Hypertension and Heart Failure Flashcards
Define hypertension, moderate hypertions and severe
140/90
160/100
180/110
What are causes of secondary hypertension?
Coarctation of the aorta Renal artery stenosis Conn's disease Cushing's Phaeochromocytoma
What is initial management of hypertension?
Lifestyle advice
- Normal body weight
- Reduce salt intake
- Limit alcohol consumption
- Engage in regular aerobic physical exercise
- Consume five-a-day
- Reduce fat intake
- Smoking cessation
What is the pathway of treatment for hypertension
- If the patient is younger than 55 and not black (African or Caribbean) then you should start with an ACE inhibitor
- If the patient is 55 or older, or black, you should start with a calcium channel blocker (Amlodipine) (or thiazide, but I think CCB is standard)
- You then add in the one you haven’t given yet so you have ACE inhibitor + Calcium Channel Blocker
- Then you add in a thiazide type diuretic
- Then (step four) you add in further diuretic therapy, an alpha blocker, or a beta-blocker.
What are causes of heart failure
• Ischaemic heart disease o Leads to left ventricular dysfunction • Hypertension • Cardiomyopathies (alcohol, idiopathic, iron overload, chemotherapy) • Valve disease
What is standard treatment of heart failure?
o Antagonise the RAAS with ACEIs, ARBs, aldosterone blockade (spironolactone)
• Evidence suggests Ramipril reduces mortality
• ARBs are also effective
• But aldosterone can return to normal despite this – has deleterious effect
o Potassium and magnesium loss leads to arrthymias
o Myocardial fibrosis
o Endothelial dysfunction – acute coronary events
o Can lead to sudden death
• Spironolactone increases survival (RALES study)
o Beta-blockers (not in acute heart failure! In acute heart failure can lead to low cardiac output)
• Reduce heart rate
• Reduce cardiac output
• Which reduces myocardial oxygen demand
• Reduce mobilisation of glycogen
• Negate unwanted effects of adrenaline and noradrenaline
• They have also been shown in trials to reduce all-cause mortality in stable chronic heart failure
Loop/thiazide/aldosterone antagonist can be added to relieve oedema
Why should you be careful when using beta blockers?
Start low and titrate up slowly as slowing HR too much will reduce CO and make HF worse
You have to reduce just the right amount and O2 demands of heart will be reduced
Don’t give verapamil (CCB) and beta blocker –> bradycardia and hypotension
Example, indication, MOA, ADR of ACE inhibitors
Ramipril, Lisonopril
Heart failure
LV dysfunction
MI
Diabetic nephropathy
Blocks conversion of angiotensin 1 to angiotensin 2 preventing it exerting effects via stimulation of sympathetic NS, vasoconstriction of arterioles, tubular Na resorption, aldosterone secretion and ADH secretion.
Potentiates action of bradykinin (vasodilator) as this is normally broken down by ACE –> bradykinin build up can lead to dry cough
ADR: Dry cough Hyperkalaemia Angio-oedema Renal failure Teratogenic
Example, indication, MOA, ADR of ARBs
Losartan, vallarta
If intolerant to ACEIs
Hypertension with LVH
Type 2 DM
Block angiotensin 2 receptors causing same effects as ACE inhibitor without build up of bradykinin so no dry cough
Renal failure
Hyperkalaemia
Teratogenic
Example, indication, MOA of CCBs
Amlodpine (dihydropyridine)
Verapamil (phenylalkylamine)
Diltiazem (Benzothiazepin)
Amlodipine – in elderly or isolated systolic hypertension
Others - angina
Bind to alpha subunit of l-type calcium channels which reduces calcium entry to smooth muscle cells, causing vasodilation of peripheral, coronary and pulmonary arteries, reducing BP.
Verapamil depresses the SA node and AV conduction leading to bradycardia, amlodipine causes baroreflex mediated tachycardia.
What are the three types of calcium channel blockers?
Amlodpine (dihydropyridine)
Verapamil (phenylalkylamine)
Diltiazem (Benzothiazepin)
What are dihydropyrindes for? ADRs?
Good for lowering blood pressure
Amlodipine is used for BP, the other two are more anti-arrthymic
Amlodipine has good bioavailability, is protein bound, and metabolised by the liver.
ADRs include:
• Tachycardia and palpitations (amlodipine)
• Flushing, sweating and throbbing headaches
• Oedema
• Gingival hyperplasia
What are phenylalkylamines for? ADRs?
Verapamil is both anti-arrthymic and a peripheral vasodilator which reduces preload and contractility. It also prolongs the refractory period of the myocardium. ADRs include:
• Constipation
• Bradycardia
• Reduced cardiac contractility which can worsen heart failure
What are benzothiazepines for? ADRs?
Dilating coronary vessel - good for angina
Diltiazem has the same effect as verapamil. ADRs include:
• Bradycardia
• Negative inotropy which can worsen heart failure
Example, indication, MOA of thiazide diuretics?eta blockers
Bendroflumethiazide, Indapamide
Elderly, isolated systolic hypertension, heart failure
Reduces sodium reabsorption in the distal convoluted tubule, reduces blood pressure (decrease in blood volume, fall in TPR)
ADRs:
Hypokalaemia
Hyperuricaemia – contraindicated in gout
Impaired glucose tolerance - especially with beta blockers so don’t use together in DM
High levels of cholesterol and triglycerides
Activates RAAS (give with ACEI)
