Makindo Medical Notes

Related Subjects: | Assessing Chest Pain | Hypertension | Hypertension in Pregnancy | Malignant Hypertension | Preeclampsia, Eclampsia, and HELLP | Acute Heart Failure | Chronic Heart Failure

About Hypertension

• Defined as blood pressure (BP) > 140/90 mmHg.
• In more than 95% of cases, there is no specific underlying cause (essential hypertension).

Risk Factors

• Ethnicity: Black, Japanese
• Genetic factors
• High salt intake, alcohol excess
• Obesity, sedentary lifestyle
• Impaired intrauterine growth, low birth weight

Clinical Clues to Secondary Causes

• Radio-femoral delay or murmur: suggests coarctation of the aorta
• Bruit over renal artery: suggests renal artery stenosis
• Acromegalic or Cushingoid appearance: consider endocrine causes
• Episodes of sweating, anxiety, and hypertension: consider phaeochromocytoma
• Renal masses: polycystic kidney disease

Complications and Effects of Hypertension

• High BP itself
• Hypertensive retinopathy (Grades III-V), haemorrhages, exudates, or papilloedema
• Left ventricular hypertrophy (LVH): forceful or displaced apex beat
• Acute pulmonary oedema
• Stroke
• Proteinuria

Measuring BP

• Use an appropriately sized cuff.
• Avoid smoking or caffeine 30 minutes before the measurement.
• The patient should sit quietly for 5 minutes before measuring.
• If readings are high, repeat measurements on another occasion.
• Consider ambulatory BP monitoring for confirmation, especially in cases of suspected "white coat hypertension."

Grading of Hypertension

Grade	Systolic BP (mmHg)	Diastolic BP (mmHg)	Clinical Significance
Normal	< 120	< 80	Blood pressure is within normal range. Recommend healthy lifestyle practices.
Elevated	120-129	< 80	Early indication of elevated BP. Increased risk of developing hypertension without intervention.
Grade 1 Hypertension	130-139	80-89	Mild hypertension. Lifestyle changes are recommended, and medication may be needed with cardiovascular risk factors.
Grade 2 Hypertension	140-159	90-99	Moderate hypertension. Requires lifestyle changes and antihypertensive medications.
Grade 3 Hypertension	> 160	> 100	Severe hypertension. Aggressive management is necessary to prevent serious complications.
Hypertensive Crisis	> 180	> 120	Emergency situation requiring immediate medical attention to prevent organ damage.

Hypertensive Retinopathy Grading

Grade	Retinal Findings	Clinical Significance
Grade 1	Mild arteriolar narrowing and "copper wiring."	Early stage of hypertensive retinopathy; asymptomatic.
Grade 2	Moderate arteriolar narrowing, AV nicking.	Indicates more severe hypertension; risk of heart and kidney damage increases.
Grade 3	Retinal haemorrhages, cotton wool spots, exudates.	Significant damage to the retina; increased risk of stroke and kidney disease.
Grade 4	Papilledema with all features of Grade 3.	Medical emergency; indicative of malignant hypertension.

Older patients, especially those over 80, often have asymptomatic high blood pressure, which may not always be classified as malignant hypertension. Reducing BP too quickly can be harmful.

When to Screen for Secondary Causes of Hypertension

• Age <40 or sudden worsening of BP
• Uncontrolled hypertension despite 3 medications
• BP >180/110 with papilloedema or retinal haemorrhage
• Stroke occurring before age 50

Exclude Secondary Causes of Hypertension

Probable Diagnosis	Clinical Clues	Diagnostic Testing
Renal parenchymal hypertension	Estimated GFR < 60 mL/1.73 m²/min, Urine albumin-to-creatinine ratio > 30 mg/g	Renal ultrasound
Renovascular disease	New elevation in serum creatinine, significant elevation in serum creatinine with initiation of ACEI or ARBs, refractory hypertension, flash pulmonary edema, abdominal bruit	MR or CT angiography, invasive angiogram
Coarctation of the aorta	Arm pulses > leg pulses, arm BP > leg BP, chest bruits, rib notching on chest radiograph	Chest MRI or CT, aortogram
Primary aldosteronism	Hypokalemia, refractory hypertension	Plasma renin and aldosterone, 24-hr urine potassium, 24-hr urine aldosterone and potassium after salt loading, adrenal CT, adrenal vein sampling
Cushing syndrome	Truncal obesity, wide and blanching purple striae, muscle weakness	24-hr urine cortisol, dexamethasone suppression test, adrenal CT
Pheochromocytoma	Spells of paroxysmal hypertension, palpitations, perspiration, pallor, pain in the head	Plasma and 24-hr urine metanephrines and catecholamines, adrenal CT
Obstructive sleep apnea	Loud snoring, daytime somnolence, obesity, large neck	Sleep study

