Coronary microcirculation into different models of left ventricular hypertrophy - hypertensive and athlete's heart: a contrast echocardiographic study

The study was carried out in two different models of left ventricular hypertrophy: athlete's heart and essential arterial hypertension. Three groups of strictly age-matched males were studied: one group of 10 young adult untreated essential hypertensive patients (H), a second group of 10 athletes (A), and a group of 10 healthy individuals as controls (C). A Sonos 5500 echograph with S4 harmonic transducer was used with Levovist (ultrasonic tracer) before and after dipyridamole injection; digitised images of quantitative myocardial contrast echocardiography were collected with Power Harmonic Doppler. Angio images were analysed using dedicated PC software by placing a region-of-interest on the septum. Peak intensity, half-time (HT), the area under the curve of appearance and disappearance of microbubbles at 213 of PI, both in absolute and indexed values (/LVMi), were sampled. The per cent increase of PI after dipyridamole was significantly higher in C (+73%, P<0.01) than in H (+31%) and in A (+33%) (P<0.05). The area of appearance was significantly lower in H in comparison with C and A, both at rest and after vasodilatation. The disappearance area after dipyridamole was significantly higher in C and in A (+124%) than in H (+104%) (P<0.05). Some hypothesis could be made: an impairment in the coronary microcirculatory function in hypertensive patients could be because of an increase in the arteriolar resistance. Anglogenesis and several different functional adaptations are the mechanisms that allow an optimal distribution of oxygen and of substrates to the hypertrophied myocardium of the athletes.