Investigations and Treatment of Hypertension

Investigations to be done in patients of hypertension

The aim of general investigations in hypertension is to screen for secondary causes and complications and to evaluate concomitant risk factors for atherosclerosis.

Urinalysis

Urine strip testing may reveal blood and protein, suggestive of renal disease. Urine microscopy is necessary to confirm the presence of red blood cells and also casts.

Urea and electrolytes

Urea and creatinine may be elevated with renal failure, and low serum potassium levels in untreated patients may be due to Conn's syndrome.

Blood glucose

Plasma glucose is performed to screen for diabetes as it is associated with atherosclerosis, renal vascular disease and nephropathy. All of these may contribute to hypertension. Moreover, causes of secondary hypertension such as Cushing's syndrome, acromegaly and phaeochromocytoma are associated with hyperglycaemia.

Serum cholesterol

Serum cholesterol screening should be performed as it is an additional risk factor for atherosclerosis and may require treatment for the prevention of cerebrovascular and ischaemic heart disease.




Electrocardiogram

A 12 lead ECG is required as a baseline investigation and to screen for left ventricular hypertrophy, a complication of hypertension.


Specific investigations

Specific investigations are usually tailored to suspected secondary causes. Relevant investigations for phaeochromocytoma , Cushing's syndrome , Conn's syndrome , coarctation of the aorta and renal artery stenosis in selected patients depending on the clinical judgment .

Renal ultrasound

Renal ultrasound is a good screening investigation for hypertensive patients when the suspected underlying cause is renal disease. It is best at detecting structural disorders such as polycystic kidney disease and renal artery stenosis.


Treatment of High Blood Pressure or, Hypertension:

Apart from blood pressure lowering, an important aspect of the management of hypertension encompasses modification of cardiovascular risk.

Lifestyle and risk factor modification

Weight loss towards ideal weight, regular exercise, limiting alcohol consumption, reduced salt intake and increased fruit and vegetable intake have been proven in clinical trials to reduce blood pressure and may obviate the need for pharmacological therapy for hypertension. This advice should be offered to all patients and is best supplemented with written information.

Low Dose Aspirin:

Aspirin reduces major cardiovascular events in hypertensive patients and should be prescribed for primary prevention in patients aged 50 or more with satisfactory control of blood pressure and those with target organ damage, diabetes or a 10-year coronary risk of more than 15%.

Statin to lower cholesterol

Cholesterol lowering therapy is recommended for hypertensive patients when serum cholesterol is more than 5.0 mmol/L and 10-year coronary risk is more than 30%.

Medical management

Antihypertensive medication

Each Anti hypertensive drug class has specific indications and contraindications. Click here to see the table. however, when these circumstances do not apply, the drug that has been backed by the most evidence is the thiazide diuretic, and this should be the initial agent of choice for the treatment of hypertension.

Each drug should be allowed 4 weeks before the response is assessed. The dose of each drug (except thiazide diuretics) should be increased accordingly if satisfactory control (less than 140/85 mmHg) is not achieved

If the first drug is well tolerated but the response is small, substitution with another drug is appropriate when hypertension is mild and uncomplicated. However, in severe or complicated hypertension it is safer to add drugs stepwise until blood pressure control is attained. Drug combinations are best tailored to the individual.



Prognosis of Hypertension

Death from hypertension relates primarily to the increased risk of ischaemic heart disease and stroke. The risk of premature death increases with blood pressure and age. Each 20 mmHg increase in systolic (or 10 mmHg increase in diastolic) pressure increases the risk of death by coronary heart disease or stroke approximately 2-fold in patients aged 40-69 years, and approximately 1.5-fold in patients aged 70-89 years

Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension

Choice of Medication in Hypertension

Choice of drug therapy for hypertension

Class of drug	Indication		Contraindications
	Compelling	Possible	Possible	Compelling
α-Blockers	Prostatism	Dyslipidaemia	Postural hypotension	Urinary incontinence
ACE inhibitors	Heart failure	Chronic renal disease	Renal impairment	Pregnancy
	Left ventricular dysfunction	Type II diabetic nephropathy	Peripheral vascular disease	Renovascular disease
	Type I diabetic nephropathy
Angiotensin II receptor antagonistsc	Cough induced by ACE inhibitor	Heart failure Intolerance of other antihypertensive drugs	Peripheral vascular disease	Pregnancy Renovascular disease
β-Blockers	Myocardial infarction Angina	Heart failure	Heart failure Dyslipidaemia Peripheral vascular disease	Asthma or chronic obstructive pulmonary disease Heart block
Calcium antagonists (dihydropyridine)	Isolated systolic hypertension in elderly patients	Angina Elderly patients	-	-
Calcium antagonists (rate limiting)	Angina	Myocardial infarction	Combination with β-blockade	Heart block Heart failure
Thiazides	Elderly patients	-	Dyslipidaemia	Gout

Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension