[Concentric left ventricular hypertrophy in patients with aortic regurgitation]

Chronic aortic regurgitation (AR) is a disease incorporating volume overload of the left ventricle (LV) which is characterized by hyperactive left ventricular dilatation (LVD). However, we have encountered several patients who had concentric LV hypertrophy (LVH) instead of LVD. We therefore studied 50 consecutive patients with isolated AR but without aortic stenosis and found seven patients with concentric LVH having LV wall thickness (determined by summing ventricular septal and posterior wall thicknesses) exceeding 30 mm and LV diastolic diameters of less than 60 mm. These seven patients with AR and LVH were older (55 +/- 27 vs 42 +/- 11 years) and tended to have milder degree of AR, compared with the remaining 43 patients having AR and LVD. However, patients with AR and LVH did not differ from AR and LVD as to the cardiothoracic ratio, SV1 + RV5, T-waves, ejection fraction, operative findings of valvular morphology and underlying etiologies. In contrast, patients with AR and LVH presented higher systolic (196 +/- 41 vs 149 +/- 26 mmHg, p less than 0.01) and diastolic pressures (74 +/- 14 vs 51 +/- 13 mmHg, p less than 0.01) and higher systemic vascular resistance (1,854 +/- 399 vs 1,388 +/- 352 dyne.sec.cm-5, p less than 0.05) during catheterization than did those with AR and LVD. However, blood pressure at the time of admission was not different in the two groups. These observations indicate that concentric LVH is not rare among patients with AR, and that an association of pressure overload with volume overload of the LV, particularly during exercise or stress, may lead to concentric LVH, even in patients with chronic AR.