J Korean Soc Echocardiogr.  1994 Jul;2(1):13-22. 10.4250/jkse.1994.2.1.13.

Left Ventricular Blood Flow Pathways According to the Infarct Location

• Sohn DW
• Cho SU
• Kim HS
• Kim CH
• Oh BH
• Lee MM
• Park YB
• Choi YS
• Seo JD
• Lee YW

• KMID: 2410455
• DOI: http://doi.org/10.4250/jkse.1994.2.1.13

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.

Keyword

Blood flow pathway; Myocardial infarction; Contrast echocardiography

MeSH Terms

Animals
Arteries
Coronary Vessels
Diastole
Dihydroergotamine
Dogs
Echocardiography
Heart Atria
Heart Rate
Heart Ventricles
Incidence
Infarction
Ligation
Methods
Myocardial Infarction
Thorax
Dihydroergotamine

Figure

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  Fig. 1. A: Mitral inflow–E and A waves were merged (EA) because of the rapid heart rate. B: Mitral inflow wave turing around at the apex and going toward left ventricular outflow(EA').

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  Fig. 2. Mitral inflow not reaching the apex and diverted to the left ventricular outflow.

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  Fig. 3. Normal left ventricular blood flow pathways. A, B, C: Apical 4 chamber view showing centrally directed flow. D, E, F: Parasternal short axis view-In 2 cases initial mitral inflow directed interiorly and turned counterclockwise to the outflow tract.

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  Fig. 4. In anterior infarction mitral inflow was deviated anteriorly and during the following systole turbulance was noted at the center of the cavity.

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  Fig. 5. In inferior infarction. Note the inferiorly deviated mitral inflow.

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  Fig. 6. In lateral infarction. Mitral inflow was deviated laterally.

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  Fig. 7. Upper panel: In anterior infarction, reflected mitral inflow shown before infarction was abolished after the infarction. Lower panel: Reflected mitral infarction was preserved after the infarction.

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  Fig. 8. DMI(+) group showed significantly higher heart rate than DMI(–) group.

Reference

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