Impact of Atrioventricular Compliance on Pulmonary Artery Pressure in Mitral Stenosis

Abstract

Background-The decay of the pressure gradient across a stenotic mitral valve is determined by the size of the orifice and net AV compliance (C n ). We have observed a group of symptomatic patients, usually in sinus rhythm, characterized by pulmonary hypertension (particularly during exercise) despite a relatively large mitral valve area by pressure half-time. We speculated that this discrepancy was due to low atrial compliance causing both pulmonary hypertension and a steep decay of the transmitral pressure gradient despite significant stenosis. We therefore tested the hypothesis that C n is an important physiological determinant of pulmonary artery pressure at rest and during exercise in mitral stenosis. Methods and Results-Twenty patients with mitral stenosis were examined by Doppler echocardiography. C n , calculated from the ratio of effective mitral valve area (continuity equation) and the E-wave downslope, ranged from 1.7 to 8.1 mL/mm Hg. Systolic pulmonary artery pressure (PAP) increased from 43Ϯ12 mm Hg at rest to 71Ϯ23 mm Hg (range, 40 to 110 mm Hg) during exercise. There was a particularly close correlation between C n and exercise PAP (rϭϪ0.85).Patients with a low compliance were more symptomatic (PϽ0.025). Catheter-and Doppler-derived values for C n , determined in 10 cases, correlated well (rϭ0.79). Conclusions-C n , which can be noninvasively assessed, is an important physiological determinant of PAP in mitral stenosis. Patients with low C n represent an important clinical entity, with symptoms corresponding to severe increases in PAP during stress echocardiography.

Serial changes in nasal potential difference and lung electrical impedance tomography at high altitude

“…In keeping with the findings of Boussuges et al (3), we also found alterations in transmitral flow on echo-Doppler with a decrease in the E/A ratio on ascent to high altitude, suggestive of a reduction in left ventricular diastolic compliance. A fall in diastolic compliance would increase the risk of developing pulmonary edema on exercise (45), and one may argue that some of the increase in EVLW seen in this study could be due to repeatedly elevated Ppc during physical activity. Nevertheless, the failure of the Poon analysis to demonstrate any relationship between either mean or systolic Ppa and either the changes in EIT or FVC, while demonstrating a strong relationship between the changes in EIT or FVC and NPD, argues against the subclinical pulmonary edema seen in this study being of predominantly hydrostatic origin.…”

Correlation of Net Atrioventricular Compliance with the Outcome of Successful Percutaneous Transvenous Mitral Valve Commissurotomy

“…Patients with low Cn were more symptomatic with symptoms corresponding to severe increases in pulmonary artery pressures during stress echocardiography. 11 Mitral stenosis is best described as a disease continuum, with no single value that can define its severity. More specifically, a wide variation in pulmonary pressures for the same range of mitral obstruction emphasizes the need to identify key factors implicated in the development of pulmonary hypertension and functional limitation in MS. 12 The presence of pulmonary hypertension is fundamental in the clinical decision-making process for mitral stenosis (MS).…”

A Comparison of 2 Mitral Annuloplasty Rings for Severe Ischemic Mitral Regurgitation: Clinical and Echocardiographic Outcomes

“…Moreover, right atrial pressure is frequently assumed to be 5 mm Hg in normal subjects 30 and 10 mm Hg in patients with heart disease. 31 Though we have demonstrated higher risk of functional mitral stenosis in patients receiving a Profile rigid ring, this cannot be generalized to all category or rigid rings; moreover, we cannot say whether or not this actually results in a poorer clinical outcomes or survival rate in the long run. Long-term follow-up data and more investigations are needed to address this issue.…”