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.

Noninvasive assessment of pulmonary vascular resistance using Doppler tissue imaging of the tricuspid annulus.

BACKGROUND: Pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) are important hemodynamic parameters in patients with advanced cardiopulmonary disease. We undertook this study to determine whether Doppler tissue imaging of the tricuspid annulus could be used to assess PAP and PVR noninvasively. METHODS: We studied 50 consecutive patients with suspected chronic thromboembolic pulmonary hypertension referred to our center for evaluation. We performed preoperative transthoracic echocardiography with Doppler tissue imaging of the tricuspid annulus. All patients then underwent cardiac catheterization with invasive determination of cardiac output, PAP, and PVR. RESULTS: The systolic velocity of the tricuspid annulus (tS(m)) had an inverse relationship with catheterization-derived mean PAP, with a correlation coefficient of -0.493 (P = .0003). The inverse correlation of tS(m) with catheterization-derived PVR was more striking, with a correlation coefficient of -0.710 (P < .0001). Based on the data, we derived the following logarithmic regression equation: PVR = 3698 - 1227 x ln(tS(m)). CONCLUSIONS: Doppler tissue imaging of the lateral tricuspid annulus is a useful clinical tool that can provide a noninvasive estimate of PVR in patients with chronic thromboembolic pulmonary hypertension. In this population, decreasing values of tS(m) predicted progressively higher measurements of PVR.