U12C1 Hypertension Flashcards
What is the normal vs abnormal range for blood pressure?
- Normal is a range
• Systolic 90-120 mmHg
• Diastolic 60-80 mmHg
• mean = 70-93 mmHg - Abnormal is a range
• Stage 1: 140/90 < ABP 159/99
• Stage 2: 160/100 < ABP < 180/120
• Stage 3: SBP > 180 or DBP > 120
What are the variants of hypertension?
-
Isolated Systolic Hypertension
• SBP > 140; DBP < 90
• Pulse pressure high
• Most common
• ↓ elasticity of vessels -
Isolated Diastolic Hypertension
• SBP < 140; DBP > 90
• Least common -
Mixed Hypertension
• SBP > 140; DBP > 90
What are the aetiologies of hypertension?
- > 90%: Essential hypertension
• Essential = cause unknown (idiopathic)
• Primary = no clear causative factor - <10%: Secondary hypertension
• Renal disorders → (role of kidneys)
• Endocrine:
• 1° hyperaldosteronism → (fluid regulation)
• Phaeochromocytoma → (sympathetic NS)
• Cushing’s syndrome → (cortisol) -
Drug-induced
• Abuse: e.g., cocaine → (sympathetic NS)
• Iatrogenic: e.g., combined oral contraceptive, glucocorticoids - Pregnancy = pre-eclampsia
What physiologies cause hypertension?
- cardiac output
- peripheral resistance
- autonomic nervous system
- endothelium
- vasoactive peptides
- RAAS
What does EDRF cause?
(endothelium-derived relaxing factor) = nitric oxide (NO) → vasodilation
• ↑guanylyl cyclase → ↑cGMP → ↑PKG → sm. muscle relaxation
• Atheroma → ↓NO production
• Sodium nitroprusside (↑NO) used in hypertensive emergencies
• Sildenafil inhibits phosphodiesterase V (PDEV) → ↑cGMP
What is prostacyclin?
(PGI₂) (lipid)→ vasodilation
• Analogues (e.g., iloprost) used to treat pulmonary hypertension
What is endothelin?
(peptide) → vasoconstriction
• ET receptor antagonists (e.g., macitentan) used to treat pulmonary hypertension
Vasodilators
- Bradykinin → vasodilation
• ACE inhibitors block bradykinin inactivation (see later)
- Natriuretic peptides (A, B & C)
• ANP = Atrial: secreted by atrium
• BNP = Brain: secreted by ventricles (!)
• CNP = C-type
• → ↑Na⁺ & H₂O excretion
• Receptor: NPR1 is a transmembrane guanylyl cyclase
→ ↑cGMP → smooth muscle relaxation → vasodilation
• Dysfunction may → fluid retention & hypertension
Vasoconstrictors
Vasopressin = anti-diuretic hormone (ADH)
• Vasoconstrictor, ↑BP & ↑H₂O reabsorption
What is Liddle syndrome and EnaCs?
What are the non-modifiable risk factors for hypertension?
What are the modifiable risk factors for hypertension?
What is the pathophysiology of hypertension?
What is the short and long term regulations for low blood pressure?
What are baroreceptor reflexes?
What is the effect of taking stimulants?
What are the different drug classes?
What are the blood test results for hypertension?
- Electrolyte levels: Electrolytes like sodium, potassium, and chloride can impact blood pressure regulation. Abnormal levels may indicate issues like dehydration, kidney problems, or hormonal imbalances.
- Kidney function tests (e.g., creatinine, blood urea nitrogen): High blood pressure can damage the kidneys over time, so these tests evaluate how well the kidneys are functioning. Elevated creatinine levels may suggest reduced kidney function or kidney damage, which can occur as a complication of long-term hypertension. Creatinine is a waste product produced by muscles and removed from the blood by the kidneys. When kidney function declines, creatinine levels in the blood rise. There will be low eGFR due to damage. Elevated BUN levels can also indicate impaired kidney function. BUN is a waste product formed when the liver breaks down proteins. The kidneys filter out urea from the blood, and high levels may suggest decreased kidney function.
- Glucose levels: Elevated blood sugar levels may indicate diabetes, which can contribute to hypertension and its complications.
- Lipid profile: High cholesterol levels can increase the risk of heart disease, which often coexists with hypertension.
- Thyroid function tests: Thyroid disorders can affect blood pressure regulation.
- C-reactive protein (CRP): Elevated CRP levels may suggest inflammation in the body, which can contribute to cardiovascular disease.
- Complete blood count (CBC): This can reveal if there’s anemia (low red blood cell count), which may affect oxygen delivery to tissues and organs.
What would a fundoscopy show in hypertension?
Fundoscopy uses a fundoscope to visualise the fundus of the eye. This is an important tool used in emergency settings and also as part of regular check ups in conditions such as diabetes and chronic hypertension or during a routine optometry appointments.
Retinal abnormalities grading:
• Grade 1 – increased tortuosity and reflectiveness of the retinal arteries (silver wiring)
• Grade 2 – grade 1 plus arteriovenous nipping
• Grade 3 – grade 2 plus flame-shaped haemorrhages and soft ‘cotton wool’ exudates
• Grade 4 – grade 3 plus papilloedema.
What are the non-pharmacological management of hypertension?
Why would a b-blocker not be used to treat a cocaine overdose?
What would an ECG show for hypertension?
- Left Ventricular Hypertrophy (LVH):
• One of the most common ECG findings
• Increased voltage amplitudes in the QRS complexes,
• In leads facing the left side of the heart (I, aVL, V5, V6). - Left Atrial Enlargement (LAE):
• Wide and notched P wave (called P mitrale)
• In leads II, III, and aVF. - ST-T Changes:
• ST-segment depression or T-wave inversion.
• These changes may not be specific to hypertension and can also be
influenced by other cardiovascular conditions - Arrhythmias:
• Atrial fibrillation.
• Irregularly irregular R-R intervals and absence of distinct P waves.
What is an ECG and what are the electrode positions?
What are the different ECG leads?
How do you interpret an ECG?
