10 Acute blood pressure variability response to antihypertensive drugs in an experimental model of preeclampsia

Abstract

Introduction Increased blood pressure (BP), especially sudden, unexpected and severe rises in women with preeclampsia considerably increases the risk of peripartum complications. A specific quantitative criterion for diagnosing labile blood pressure does not exist and minimal evidence is available to guide therapeutic decisions. Objective To assess the effect of antihypertensives commonly used to manage hypertension in pregnant women on blood pressure lability at rest in an experimental model of preeclampsia (EPE). Methods EPE was established in Papio hamadryas ( n =6) by surgically ligating the non-dominant uterine branch artery to reduce perfusion by 30–40%. EPE was confirmed by assessing proteinuria (urine protein:creatinine ratio mmol/L), BP changes (intra-arterial radiotelemetry) and soluble fms-like tyrosine kinase receptor-1 (sFLT-1) (ELISA). BP readings were collected every 20s before and after antihypertensive treatment. Equipotent doses of labetalol, methyldopa and hydralazine were given. Lability was defined by SD1 and SD2 values as measures of short-term variability (STV) and long-term variability (LTV) respectively. These values were generated using Poincare plots (Spike2 v8.06). Prism GraphPad6 v6.05 was used for parametric testing, data expressed as mean±SEM and significance set at p Results All animals developed EPE, demonstrated by systolic BP rise of 7.1mmHg ( p p p p p p p =0.03). Diastolic STV was not significantly affected. The three drugs did not significantly affect systolic or diastolic LTV. Conclusions Systolic STV was affected by drug choice but not diastolic STV or LTV in EPE.