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Changes of the carotid artery Doppler flow velocity pattern after sublingual nitroglycerin in patients with
J W Jeong1, O K Park, Y K Park
1Division of Cardiology, Wonkwang University School of Medicine, Iksan, Korea.
Insights
Carotid Doppler echography effectively assesses peripheral hemodynamic changes in hypertension. Nitroglycerin response was blunted in hypertensives, indicating altered wave reflection dynamics.
Area of Science:
- Cardiovascular Medicine
- Diagnostic Imaging
- Hypertension Research
Background:
- Hypertension significantly impacts peripheral hemodynamics.
- Assessing these changes is crucial for managing cardiovascular risk.
- Non-invasive methods are needed to evaluate vascular function in hypertensive patients.
Purpose of the Study:
- To determine the utility of carotid Doppler echography in assessing peripheral hemodynamic alterations in hypertensive individuals.
- To investigate the response of carotid artery hemodynamics to nitroglycerin in hypertensives compared to normotensives.
Main Methods:
- Carotid Doppler echography was used to measure flow velocity patterns, wave characteristics (P, T, P/T ratio), and carotid artery diameter.
- Measurements were taken before and after sublingual nitroglycerin (NTG) administration.
- 28 hypertensive patients and 40 healthy controls were included.
Main Results:
- Hypertensives exhibited lower peak percussion wave velocity and shorter P-Tc intervals at baseline compared to controls.
- Nitroglycerin administration led to increased P-Tc and P/T ratios, and decreased T and FVI in both groups.
- The increase in the P/T ratio after nitroglycerin was less pronounced in hypertensives, suggesting impaired peripheral wave reflection.
Conclusions:
- Carotid Doppler echography is a valuable tool for evaluating peripheral hemodynamic changes in hypertensive patients.
- Findings suggest altered peripheral vascular response to nitroglycerin in hypertension, potentially due to changes in wave reflection.
- This technique aids in understanding vascular dysfunction associated with hypertension.
Objective:
To evaluate the applicability of carotid Doppler echography for the assessment of changes of peripheral hemodynamics in the hypertensives.
Subjects:
28 hypertensives (17 males, 11 females), mean age of 64 yrs and 40 normal controls (24 males, 16 females) mean age of 49 yrs.
Methods:
We recorded the right common carotid arterial Doppler flow velocity (BFV) pattern and measured the peak velocities of the percussion wave (P) and late rising tidal wave (T), the ratio of the two (P/T), the time interval between the two peaks corrected by heart rate (P-Tc), systolic flow velocity integral (FVI) and carotid artery diameter (CAD) before and after 0.4 mg dose of subligual nitroglycerin (NTG).
Results:
1) In hypertensives, the P wave velocity showed lower and P-Tc interval shorter than those of the normal controls at baseline. 2) After NTG, the P-Tc and P/T increased, but the T and FVI decreased significantly in both groups of subjects. 3) The P/T ratio was less significantly increased after NTG in the hypertensives than in the controls. These results suggest that NTG might have been involved in concomitant reduction and delay of the wave reflection from the peripheral vessels, preferentially in the normal subjects than in hypertensives.
Conclusions:
The carotid Doppler echography can be useful for the evaluation of the changes of hemodynamics in the peripheral vessel such as carotid artery in hypertensive subjects.