Lecture 9 Hypertension I Flashcards
Why does hypertension often co-exists in patients with angina heart failure and myocardial infarction
Because it is one of the major risk factors for all of those cardiovascular diseases
Complete this phase. Hypertension is an important ________ ______ of premature ______ (poor health hospital admissions etc) and _______
Preventative cause morbidity mortality
Give examples of conditions which hypertension is a major risk factor
Ischaemic and haemorrhagic stroke myocardial infarctions heart failure chronic renal disease cognitive decline
What is the effect of hypertension on the atria
Hypertension increases the risk of atrial fibrillation. This is because increases in blood pressure raise the afterload on the heart causing dilation of the atria. This can in turn cause problems with electrical conduction
What are the two-separate mechanism by which hypertension increases the risk of stroke
It can increase the risk of both haemorrhagic and ischaemic strokes directly due to the effects of raised peripheral blood pressure but also can lead to atrial fibrillation. Atrial fibrillation has its own independent risk of causes stroke
What are the implications of a 2mmHg increase in blood pressure
A 7% increased risk of mortality from IHD and a 10% increase in mortality from stroke
Why when patients first present with high blood pressure in the clinic it is referred to as suspected hypertension
Because a number of spurious factors may mean that their clinic blood pressure is higher than normal. This could be due to the anxiety of going to the clinic as well as a number of other situational factors
What is the threshold for diagnosis of suspected hypertension
A clinic blood pressure 140/90mmHg or higher
What is usually done when a patient first presents with suspected hypertension
People with suspected hypertension are offered ambulatory blood pressure monitoring (ABPM) to confirm a diagnosis of hypertension. This is a cuff the patients wear for 24hrs to measure the blood pressure over a sustained period of time in an environment the patient is comfortable in
What is the main benefit of ambulatory blood pressure monitoring in terms of diagnosing the cause of a patients’ hypertension
ABPM also measures heart rate this allows you to determine if the high blood pressure can be associated with increased heart rates
ABPM blood pressures are usually higher than clinic blood pressures T or F
F – vice versa
What is the threshold for diagnosis of stage 2 hypertension
A clinic blood pressure consistently around 160/100mmHg and a ABPM consistently around 150/95mmHg
What blood pressures are associated with severe hypertension
Systolic pressures >180mmHg and diastolic pressures >110mmHg
What are the two different categories of hypertension
Primary (essential) hypertension where the is no obvious cause of the hypertension. Secondary hypertension where the patient is usually young and resistant to blood pressure treatment. This is where there is an underlying cause associated with the kidney or endocrine system
Give some examples of conditions that could cause secondary hypertension
Cushing’s syndrome Liddle’s syndrome
Alongside antihypertensive drug therapy what additional treatments are recommended for patients with primary hypertension
Lifestyle modifications such as diet and exercise smoking cessation and a lower salt intake
Antihypertensive drugs are only administered to patients aged under 80 years with stage 1 hypertension how have one or more of which risk factors
Diabetes target organ damage (left ventricular hypertrophy) renal disease (microalbuminuria) established cardiovascular disease (MI stroke heart failure) or a 10-year cardiovascular risk of 20% or greater
What system is used to calculate a patient’s 10-year cardiovascular risk
QRISK2 score
Antihypertensive drug treatments are prescribed to people of any age with stage 2 hypertension T of F
T
What are the ideal blood pressure targets for antihypertensive drugs
Under 80 years – <140/90mmHg clinic blood pressure (<135/85mmHg ABPM). Over 80 years – <150/90mmHg clinic blood pressure (<145/85mmHg ABPM)
Why are clinicians less inclined to lower the blood pressure of patients over 80
There can be a number of issues with lowering an elderly patients blood pressure too much such as cognitive decline syncope and confusion
What are the two main variables that are increased in patients with hypertension
Peripheral resistance and cardiac output
What is the predominant cause of the high blood pressure in patients with primary hypertension
An increase in peripheral resistance
Interplay between which two systems causes an increase in peripheral resistance
Sympathetic nervous system and RAAS
Local vascular mediators can also account for a patients hypertension T or F
T
Why is cardiac output not an ideal therapeutic target in patients with hypertension
Cardiac output is usually normal in most patients with hypertension
Aside from its stimulation of Na+ and water retention through the release of aldosterone how has angiotensin II also been implicated in causing hypertension
It also stimulates vascular growth causing hyperplasia and hypertrophy
What are the 9 different targets that can intervene with the neurohumoral response by the sympathetic nervous system and RAAS system
Renin inhibitors ACE inhibitors angiotensin receptor blockers aldosterone antagonists β adrenoceptor antagonists α adrenoceptor antagonists (thiazide) diuretics Ca2+ channel blockers and centrally acting sympathetic drugs
Which are the main classes of diuretics used in hypertension
Thiazide-like diuretics and aldosterone antagonists
Give some examples of diuretics used in hypertension
Bendroflumethiazide hydrochlorothiazide chlorthalidone and spironolactone
Why is spironolactone sometimes used in hypertension
It can be the case that the patients hypertension can be driven by high aldosterone levels. This could be due to Conn’s syndrome or adrenal tumours that increase the secretion of aldosterone. Hence using an aldosterone antagonist that is also a K+ sparing diuretic may be very beneficial
What are the main side effects associated with the types of diuretics used in hypertension
Hyponatremia hypokalaemia hypomagnesaemia hypocalcaemia hyperuricaemia (gout) impaired glucose tolerance and erectile dysfunction
What are the main clinical indications for β blockers
Ischaemic heart disease heart failure arrhythmia hypertension
How does the dose of β blockers differ in hypertension compared to heart failure
Whereas in heart failure where doses are started low and gradually increase you can prescribe higher levels of β blockers in hypertension
Give some examples of β blockers licenced for use in hypertension
Bisoprolol carvedilol metoprolol atenolol propranolol nadolol
What is the difference between selective and non-selective β blockers
Selective β blockers are always selective for the β1 adrenoceptor whereas non-selective β blockers bind both β1 and β2 adrenoceptors
Give some examples of non-specific β blockers
Nadolol carvedilol propranolol
Give some examples of specific β blockers
Metoprolol bisoprolol
What can be said about the selectivity of atenolol
It is an intermediate selectivity between being β1-selective and non-selective
What is meant by a cardioselective β blocker and why is this a misnomer
Cardioselective is used to imply β1AR selectivity as the airway receptors are mainly β2 receptors. However this is a misnomer as up to 40% of cardiac βARs are β2 adrenoceptors
What condition majorly contraindicate the use of β blockers in hypertension
Asthma – due to any potential antagonism of the β2ARs in the airway causing bronchoconstriction
What are the main adverse effects of β blockers
Fatigue due to blocking sympathetic nervous system headache sleep disturbance/nightmares bradycardia hypotension cold peripheries due to a shutting down of peripheral circulation to maintain central blood pressure and finally erectile dysfunction
Which conditions can β blockers often worsen
Asthma (may be severe) or COPD – because of the β2 effects peripheral vascular disease causing claudication (cramping because of decreased blood flow) or Raynaud’s and also it can worsen heart failure
