Abstract 2693: Mitral E/E’ underestimates Pulmonary Capillary Wedge Pressure During Exercise.
Background. Previous studies have shown that resting LV filling pressures can be estimated noninvasively by use of the ratio of the early diastolic transmitral filling velocity (E) to the early diastolic septal tissue velocity (E’). Yet, limited data exist regarding the accuracy of this measurement during exercise. In this study, we therefore sought to evaluate the possible value of exercise E/E’ for predicting invasively measured pulmonary capillary wedge pressure (PCWP).
Methods. 22 patients (57 ± 15 years, 10 males) with heart failure (n=14), valve disease (n=6) or pulmonary hypertension (n=2) underwent right heart catheterization during symptom limited bicycle exercise. For each patient, PCWP and Doppler measurements of E/E’ were acquired in left lateral decubitus, after 5 min of sitting and during the last minute of each exercise stage.
Results. With exercise, heart rate increased from 78 ± 17 bpm to 118 ± 21 bpm, as did systolic blood pressure (from 128 ± 29 to 169 ± 30 mmHg, p<0.001), PCWP (from 15 ± 6 to 24 ± 9 mmHg, p<0.001), E velocity (from 84 ± 34 to 111 ± 41 cm.s-1 p<0.001) and septal E’ (from 6.2 ± 2.7 to 9.0 ± 4.3 cm.s-1 p<0.01). At rest, in both recumbent and sitting positions, E/E’ correlated well with PCWP (solid circle, y = 0.7856 X + 4.2084, r = 0.72). During exercise, E/E’ also correlated with PCWP (open circle, y = 0.5253x + 1.7168, r = 0.64). The relationship was nonetheless shifted downward and to the right compared to rest.
Conclusion. While E/E’ correlates with PCPW both at rest and during exercise, the relationship between these 2 parameters is different under these 2 conditions. Therefore, E/E’ values defining elevated LV filling pressures at rest cannot be used during exercise.