The net atrioventricular compliance in mild to moderate hypertensive patients during the early left ventricle filling: A case series.

BACKGROUND: The compliance is considered one of the most important parameters which is defined as the change in volume with given change in pressure (dv/dp). It is varying inversely with both diastolic filling and modulus of chamber stiffness. AIMS: This study aimed to deduce the net atrioventricular compliance which is affected the trans mitral blood flow. MATERIALS AND METHODS: This study focuses on study group of 25 patients (15 males and ten females) with mild to moderate hypertension and mean age (49 ± 5.9) who were investigated for atrioventricular compliance and compared with 18 normal individuals (ten males and eight females) with a mean age of (44.9 ± 14.9) years old. The measurement of mitral valve area and the deceleration flow rate during ventricular early filling were taken from peak E wave to the minimum of the descending E wave. The atrioventricular (net) compliance was calculated according to the theoretical calculation Formula. RESULTS: When the atrioventricular compliance is measured during the early filling, a decrease in the net compliance of 50.27% in normal individuals was observed. The isovolumetric relaxation time was lower by 32.9% in normal individuals than in patients with mild to moderate hypertension. CONCLUSION: The increase in the atrioventricular net compliance for hypertensive patients is thought to be attributed to the compensatory mechanism of cardiac muscle before fibrosis can take place leading to a consequent increase in compliance measured during the early diastolic filling stage of the cardiac cycle.

Mechanical Function of Internal Jugular Vein Valve: Post-analysis of M-Mode Imaging under Cardiac Monitoring.

Because the internal jugular vein (IJV) valve is the only protective valve between the brain and heart, recent studies have focused on the dynamic behaviour of the valve and its importance in regulating the cerebral blood outflow pathway. However, the mechanism underlying valve opening and closure, as well as the normal opening time, has not been investigated before. The aim of the study described here was to investigate IJV physiology in healthy young adults by means of ultrasound imaging. Twenty-four normal young adults (16 male, 8 female, 21.79 ± 0.79 y of age) were enrolled in this study. Each participant underwent IJV B- and M-mode ultrasound scans of the neck veins in supine position. Data on IJV leaflet movement and IJV blood velocity were extracted from images with the associated electrocardiogram traces to analyze the opening and closure cycles of IJV leaflets. The normal opening time calculated in this study includes 70% of the dynamic valve cycle. The normal opening time of the IJV valve could be a new physiologic metric and serves as a premise for further studies in the field of cerebral venous return.