Hypertension

Document Sample
Hypertension Powered By Docstoc
					                          Hypertension




Kieran McGlade Nov 2001    Department of General Practice QUB
          Aetiology of Hypertension
• Primary – 90-95% of cases – also termed “essential” of
  “idiopathic”
• Secondary – about 5% of cases
   – Renal or renovascular disease
   – Endocrine disease
            •   Phaeochomocytoma
            •   Cusings syndrome
            •   Conn’s syndrome
            •   Acromegaly and hypothyroidism
      – Coarctation of the aorta
      – Iatrogenic
            • Hormonal / oral contraceptive
            • NSAIDs
Kieran McGlade Nov 2001     Department of General Practice QUB
             This left ventricle is very thickened (slightly over 2 cm in
             thickness), but the rest of the heart is not greatly enlarged.
             This is typical for hypertensive heart disease. The
             hypertension creates a greater pressure load on the heart to
             induce the hypertrophy.

Kieran McGlade Nov 2001        Department of General Practice QUB
            The left ventricle is markedly thickened in this patient
            with severe hypertension that was untreated for many
            years. The myocardial fibers have undergone
            hypertrophy.

Kieran McGlade Nov 2001      Department of General Practice QUB
                                HOT
• Hypertension Optimal Treatment
• Largest intervention trial in hypertension.
  Published in 1998
• Conducted in General Practice. 18,790
  patients in 26 countries
• Followed up for an average of 3.8 years


Kieran McGlade Nov 2001   Department of General Practice QUB
                          H O T Findings
• Lowest incidence of major CV events
  occurred at a mean achieved DBP of 83
  mmhg. This target (compared to mean
  achieved of 105 mmHg was associated with
  a 30% reduction in main CV events.
• In diabetes – Diastolic< or = 80mmhg 51 %
  lower risk compared to 90 mmHg

Kieran McGlade Nov 2001     Department of General Practice QUB
         Global heart threat from diabetes:
         A global explosion in the number of cases
         of diabetes is threatening to reverse the
         reduction in deaths from heart disease in
         many western countries, including the
         United Kingdom. To coincide with World
         Diabetes Day on 14 November, Diabetes
         UK is calling for action to be taken to
         reduce the 20,000 deaths per year from
         coronary heart disease (CHD) among
         people with diabetes in the UK.




Kieran McGlade Nov 2001   Department of General Practice QUB
          Hypertension and Diabetes
• Hypertension co-exists with type II in about
  40% at age 45 rising to 60% at age 75.
• 70% of type II patients die from cardio-
  vascular disease.
• At least 60% of patients will require 2 or 3
  antihypertensive agents to achieve tight
  control.

Kieran McGlade Nov 2001   Department of General Practice QUB
                                Stages
•   Identification of hypertensive patients
•   Baseline investigations
•   Initiating therapy
•   Reviewing patients
•   Stepping up therapy
•   Motivation and compliance


Kieran McGlade Nov 2001   Department of General Practice QUB
             Investigation of the New
                   Hypertensive
•   History and examination
•   Exclude secondary Hypertension
•   Urea and electrolytes
•   FBP and ESR
•   ECG
•   Lipid profile

• Chest x-ray no longer routinely indicated
Kieran McGlade Nov 2001   Department of General Practice QUB
    Clinical clues to renal vascular
                disease
• Hypertension under 50 Yrs of age.
• Generalised vascular (esp peripheral)
  disease.
• Mild – moderate renal dysfunction.
• Sudden onset pulmonary oedema.



Kieran McGlade Nov 2001   Department of General Practice QUB
                          Ladder Approach
•   Bendrofluazide
•   Bendrofluazide + Atenolol or ACE
•   Calcium Channel blocker
•   Alpha blocker




Kieran McGlade Nov 2001      Department of General Practice QUB
                      Tailored Approach
•   Assessment of overall cardiovascular risk
•   Recognition of co-morbidities
•   Lipid profile
•   Renal function
•   Existing contra- indications



Kieran McGlade Nov 2001   Department of General Practice QUB
Kieran McGlade Nov 2001   Department of General Practice QUB
            Coronary Risk Calculator

• Launch risk calculator program




Kieran McGlade Nov 2001   Department of General Practice QUB
Compelling and possible indications and contrindications for
the major classes of antihypertensive drugs

                                                       INDICATIONS                                                                                        CONTRAINDICATIONS

CLASSS OF DRUG                                   COMPELLING                                                 POSSIBLE                                       POSSIBLE                        COMPELLING

a-blockers                                       Prostatism                                                 Dyslipidaemia                                  Postural Hypotension            Unrinary incontinence


Angiotensin converting enzyme (ACE) inhibitors   Heart failure                                              Chronic renal disease *                        Renal impairment *              Pregnancy
                                                 Left ventricular dysfunction                               Type II diabetic nephropathy                   Peripheral vascular disease †   Renovascular disease

Angiotensin II receptor antagonists              Cough induced by ACE inhibitor ‡                           Heart failure                                  Peripheral vascular disease     Pregnancy
                                                                                                            Intolerance of other antihypertensive drugs                                    Renovascular disease
                                                 Myocardial infarction                                      Heart failure
b-blockers
                                                 Angina

                                                                                                                                                           Heart failure

                                                                                                                                                           Dyslipidaemia                   Asthma or COPD
                                                                                                                                                           Peripheral vascular disease     Heart block




Calcium antagonists (dihydropyridine)            Isolated systolic hypertension (ISH) in elderly patients   Angina                                          _                               _
                                                                                                            Elderly patients

Calcium antagonists (rate limiting)              Angina                                                     Myocardial infarction                          Combination with b-blockade     Heart block
                                                                                                                                                                                           Heart failure
Thiazides                                        Elderly patients including ISH                              _                                             Dyslipidaemia                   Gout



* ACE inhibitors may be beneficial in chronic renal failure but should be used with caution. Close supervision and specialist advice are needed when there is established and
significant renal impairment

† Caution with ACE inhibitors and angiotensin II receptor antagonists in peripheral vascular disease because of association                                with renovascular disease.

