Cardiovascular Flashcards
Where does excitation within the heart begin?
The pacemaker cells within the Sino-Atrial Node
Each pacemaker cell produces a SPP (__________ _________ __________) which trigger an _______ ________ when they combine and exceed a threshold.
Spontaneous Pacemaker Potential
Action Potential
What ions move Before/during and after pacemaker potential depolarizations?
Before- Na+ ion influx
During- Ca2+ influx through L-type channels
After- K+ efflux- repolarization
Through what junctions does excitation spread?
Gap junctions
What is unique about myocyte action potentials?
They exhibit a plateau phase which is maintained by Ca2+ channels.
What effect does vagal tone have on the heart rate?
The vagal tone slows the intrinsic heart rate (which is around 100bpm) to the normal resting heart rate (60bpm).
What effect does parasympathetic stimulation have on heart function?
negative chronotropic- slows heart rate and increases AV nodal delay
What receptors are involved in vagal stimulation of the heart?
Muscarinic M2 acetylcholine receptors
What effect does sympathetic stimulation have on the heart and what receptors do they use?
Positive chronotropic effect and positive inotropic effect- increases heart rate and decreases AV nodal delay Beta1 adrenoceptors (noradrenaline)
What do cardiac sympathetic nerves supply?
SA and AV nodes
myocardium
What drug is used to increase the heart rate during extreme bradycardia?
How does it act?
Atropine
Competitive inhibitor of muscarinic M2 receptors
why is Ca2+ necessary for muscle contraction?
It removes the troponin and tropomyosin from the myosin heads allowing crossbridge formation
Where is Ca2+ stored in myofibrils?
the sarcoplasmic reticulum
What is the purpose of transverse tubules?
They carry action potentials to the sarcoplasmic reticulum
What does the Frank-Starling curve show?
The greater the end diastolic volume the greater the stroke volume
What does one Cardiac cycle consist of?
The period from the beginning of one heart beat to the beginning of the next.
During contraction and relaxation the volume of the ventricles remains constant. What do you call these states?
Isovolumetric ventricular contraction and relaxation.
What causes the dicrotic notch?
Valve vibration
where would you place your stethoscope bell to listen to each of the four valves?
Aortic- 2nd intercostal space on right beside sternum
Pulmonary- 2nd intercostal space on left side of sternum
Tricuspid- 4th intercostal space on left side beside sternum
Mitral- 5th intercostal space mid-clavicular line
Where is most of the blood stored?
Peripheral venous pool
What name is given to the sounds heard when investigating the blood pressure?
Korotkoff sounds
Which blood vessels contribute most to systemic vascular resistance?
Arterioles
how do you investigate postural hypotension?
Ask patient to lie flat for 3 minutes then record change in blood pressure
systolic drop by 20mmHg or more
diastolic drop by 10mmHg or more
Where is Angiotensinogen produced?
the liver
Where is Angiotensin I converted to Angiotensin II?
what catalyses this reaction?
Lung Vascular endothelium
Angiotensin Converting Enzyme
Where is Renin released from?
The kidneys
What effect do natriuretic peptides have on the blood vascular system?
Vasodilation, sodium and water excretion, reduced renin release
Brain type Natriuretic Peptide is synthesised in the brain and ventricles. When BNP is found in the serum, what does this signify?
Heart failure
How many Standard, augmented and precordial leads does an ECG possess?
standard- 3
augmented- 3
precordial- 6
How long should the QRS complex last for?
less than 0.1 seconds.
how long should the PR interval be?
0.08-0.10secs
Name the two layers of the pericardium. Which layer secretes pericardial fluid?
Fibrous and serous
serous secretes pericardial fluid
Into which chamber does the coronary sinus drain?
the right atrium
What is cardiogenic shock?
Sustained hypotension due to damage to the heart and thus low cardiac contractility.
What is vasoactive shock?
Vasoactive mediators cause increased capillary permeability resulting in low serum volume and therefore shock.
Pathogenesis of ischaemic heart disease: begin with initial _________ injury. _____ and __________ accumulate at the site of damage. ______ _______ migrates to the area and eventually a ________ cap forms
endothelial Lipids macrophages Smooth muscle collagenous
What is stenosis?
The narrowing of a blood vessel lumen
What is an aneurysm?
Abnormal and permenant dilatation of an artery
What is an aortic dissection?
Splitting of the aorta into to channels
What is the difference between somatic and visceral pain? How do they present?
