HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 288/5/H2375    most recent 00946.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Urheim, S. Articles by Smiseth, O. A. Search for Related Content PubMed PubMed Citation Articles by Urheim, S. Articles by Smiseth, O. A.

Regional myocardial work by strain Doppler echocardiography and LV pressure: a new method for quantifying myocardial function

Institute for Surgical Research and Department of Cardiology, Rikshospitalet University Hospital, Oslo, Norway

Submitted 10 September 2004 ; accepted in final form 30 December 2004

There is a need for better methods to quantify regional myocardial function. In the present study, we investigated the feasibility of quantifying regional function in terms of a segmental myocardial work index as derived from strain Doppler echocardiography (SDE) and invasive pressure. In 10 anesthetized dogs, we measured left ventricular (LV) pressure by micromanometer and myocardial longitudinal strains by SDE and sonomicrometry. The regional myocardial work index (RMWI) was calculated as the area of the pressure-strain loop. As a reference method for strain, we used sonomicrometry. By convention, the loop area was assigned a positive sign when the pressure-strain coordinates rotated counterclockwise. Measurements were done at baseline and during volume loading and left anterior descending coronary artery (LAD) occlusion, respectively. There was a good correlation between RMWI calculated from strain by SDE and strain by sonomicrometry (y = 0.73x + 0.21, r = 0.82, P < 0.01). Volume loading caused an increase in RMWI from 1.3 ± 0.2 to 2.2 ± 0.1 kJ/m³ (P < 0.05) by SDE and from 1.5 ± 0.3 to 2.7 ± 0.3 kJ/m³ (P = 0.066) by sonomicrometry. Short-term ischemia (1 min) caused a decrease in RMWI from 1.3 ± 0.2 to 0.3 ± 0.04 kJ/m³ (P < 0.05) and from 1.3 ± 0.3 to 0.5 ± 0.2 kJ/m³ (P < 0.05) by SDE and sonomicrometry, respectively. In the nonischemic ventricle and during short-term ischemia, the pressure-strain loops rotated counterclockwise, consistent with actively contracting segments. Long-term ischemia (3 h), however, caused the pressure-strain loop to rotate clockwise, consistent with entirely passive segments, and the loop areas became negative, –0.2 ± 0.1 and –0.1 ± 0.03 kJ/m³ (P < 0.05) by SDE and sonomicrometry, respectively. A RMWI can be estimated by SDE in combination with LV pressure. Furthermore, the orientation of the loop can be used to assess whether the segment is active or passive.

sonomicrometry; pressure-strain loop

This article has been cited by other articles:

				B. Bijnens, P. Claus, F. Weidemann, J. Strotmann, and G. R. Sutherland Investigating Cardiac Function Using Motion and Deformation Analysis in the Setting of Coronary Artery Disease Circulation, November 20, 2007; 116(21): 2453 - 2464. [Full Text] [PDF]