Unilateral Pulmonary Edema in Patients With Acute Mitral Regurgitation Caused by Chordal Rupture.

Background: Cardiogenic unilateral pulmonary edema (UPE) has been reported as an unusual condition and to occur in association with severe mitral regurgitation (MR). However, the prevalence of UPE in patients with severe MR remains unknown. Methods and Results: Among 143 consecutive patients with chordal rupture and significant MR, 38 patients with acute severe MR were studied. The prevalence of UPE was 50% (19 patients); all these patients had right-sided UPE. Eight (21%) patients had bilateral pulmonary edema (BPE). All 8 patients with BPE and 18 of 19 patients with UPE had chordal rupture of the posterior leaflet. All patients with UPE and BPE had severe MR with similar left atrial size. Chest radiographs taken ≤48 h from symptom onset diagnosed UPE in 15 of 19 (79%) patients and BPE in 3 of 8 (38%) patients (P=0.037). Chest radiographs taken >48 h from symptom onset diagnosed UPE in 4 (21%) patients and BPE in 5 (62%) patients (P=0.037). Conclusions: The prevalence of UPE was estimated as 50%; it was most frequently right sided and almost always associated with chordal rupture of the posterior leaflet. UPE is not rare, but common, particularly shortly after the development of acute severe MR caused by chordal rupture.