CVS part 2 Flashcards
How do you decrease heart rate?
By inhibiting calcium channels using calcium channel blockers (CCBs) like verapamil and If channels using lvabradine
What does “heart rate” mean
number of heart beats per min
What does “stroke volume” mean
volume of blood ejected from the heart per beat
What does “cardiac output” mean
Volume of blood ejected from the heart per min (ml/min)
What does “blood flow” mean
Volume of blood circulating per min
What does “blood pressure” mean
Pressure of circulating BF on blood vessel walls
What does “total peripheral resistance” mean
Resistance of blood vessels to blood flow
How do you calculate “cardiac output”
heart rate x stroke volume
What leads to heart failure?
A drop in stroke volume leads to poor cardiac output
how do you calculate arterial blood pressure
cardiac output x total peripheral resistance
What causes hypertension
high total peripheral resistance leads to high blood pressure - hypertension
How do you decrease heart rate?
By inhibiting calcium channels using calcium channel blockers (CCBs) like verapamil and If channels using lvabradine
What is angina?
Angina is where you have attacks of chest pain caused by reduced blood flow to your heart.
What reduces irregular heart rate and regulated electrical activity?
Anti-arrhythmic drugs, e.g., Na channel or K channel blockers
Heart sounds are a result from
- Vibrations induced by closure of cardiac valves
- Vibrations in ventricular chambers
- Turbulent blood flow through valves
S1 - “lubb”
Closure of tricuspid/mitral values at beginning of ventricular systole
S2 - “dupp”
Closure of aortic/pulmonary valves at beginning of ventricular diastole
S3 – occasional
Turbulent blood flow into ventricles, detected near end of first 1/3 diastole – common in young
S4 - pathological in adults
Forceful atrial contraction against a stiff ventricle – potentially abnormal
aortic stenosis
It is a murmur heard between S1 and S2, due to reduced ejection of blood through aortic valve
Consequences of dilated heart like heart failure:
- ↑ Afterload
- Decreased SV/CO
- poor blood flow to end organs
Consequences of chronic high arterial blood pressure
- ↑ Afterload
- Increased energy expenditure to maintain SV
- Ultimately decreased SV/CO
- poor blood flow to end organs
- High blood pressure is bad for the heart!
Hypovolemic shock
an emergency condition in which severe blood or other fluid loss makes the heart unable to pump enough blood to the body. This type of shock can cause many organs to stop working.
What type of drugs increase heart rate and contractility?
Drugs that mimic sympathetic activity (sympathomimetics)
or activate β1 adrenoceptors (β agonists)
What type of drugs reduce heart rate and contractility?
Drugs that inhibit β1 adrenoceptors (β antagonists)
reduce heart rate and contractility
Beta adrenergic agonists or beta agonists
medications that relax muscles of the airways, causing widening of the airways and resulting in easier breathing. They are a class of sympathomimetic agents, each acting upon the beta adrenoceptors.
When are β adrenoceptor agonists used?
Cardiac arrest, anaphylaxis, cardiogenic shock (v. high mortality) caused by infection/inflammation (e.g., sepsis) and/or haemorrhage
i.e. Conditions where CO is compromised
When are β adrenoceptor antagonists used?
- Used for angina, hypertension, arrhythmias, chronic heart failure
- Conditions where you want to ↓ HR, contractility, the excitability of the heart
and when ↓ O2 demands
Examples of β adrenoceptor antagonists
Bisoprolol, Atenolol (β1 antagonist)
Propranolol (non-selective β1 & β2 antagonist)
Pilocarpine
Relieves intraocular pressure (IOP) in glaucoma
Glaucoma
It is a common eye condition where the optic nerve, which connects the eye to the brain, becomes damaged. It’s usually caused by fluid building up in the front part of the eye, which increases pressure inside the eye
Bethanechol
It relieves urinary retention
urinary retention
a condition in which you cannot empty all the urine from your bladder
bradycardia
a slow heart rate
What are Atropine and Hyocine used for?
Used for sinus bradycardia induced after myocardial infarction
Ischemia
a condition in which the blood flow (and thus oxygen) is restricted or reduced in a part of the body. Cardiac ischemia is the name for decreased blood flow and oxygen to the heart muscle.
Why is total peripheral resistance important?
it controls Blood Flow and Blood Pressure
Vasodilation
This increases blood flow and decreases blood pressure.
Vasoconstriction
This decreases blood flow and increases blood pressure
EXCESSIVE CONSTRICTION
causes e.g., Hypertension and as a result you will have poor blood flow to end organs
Hypotension
It is low blood pressure, a blood pressure under 90/60 mm/Hg.
EXCESSIVE VASODILATATION
(e.g., sepsis, very low BP, no drive for blood flow) you also have poor blood flow to end organs
Vasodilation
It is the widening of blood vessels as a result of the relaxation of the blood vessel’s muscular walls.
