Feed: Borderline and labile hypertension - AggScore: 14.0

Borderline and labile hypertension

About one-third of patients found to have an abnormal blood pressure at their first visit to the doctor will have lower blood pressure on subsequent visits. This borderline group may subsequently develop established hypertension.Some individuals appear to have wide swings in blood pressure, and have been called labile hypertensives. Itseems likely that they do not form a pathologically distinctgroup, but manifest an accentuation of normal variability.As a group, they have a higher mortality than consistently normotensive individuals.

'White coat hypertension'

Some patients have such a marked stress reaction whenseeing a doctor (whether medical and whether wearing awhite coat or not) that they raise their blood pressureto hypertensive levels. They appear calm externally anddeny anxiety. This category of patients was first identifiedas a distinct subgroup on the introduction of ambulatoryBP monitoring. Whether patients with 'whitecoat hypertension' have a similar adverse prognosis asthose with established chronic hypertension is unknown.There is a suggestion that some of them will eventuallydevelop chronic hypertension later in life. These patientsshould be encouraged to undertake non-pharmacologicalmethods of lowering blood pressure, such as avoidingobesity and increasing exercise.

Some patients with essential hypertension may also havea component of 'white coat hypertension' superimposed. They are often given increasing numbers and doses of antihypertensivedrugs. Repeated ambulatory blood pressuremonitoring may be required to gauge their true responseto treatment.

Isolated systolic hypertension

Because of arteriosclerotic changes in the major vessels ofthe elderly, the pulse pressure widens, with a greater rise insystolic than in diastolic pressure. Thus, isolated systolichypertension may be observed. Even in isolation, systolichypertension is associated with an excess risk of morbiditythrough stroke, myocardial infarction and congestive cardiacfailure. Benefit of treatment in such cases is likely, andit is reasonable to aim for a systolic pressure reduction to<150mmHg.

Benign or essential hypertension'

Essential hypertension' is commonly used to mean idiopathicor primary hypertension. The majority of patientswith hypertension (over 90%) have no known cause,and thus fall into the category of essential hypertension.This condition affects a vast proportion of the population- possibly as many as 20% of the middle-aged subjects inthe UK, depending on the blood pressure levels adoptedas the definition of hypertension. The diagnosis depends onan established elevated systemic pressure in the absenceof changes in the ocular fundi and of proteinuria, andwhere no identifiable cause of pressure elevation hasbeen demonstrated. Essential hypertension can affect anyage group and can, when untreated, lead to many complications,including malignant and accelerated-phasehypertension.

Malignant and accelerated-phasehypertension

Malignant or accelerated-phase hypertension is associatedwith vascular fibrinoid necrosis and loss of precapillaryarteriolar autoregulation. The consequence is capillaryvessel rupture and tissue necrosis through haemorrhageand ischaemia. The brunt of the damage is borne by renal,adrenal, cerebral, retinal, pancreatic and mesenteric vessels,for reasons that remain unclear. The clinical findingsare elevated levels of blood pressure (which may besevere), associated with haemorrhages and exudatesvisible on the retina. Proteinuria due to similar vascularchanges in the kidney is usual.