Hypertension in a nutshell

Prof. Dr. Mohmed Awad
Prof. of Cardiology Ain Shams university
Hypertension in a nutshell
Hypertension is a very common and serious health problem worldwide.
It is also one of the major risk factors behind atherosclerosis, coronary artery disease and stroke.
In addition it is an important cause for renal failure.
Hypertension is defined as blood pressure (BP) exceeding 140/90 measured in several occasion.
Recent recommendations consider the borderline zone between130/80 and 140I90 as abnormal for diabetics and as unfavorable for the average individual.
These definitions were based on studies which proved that BP even slightly higher than these figuers is associated with considerable increase in cardiovascular morbidity and mortality.
Hypertension is classified into primary (essential) and secondary.
Primary hypertension includes 95% of all the hypertensive population.
lt is essentially due to some error in the mechanisms by which the body adjusts the systemic arterial blood pressure within the Physiologic range. so it is a kind of malfunction in the BP regulating mechanisms .
It may start to appear at any age but commonly between the third and the fifth decades with a strong hereditary tendency.
Secondary hypertension is much less common.
The most important causes for secondary hypertension are : acute and chronic interstitial kidney diseases, renal artery stenosis, pheochromocytoma , Hypo and hyperthyroidism, aortic coarctation , sleep apnea syndrome and toxemia of pregnancy .
It is important to notice that not every individual with casual BP reading of more than 140/90 in one or even two occasions should be considered hypertensive.
The BP is easy to change from moment to moment and is affected by many common factors as anxiety , emotions , exercise and smoking .
Elevated BP secondary to these factors is usually temporary,so it is the job of the clinician to find out whether the elevated BP is secondary to some of these factors with no necessity to treat or due to hypertension and deserves lifelong treatment and follow up .
It is allways advisable to let the patient rest enough time in the doctors office before measuring BP . The doctor has to speak to patient to ease his anexiety and if the BP was found elevated it has to be measured again after few minutes and in more than one visit.
The BP should not be measured shortly after meals or after smoking . BP measurement in home circumstances and ambulatory BP monitoring for 24 hours help to exclude patients with what is called « office hypertension “ all these are important means to avoid labeling an individual as hypertensive while simply he is anxious or emotionally fragile.
The presence of changes secondary to hypertension as retinal changes , LV hypertrophy or LV diastolic dysfunction may solve the issue indicating that the elevated BP is pathological and deserves immediate treatment.
Fundus examination , ECG and Echocardiogram are helpful in the evaluation of patient with high BP.
Management of hypertension starts with lifestyle modification Reducing salt intaka is an essential step . All kinds of salty food should be discouraged.
The patient should have a basic diet low in salt.
He should avoid eating in fast food chains as most of the meals have high salt content to compensate for the poor quality of ingradients .
Caffeine containing beverages should be restricted like coffee , chocolate and cola drinks . Also the caloric content of the diet should be observed to avoid weightgain .
Since obesity is linked to hypertension so over weight individuals should reduce weight through diet and exercise.
Exercise is highly desirable since it helps to reduce BP through several mechanisms.
Nicotine was found to increase BP temporary so smoking should be strongly discouraged.
These simple measures may reduce the BP sufficiently to obviate or postpone the need for drug treatment or help better control with fewer medications.
There are currently 7 groups of antihypertensive drugs in use.
These are: Diuretics. b- Adrenergic blockers, a - adrenergic blockers, centrally acting drugs , calcium channel blockers , angiotensin converting enzyme inhibitors , and angiotensin receptor blockers.
It was found that more than 50% of hypertensive will need a combination of 2 drugs or more to control their BP.
So combining different medications is needed in the majority of hypertensive patients.
Initial therapy usually starts with low dose diuretic, a beta blocker, angiotensin converting enzyme inhibitor (ACE inhibitor) or calcium channel blocker.
Now with the growing use of angiotensin receptor blockers (ARBs) They may also be used as a first step treatment.
As an initial treatment diuretics should begin with low doses such as the equivalent of 25 mg hydrochlorothiazide or chlorothalidone or 2-5 mg in dopamine daily .
Serum potassium level should be monitored once or twice a year and the addition of a potassium sparing diuretic is desirable .
Patients with elevated serum uric acid and those with dyslipidemia should be followed up for their metabolic abnormality and should be advised to follow an appropriate diet regimen .
There are certain clinical setting in which beta blockers are excellent choice as first line therapy .
These include young patients with high renin essential hypertension and anxiety prone patients with increased adrenergic tone .
ln addition beta blockers are highly recommended in the ischemic hypertensive patient.
The ACE inhibitors are effective first line drugs in hypertension.
They are also useful in the treatment of diabetic patients, because they do not impair glucose tolerance and can reduce proteinuria and slow the progression of diabetic nephropathy.
They are also quite valuable in patients with impaired LV contractility .
They improve endothelial function and lead to regression of LV hypertrophy.
A persistent dry cough can be a bother some side effect that sometimes necessitates shift to another medication .
ACE inhibitors make very effective combination with diuretics.
Angiotensin receptor blockers possess most of the advantages of ACE inhibitors.
They are highly tolerated‘ medication.
Losartan was found effective to slow down the deterioration in kidney function in patients with already impaired kidney function .
The calcium channel blockers are also effective first line drugs in the treatment of hypertension.
They do not lead to any metabolic derrangernent and can be used in patients with renal impairment.
Edema, flushing and headache are common side effects.
Peripheral edema is due to a redistribution of intravascular volume not to retention of salt and water.
Tailoring of drug regimen according to the type of patient, the associated medical problems, the degree and type of hypertension and the occurrence of certain side effect to certain patient is the only way to keep the blood pressure well controlled, preventing target organ damage with the least discomfort to the patient .
Patient education about the nature of the disease and the medication is also another way to keep adherence to treatment.