Abstract 1941: Abnormal Arterial Hemodynamics After Repair of Tetralogy of Fallot
Background Recent histological studies of the aortic wall of tetralogy of Fallot (TOF) have revealed massive degeneration of the tunica media of the aorta. Such changes in arterial wall structure may significantly alter arterial wall mechanical properties, and may thereby cause abnormal arterial hemodynamics that could result in ventricular dysfunction and aortic dilation after repair of TOF.
Methods and Results The subjects were 38 patients who had undergone complete repair of TOF, and 55 age-matched control subjects. Systemic arterial hemodynamics were investigated by measuring aortic input impedance during cardiac catheterization. The TOF patients had significantly higher characteristic impedance (158 ± 43 for TOF and 105 ± 49 dyne.s.cm−5.m2 for controls) and pulse wave velocity (561 ± 139 for TOF and 417 ± 91 cm/s for controls) and significantly lower total peripheral arterial compliance (0.93 ± 0.39 for TOF and 1.24 ± 0.58 for controls ml/mm Hg/m2) than the controls (for all 3 variables, p < 0.01 vs. controls), suggesting that central and peripheral arterial wall stiffness increase after TOF repair. In addition, the TOF patients had significantly higher arterial wave reflection than the controls. These abnormalities in arterial hemodynamics of TOF patients increased the pulsatile load on the left ventricle and significantly contributed to decreased cardiac output, even when RV function was taken into account by multivariate regression analysis. We also found that the increase in aortic wall stiffness was closely associated with the increase in aortic root diameter; this is the first report of an abnormal aortic mechanical property underlying the increased aortic dilation commonly observed in TOF patients.
Conclusions These results indicating abnormal arterial hemodynamics after TOF repair highlight the importance of regular monitoring of the systemic arterial bed and potentially relevant cardiovascular events in long-term follow-up of TOF.