Background: Accurate assessment of aortic valve area (AVA) is important for clinical decision-making in patients with aortic valve stenosis (AS). The role of three-dimensional echocardiography (3D) in the quantitative assessment of AS has not been evaluated so far. Objectives: To evaluate the reproducibility and accuracy of real-time three-dimensional echocardiography (RT3D) and 3D-guided two-dimensional planimetry (3D/2D) for assessment of AS, and compare these results with those of standard echocardiography and cardiac catheterisation (Cath). Methods: AVA was estimated by transthoracic echo-Doppler (TTE) and by direct planimetry using transoesophageal echocardiography (TEE) as well as RT3D and 3D/2D. 15 patients underwent assessment of AS by Cath. Results: 33 patients with AS were studied (20 men, mean (SD) age 70 (14) 2 for TEE. Correlation coefficient r for AVA assessment between each of 3D/2D, RT3D, TEE planimetry and Cath was 0.81, 0.86 and 0.71, respectively. The intraobserver variability was similar for all methods, but interobserver variability was better for 3D techniques than for TEE (p,0.05). Conclusions: The 3D echo methods for planimetry of the AVA showed good agreement with the standard TEE technique and flow-derived methods. Compared with AV planimetry by TEE, both 3D methods were at least as good as TEE and had better reproducibility. 3D aortic valve planimetry is a novel non-invasive technique, which provides an accurate and reliable quantitative assessment of AS.

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SUMMARY The duration of the acceleration phase of pulmonary systolic flow was measured by pulsed Doppler echocardiography in 39 normal subjects and 67 patients with heart disease to evaluate the reliability of this Doppler index as an estimate of pulmonary arterial pressure. The mean (SD) Doppler index in patients with abnormal mean pulmonary arterial pressure ( > 15 mm Hg) was significantly shorter than that in normal subjects (1 10 (30) ms vs 150 (10) ms). The Doppler index was significantly related to the mean pulmonary arterial pressure (r = -0 75) the pulmonary blood flow (r = 0 46), and the total pulmonary vascular resistance (r =-0-68). Forty four of 45 patients with an abnormal index (< 120 ms) showed abnormal mean pressure (> 15 mm Hg). Without exception patients with a low index ( < 90 ms) had distinct pulmonary hypertension ( > 25mm Hg). Twelve of 22 patients with a normal index (> 130 ms), however, also showed abnormal pressures. Nine of the 12 had an atrial septal defect and they had high pulmonary arterial pressure associated with high blood flow. Eighteen patients with valvar heart disease, whose mean pulmonary arterial pressure ranged from 16mm Hg to 24mm Hg, had a significantly shorter acceleration phase and a higher total vascular resistance than 11 patients with atrial septal defect in whom the pressure range was similar (120(20) ms vs 140(20) ms, 3 8 (1 1) hybrid resistance unit vs 1 6 (0-5)).Thus although the acceleration time of the pulmonary systolic flow is useful for the evaluation of pulmonary hypertension, it is a complex index that is affected not only by pulmonary arterial pressure but also by pulmonary blood flow and pathological changes in the pulmonary vascular bed. Accepted for publication 12 March 1986 patients with pulmonary hypertension is characteristically shorter than that in normal subjects,4 and the duration of the acceleration phase decreases as the pulmonary hypertension progresses.4 5 This Doppler index may provide a non-invasive method for the evaluation of pulmonary arterial pressure. Pulmonary arterial pressure, however, depends on pulmonary flow volume and pulmonary vascular impedance. The -duration of the acceleration phase in a patient with high flow volume may be different from that in another patient with high peripheral resistance, even if pulmonary arterial pressure is the same in both patients. Furthermore, right ventricular contractility may affect the pulmonary systolic flow pattern.We have studied the relation between the duration of the acceleration phase of pulmonary systolic flow and haemodynamic variables in various diseases to 158

Summary Background External low‐frequency ultrasound (USD) in combination with microbubbles has been reported to recanalize thrombotically occluded arteries in animal models. Objective The purpose of this study was to examine the enhancing effect of thrombus‐targeted bubble liposomes (BLs) developed for fresh thrombus imaging during ultrasonic thrombolysis. Methods In vitro: after the administration of thrombus‐targeted BLs or non‐targeted BLs, the clot was exposed to low‐frequency (27 kHz) USD for 5 min. In vivo: Rabbit iliofemoral arteries were thrombotically occluded, and an intravenous injection of either targeted BLs (n = 22) or non‐targeted BLs (n = 22) was delivered. External low‐frequency USD (low intensity, 1.4 W cm−2, to 12 arteries, and high intensity, 4.0 W cm−2, to 10 arteries, for both the targeted BL group and the non‐targeted BL group) was applied to the thrombotically occluded arteries for 60 min. In another 10 rabbits, recombinant tissue‐type plasminogen activator (rt‐PA) was intravenously administered. Results In vitro: the weight reduction rate of the clot with targeted BLs was significantly higher than that of the clot with non‐targeted BLs. In vivo: TIMI grade 3 flow was present in a significantly higher number of rabbits with USD and targeted BLs than rabbits with USD and non‐targeted BLs, or with rt‐PA monotherapy. High‐intensity USD exposure with targeted BLs achieved arterial recanalization in 90% of arteries, and the time to reperfusion was shorter than with rt‐PA treatment (targeted BLs, 16.7 ± 5.0 min; rt‐PA, 41.3 ± 14.4 min). Conclusions Thrombus‐targeted BLs developed for USD thrombus imaging enhance ultrasonic disruption of thrombus both in vitro and in vivo.