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Relation of a decrease in arterial compliance to ST segment depression on exercise electrocardiograms in patients
S Ohtsuka1, M Kakihana, H Watanabe
1Department of Internal Medicine, University of Tsukuba, Japan.
Insights
Reduced arterial compliance in hypertension patients may increase pulse pressure and negatively impact coronary circulation, despite no significant effects on left ventricular function. This finding highlights potential risks for hypertensive individuals with decreased arterial elasticity.
Area of Science:
- Cardiology
- Vascular Physiology
- Hypertension Research
Background:
- Hypertension is characterized by decreased arterial compliance (ACo) and increased arterial resistance.
- Understanding the cardiac implications of reduced ACo in hypertensive patients is crucial for risk stratification.
Purpose of the Study:
- To investigate the influence of decreased arterial compliance on cardiac function and coronary circulation in hypertensive patients.
- To compare hemodynamic, echocardiographic, and exercise stress test parameters between hypertensive patients with normal and reduced ACo.
Main Methods:
- Patients with hypertension were divided into two groups based on arterial compliance values (ACo > or = 0.9 ml/mmHg vs. ACo < 0.9 ml/mmHg).
- Echocardiography, hemodynamic measurements, and ergometer exercise stress tests were performed.
- Variables including left ventricular function, pulse pressure, and exercise-induced ST segment depression were analyzed.
Main Results:
- No significant differences were observed in left ventricular wall thickness, volume, cardiac output, or ejection fraction between the groups.
- Hypertensive patients with lower ACo exhibited higher pulse pressure.
- Exercise stress testing revealed significantly more frequent ST segment depression in the group with lower ACo (92% vs. 27%).
Conclusions:
- Decreased arterial compliance in hypertension may not significantly alter left ventricular structure or systolic function.
- Reduced ACo is associated with increased pulse pressure and may adversely affect coronary circulation, indicated by exercise-induced electrocardiographic changes.
- Arterial compliance is an important factor to consider in the cardiovascular risk assessment of hypertensive patients.
Abstract:
Decreased arterial compliance (ACo) and increased arterial resistance are the major alterations of arterial function in patients with hypertension. The influence of decreased ACo on the heart was investigated in patients with hypertension. Patients with a systolic blood pressure of > 140 mmHg, a diastolic blood pressure of > 90 mmHg, or both, who had normal coronary arteriograms were enrolled. These patients were divided into two groups according to the value of ACo: Group I, patients with ACo > or = 0.9 ml/mmHg (n = 15); and Group II, patients with ACo < 0.9 ml/mmHg (n = 13). There were no significant differences in arterial resistance, age, gender, and body surface area between the groups. Echocardiographic, hemodynamic, and exercise stress test variables were compared between the groups. There were no differences between the groups in left ventricular (LV) wall thickness and volume, cardiac output, LV end-diastolic pressure, and LV ejection fraction. However, pulse pressure was higher in Group II than in Group I. Ergometer exercise stress testing revealed that, although exercise duration and the peak rate-pressure product were similar in the two groups, ST segment depression of > or = 1.0 mm on the exercise electrocardiograms was induced more frequently in Group II than in Group I (92% vs. 27%, p < 0.001). Thus, the decrease in ACo in patients with hypertension may not significantly affect LV wall thickness, volume, or ejection fraction; however, it may increase pulse pressure and may adversely affect coronary circulation, as suggested by the ST segment depression on exercise electrocardiograms.