PERSISTENT VENTRICULAR ADAPTATIONS IN POSTOPERATIVE COARCTATION OF THE AORTA

[摘要] To evaluate ventricular performance and myocardial contractility after surgical correction of congenital coarctation of the aorta, we studied 25 patients (16 men and 9 women, mean age 26.1 years [range 19 to 34]), an average of 10.6 years (range 2 to 25) after repair. Radionuclide ventriculography at rest and exercise and digitized, quantitative two-dimensional echocardiography were performed. Data from derived, high resolution time-activity curves by radionuclide ventriculography, combined with noninvasive hemodynamic/ventricular volume data, were compared with values in an age- and sex-matched normal population. Despite essentially identical baseline and exercise hemodynamics, postoperative coarctation subjects demonstrated enhanced ventricular contraction, as determined by the peak ejection rate at rest (-3.79 versus -3.20 stroke volume/s, p < 0.01) and exercise (-3.00 versus -2.90 stroke volume/s, p = NS), and overall ejection fraction at rest (56.4 versus 48.0%, p < 0.01) and exercise (70.8 versus 59.3%, p < 0.01). An intrinsic activation-contraction delay was observed, as illustrated by a prolonged time to peak ejection rate at rest (27.7 versus 21.5% of the RR interval, p < 0.01) and exercise (28.4 versus 21.2% of the RR interval, p < 0.01), and total systolic time at rest (50.2 versus 43.4% of the RR interval, p < 0.01) and exercise (56.8 versus 50.4% of the RR interval, p < 0.01). Although left ventricular meridinal wall stress was statistically indistinguishable (62 versus 74 mm Hg/mm2, p = NS), intrinsic myocardial contractility, as assessed by the peak systolic pressure/volume ratio, was increased in the postoperative coarctation group (1.88 versus 2.87 mm Hg/ml, p < 0.01). These data confirm the presence of enhanced ventricular performance and myocardial contractility after remote coarctation repair and suggest the persistence of adaptive mechanisms originally necessary to maintain cardiac compensation in the early postnatal period.

[发布日期] 1986-07-01