Related Experiment Videos
Cardiac load and function in hypertension. Ultrasonic and hemodynamic study
Insights
Primary hypertension affects heart function differently based on cardiac structure. Left ventricular hypertrophy and enlargement in hypertensive patients significantly impair both left and right ventricular function, suggesting a global cardiac contractile issue.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Primary hypertension is a common condition.
- Hypertension can lead to cardiac structural changes, including left ventricular hypertrophy.
- The impact of these structural changes on overall cardiac function requires further elucidation.
Purpose of the Study:
- To classify hypertensive patients based on echocardiographic findings.
- To evaluate the functional status of both ventricles in relation to cardiac structure.
- To investigate the interdependence of right and left ventricular function in hypertension.
Main Methods:
- Echocardiography was used to classify 46 hypertensive patients into three groups based on heart size and left ventricular hypertrophy.
- Cardiac function was assessed using stroke index-filling pressure relation and mean rate of ejection.
- Left ventricular mean rate of circumferential fiber shortening (Vcf) was measured.
Main Results:
- Group I (normal heart) showed maintained ventricular function compared to controls.
- Group II (concentric hypertrophy) exhibited augmented ventricular function.
- Group III (hypertrophy with enlargement) displayed reduced ventricular function in both ventricles.
- Functional patterns in Groups II and III suggest changes in contractile state rather than solely afterload.
Conclusions:
- Hypertension-induced cardiac structural changes correlate with distinct ventricular functional patterns.
- Left ventricular hypertrophy and enlargement significantly impact global cardiac performance.
- Functional interdependence between ventricles in hypertension points towards alterations in the heart's overall contractile state.
Abstract:
On the basis of echocardiographic measurements, 46 patients with established, uncomplicated primary hypertension (diastolic pressure = 100 mm Hg) were classified as: those with a normal-sized heart (Group I, 13 patients); those with left ventricular concentric hypertrophy (Group II, 19 patients); and those with left ventricular hypertrophy and enlargement (Group III, 14 patients). Eighteen age-matched healthy subjects were investigated as the controls. The function of both the left and right ventricle, evaluated by the stroke index-filling pressure relation and by the mean rate of ejection, was maintained in Group I, augmented in Group II and reduced in Group III, in comparison with the controls. Left ventricular mean rate of circumferential fiber shortening (Vcf) was normal in Group I, significantly augmented in Group II and definitely reduced in Group III. It could not be established whether the divergent variation from normal of the Vcf in Groups II and III reflected opposite changes in ventricular contractility or in afterload (wall stress during ejection), or both. However, the parallel functional pattern of the right and left ventricle in these two groups suggests a functional interdependence of the two sides which cannot be interpreted in terms of afterload but is best explained by changes in the contractile state of the whole heart.