[Left and right ventricular diastolic properties in essential hypertension during cold pressor test: noninvasive assessment by pulsed Doppler echocardiography]
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N Hamazaki1, T Shimizu, A Okamura
1Department of Medicine, Dokkyo University School of Medicine, Tochigi.
Insights
Essential hypertensive patients exhibit impaired diastolic function, worsened by increased afterload during the cold pressor test. Nifedipine did not significantly alter these diastolic properties.
Area of Science:
- Cardiology
- Physiology
Context:
- Essential hypertension (HT) affects diastolic properties of the heart ventricles.
- Assessing ventricular diastolic function is crucial for understanding cardiovascular health in hypertensive individuals.
Purpose:
- To evaluate the diastolic properties of the left and right ventricles in essential hypertensive patients without left ventricular hypertrophy.
- To investigate the impact of the cold pressor test (CPT) and nifedipine administration on ventricular diastolic function in HT patients.
Summary:
- Pulsed Doppler echocardiography revealed significantly greater peak blood flow velocities from atrial contractions (ALV, ARV) and increased atrial contraction to rapid filling ratios (A/R) in HT patients compared to controls at rest.
- During the CPT, HT patients showed reduced peak rapid filling flow velocity and further increased A/R ratios, indicating worsened diastolic function with increased afterload.
- Nifedipine administration did not significantly alter diastolic indices or systolic blood pressure in either group, at rest or during CPT.
Impact:
- These findings demonstrate that increased afterload exacerbates abnormal diastolic properties in both ventricles of hypertensive patients.
- The study highlights the sensitivity of diastolic function to hemodynamic changes in essential hypertension.
- Results suggest that while nifedipine may not acutely improve these specific diastolic parameters under stress, understanding diastolic dysfunction is key in managing hypertension.
Abstract:
The diastolic properties of the left and right ventricles of 17 essential hypertensive patients (HT) without left ventricular hypertrophy and of 12 normotensive subjects were assessed by pulsed Doppler echocardiography during the cold pressor test (CPT) and after administration of nifedipine (10 mg). The results were as follows: 1. The peak blood flow velocities due to the left and right atrial contractions (ALV, ARV) at rest in the HT group were significantly greater (p less than 0.001) than those in the control group. The ratios of peak velocities due to atrial contraction and rapid filling of each ventricle (A/R) in the HT group were significantly increased (p less than 0.001) compared with those of the controls. 2. The peak rapid filling flow velocity of each ventricle during cold pressor test in the HT group was significantly less and the A/R of each ventricle was significantly (p less than 0.001) greater compared to those at rest. 3. Diastolic indices and systolic blood pressure did not change significantly after administration of nifedipine at rest or during cold pressor test. These results indicate that abnormal diastolic properties of the left and right ventricles are further deteriorated by increasing afterload.