BIVENTRICULAR LONG AXIS FUNCTION AFTER REPAIR OF TETRALOGY OF FALLOT

Right ventricular restrictive physiology is common after repair of tet ralogy of Fallot and relates to exercise performance and symptomatic a rrhythmias. In this study, we examined biventricular long axis functio n in an attempt to clarify further the mechanical substrate of this ph enomenon. We studied prospectively 95 patients with tetralogy of Fallo t (age range 134.3 years) at a median of 4.3 years after repair with D oppler and M-mode echocardiography. Pulmonary arterial, tricuspid, and mitral Doppler spectrals and 2-D guided Mmode recordings of ventricul ar minor and long axes were obtained with simultaneous phonocardiogram and respirometer recordings. Right ventricular restriction was de fin ed by the presence of antegrade pulmonary arterial flow during atrial systole throughout the respiratory cycle. Restrictive right ventricula r physiology was demonstrated in 36 (39%) [group 1] of the 92 patients in whom the data were analyzed. Left ventricular function (FS, isovol umic relaxation time and transmitral E wave deceleration time) was not different in the two groups (p < 0.1, p < 0.6, and p < 0.8, respectiv ely). The presence of antegrade diastolic flow shortened the pulmonary regurgitation in the restrictive group (PR duration/root RR 10.7 +/- 2.1 vs 12.1 +/- 2.1, p < 0.01). Then was delayed onset of shortening ( 97.4 +/- 24 vs 88.8 +/- 24 ms, p = 0.01), and the amplitude of right a trioventricular ring excursion, corrected for body surface area, was s ignificantly lower during atrial systole in the restrictive group (0.4 3 +/- 0.15 vs 0.54 +/- 0.2 cm/m(2), p < 0.01). There was also a tenden cy toward a smaller ratio of right to left total atrioventricular ring excursion in the same group (1.14 +/- 0.19 vs 1.22 +/- 0.23, p = 0.1) . Impaired long axis function in patients with restrictive right ventr icular physiology following repair of tetralogy of Fallot is associate d with abnormal diastolic filling and may contribute to the longterm c ardioprotective effect of restrictive physiology by Limiting the degre e of right ventricular dilatation.