was assessed by measurements of segment length (SL), velocity of SL shortening and regional myocardial "work", i.e., pressure-length loops in normal, moderately, and severely ischemic zones. Regional intramyocardial electrograms were measured from the same sites along with regional myocardial blood flow as determined by the radioactive microsphere technique. Coronary occlusion resulted in grade...

The effects of coronary occlusion and of subsequent propranolol administration were examined in 18 conscious dogs. Overall left ventricular (LV) function was assessed by measurements of LV pressure and dP/dt, and regional myocardial function was assessed by measurements of segment length (SL), velocity of SL shortening and regional myocardial "work", i.e., pressure-length loops in normal, moder...

The relationship between epicardial and transmural function (measured with sonomicrometers) was examined in 13 anesthetized open-chest dogs. Systolic wall thickening was used as a standard of integrated transmural function to compare with epicardial function measured as segment shortening parallel to surface fibers. Three levels of coronary inflow restriction were produced by using decrements i...

Left ventricular high fidelity pressure measurements and simultaneous biplane cineangiocardiography were performed in 12 patients with severe aortic valve disease (aortic stenosis in 10, aortic insufficiency in 1 and combined valve lesion in 1). Left ventricular contractility was estimated from maximal rate of left ventricular pressure rise (max dP/dt), peak measured velocity of contractile ele...

We used ultrasonic segment length gauges to examine the regional behavior of midwall fibers at different sites around the left ventricular minor axis in 12 anesthetized dogs. In six dogs (group I) with circumferentially oriented midwall gauges, significantly greater shortening of anterior than lateral or posterior wall segments was demonstrated over a range of left ventricular end-diastolic pre...

OBJECTIVES We sought to assess whether isoproterenol stress echocardiography could detect in advance in which patients hypertrophic cardiomyopathy would progress to a phase resembling dilated cardiomyopathy. BACKGROUND In a few patients, hypertrophic cardiomyopathy has been reported to progress to a phase characterized by systolic dysfunction and left ventricular dilation, resembling dilated ...

This study was undertaken to evaluate the cardiac dimensions and various indices of myocardial function, determined by echocardiography, in a group of 12 infants with congenital hypothyroidism. Left ventricular systolic and diastolic dimensions, posterior wall thickness, enddiastolic and systolic volumes were all significantly lower in the hypothyroid infants compared with 25 normal infants of ...

Background Regional performance of the hypertrophied left ventricle (LV) in hypertrophic cardiomyopathy (HCM) is still incompletely characterized with studies variably reporting that the hypertrophied myocardium is hypokinetic, akinetic, or has normal function. Different imaging modalities (M-mode or two-dimensional echocardiography) and methods of analysis (fixed or floating frame of reference...

AIMS Hypertrophic cardiomyopathy (HCM) is a disease with marked regional differences in wall thickness. However, the relation between myocardial function and wall thickness has not been well studied. Ultrasonic strain rate (SR) imaging makes it possible to study the regional myocardial deformation. We investigated whether regional systolic deformation is reduced in paediatric patients with HCM ...

cent a systolic 'bulge'. The a-E interval and the time to the systolic peak of the apex cardiogram were significantly shortened. The systolic time intervals showed shortening of the pre-ejection period i, isovolumetric contraction time, electromechanical systole, and ejection time along with the E-J interval which represents the phase of maximum ventricular ejection. The changes observed were t...