Published online Jul 31, 1994.
https://doi.org/10.4250/jkse.1994.2.1.13
Left Ventricular Blood Flow Pathways According to the Infarct Location
Abstract
Background
Even after correction for infarct size, there are differences in the survival and the incidence of embolic complication according to infarct location. Blood flow pathway in the left ventricle changes with alteration of left ventricular geometry and this difference in the blood flow pathway might be one of the conceivable causes. Left ventricular blood flow pathway was evaluated using contrast echocardiography.
Method
Eight Mongrel dogs weighing around 15kg were used. Contrast echocardiography was performed injecting agitated saline in the left atrium in the open chest dogs. Theree aspects were analysed at the baseline and after ligation of coronary arteries −4 in left anterior descending arteries and 4 in left circumflex arteries. 1) left ventricular blood flow pathway during early diastole, 2) persistence of mitral inflow reflected at the left ventricular outflow tract(RMI). 3) Presence of Mitral inflow not reaching the apex and diverted to the left ventricular outflow tract(DMI).
Results
1) Left ventricular blood flow pathway during early diastole. At the baseline(8 cases)-6: centrally directed flow 2: inferiorly directed flow After the infarction(5 cases)-2 anterior infarction : anteriorly directed flow 2 inferior infarction : inferiorly directed flow 1 Iateral infarction : Iaterally directed flow 2) Persistence of RMI. RMI was present at the baseline in 6 cases : RMI was abolished in 2 cases where anterior infarction was induced, RMI persisted in 4 cases where inferior infarction was induced. 3) Presence of DMI. Presence of DMI according to the infarct location could not be evaluated because of the limited number of cases. But in overall cases. before and after the infarction, DMI was present in 7 cases and DMI was absent in 6 cases. DMI(+) group has significantly higher heart rate than DMI(−) group(158.3±17.2 vs 119.5±14.5)(p<0.05).
Conclusion
Blood flow pathway differs according to the infarct location. Blood flow pathway was more similar to the narmal pathway in inferior infarction than anterior infarction. Increase in the heart rate accompanied by left ventricular dysfuction predispose to the diversion of mitral inflow to the left ventricular outflow tract without reaching the apex possibly causing blood stasis at the apex.
