Immediate functional effects of left ventricular reduction: A Doppler echocardiographic study in the rat

Immediate functional effects of left ventricular reduction: A Doppler echocardiographic study in the rat

Autor Kanashiro, R. M. Google Scholar
Saraiva, R. M. Google Scholar
Alberta, A. Google Scholar
Antonio, E. L. Google Scholar
Moises, V. A. Google Scholar
Tucci, PJF Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo Background: Immediate functional effects of left ventricle reduction (LVR) are not yet fully defined. Those effects have been studied in the experimental model of myocardial infarction scar plication (MISP) in the rat.Methods and Results: A Doppler echocardiogram was performed immediately before and after MISP in 20 rats with infarction of the left ventricle (LV) larger than 40%. LV diastolic volume reduction (475 +/- 114 versus 185 +/- 65 mu L) was accompanied by heart rate decrease (230 +/- 25 versus 166 +/- 27 beats/min) and increase of ejection fraction (37 +/- 7 versus 67 +/- 12%), fractional shortening (18 +/- 3 versus 46 +/- 8%) and posterior wall shortening velocity (1.50 +/- 0.62 versus 2.01 +/- 0.46 cm/s). LV diastolic volume/ stroke volume slope was steeper after LVR, suggesting enhancement of the Frank-Starling mechanism. Restrictive pattern of left atrial emptying was alleviated after LVR (E wave: 101 +/- 15 versus 66 +/- 14 cm/s; E/A ratio: 6.8 +/- 2.9 versus 5.0 +/- 2.2; E wave deceleration time: 36 +/- 6 versus 51 +/- 10 msec) even though left atrial diameter (0.69 +/- 0.07 versus 0.66 +/- 0.06 cm) and A wave (18.0 +/- 9.4 versus 15.8 +/- 7.8 cm/s) did not vary. Additionally, a pulmonary flow profile suggesting pulmonary hypertension was observed in 12 of 17 animals before, and in only 3 after, LVR.Conclusion: LVR favors cardiac function not only by reducing afterload. the present data are in consonance with previous suggestions that the Frank-Starling mechanism is enhanced after MISP and, in addition to LV ejection function improvement, the unprecedented facilitation of left atrial emptying after LVR was particularly noteworthy. Even though LVR restricts ventricular distensibility, atrial emptying can be facilitated, probably on account of LV ejection improvement.
Assunto LV reduction
ventricular function
Frank-Starling mechanism
atrial function
Idioma Inglês
Data 2006-03-01
Publicado em Journal of Cardiac Failure. Philadelphia: Churchill Livingstone Inc Medical Publishers, v. 12, n. 2, p. 163-169, 2006.
ISSN 1071-9164 (Sherpa/Romeo, fator de impacto)
Editor Churchill Livingstone Inc Medical Publishers
Extensão 163-169
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000236385200014

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