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[Mitral flow propagation velocity assessed with M-mode color Doppler in patients with dilated cardiomyopathy]
1Serviço de Cardiologia dos Hospitais da Universidade de Coimbra, Coimbra, Portugal.
Insights
Propagation velocity (PV) effectively quantifies left ventricular (LV) diastolic function in dilated cardiomyopathy. This load-independent indicator correlates with classic LV filling parameters, aiding severity assessment.
Area of Science:
- Cardiology
- Echocardiography
- Diastolic Function
Background:
- Diastolic dysfunction is often overlooked in severe left ventricular (LV) dysfunction due to quantification challenges.
- Propagation velocity (PV) of mitral inflow is a proposed load-independent indicator of LV diastolic function.
- This study aimed to validate PV in quantifying LV filling and risk stratification in dilated cardiomyopathy (DC).
Purpose of the Study:
- Correlate PV with patient characteristics and classic systolic and diastolic function parameters.
- Validate PV as an indicator of LV filling.
- Assess PV's utility in risk stratification for DC patients.
Main Methods:
- Prospective study of 32 DC patients with low ejection fraction.
- Echocardiographic assessment of LV systolic function (ejection fraction, fractional shortening, cardiac output).
- Transmitral flow Doppler analysis (IVRT, E/A ratio, DT) and Tei index.
- PV calculated using Color M-mode echocardiography.
Main Results:
- High prevalence of diastolic dysfunction (78.1% delayed relaxation, 9.4% restrictive pattern).
- PV showed no correlation with age, body surface, or LV geometry.
- Significant correlations found between PV and E/A ratio (r=0.61), IVRT (r=-0.50), DT (r=-0.41), and Tei index (r=-0.36).
Conclusions:
- PV strongly correlates with classic LV filling parameters in patients with predominant delayed relaxation.
- PV is a potentially easy, fast, and reproducible quantitative indicator of DC severity.
- PV may aid in assessing LV diastolic function and severity in DC patients.
Background:
The role of diastolic disfunction in the setting of severe left ventricular (LV) disfunction is usually forgotten due to difficulties in quantification and interpretation. The propagation velocity (PV) of mitral inflow into the left ventricle has been proposed as a load independent indicator of LV diastolic function. Our aim was to correlate PV with age, body surface, chambers dimensions, wall thickness and with classic parameters of systolic and diastolic function. We had in mind the validation of this index in the quantification of LV filling and in risk stratification of patients with dilated cardiomyopathy (DC).
Material And Methods:
We prospectively studied 32 consecutive patients, mean age 56.1 +/- 15.7 years, 22 (68.75%) male, mean ejection fraction 28.1 +/- 7.5%. All of them were in NYHA class < or = II and on ACE inhibitors. Eight (25%) were on beta-blockers. Patients without sinus rhythm, paced or with significant hypertensive, congenital or valvular heart disease were previously excluded. The following parameters of LV systolic function were assessed by echocardiography: fractional shortening, ejection fraction and cardiac output. LV filling was assessed by transmitral flow pulsed Doppler analysis: isovolumic relaxation time (IVRT), peak E and A wave velocities, E wave deceleration time (DT). We also evaluated a new Doppler index of combined systolic and diastolic myocardial performance (Tei index). PV (cm/s) was calculated by Color M-mode. Univariate regression analysis was performed (PV as dependent variable).
Results:
We detected a high prevalence of diastolic function disturbances: 25 (78.1%) patients with a delayed relaxation pattern and only 3 (9.4%) with a restrictive pattern. PV did not correlate with age, body surface and LV geometry. There was a significant correlation between PV and E/A ratio (r = 0.61; p < 0.0001), IVRT (r = -0.50; p = 0.006), DT (r = -0.41; p = 0.01) and Tei index (r = -0.36; p = 0.04).
Conclusions:
Our results indicate that, in patients with a predominance of delayed relaxation, there is a strong relationship between PV and the classic parameters of LV filling. For similar levels of systolic impairment, PV could be an easy, fast and reproducible quantitative indicator of severity on DC.