TRANSTHORACIC DOPPLER-ECHOCARDIOGRAPHY OF NORMALLY ORIGINATING CORONARY-ARTERIES IN CHILDREN

Transthoracic Doppler color flow and spectral velocity patterns of nor mal coronary arteries in children have not been well studied. We desig ned this study to evaluate coronary artery flow velocity characteristi cs in normal and hypertrophied hearts. Sixty-eight children with optim al two-dimensional echocardiographic images of the left coronary arter y (LCA) and right coronary artery (RCA) were prospectively studied. Th e heart was normal in 45 children, and 23 had left and/or right ventri cular hypertrophy assessed by echocardiography (mean age 5.8 versus 5. 2 years, p = NS). Color flow signals were detected in the LCA in 63(92 %) of the 68 children studied, and pulsed Doppler spectral waveforms w ere recorded in 47 (69%). The latter were recorded in 26 (58%) of 45 n ormal children and in 21 (91%) of 23 children with left ventricular hy pertrophy. Diastolic RCA flow signals were detected mostly in those wi th right ventricular hypertrophy (10 of 10). Higher levels of LCA maxi mum diastolic velocity (42 +/- 23 versus 24 +/- 6 cm/sec, p = 0.0004), increased diastolic flow (16 +/- 15 versus 6 +/- 4 ml/min, P = 0.01), and delayed time to peak diastolic velocity expressed as a percentage of diastolic spectral duration (38% +/- 14% versus 20% +/- 8%, p = 0. 0001) were observed in children with left ventricular hypertrophy than in those in normal children. A strong correlation was present between Doppler-derived LCA flow and left ventricular mass/m(2) (r = 0.7, p = 0.001). In normal hearts, LCA spectral velocity pattern did not chang e with increasing age, but the time velocity integral became progressi vely larger, resulting in a strong correlation with weight (p < 0.001, r = 0.78). This study demonstrates (1) LCA flow signals can be detect ed and quantitated in the majority of children with and those without left ventricular hypertrophy. (2) Left ventricular hyper trophy is ass ociated with increased LCA flow, higher diastolic velocity, and delaye d peak diastolic velocity. (3) RCA flow signals are mostly detected wh en there is right ventricular hypertrophy. Studies on larger groups of patients are needed to further confirm our observations and to enhanc e understanding of coronary artery flow reserve.