Differential Regurgitation in Branch Pulmonary Arteries After Repair of Tetralogy of Fallot

Abstract

Background-The importance of pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) is increasingly recognized, but little is known regarding its underlying mechanisms. This phase-contrast cine magnetic resonance (PC MR) study was performed to evaluate the relative contribution of each lung to total regurgitant volume. Methods and Results-Twenty-two patients with significant PR underwent a PC MR 3 to 16 years after repair of TOF.Regurgitant fraction of the main pulmonary artery was 39Ϯ10%. Regurgitant fraction of the left pulmonary artery (LPA; 46Ϯ18%) was greater than that of the right pulmonary artery (34Ϯ16%; Pϭ0.002). The average contribution of the LPA to the total regurgitant flow volume was 54Ϯ19%, whereas its average contribution to the total forward flow volume was 44Ϯ13% (Pϭ0.002). In 4 patients, regurgitant flow in the LPA accounted for 75% to 100% of the total regurgitant flow. There was a linear relationship between regurgitant fraction and fraction of the regurgitant flow duration in the main pulmonary artery (PϽ0.001) and right pulmonary artery (Pϭ0.001) but not in the LPA (Pϭ0.129). Conclusions-PR after repair of TOF is commonly associated with differential regurgitation in the branch pulmonary arteries, which is usually greater in the LPA. Although the cause of this disparity requires further investigation, those patients with a significant unilateral contribution to total PR may be amenable to localized techniques to reduce regurgitation. (Circulation. 2003;107:2938-2943.)

Pulmonary regurgitation after tetralogy of fallot repair: A diagnostic and therapeutic challenge

“…Further delineation of regurgitation in the branch pulmonary arteries was performed by Kang et al . [29] Their phase contrast cine MR comparison of regurgitation showed greater regurgitation fractions in the left pulmonary artery compared to the right, consistent with Figure 3.…”

Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

“…Since it provides accurate quantitative information on biventricular size and function, blood flow measurements, myocardial viability, and cardiovascular anatomy, in many centers CMR has become the preferred method of noninvasive imaging in patients with repaired TOF [10,45,50,54,97,110-113]. At Children's Hospital Boston, postoperative TOF is the most common diagnosis in patients referred for CMR, accounting for ~23% of patients.…”

Numerical Study for Blood Flow in Pulmonary Arteries after Repair of Tetralogy of Fallot

“…Phase contrast magnetic resonance (PC-MR) technology is an established noninvasive technique to estimate blood flow in the vessels and has been used to investigate the PR phenomena in repaired TOF patients. According to Kang et al's [1] PC-MR measurements of repaired TOF, it was found that the regurgitation fraction (RF, i.e., backward flow volume/forward flow volume) of PR in left pulmonary artery (LPA) is higher than right pulmonary artery (RPA) in repaired TOF. The reason causing this discrepancy of RF is still not clear.…”

“…Kang et al [1] discussed the difference of PR between left and right pulmonary arteries from PC-MRI measurements for 22 patients after repaired TOF surgery. They found that the regurgitant fraction in LPA is greater than that in RPA and MPA in most of repaired TOF patients.…”

“…They found that the regurgitant fraction in LPA is greater than that in RPA and MPA in most of repaired TOF patients. Meanwhile, Kang et al [1] also indicated that the relationship between the regurgitant fraction and fraction of regurgitant flow duration in MPA and RPA is linear. Wu et al [3] investigated the effect of pulmonary regurgitation on perfusion of the lungs in 43 patients after repaired TOF using PC-MRI.…”