Somatic pain- follows somatic dermatomes
Visceral pain- Originates from the organs
somatic- sharp, localised, stabbing pain
visceral- dull, aching, poorly localised
What does TLOC stand for?
Transient Loss of Consciousness
What is syncope?
transient loss of consciousness because of cerebral hypoperfusion
name the three types of reflex syncope.
Vasovagal
situational
Carotid sinus
Where are lipoprotein lipases located?
The capillary endothelium of adipose/muscle tissue
Where are LDL receptors expressed?
Liver
What Function does HDL have?
It is involved in the elimination of excess cholesterol.
Describe the action of Statins.
Statins are competitive inhibitors of HMG-CoA. They stop cholesterol formation in the liver. This decrease in synthesis causes an increase in LDL receptor expression in the liver leading to enhanced LDL clearance.
What are fibrates?
Agonists to nuclear receptors which enhance the transcription of Lipoprotein lipases
what drug reduces the absorption of cholesterol in the duodenum by inhibiting NPC1L1?
Ezetimibe
Name three clinical signs of hyperlipidaemia
Xanthoma
Xanthelasma
Corneal Arcus
Milky blood/serum
name two possible side effects of statins
Rhabdomyolosis, myalgia
Is familial Hypercholesterolaemia an autosomal dominant or recessive disorder?
Autosomal dominant
Which ducts drain into the right and left venous angles?
Right- Right lymphatic duct
Left- Thoracic duct
What is the difference between primary and secondary hypertension?
Primary- no obvious cause
secondary- Due to a medical condition e.g. aldosteronism, cushings syndrome, phaochromocytoma, renal damage, coarction of the aorta
In what way does hypertension remodel the heart?
Left ventricular hypertrophy
this is poorly perfused leading to interstitial fibrosis
What is the best diagnostic test for hypertension?
An Ambulatory Blood Pressure Monitor
What may be exhibited in the eyes of hypertensive patients?
Hypertensive retinopathy
Outline the four stages of treatment for hypertensive patients who are under 55
A to
A+C/A+D
A+C+D
more D + B
How would hypertension treatment for over55s/afro-Carribbean differ than for under 55s?
they start on C or D rather than A
What is the best treatment for complicated hypertension?
Spironolactone
What drug may worsen peripheral vascular disease?
Beta blockers
nitrates cause a decrease in intracellular ________ leading to the __________ of vascular smooth muscle.
calcium
relaxation
Which is stronger- loop diuretics or thiazide diuretics? How do they act?
Loops stronger
they block Na+ reabsorption in the kidneys
Name two cardioselective beta blockers
Atenolol, Bisoprolol
Propranolol and carvedilol are examples of what drug?
Non-selective beta blockers
What is amlodipine?
A calcium channel blocker
What is lisonopril? Give a common side effect of such drugs
An ACE inhibitor. Cough
What receptors do ARBs block? give an example of an ARB
Angiotensin II receptors
losartan
Arterial thrombi are treated with __________ whereas venous thrombi are treated with __________.
Antiplatelets
anticoagulants
Give two examples of parenteral anticoagulants
Heparin and fondaparinux
In traditional VTE treatment __________ anticoagulants are given first and _______ is given which is a ________ __ antagonist. The __________ coagulants are withdrawn once the _________ has a therapeutic effect (5 days) and has been at such a level for two days.
Parenteral warfarin Vitamin K antagonist Parenteral warfarin
Enoxiparin and dalteparin are examples of what?
Low Molecular Weight Heparin (LMWH)
Name four DOACs
edoxaban
apixaban
rivaroxiban
dabigatran
How does dabigatran differ from the other oral anticoagulants?
It is a thrombin inhibitor whereas the others are factor Xa inhibitors
How is the anticoagulant effect of Vitamin K antagonists measured? What system is used to standardise this assessment?
Measured using Prothrombin time
International Normalised Ratio
Name two possible side effects of vasodilators
headaches and flushing
Describe the action of the antiplatelet Aspirin
Reversible inhibition of platelet COX-1 and thromboxane production.
Ivabradine, nicorandil and ranolazine are examples of what type of drug?
Anti-anginals
what is GTN spray used for?
prophylactic and rapid onset angina treatment.
Is the peak flow in the coronary arteries during systole or diastole?
Diastole
When the cerebral MAP rises vessels ___________ to restrict blood flow.
Vasoconstrict
Increased C02 in the brain causes blood vessel __________ while decreased C02 causes __________.
Vasodilation
Vasoconstriction
How do you calculate the cerebral perfusion pressure?
