An Expert System on Detection, Evaluation and Treatment of Hypertension - Artificial Intelligence and Symbolic Computation - page 253

- Other cardiovascular disease (CVD) risk-related (Boolean) facts (**): target
organ damage (TOD), associated clinical alterations (ACA), diabetes (1).
- Other pathologies suffered by the patient (Boolean) (***): heart failure, post
myocardial infarction, high CVD risk (2), diabetes (1), chronic kidney disease
(3), recurrent stroke prevention.

2.2 First Subsystem: CDV Risk Evaluation

The patient's SBP and DBP are used to allocate him in a (refined) category of
BP (Normal/ Prehypertension/ Stage 1 Hypertension/ Stage 2a Hypertension/
Stage 2b Hypertension). This classification is intermediate between those of [9]
and of [10, 11].
The computational processes involved are simple because the cases are al-
ready separated (disjoint), so they can be translated into IF...THEN... rules,
that can be applied using classifications in simple procedures.
The assessment of the factors in (*) is provided by history, physical exami-
nation, laboratory tests, electrocardiograms...
From the refined BP category obtained and the data in (*), a grade of
CVD risk is calculated using tables [7, 8], that we have also translated into
IF...THEN... rules. The computational processes are simple too (because the
cases are again disjoint). The same will happen with the second subsystem.

2.3 Second Subsystem: Hypertension Detection, Evaluation

and Treatment

Now the items in (**) and (***) are assessed: (1) has already been asked in ( );

(2) has just been evaluated from the data in (*) by the first subsystem; (3) is
deduced from (

†

) and the information about the rest of the items can be found
in the patient's clinical history.
The patient's SBP and DBP are used to allocate him in a category of BP
(Normal - Prehypertension - Stage 1 Hypertension - Stage 2 Hypertension). This
classification is the one suggested in [10, 11].
From this information, and following a certain treatment algorithm, the au-
thors of [10, 11] recommend:

‡

- individuals who are prehypertensive: practice lifestyle modifications in order
to reduce the risk of developing hypertension (no drug therapy)
- individuals with hypertension (stages 1 and 2) be treated with an appropriate
drug therapy if a first trial of lifestyle modification fails:
• individuals with hypertension of stage 1 (not suffering other pathologies)

that need drug therapy be treated with thiazide diuretic (THIAZ) or a
combination including this therapy

• individuals with hypertension of stage 2 (not suffering other pathologies)

that need drug therapy be treated with a 2-drug combination

• individuals with hypertension of any stage (also suffering from other

pathologies) that need drug therapy should have it adjusted according
to those pathologies.