Clues to Secondary Cause

Suspected Diagnosis	Clinical Clues	Diagnostic Testing
Primary aldosteronism	Drug-resistant hypertension, hypertensive heart disease (left ventricular hypertrophy, atrial fibrillation), hypokalemia, incidentally discovered adrenal mass	Plasma renin and serum aldosterone; 24-hour urine aldosterone after oral salt loading; adrenal vein sampling
Chronic kidney disease	Estimated GFR <60 mL/min/1.73 m², Urine albumin-to-creatinine ratio ≥30 mg/g	Renal sonography
Renovascular disease	New elevation in serum creatinine; marked elevation in serum creatinine with ACE inhibitor or ARB; drug-resistant hypertension, flash pulmonary edema, abdominal or flank bruit	Renal duplex Doppler sonography; CT or MR angiography; invasive angiography
Coarctation of the aorta	Arm pulses > leg pulses, arm BP > leg BP, chest bruits, rib notching on chest radiography	MR angiography; TEE; invasive angiography
Cushing syndrome	Incidental adrenal mass, truncal obesity, wide and blanching purple striae, muscle weakness	1 mg dexamethasone-suppression test; urinary cortisol after dexamethasone; adrenal CT
Pheochromocytoma	Incidental adrenal mass; paroxysms of hypertension, palpitations, perspiration, and pallor; diabetes	Plasma metanephrines; 24-hour urinary metanephrines and catecholamines; abdominal CT or MR imaging

Investigations and Vascular Assessment

• Blood glucose, lipid profile, age, sex, smoking, and family history
• FBC, ESR, CRP
• U&E for hypokalaemia and renal function
• Urinalysis for protein or blood (suggests renal disease)
• ECG for LVH, AF, or ischaemic heart disease
• Echocardiogram if needed

Organ Damage from Chronic Hypertension

Complication	Description	Pathophysiology	Clinical Consequences
Stroke	Hypertension is a major risk factor for ischaemic and hemorrhagic strokes.	Damages blood vessels in the brain, leading to narrowing, blockage, or rupture.	Neurological deficits, paralysis, speech difficulties, long-term disability, or death.
Renal Failure	Hypertension can lead to chronic kidney disease (CKD) and end-stage renal disease (ESRD).	Increased blood pressure damages the small blood vessels in the kidneys, impairing their ability to filter waste from the blood.	Leads to the need for dialysis or kidney transplantation and increases cardiovascular risk.
Congestive Cardiac Failure (CCF)	Hypertension is a leading cause of left ventricular hypertrophy, which can progress to heart failure.	Increased afterload from hypertension causes the heart to work harder, leading to hypertrophy and eventual failure to pump efficiently.	Symptoms include shortness of breath, fluid retention, fatigue, and reduced exercise tolerance.
Myocardial Infarction	Hypertension accelerates atherosclerosis, leading to coronary artery disease and myocardial infarction (heart attack).	Chronic high BP damages arterial walls, increasing plaque formation and risk of rupture and thrombosis.	Leads to chest pain, heart failure, arrhythmias, and can be fatal without prompt treatment.
Atrial Fibrillation	Hypertension significantly increases the risk of developing atrial fibrillation (AF).	Increased pressure causes left atrial enlargement and fibrosis, leading to electrical disturbances and AF.	Irregular heart rhythm, increased risk of stroke, potential heart failure.
Central Retinal Vein Thrombosis	Hypertension can lead to central retinal vein occlusion, causing vision loss.	High BP damages the retinal veins, leading to thrombosis and impaired venous outflow.	Sudden, painless vision loss; risk of permanent blindness if untreated.

British Hypertensive Society Guidelines

Step	White Male < 55	Black or Over 55
1	ACEI or ARB	CCB or Thiazide Diuretic
2	ACEI or ARB + CCB or Thiazide Diuretic	Same as left column
3	ACEI or ARB + CCB + Thiazide Diuretic	Same as left column
4	Add alpha-blocker or another diuretic	Same as left column

Management

• Non-drug Measures:
  • Correct obesity
  • Reduce alcohol intake
  • Reduce salt intake
  • Engage in regular exercise
  • Eat more fruits and vegetables
  • Consume low saturated fats
  • Stop smoking

Medications Used in Hypertension

Drug Class	Drug Name	Typical Dose	Mechanism of Action	Pharmacology
ACE Inhibitors	Ramipril	2.5-10 mg once daily	Inhibits angiotensin-converting enzyme, leading to vasodilation and lower BP.	Reduces vasoconstriction and aldosterone secretion. Renal protective in patients with diabetes or CKD.
ARBs	Losartan	50-100 mg once daily	Blocks angiotensin II receptors, reducing vasoconstriction and aldosterone release.	Preferred in patients who cannot tolerate ACE inhibitors (e.g., due to cough). Renoprotective in patients with CKD.
Calcium Channel Blockers	Amlodipine	5-10 mg once daily	Blocks calcium entry into vascular smooth muscle, leading to vasodilation.	First-line for older patients and African or Caribbean populations. May cause peripheral edema.
Thiazide Diuretics	Indapamide	1.5 mg once daily	Inhibits sodium reabsorption in the distal tubule, promoting diuresis.	Effective in older patients. May cause hypokalemia and dehydration.
Beta-Blockers	Atenolol	25-100 mg once daily	Blocks beta-adrenergic receptors, reducing heart rate and BP.	Less commonly used as first-line; more suitable in ischaemic heart disease. May cause bradycardia, fatigue, cold extremities.
Aldosterone Antagonists	Spironolactone	25-50 mg once daily	Inhibits aldosterone, reducing sodium and water retention.	Used in resistant hypertension. May cause hyperkalemia or gynecomastia.