CPP= MAP- intracranial pressure
Name two alternatives of aspirin
ticagrelor
clopidogril
What are the main investigations for angina and MI?
Echocardiogram, Electrocardiogram, blood tests
Name two types of coronary revascularisation
CABG- Coronary Artery Bypass Graft
PCI- Percutaneous Coronary Intervention
D-Dimer is released into the blood when ______ from a clot is broken down. It has a high ________ predictive value
Fibrin
Negative
Name three side effects of diuretics
hyponatraemia
hypokalaemia
gout
Define a stroke
Acute onset of focal neurological symptoms due to disruption of blood supply
Identify the two types of stroke
Ischaemic and haemorrhagic
What are the two main investigations for strokes?
CT and MRI of the brain
How do you manage an ischaemic stroke?
Thrombolysis/thrombectomy
What is the main investigation for intermittent claudication?
Ankle/Brachial blood pressure index
What are the two main risk factors of critical limb ischaemia?
Smoking and Diabetes
the AV node and Purkinje fibres are known as _______ pacemakers. Meanwhile the SA node is dominant- this domination is called ________ __________.
latent
overdrive suppression
If the SA frequency is pathologically low, the latent pacemakers may become the dominant pacemakers. they would be said to produce ______ beats and a ______ rhythm.
escape beats
escape rhythm
When the latent pacemaker frequency is pathologically high they are said to be producing _______ beats and a _______ rhythm.
ectopic beats
ectopic rhythm
Early Afterdepolarizations occur during phase _ and __and delayed afterdepolarizations occur during phase __
EADs-2+3
DADs- 4
name some causes of triggered activity.
Digoxin, catecholamines, hypoxia, acidosis
name the two types of second degree heart block
Mobitz type I and II
What is the difference between ventricular and supraventricular arrhythmias?
ventricular- ventricle myocardium
supraventricular- SA, AV, atria
Name three possible symptoms of an arrhythmia.
Palpitations, syncope, dizziness
name three arrhythmia investigations
Exercise ECG, echocardiogram, electrophysiological study
How do you treat an acute supraventricular tachycardia?
Carotid baroreceptor massage, IV adenosine
Ventricular tachycardia is a life threatening condition that can appear with either a __________ pattern or a ___________ pattern.
monomorphic
polymorphic
How do you treat ventricular tachycardia?
defibrillation/CPR
What are the three signs of a MI on a ECG?
ST elevation- wihtin hours
T wave inversion- within days
Q wave formation- old MI
What protein may appear in the serum signifying an MI?
Troponin
Describe the pressure difference that means that filtration is favoured over absorption in the arterioles
the capillary hydrostatic pressure is greater than the capillary osmotic pressure
What is oedema?
When fluid accumulates in the interstitial space
Name one cause of pulmonary oedema
Left ventricular failure- puts back pressure on the blood vessels of the lungs- capillary hydrostatic pressure then exceeds osmotic pressure
How would pulmonary oedema present on a chest X-ray?
Bat wing pattern of consolidation (perihilar consolidation)
Name two clinical signs of pulmonary oedema
SOB
basal crepitations
Peripheral and pulmonary oedema are signs of what condition?
Heart failure
What is the difference between HFrEF and HFpEF?
HFrEF- heart failure with reduced ejection fraction- reduced ejection force due to ventricular damage
HFpEF- heart failure with preserved ejection fraction- reduced ventricular filling due to myocardial stiffness
Heart failure is associated with the presence of what hormone in the blood?
BNP
Name four investigations of heart failure
Echocardiogram
blood tests
ECG
Chest X-ray
Identify Three ways in which heart failure could be managed
Exercise therapy
cardiac rehabilitaion
Salt intake restriction
What is Ivabradine? Where is this treatment used?
It is a funny channel blocker
heart failure
What is Digoxin?
A cardiac glycoside used for patients in atrial fibrillation with heart failure. it increases heart rate and force of contraction
What is the treatment for ventricular fibrillation and ventricular tachycardia?
Defibrillation
What causes Atrial fibrillation?
Ectopic foci in the pulmonary vein ostia
Name the four classifications of Atrial fibrillation.
Paroxysmal
persistent
longstanding persistent
Permanent
What would the ECG of a atrial fibrillation patient show?
Chaotic atrial activity- f waves
irregular rhythm
no clear p waves
often ventricular tachycardia
Treatment of AF is induced to control the rate and rhythm of the heart. what is usually used to control the rate?