Angiotensin II receptor (AT1) antagonists (ARB) e.g., Losartan - helps:
Hypertension, heart failure
(they are Vasoconstrictor Receptors blockers)
Angiotensin-converting enzyme inhibitors (ACEi) e.g., Enalapril - helps:
Hypertension, heart failure
(they are Vasoconstrictor Receptors blockers)
α1-adrenoceptor antagonists e.g., Prazosin - helps:
Drug-resistance hypertension
(they are Vasoconstrictor Receptors blockers)
ETA receptor antagonists e.g., Bosentan - helps:
Drug-resistance hypertension
(they are Vasoconstrictor Receptors blockers)
VGCC blockers (CCB) e.g., Amlodipine
Hypertension angina
(Ca influx blockers)
Nitrates e.g., Glyceryl trinitrate (GTN)
Angina
(Contractile mechanism relaxants)
Nitrates e.g., Glyceryl trinitrate (GTN)
Angina
(Contractile mechanism relaxants)
PDE5 inhibitors e.g., Sildenafil
Erectile dysfunction
(Contractile mechanism relaxants)
Oedema
It is a build-up of fluid in the body which causes the affected tissue to become swollen.
Deep vein thrombosis (DVT)
It is is a blood clot that develops within a deep vein in the body, usually in the leg.
What is hypertension?
Persistently raised arterial blood pressure (BP)
Hypertension risk factors:
Age
Sex - up to 65 M>W, 65-74 W>M
Ethnicity
Genetic factors
Social deprivation
Lifestyle – smoking, alcohol, salt, obesity, lack of exercise
Stress and anxiety
Arteriosclerosis
Arteriosclerosis is a broader term for the condition in which the arteries narrow and harden, leading to poor circulation of blood throughout the body.
Atherosclerosis
a condition that involves the hardening/stiffening of the artery walls because the arteries become clogged with fatty substances called plaques, or atheroma.
hypertension diagnosis
- check the pulse manually
- if pulse is irregular, measure blood pressure
- if BP ≥ 140/90, take a 2nd reading
- if 2nd reading is substantially different take a 3rd reading
- you then take lower of the last 2 = as the clinic blood pressure.
- Suspect HTN if the BP ≥ 140/90
- If clinic systolic BP at least 180 mmHg or clinic diastolic BP at least 120 mmHg:
- Same day referral for accelerated HTN (retinal haemorrhage +/- papilloedema or suspected phaeochromocytoma or life threatening symptoms (new onset confusion, chest pain, signs of heart failure, AKI)
- If no symptoms carry out investigations for target organ damage asap.
- Target organ damage = start treatment immediately
- No target organ damage = repeat BP within seven days
White coat HTN
Suspect a ‘white coat effect’ in people with persistently raised clinic blood pressure readings whose home or ambulatory blood pressure monitoring readings are lower, with a discrepancy of > 20/10 mmHg.
What signs do people with white coat HTN exhibit
They may also exhibit signs in clinic such as tachycardia, sweating, or palpitations.
Masked hypertension
This is when patients’ blood pressure is classed as normal in the clinic or office (<140/90 mmHg), but they have an elevated BP when taken outside the clinic using ABPM or HBPM (ambulatory daytime BP or home BP>135/85 mmHg).
Why does APBM need to be carried out?
because of masked HTN and white coat HTN diagnosis should be confirmed with ambulatory BP monitoring (APBM). Home BP monitoring (HBPM) if ABPM not tolerated.
What is APBM and what does it involve?
Ambulatory Blood Pressure Monitoring (ABPM) is when your blood pressure is measured as you move around, living your normal daily life. 2 measurements are taken per hour during person’s usual waking hours. Average of 14 measurements used as BP.
What is HBPM and what does it involve?
2 measurements are taken 1 minute apart when person seated. Recorded twice daily, morning and evening. 4-7 days. Discard measurements taken on first day. Average of all remaining measurements.
What is left-ventricular hypertrophy (LVH)
a term for a heart’s left pumping chamber that has thickened and may not be pumping efficiently. This is as a result of aortic stenosis or high blood pressure which overwork the heart muscle.
What is aortic stenosis?
It is a type of heart valve disease (valvular heart disease). The valve between the lower left heart chamber and the body’s main artery (aorta) is narrowed and doesn’t open fully. This reduces or blocks blood flow from the heart to the aorta and to the rest of the body.
Diagnosis for hypertension:
- Target organ damage:
- ECG for left-ventricular hypertrophy (LVH)
- Renal function tests (U&Es) for renal impairment.
- urine tests (proteinuria or albuminuria, haematuria) for renal impairment.
- Eye screening/ fundoscopy for hypertensive retinopathy - Assess cardiovascular risk:
measure Hba1C and cholesterol levels - Calculate person’s 10-year risk of developing cardiovascular disease (CVD) using QRISK3 assessment tool
What is Hypertensive Retinopathy
it is retinal vascular damage caused by hypertension. It
