Most patients diagnosed with hypertension are asymptomatic; therefore, screening is essential. Patients are usually evaluated through history, physical examination, and routine laboratory tests. The three objectives are to:
Assess risk factors
Reveal identifiable causes
Detect target-organ damage, including evidence of cardiovascular disease.
History may elicit family history of hypertension or coronary artery disease risk factors. It is important to assess overall cardiac risk burden. The age of onset may be of value when considering aetiology, as the proportion of secondary causes diminishes with increasing age. Patients at increased risk for essential hypertension include those over 60 years of age, or with diabetes, or of black ancestry. Excess alcohol intake or lack of exercise should be documented. A thorough medication history should be taken including screening for use of oral contraceptive pills, non-steroidal anti-inflammatory drugs, sympathomimetics, or herbal medications. Most patients are asymptomatic, but clinical indications of hyperthyroidism, hypothyroidism or catecholamine excess (e.g., tachycardia, weight loss, sweating, or palpitations), or end-organ damage (e.g., shortness of breath, chest pain, or sensory/motor deficits) should be sought. Headache or visual changes are unusual.
Blood pressure (BP): the patient should be seated quietly for at least 5 minutes, with feet on the floor and arm supported at heart level. Caffeine, smoking, and exercise should be avoided for 30 minutes prior to examination. An appropriately sized cuff should be used and the patient’s arm should be supported (e.g., resting on a desk). The bladder should encircle at least 80% of the arm, and the width of the bladder should be at least 40% of the arm circumference. At the first visit, blood pressure should be recorded in both arms, using the arm that gives the higher reading for subsequent visits. Two or more measurements should be made on two or more occasions and the average recorded. Verification should be obtained in the contralateral arm. Pre-hypertension is a reading of 120 to 139/80 to 89 mmHg. Hypertension is ≥140/90 mmHg in adults.
Examination of optic fundi
Calculation of BMI from height and weight
Auscultation for possible carotid, abdominal, or femoral bruits
Palpation of the thyroid gland
Examination of the heart and lungs
Examination of the abdomen for enlarged kidneys, masses, distended urinary bladder, or abnormal aortic pulsation
Palpation of the lower extremities for oedema and pulses
Physical examination may reveal end-organ damage associated with untreated hypertension: for example, retinopathy, vascular bruits, signs of congestive heart failure, evidence of aortic aneurysm (pulsatile mass/bruit), left ventricular hypertrophy (displaced point of maximal impact), or neurological deficit(s). Absence of femoral pulses suggests coarctation of the aorta. An abdominal bruit may suggest aortic aneurysm or renal artery stenosis. Occasionally, patients may have stigmata of endocrinopathy such as Cushing's disease (moon face, centripetal obesity, striae), acromegaly (acral enlargement), Graves' disease (goitre, exophthalmos, pretibial myxoedema), or hypothyroidism (dry skin, delayed return of deep tendon reflexes), indicating a secondary cause of hypertension.
White-coat hypertension is suspected when blood pressure readings in the clinic exceed those outside of the clinical setting. Ambulatory blood pressure monitoring (ABPM) may be helpful in patients with suspected white-coat hypertension, and also in cases of apparent drug resistance or episodic hypertension. Home blood pressure monitoring (HBPM) is useful for the initial diagnosis and the long-term follow-up of hypertension. The US Preventive Services Task Force recommends out-of-office blood pressure measurement prior to diagnosis of hypertension; ABPM is the preferred method, and HBPM is an acceptable alternative. There is no universal agreement on definitions of hypertension measured by ABPM, but European guidelines suggest a cut-off of 135/85 mmHg for daytime ABPM or home blood pressure. Out-of-office blood pressure measurements to confirm diagnosis of hypertension are also recommended by the American College of Cardiology/American Heart Association (ACC/AHA). Corresponding values of office BP, home BP, daytime ABPM, night-time ABPM, and 24-hour ABPM are provided by the ACC/AHA. For example, an office BP measurement of 130/80 mmHg corresponds to home BP 130/80 mmHg, daytime ABPM 130 mmHg, night-time ABPM 110/65 mmHg, and 24-hour ABPM 125/75 mmHg. ACC/AHA: corresponding values of systolic blood pressure/diastolic blood pressure for clinic, home blood pressure monitoring, daytime, nighttime, and 24-hour ambulatory blood pressure monitoring measurements external link opens in a new window Auscultatory devices (e.g., mercury, aneroid) are not generally useful for HBPM because patients rarely master the required technique for blood pressure measurement using these devices. Automated validated devices should be used instead.
