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Diastolic blood pressure and left ventricular filling
W F Graettinger1, J V Longfellow, R C Klein
1Hypertension Center, VA Medical Center, Long Beach, CA 90822.
Insights
Diastolic blood pressure, not systolic, impacts left ventricular filling patterns in adolescents. These changes, particularly noticeable in those with specific ECG patterns, may signal early pre-hypertensive alterations.
Area of Science:
- Cardiology
- Physiology
- Echocardiography
Background:
- Diastolic left ventricular (LV) filling is influenced by various factors including age and hypertension.
- Doppler-echocardiography is a key tool for assessing cardiac function.
Purpose of the Study:
- To investigate the influence of blood pressure (BP) on LV diastolic filling in normotensive adolescents.
- To determine if systolic BP or diastolic BP has a greater impact on LV filling parameters.
Main Methods:
- Utilized Doppler-echocardiography to measure transmitral flow velocities, diastolic flow integrals, and early diastolic deceleration in 43 normotensive volunteers (aged 12 +/- 0.98 years).
- Analyzed the relationship between systolic and diastolic BP with LV mass and Doppler-derived LV filling indices.
- Correlated ECG findings (bimodal vs. unimodal P waves) with diastolic BP and LV filling patterns.
Main Results:
- Systolic BP correlated with LV mass but not with LV filling indices.
- Diastolic BP was inversely related to peak early diastolic flow velocity and early diastolic flow velocity integral.
- The ratio of late-to-early filling (A/E) showed a direct relationship with diastolic BP, especially in adolescents with bimodal P waves on ECG.
- These findings were independent of heart rate and LV hypertrophy.
Conclusions:
- Diastolic BP significantly influences LV diastolic filling patterns in normal adolescents.
- The observed changes may represent early pre-hypertensive alterations in LV diastolic function.
- ECG characteristics, specifically bimodal P waves, may identify adolescents more susceptible to these diastolic BP-related changes.
Abstract:
Many factors appear to influence diastolic left ventricular (LV) filling, including age, hypertension, and myocardial and coronary disease. Doppler-echocardiography was used to asses the influences of blood pressure (BP) on LV filling in 43 normotensive volunteers aged 12 +/- 0.98 years with heart rates less than or equal to 90 beats/min. Doppler peak diastolic transmitral flow velocities, diastolic flow integrals, and early diastolic deceleration were measured. An interesting difference was noted between the influence of systolic and diastolic BP. Systolic BP was related to LV mass (r = 0.43; P less than 0.005), but was unrelated to any of the Doppler filling indices. Diastolic BP was unrelated to LV mass, but was inversely related to peak early diastolic flow velocity (r = -0.37; P less than 0.05), early diastolic flow velocity integral (r = -0.34; P less than 0.05). The ratio of late-to-early filling (A/E) was directly related to diastolic BP (r = 0.42; P less than 0.005). The relationship between A/E and diastolic BP was strong in subjects (n = 21) with bimodal P waves in electrocardiogram (ECG) lead V1 (r = 0.61; P less than 0.005), but absent in those (n = 15) with unimodal P waves (r = 0.18; P = NS). Thus, the pattern of LV filling is related to the level of diastolic BP in normal adolescents, especially in those with bimodal P waves on ECG. These diastolic BP related changes are independent of heart rate and LV hypertrophy and may represent very early pre-hypertensive alterations in LV diastolic function.