‡ If ACE inhibitor indicated

f b-blockers may worsen heart failure, but in specialist hands may be used to treat heart failure

                  Kieran McGlade Nov 2001                                       Department of General Practice QUB
British Hypertension Society Guidelines 2000
                        Therapeutic targets
                            Measured in clinic                                  Mean daytime ABPM
                                                                                or home measurement


Blood Pressure                No diabetes         Diabetes                     No diabetes    Diabetes
Optimal                       <140/85             <140/80                      <130/80        <130/75
Audit Standard                <150/90              <140/85                      <140/85        <140/80




The audit standard reflects the minimum recommended levels of BP control. Despite best practice, it may not be
achievable in some treated hypertensive patients.
NB: Both systolic and diastolic targets should be reached


British Hypertension Society Guidelines
        Kieran McGlade Nov 2001           Department of General Practice QUB
                                   Logical Combinations

                                          b-                                ACE          a-
                        Diuretic                             CCB
                                       blocker                            inhibitor   blocker
   Diuretic                    -                                  -                    

  b-blocker                                   -                  *         -           

    CCB                        -              *                    -                   

ACE inhibitor                                 -                            -           

   a-blocker                                                                          -
* Verapamil + beta-blocker = absolute contra-indication

     Kieran McGlade Nov 2001         Department of General Practice QUB
          ACE Inhibitor Side Effects
•   Cough (15% of patients. Is reversible)
•   Taste disturbance (reversible)
•   Angiodema
•   First-dose hypotension
•   Hyperkalaemia ( esp. in patients with type
    II diabetes and renal dysfunction)


Kieran McGlade Nov 2001   Department of General Practice QUB
                          Follow-up
• For patients with BP stabilised by management,
  follow up should normally be three monthly (interval
  should not exceed 6 months), at which the following
  should be assessed by a trained nurse:

• *      Measurement of BP and weight
  *      Reinforcement of non-pharmacological advice
  *      General health and drug side-effects
  *      Test urine for proteinuria (annually)



Kieran McGlade Nov 2001   Department of General Practice QUB
                  Web based references
• British Hypertension Society:
  http://www.hyp.ac.uk/bhs/
• Summary Guidelines 2000:
  http://www.hyp.ac.uk/bhs/gl2000.htm
• Hypertension audit protocol from Leicester
  http://www.le.ac.uk/genpractice/gpaudit/htn
  prot.html

Kieran McGlade Nov 2001   Department of General Practice QUB
     Drug Treatment of Essential
     Hypertension in Older People
• Hypertension is very common, occuring in
  over 50% of older people, and is a major
  risk factor for stroke and ischaemic heart
  disease.
• Drug treatment of hypertension in older
  people saves lives and prevents unnecessary
  morbidity.
• Treating isolated systolic hypertension also
  saves lives.
Kieran McGlade Nov 2001   Department of General Practice QUB
     Drug Treatment of Essential
     Hypertension in Older People
• There is strong evidence to support the use
  of diuretics as first-line agents.
• Antihypertensive treatments are most cost-
  effective when targeted at older patients.
• There is evidence of under detection and
  under treatment of hypertension.
• Factors influencing patient adherence with
  treatment are not well understood and
  require further research.
Kieran McGlade Nov 2001   Department of General Practice QUB
RECOMMENDATIONS                        (for the treatment of the elderly)


   •Through the wider use of antihypertensive therapies more older
   people would be able to maintain a healthy and active lifestyle.
   •Through the wider use of antihypertensive therapies more older
   people would be able to maintain a healthy and active lifestyle.
   •For first-line agents there is strong evidence to support the use of
   diuretics and some evidence for the use of beta-blockers.
   •Systems to ensure that older people with hypertension are
   diagnosed, treated and followed up need to be developed.
   •A system of audit should be cultivated to assure adequate treatment.
   •High quality research on patient adherence with antihypertensive
   medications is needed.

NHS Centre for reviews and dissemination 1999
     Kieran McGlade Nov 2001   Department of General Practice QUB
                          Practical Points
•   15 – 20% of adult western population.
•   Isolated systolic hypertension just as dangerous.
•   Primary cause identified in only 5%.
•   Investigate – Urine, FBP, ESR, ECG, U&E, Lipids.
•   Target < 140/85.
•   Bendrofluazide 2.5 mg a good starting point.
•   Refer patients needing more than 3 drugs to control their
    hypertension.



Kieran McGlade Nov 2001     Department of General Practice QUB

				
DOCUMENT INFO
Shared By:
Tags:
Stats:
views:20
posted:3/25/2012
language:English
pages:25
Description: Lectures in Cardiology