Masked hypertension is suspected when out-of-office blood pressure measurements exceed those taken in the clinical setting. In adults with elevated office BP (120-129/<80 mmHg) but not meeting the ACC/AHA criteria for hypertension, screening for masked hypertension with daytime ABPM or HBPM is reasonable.
Automated office blood pressure (AOBP) is another option that has been designed to more accurately measure blood pressure. Multiple measurements are taken while the patient is alone in a quiet room, sitting with legs uncrossed, back supported, and arm supported at heart level. Depending on the device used, 3 to 6 measurements are taken over a short time period and the mean blood pressure is calculated. AOBP measures about 5 mmHg lower than research-quality BPs, and 10 to 15 mmHg lower than routine office BP measurements. When using AOBP, hypertension is defined as ≥135/85 mmHg.
Routine metabolic panel and lipid levels are required. Glomerular filtration rate is calculated according to the Modification of Diet in Renal Disease (MDRD) formula or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.[ Glomerular Filtration Rate Estimate by the IDMS-Traceable MDRD Study Equation ][ Glomerular Filtration Rate Estimate by CKD-EPI Equation ] In particular, features of the metabolic syndrome (hyperglycaemia, dyslipidaemia) or hyperuricaemia should be noted. Haemoglobin and routine urinalysis with albumin excretion are also recommended for possible identification of causes of hypertension. An ECG should be obtained.
More extensive testing for secondary causes of hypertension is generally not indicated, unless blood pressure is difficult to control or clinical or routine lab data suggest identifiable secondary causes such as signs of unprovoked hypokalaemia or renal insufficiency. Echocardiogram and carotid Dopplers may have prognostic implications, but they are not routinely recommended except as recommended by guidelines. There was increased risk of mortality and cardiovascular events in patients with increased left ventricular mass and abnormal geometric left ventricular hypertrophy on echocardiogram. Increased cardiovascular events were associated with higher intima media thickness values on carotid Dopplers.
Sleep study may be considered in cases of resistant hypertension and also for patients with signs or symptoms of obstructive sleep apnoea.
If secondary hypertension is suggested by history, or physical or routine laboratory testing, further testing can be performed.
Signs/symptoms of catecholamine excess require phaeochromocytoma screen.
Signs/symptoms of hyper- or hypothyroidism require thyroid-stimulating hormone.
Unprovoked hypokalaemia prompts measurement of plasma renin activity/aldosterone, catecholamines, and a search for clues (such as striae) to suggest hypercortisolism.
Measurement of plasma aldosterone and renin is also indicated in the following situations: BP is sustained above 150/100 mmHg on 3 measurements over different days, with hypertension resistant to 3 conventional antihypertensive drugs (including a diuretic), or controlled BP (140/90 mmHg) on 4 or more antihypertensive drugs; hypertension and spontaneous or diuretic-induced hypokalaemia; hypertension and adrenal incidentaloma; hypertension and sleep apnoea; hypertension and a family history of early-onset hypertension or cerebrovascular accident at a young age (40 years); hypertensive first-degree relatives of patients with primary aldosteronism.
Renal artery imaging is done for young patients with difficult-to-control hypertension or who have abdominal bruits. Imaging may show renal scarring or lesions.
How to perform an ECG animated demonstration
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