Blood Pressure Control Levels And Ciradian Rhythm-specific Impact Of Ventricular-arterial Coupling In Patients With Primary Hypertension

Objective: to study the effects of blood pressure control levels and circadian rhythm on ventricular-arterial coupling in patients with primary hypertension by ultrasound.Methods: eighty-four subjects with primary hypertension were divided into2 groups: well-controlleds(24h SBP?130mm Hg or24 h DBP?80mm Hg,n=37),poorly-controlleds(24h SBP>130mm Hg or 24 h DBP>80mm Hg,n=47),according to the 24 hours average blood pressure.Or 4groups divided by the nighttime systolic blood pressure decrease rate(?SBP%):dippers(10%??SBP%<20%,n=20),non-dippers(0%??SBP%<10%,n=45)and reverse dippers(?SBP%<0%,n=19).The normal control 32 subjects,who are free of cardiovascular diseases.Cardiovascular structure and function parameters were measured by ultrasound: carotid arterial maximum diameter(Dmax),minimum diameter(Dmin),intima-media thickness(IMT),left ventricular end-diastolic diameter(LVDd),left ventricular end-systolic diameter(LVDs),left ventricular mass index(LVMI),left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricularejection fraction(EF),left ventricular isovolumetric contraction time(ICT),ejection time(ET),isovolumetric relaxation time(IRT),left ventricular outflow tract flow peak velocity(VLVOT)and acceleration time(AT).The following indices were calculated: Carotid artery diameter change rate(diff D%),left ventricular Tei index,effective arterial elastance(Ea),left venturicular end-systolic elastance(Ees)and ventricular-artery coupling index(Ea/Ees).And brachial-ankle pulse wave velocity(ba-PWV)was detected,an indice of arterial stiffness.Cardiovascular structure and function parameters were measured.And the relationship of ventricular-arterial coupling in all groups was analyzed.Results: The effective arterial elastance(Ea)and the ratio of effective arterial elastance to left venturicular end-systolic elastance(Ea/Ees)were higher significantly in the poorly-controlleds.Ea was positively correlated with Ees in the normal controls,but not in hypertensive patients.And Ea/Ees was positively correlated with 24 hour systolic blood pressure(SBP),daytime SBP and nighttime SBP respectively.The brachial-ankle pulse wave velocity(ba-PWV)was significantly quicker step by step in the normal controls,dippers and non-dippers.Ea,Ees or Ea/Ees has no significantly difference in dippers,non-dippers and reverse dippers,respectively.Conclusion: Blood pressure control levels especially the SBP is closely related to the ventricular-arterial coupling in hypertensive patients.Abnormal blood pressure circadian rhythm may aggravate the vascular damage.Blood pressure circadian rhythm has nothing to do with ventricular-arterial coupling.