Increased myocardial ultrasonic reflectivity is associated with extreme hypertensive left ventricular hypertrophyA tissue characterization study in humans

We assessed myocardial reflectivity pattern in a large spectrum of left ventricular mass values, covering the extremes from absent to severe myocardial hypertensive hypertrophy. Quantitatively assessed ultrasonic backscatter is an index of ultrasonic tissue characterization directly related to the morphometrically evaluated collagen content in humans. We enrolled 88 essential hypertensives. With an echo prototype implemented in our Institute, integrated values of the radiofrequency signal of myocardial walls were obtained and normalized for those of the pericardium (Integrated Backscatter Index, IBI, %). Left ventricular mass index (LVMI) was measured by Devereux formula. There was a weak correlation between septal IBI and LVMI (r = 0.35; P < .001). On the basis of LVMI values, three groups of hypertensives were identified, with absent (Group I, n = 23; LVMI < 125 g/m2), mild to moderate (Group II, n = 44; LVMI from 125 to 174 g/m2), or severe (Group III, n = 21; LVMI > 175 g/m2) left ventricular hypertrophy. The Integrated Backscatter Index in the septum was lower in patients of Group I (IBI = 23.3% +/- 3.6%) and II (IBI = 26.5 +/- 7.6; P = NS v Group I), in comparison with patients of Group III (IBI = 31.1 +/- 5.9; P < .02 v II; P < .0001 v I). An increased myocardial wall reflectivity is detectable only in the presence of extreme forms of hypertensive left ventricular hypertrophy.