Publications by authors named "Katherine J Middleton"

We sought to examine the hemodynamic determinants and clinical application of the peak acceleration rate of early (Ea) diastolic velocity of the mitral annulus by tissue Doppler. Simultaneous left atrial and left ventricular (LV) catheterization and Doppler echocardiography were performed in 10 dogs. Preload was altered using volume infusion and caval occlusion, whereas myocardial lusitropic state was altered with dobutamine and esmolol.

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In the present study, we performed simultaneous epicardial echocardiography and left heart catheterization on ten adult dogs to investigate the effects of ischaemia and tachycardia on the mitral annulus early (E(a)) and late (A(a)) diastolic velocities and the haemodynamic mechanisms involved. Left atrial pressure and left ventricular (LV) volumes and pressures were measured with 5 French Millar catheters. In each dog, inferior vena cava occlusion was used to alter preload and circumflex coronary artery occlusion was applied to induce ischaemia at two different cycle lengths: 450 and 550 ms.

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Background: Patients with hypertrophic obstructive cardiomyopathy have left ventricular (LV) diastolic dysfunction due, in part, to temporal heterogeneity in regional function. The acute effect of the relief of LV outflow tract obstruction is unknown. Therefore, we investigated the effects of nonsurgical septal reduction therapy (NSRT) on regional function.

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