HTN Etio-pathophysiology

What is Hypertension?

• HTN is defined as persistent SBP and/or DBP (office or out-of-office) levels above which harm and significant increment of morbidity and mortality are observed if left untreated.

The risk of morbidity and mortality increases -
progressively with increasing systolic and diastolic
..blood pressure

Problem Size

• HTN is a leading cause of morbidity and mortality, afflicting more than 1.2 billion people across the globe.

• More than half of people with hypertension remain untreated.

• The rate of hypertension in Saudi Arabia has risen from 25.5% among adults in 2011, to 29.2% in 2019.Z

• A recent study found that 33% of individuals from Middle Eastern countries suffered from HTN, 51% of whom were unaware of their diagnosis. While 47% of people with HTN were treated, only 19% had controlled blood pressure levels.Z

Importance of HTN RX

• The most common chronic condition treated by family physicians
• Increased risk of heart failure, MI, CVD, and death
• Rx reduces the risk of these events
• Lifestyle modifications reduce the BP:
  • DASH diet
  • Decrease salt intake
  • Regular exercise
  • Moderate weight reduction

Risk Factors

Non-modifiable Factors

• Race
  • Black people
• Gender-related risk patterns
  • Men and postmenopausal women
• Fetal factors
  • Babies born with low birth weight get high BP
• Family history
  • Family history of hypertension and CVS diseases
• Advanced age
  • more than 60 or older

Modifiable Factors

• Smoking

• Increased alcohol consumption

  • systolic BP is affected more

• Stress

  • increase sympathetic activity

• Obesity

  • Leptin hormone derived from adipose tissue, causes increase sympathetic activity via hypothalamus

• Increased salt intake

  • causes increase blood volume, increase cardiac output, increase peripheral resistance

Additional Risk Factors

• Unhealthy lifestyle (low physical activity) and obesity remain some of the most prevalent risk factors for hypertension in the Saudi population.

• Other common risk factors in the Saudi population are diabetes and hypercholesterolemia.

Causes of Hypertension

1. Primary (essential) Hypertension: Has no known cause (idiopathic)

   • Multi-factorial etiology:
     1. Genetic Factors
        • Positive Family History
     2. Environmental Factors
        • Obesity
        • Increased Sodium Intake
        • Stress
        • Increased Alcohol Intake
   • 95% of hypertensive patients fall into this category. (Primary (essential or idiopathic).)

2. Secondary Hypertension: Due to an underlying medical condition:

   • Endocrine
   • Cardiovascular
   • Renal
   • Chronic alcohol abuse
   • Medications

Signs Suggesting Secondary HTN Z

• Age of HTN diagnosis <20–30 or >55–60 years
• Family history of premature CV disease (<55 years)
• Early TOD
• Symptoms & signs suggestive of secondary HTN (Table 2)

Renal Causes of Secondary Hypertension

• Polycystic disease
• Renal artery stenosis
• Renin-producing tumors
• Chronic renal disease
• Renal vasculitis

Endocrine Causes

• Adrenocortical hyperfunction (Cushing’s syndrome)
  • primary aldosteronism, congenital adrenal (hyperplasia)
• Exogenous hormones (glucocorticoids, estrogen)
• Pheochromocytoma
• Hypothyroidism
• Hyperthyroidism
• Pregnancy-induced

Cardiovascular Causes

• Coarctation of aorta
• Vasculitis
• Increased intravascular volume

Medications That May Cause Hypertension

• Steroids
• Oral contraceptives
• Amphetamines and cocaine
• Nonsteroidal anti-inflammatory drugs
• Psychiatric medications: carbamazepine, lithium, and tricyclic antidepressants

Stages of Hypertension

• Stage-1 hypertension

  • Clinic BP 140/90 to 159/99 mmHg
  • ABPM daytime average or HBPM 135/85 mmHg to 149/94 mmHg.

• Stage 2 hypertension

  • Clinic BP 160/100 mmHg to <180/120 mmHg
  • ABPM or HBPM average BP of 150/95 mmHg or higher.

• Stage 3 or severe hypertension

  • Clinic BP ≥180 or clinic diastolic BP of ≥120 mmHg

Hypertensive Crisis

(BP >180/120 mm Hg) categorized as either

• Hypertensive emergency (extreme BP elevation with acute or progressing target organ damage)

• Hypertensive urgency (severe BP elevation without acute or progressing target organ injury).

• Malignant hypertension when diastolic BP more than 130mmHg. Unless treated, it may lead to death due to renal failure, heart failure, or stroke.

Long Term Complications & End Organ Damages with HTNY

Complications of HTNY

• Organs affected
  • Heart
  • Blood vessels
  • Brain
  • Kidney
  • Eyes

Specific ComplicationsY

• Atherosclerosis (1)

  • Formation of fibro fatty lesions in the intimal lining of the large and medium sized arteries such as aorta and its branches, coronary arteries and cerebral arteries.

• Stroke or Heart Attack (2)

  • If an atherosclerotic plaque breaks off inside the artery, or the blood vessel ruptures, a blood clot can form within the artery. If this blocks blood flow to the brain it can lead to a stroke. If it blocks blood flow to the heart it can result in a heart attack.

• Aneurysm (3)

  • The blood vessels have been weakened to such an extent that part of the blood vessel wall ‘balloons’ or bulges.

• Vascular Dementia (4)

  • High blood pressure can cause the blood vessels that supply your brain with blood to narrow or become damaged.

• Hypertensive Retinopathy (5)

  • Grade 1: Arteriolar thickening, tortuosity and increased reflectiveness (‘silver wiring’)
  • Grade 2: Grade 1 plus constriction of veins at arterial crossings (‘arteriovenous nipping’)
  • Grade 3: Grade 2 plus evidence of retinal ischaemia (flame-shaped or blot haemorrhages and ‘cotton wool’ exudates)
  • Grade 4: Grade 3 plus papilloedema

Signs & Symptoms

• Severe headache (1)
• Fatigue or confusion (2)
• Vision problems (3)
• Chest pain (4)
• Difficulty breathing (5)
• Irregular heartbeat (6)
• Hematuria (7)
• Lower limb edema (8)