of more than 1.1 cm is diagnostic for LVH.
Several sets of criteria are used to diagnose LVH via electrocardiography (Sokolow-Lyon index, Cornell voltage, Framingham, and Romhilt-Estes2-5). None of them is perfect; however, using multiple criteria sets increases the sensitivity and specificity.
The muscle enlargement is not permanent in all cases, and in some cases the growth can regress with a reduction in BP.6 Left ventricular strain is a pattern of asymmetric ST-segment depression and T-wave inversion. It is most commonly seen in one or more leads that measure left ventricle function.
ECG voltage criteria for LVH can mimic other more serious conditions, such as ischemia and coronary artery disease. Unnecessary extensive workup can be avoided if the clinician is aware of these voltage criteria. JAAPA
Rami Khouzam worked at the Farmington Heart Center, Farmington, New Mexico, at the time this article was written. The author has indicated no relationships to disclose relating to the content of this article.
Erich Fogg, PA-C, MMSc, department editor
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