Assessment of left atrial volume before and after pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Impaired left ventricular diastolic filling is common in chronic thromboembolic pulmonary hypertension (CTEPH), and recent studies support left ventricular underfilling as a cause. To investigate this further, we assessed left atrial volume index (LAVI) in patients with CTEPH before and after pulmonary thromboendarterectomy (PTE). METHODS: Forty-eight consecutive CTEPH patients had pre- & post-PTE echocardiograms and right heart catheterizations. Parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, LAVI, & mitral E/A ratio. Echocardiograms were performed 6 ± 3 days pre-PTE and 10 ± 4 days post-PTE. Regression analyses compared pre- and post-PTE LAVI with other parameters. RESULTS: Pre-op LAVI (mean 19.0 ± 7 mL/m2) correlated significantly with pre-op PVR (R = -0.45, p = 0.001), mPAP (R = -0.28, p = 0.05) and cardiac index (R = 0.38, p = 0.006). Post-PTE, LAVI increased by 18% to 22.4 ± 7 mL/m2 (p = 0.003). This change correlated with change in PVR (765 to 311 dyne-s/cm5, p = 0.01), cardiac index (2.6 to 3.2 L/min/m2, p = 0.02), and E/A (.95 to 1.44, p = 0.002). CONCLUSION: In CTEPH, smaller LAVI is associated with lower cardiac output, higher mPAP, and higher PVR. LAVI increases by ~20% after PTE, and this change correlates with changes in PVR and mitral E/A. The rapid increase in LAVI supports the concept that left ventricular diastolic impairment and low E/A pre-PTE are due to left heart underfilling rather than inherent left ventricular diastolic dysfunction.

Assessment of diastolic function with Doppler tissue imaging after cardiac surgery: effect of the "postoperative septum" in on-pump and off-pump procedures.

Doppler tissue imaging (DTI) of mitral annular velocity is useful in assessing diastolic function. Most centers record at the septal or lateral segments of the annulus. Cardiopulmonary bypass produces changes in the motion of the interventricular septum. We evaluated the use of DTI after operation with and without cardiopulmonary bypass. 18 patients scheduled for cardiac surgery were prospectively examined. Nine underwent cardiopulmonary bypass. Nine had operation without bypass. DTI was performed 4 +/- 3 days before operation and again 31+/- 7 days afterwards. Early diastolic velocities of the lateral and septal segments of the mitral annulus were measured. Ejection fraction and transmitral diastolic early-to-late filling (E/A) ratios were also assessed. Early diastolic septal mitral annular velocity decreased (7.9 +/- 1.2 to 5.9 +/- 1.1 cm/s [P= .001]) after on-pump operation whereas lateral segment velocity remained unchanged (8.5 +/- 2.9 to 8.2 +/- 3.7 cm/s [P = .30]). E/A ratio did not change after operation (1.28 +/- 0.25 to 1.21 +/- 0.47 [P = .45]). In contrast, septal segment velocity in the off-pump group trended higher after operation (5.3 +/- 1.9 to 6.0 +/- 1.5 cm/s [P = .20]). Lateral segment velocity and E/A ratio also increased somewhat, but changes were not significant (6.2 +/- 1.7 to 6.7 +/- 2.9 cm/s [P = .15] and 1.1 +/- 0.5 to 1.2 +/- 0.4 [P = .13], respectively). Ejection fraction increased in both groups. Early diastolic velocity of the septal mitral annulus decreases after operation with cardiopulmonary bypass, but does not change after off-pump operation. In contrast, early diastolic velocity of the lateral segment is not affected by either on-pump or off-pump operation. Measuring lateral segment velocity is recommended for diastolic DTI after cardiopulmonary bypass, as septal DTI may incorrectly suggest diastolic dysfunction.