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Abnormal intraventricular flow patterns in left ventricular dysfunction determined by color Doppler study
F Pennestri'1, L M Biasucci, G Rinelli
1Institute of Cardiology, Catholic University Sacro Cuore, Roma, Italy.
Insights
Left ventricular (LV) flow patterns, measured by flow persistence index (FPI), reveal abnormalities in patients with myocardial infarction and dilated cardiomyopathy. This paradoxical flow is linked to the severity of LV dysfunction.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Background:
- Left ventricular (LV) function is crucial for cardiac output.
- Assessing LV flow dynamics can provide insights into cardiac health.
- Myocardial infarction (MI) and dilated cardiomyopathy significantly impact LV function.
Purpose of the Study:
- To investigate the relationship between LV flow dynamics and global/regional LV function.
- To characterize LV flow patterns in normal subjects, post-MI patients, and those with dilated cardiomyopathy.
- To quantify LV flow abnormalities using a novel flow persistence index (FPI).
Main Methods:
- Color Doppler echocardiography to measure LV flow dynamics.
- Calculation of the flow persistence index (FPI) based on systolic flow direction and duration.
- Contrast echocardiography as a control method in a subset of patients.
Main Results:
- Normal subjects exhibited rapid systolic flow inversion toward the aorta (low FPI).
- Patients with MI showed increased FPI, indicating altered flow patterns.
- Patients with LV aneurysm and dilated cardiomyopathy displayed a paradoxical antegrade LV flow pattern throughout systole (high FPI).
- FPI correlated significantly with LV volumes and ejection fraction, particularly in post-MI groups.
Conclusions:
- Paradoxical LV flow patterns are associated with both regional and global LV dysfunction.
- LV flow abnormalities can occur after MI even without severe LV dilation or dyssynergy.
- The FPI is a quantitative measure of LV dysfunction and may aid in assessing cardiac health post-MI.
Abstract:
We examined the relation between left ventricular (LV) flow dynamics measured by color Doppler, and either global or regional LV function in 19 normal subjects (group 1), in 55 patients with old myocardial infarction (MI) (29 without [group 2] and 26 with LV aneurysm [group 3]), and in 16 with idiopathic dilated cardiomyopathy (group 4). We calculated by M-mode color Doppler a flow persistence index (FPI) (duration of flow directed in systole toward the apex/LV ejection time). Contrast echocardiography was performed as a control method in 14 patients of the four groups. In normal subjects, rapid systolic inversion of flow toward the aorta was evident (FPI: 0.11 +/- 0.16). In all but one patient in group 2, a similar LV flow pattern was observed, but FPI was greater (0.32 +/- 0.26). In groups 3 and 4, a paradoxical antegrade LV flow pattern was evident during the entire period of systole (FPI: 1.13 +/- 0.42 and 1.28 +/- 0.36, respectively). LV flow patterns were reproduced in echo-contrast studies. FPI was related to LV end-diastolic volume (r = 0.77), end-systolic volume (r = 0.82), and ejection fraction (r = -0.84). However, when data were analyzed separately in the different groups, these correlations were significant only in groups 2 and 3. Paradoxical flow pattern is not peculiar to regional LV dysfunction; it also occurs in global LV dysfunction. This LV flow abnormality may develop after MI even in the absence of severe LV dyssynergy or dilation, and is quantitatively related to the degree of LV dysfunction.