A combo of Digoxin and either a beta blocker or a calcium channel blocker ( diltiazem or verapamil)
What drugs are used to treat the altered rhythm of the heart in AF? what other cardioversion therapy may be used?
Amiodarone and/or sotalol
Direct current cardioversion
The CHADSVAS score is used for what purpose?
To determine the likelihood of stroke in an individual with AF
What characterises the ECG of atrial flutter?
sawtooth pattern F waves
flutter frequency 300/min
What is a heart murmur?
Audible turbulence of blood flow in the heart
How does a pansystolic murmur compare to an ejection systolic murmur?
Pan-systolic- constant pitch throughout
ejection systolic- pitch increases approaching ejection
What type of murmur is Aortic stenosis? Where does it radiate to?
Ejection systolic murmur
Radiates to the carotids
What type of murmur is Mitral regurgitation?
Pan-systolic murmur
radiates to the axilla
What type of murmur is mitral stenosis? name an associated sign
Mid-diastolic
malar flush
What type of murmur is aortic regurgitation? Identify an associated symptom
Early diastolic
Collapsing pulse
Name two common congenital heart defects
Ventricular septal defect
Patent ductus arteriosis
What is an ICED?
Implantable Cardiac Electronic Device
Which valves are most likely to be affected by Infective endocarditis?
Mitral and aortic
Pathogenesis of endocarditis: valvular damage leads to turbulent blood flow and the aggregation of _______ and _______. Bacterial infection of the blood (__________) leads to infection of the wound. Areas of the wound could break off and cause an abscess or a __________.
Platelets
fibrin
bacteraemia
haemorrhage
What pathogens are the three main causes of Endocarditis?
Staph aureus
Strep viridans
Coxiella burnetti
Strep. viridans along with strep. pneumoniae are a part of which haemolytic group?
Alpha haemolytic
Which antibiotic is the first line treatment for Staph aureus infection?
Flucloxacillin
How does acute endocarditis present?
Overwhelming sepsis
cardiac failure
How does subacute endocarditis present? name three signs associated with it
Fever, malaise, SOB, weight loss, fatigue
Oster nodes, Janeway lesions, Roth spots
Myocarditis and pericarditis are caused by what type of infection normally?
Viral infection
Identify the three types of cardiomyopathy
Dilated
hypertrophic
restricted
ST elevation on leads II III and AVF are a sign of what?
Inferior myocardial infarction
what is losartan?
An angiotensin receptor blocker
What causes ST elevation on all leads?
Acute pericarditis
What aspect of the heart has the highest conduction velocities?
Purkinje fibres
Abdominal Aortic aneurysms begin with degradation of the ________ ________ of the media then subsequent collagen loss of the adventitia
Elastic fibres
What type of necrosis does the heart exhibit after an MI?
Coagulative necrosis
Identify the clotting factors warfarin acts upon.
10, 9, 7, 2—-(1972)
Name a thrombolytic drug used to treat a large PE
Streptokinase
The first heart sound (S1) marks the beginning of __________ while the second (S2) marks the beginning of _________. S2 can exhibit physiological splitting because there is a delay between the ______ and _________ valve closure.
systole
diastole
aortic
pulmonary
The third heart sound (S3) is an ____ diastolic low frequency ________ sound. In a young patient it is likely to be __________ but in an old patient it is likely to be _________ and caused by Left ventricular systolic dysfunction.
early
filling
physiological
pathological
The fourth diastolic heart sound (S4) is a _____ diastolic low frequency filling sound. It occurs when forceful ______ contraction occurs. It is caused by hypertension and _______ __________.
Late
Atrial
aortic stenosis
An inferior STEMI shows ST elevation in which leads?
II, III and AVF
An anteroseptal STEMI shows ST elevation in which leads?
V1-V3
An anterolateral STEMI shows ST elevation in which leads?
V4-V6, AVL and I
A lateral STEMI shows ST elevation in which leads?
AVL and I
Identify the normal range of stroke volumes in a healthy individual
55-100ml
Identify a paediatric condition that causes projectile vomiting in children of 2-6 weeks of age
Pyloric stenosis
Respiratory inspiration increases stroke volume. Why is this?
The thoracic pressure decreases on inspiration. The decreased pressure causes more blood to flow into the atrium.
Occlusion of the left circumflex artery would cause what type of MI?
Anterolateral
What causes a machine like heart murmur? What does this structure normally become?
Patent ductus arteriosus
ligamentum arteriosum
Chest pain as a result of pericarditis is relieved by doing what?
Sitting/leaning forward
