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[Intracardiac flow pattern in dilated cardiomyopathy studied with pulsed Doppler echocardiography]
Insights
Pulsed Doppler echocardiography reveals significant abnormalities in left ventricular (LV) flow dynamics in patients with dilated cardiomyopathy (DCM), impacting ejection fraction and cardiac dimensions.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Background:
- Dilated cardiomyopathy (DCM) is a significant cause of heart failure.
- Assessing left ventricular (LV) function is crucial for diagnosing and managing DCM.
- Pulsed Doppler echocardiography offers a non-invasive method to evaluate intracardiac blood flow patterns.
Purpose of the Study:
- To analyze and characterize left ventricular (LV) flow dynamics in patients with dilated cardiomyopathy (DCM) using pulsed Doppler echocardiography.
- To compare LV flow patterns and cardiac dimensions between DCM patients and normal controls.
Main Methods:
- Pulsed Doppler echocardiography was performed on 27 DCM patients and 5 normal controls, recording flow signals at multiple LV points (apex, mid-ventricle, inflow, outflow).
- Standard echocardiographic measurements including ejection fraction (EF), LV dimensions, and percent shortening were obtained.
- Left ventriculography was used to corroborate Doppler findings and assess global LV function.
Main Results:
- Doppler ejection flow signals were significantly reduced or absent in DCM patients at multiple LV sites compared to controls.
- Abnormal wide-band spectral patterns were observed in 44% of DCM patients during systole at the inflow tract.
- Diastolic flow signals were markedly diminished in DCM patients, particularly at the apex and mid-ventricle.
- DCM patients exhibited lower ejection fraction (36% vs 65%), increased LV short-to-long axis ratio (0.82 vs 0.60), and reduced percent shortening (11-15% vs 21-34%) compared to controls.
Conclusions:
- Pulsed Doppler echocardiography effectively detects characteristic alterations in LV flow dynamics in DCM.
- These flow abnormalities correlate with impaired systolic function and altered cardiac geometry in DCM.
- Doppler assessment of LV flow dynamics can serve as a valuable tool in the evaluation of dilated cardiomyopathy.
Abstract:
Left ventricular (LV) flow dynamics were analyzed by pulsed Doppler echocardiography in patients (pts) with dilated cardiomyopathy (DCM). Subjects consisted of five normal controls, 27 pts with DCM, five with myocardial infarction and five with valvular heart disease. The equipment used was a two-dimensional echocardiograph ( Toshiba SSH- 11A ) coupled with a pulsed Doppler flowmeter ( Toshiba SDS-10A). The long-axis plane through the left ventricle was obtained from an apical transducer position and Doppler flow signals were recorded at the apex (point A), the middle portion (point B), the inflow portion (point C), the portion near the mid-IVS (point D) and the outflow portion (point E) of the left ventricle, respectively. Left ventriculography was performed in all subjects, and ejection fraction (EF), the ratio of the short-axis to long-axis distance in end-diastole, percent shortening of the long axis and percent shortening of the short axis of the left ventricle were measured. Doppler signals of an ejection flow were recorded at points A, B, D and E in the normal controls, while in 27 pts with DCM Doppler signals of an ejection flow were detected only in two pts (7%) at the point A, in three pts (11%) at the point B, 16 pts (59%) at the point D and 27 pts (100%) at the point E. Twelve pts (44%) had abnormal Doppler signals with wide-band spectral pattern at the point C in systole. Toward flow signals in early diastole were recorded at the points A, B, C and D in the normal controls, while in pts with DCM the signals were visualized in only three pts (11%) at the point A, in 27 pts (100%) at the points B and C, and 10 pts (37%) at the point D. EF in pts with DCM was lower than that of the normal controls (36 +/- 11 vs 65 +/- 5%, p less than 0.005). The ratio of the short-axis to long-axis distance of the left ventricle was higher in pts with DCM compared with that of the normal controls (0.82 +/- 0.09 vs 0.60 +/- 0.02, p less than 0.005). Percent shortening of the long axis and the short axis was depressed in pts with DCM compared with the normal controls (11 +/- 5 vs 21 +/- 4%, p less than 0.02 and 15 +/- 6 vs 34 +/- 3%, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)