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Cardiac variables and blood pressure as determinants of left ventricular inflow velocities
1Department of Pathophysiology, Faculty of Medicine, University of Leuven, Belgium.
Insights
Left ventricular diastolic filling patterns are influenced by age, blood pressure, and left atrial size, not structural heart changes. These factors impact transmitral flow velocities in hypertensive patients.
Area of Science:
- Cardiology
- Echocardiography
- Hypertension Research
Background:
- Left ventricular diastolic function is crucial for cardiac health.
- Hypertension can significantly alter cardiac mechanics and filling patterns.
- Doppler velocimetry is a key tool for assessing diastolic function.
Purpose of the Study:
- To identify the determinants of left ventricular diastolic transmitral flow patterns in hypertensive patients.
- To investigate the relationship between blood pressure, age, left atrial size, and systolic function with diastolic filling.
- To determine if left ventricular structural changes correlate with diastolic dysfunction.
Main Methods:
- Doppler velocimetry was used to measure transmitral flow patterns in 40 hypertensive patients.
- Multiple regression analysis was employed to assess the relationships between various physiological parameters and diastolic filling indices.
- Echocardiographic measurements included left ventricular mass and wall thickness.
Main Results:
- The atrial to early filling peak velocity (A/E) ratio was independently associated with age, blood pressure, fractional shortening, and left atrial size.
- Peak flow velocity during atrial contraction correlated positively with age, blood pressure, and heart rate.
- Early filling velocity decreased with age but increased with heart rate, left atrial diameter, and fractional shortening.
- Left ventricular mass and wall thickness showed weak associations with the A/E ratio that did not persist in regression analysis.
Conclusions:
- Left ventricular diastolic filling is primarily determined by age, blood pressure, left atrial size, and systolic function.
- Echocardiographically measured left ventricular structural variables are not significant determinants of diastolic filling patterns in this cohort.
- These findings highlight the functional rather than structural impact of hypertension on diastolic function.
Abstract:
The determinants of the left ventricular diastolic transmitral flow pattern, measured by use of Doppler velocimetry, were assessed in 40 patients referred for hypertension. The ratio of the atrial to early filling peak velocity (A/E ratio) averaged 0.82 +/- 0.23, BP 156 +/- 19/100 +/- 13 mmHg and left ventricular mass 220 +/- 57. In multiple regression analysis the A/E ratio was independently and positively related to age (P < 0.001) and BP (P < 0.001) and inversely to the fractional shortening of the left ventricular internal diameter (P < 0.01) and left atrial size at end-systole (P < 0.05); these variables accounted for 71% of the variance of the A/E ratio. The peak flow velocity during atrial contraction was positively and independently related to age (P < 0.001), BP (P < 0.05) and heart rate (P < 0.05); early filling velocity decreased with age (P < 0.001) and was positively related to heart rate (P < 0.01), left atrial diameter (P < 0.01) and fractional shortening (P < 0.001). The weak positive associations of the A/E ratio with left ventricular mass (r = 0.32; P < 0.05) and wall thickness (r = 0.38; P < 0.05) did not persist in multiple regression analysis. In conclusion, the left ventricular diastolic filling indexes are related to age, BP, left atrial size and to systolic left ventricular function but left ventricular structural variables, as measured by echocardiography, are not significantly involved.