Case 4 Notes Flashcards
name the two contractile proteins
myosin - globular heads with thick A bands and myosin ATPase
Actin - thin I bands made up of two alpha helix strands woven between two myosin filaments
list the Regulatory proteins
Tropomyosin / troponin T/I/C
Tropomyosin function
prevents contaction in resting state
Troponin T function
ties Troponin to actin and tropomyosin
Troponin I function
inhibits ATPase in actin
Troponin C function
binds to Ca2+ ions - regulates the contraction process
Medical term / cause for breathlessness
dyspnoea - decreased oxygen or increased CO2
symptoms of dyspnoea
cough / chest pain / fever - graded from 1-4
noisy breathing / cyanosis / overuse of accessory muscles
respiratory causes of dyspnoea
decreased elasticity / increased inflammation / ++ mucus caused by obstruction (COPD) / decrease in functioning tissue (scarring) / peroneal fluid / pneumothorax (collapsed lung)
cardiac causes of dyspnoea
heart failure (pericarditis) / endocarditis / cardiomyopathy / cardiac effusion / aortic stenosis
other causes of dyspnoea not cardiac or respiratory
lung cancer / anaemia / anxiety / asthma / obesity
List the 3 heart infections
endocarditis
pericarditis
myocarditis
endocarditis causes
infection of the inner lining and valves of heart
endocarditis symptoms
flu / weight loss / cough / SOB / joint and muscle pain
endocarditis diagnosis / treatment
blood cultures / surgery
endocarditis increased risk?
pacemakers / HIV / male / heart defects
pericarditis cause
infection of outer lining of the heart leading to pericardial effusion causing pressure build up and heart compression
pericarditis symptoms
stabbing chest pain and signs of infection
pericarditis healing time
acute - few weeks
chronic - 3+ months
myocarditis causes
infection of heart muscle post chest or throat infection e.g. rubella or glandular fever
myocarditis symptoms
chest pain / fever / sweats / increased or irregular heart rate
arteriosclerosis definition
hardening or thickening of the arterial walls leading to reduced elasticity and decreased lumen diameter
arteriosclerosis treatment
artery bypass / coronary angioplasty / lifestyle changes e.g. managing diabetes better
monckebery medial calcific sclerosis definition
Ca2+ deposition in muscular arteries which does not inhibit lumen widening
atherosclerosis definition
fatty deposit buildup in vessel walls leading to stenosis (narrowing) / occlusion / chronic inflammation SMOKING
atherosclerosis stable angina steps (1-4)
1 LDL deposit cholesterol in damaged tunica intima
2 monocytes - macrophages try to remove deposits
3 macrophages - enlarge foam cells - fatty streaks
4 fibrous capsule called plaque formed
atherosclerosis ruptured plaque (steps 5-6)
5 plaque extends into the elastic layer then lumen
6 reduced blood flow ANGINA
atherosclerosis final stages (7-10)
7 calcium deposits cause plaque hardening
8 increased pressure casing plaque dislodge - rupture
9 further clotting - downstream blockage - MI/stroke
10 plaque - aneurism - hypovolemic shock
angina definition
dull sharp pain in the chest caused by ischemia to heart muscles by atherosclerosis / heart disease
angina risk factors
hypertension / diabetes / smoking / obesity / stress
types of angina (x3)
stable
prinzmetal variable angina
unstable
stable angina
brought on by obvious causes e.g. stress / exercises and relieved by rest or medication
prinzmetal variable angina
uncommon episodic variation - caused by coronary artery spasm
unstable angina
less predictable and continues when resting and is a warning of declining cardiovascular health MEDICAL EMERGENCY caused by ruptured plaque
diagnosis of angina
ECG - abnormalities
ETT - exercise tolerance test to measure hearts capability to sustain exercise
Coronary angiography - catheter and dye then Xray to show circulation effectiveness
Myocardial perfusion scintingraphy - radioactive dye that is injected then tracked
referred pain defintion / cause
activated nociceptors in viscera localised to body surface where info from multiple nociceptors converge and the brain interprets visceral pain as superficial
what nerves can angina pain be referred from
intercostal
sympathetic
vagus
phrenic
referred pain pathway for angina
1 ischemia pain from heart muscles
2 sympathetic nerve to 1st-4th sympathetic ganglia
3 to T1 - T4
4visceral somatic pain fibres join in chest arm / forearm
heart murmurs definition
sounds from turbulent blood from within the heart
heart murmurs risk factors
anemia / diabetes / rubella / hypertension / injecting drugs
abnormal heart murmurs cause / symptoms
congenital in children but defect in adults
caused by septal defects / virus / valve calcification
blue skin / weight gain / SOB / chest pain / dizziness
types of heart murmurs (x2)
abnormal
innocent
innocent heart murmurs cause / symptoms
no symtoms
caused by pregnancy / physical activity / fever
smoking affect on cardiovascular system
smoke damage = atheroma - fatty deposit in artery
CO = reduced O2 carry capacity
nicotine = simulates adrenaline = increased HR + BP
tar - increases heart workload
inflammation
increased triglycerides
chronic heart disease definition
blocked coronary arteries leading to heart attack
peripheral arterial disease definition
narrowing of vessels causing restricted blood flow to arms and legs
abdominal aortic aneurism definition
weakened areas in wall of abdominal aorta leading to rupture EMERGENCY
effect of decreased oestrogen on cardiovascular system (menopause)
- affects NO availability (vasodilation) decreased NO synthase
- affects coagulation cascade (atherosclerosis)
- L-type calcium channels affected (contraction not prevented)
- LDL:HDL ratio increases
- decreased vasodilatory enzymes
menopause effects on cardiovascular system
increased fat distribution increased blood pressure increased coagulation increased epithelial disfunction decreased oestrogen ATHEROSCLEROSIS / HEART DISEASE / STROKE
cholesterol biosynthesis
produced by liver / intestine / adrenal gland
cholesterol biosynthesis process
1 aceyl CoA from mitochondria to cytosol - HMG-CoA - mevalonate
2 melavonate - IPP - squalene - cholesterol
With HMG-CoA reductase being the limiting step (STATINS)
cholesterol defninition
lipid transported in blood with plasma proteins
cholesterol transportation types (x2)
specific
non-specific (albumin)
metabolism of cholesterol types (x3)
auto oxidation
secondary oxidation
cholesterol metabolising enzyme oxidation
in liver to make bile salt and acids
cholesterol function (x5)
animal cell membrane component component of myelin sheaths Bile salt production Molecule synthesis (vitamin D/ sex hormones) decrease permeability of H+/Na+
Blood test results for an MI (shows myocardial necrosis)
- creatine kinase (non specific)
- CKMB (cannot be monitored over a long period)
- troponin (increases in hours after heart damage)
emergency MI protocols immediate
O2 / strong IV analgesia / NO3 / heparin
emergency MI protocols long term
low dose aspirin post event primary aginoplasty (stent) beta-adrenoreceptor blockers insulin pacemakers coronary bypass graft thrombolysis
MI healing states 1 immediately 2 few days after 3 weeks after 4 months after
1 coagulative necrosis with some bleeding
2 neutrophils enter and breakdown dead cardiomyocytes
3 ingrowth of small blood vessels / meshing fibroblasts + type three collagen (most dangerous phase)
4 granulation tissue forms
5 type 3 replaced by type 1 collagen (NON CONTRACTILE)
cardioversion definition
shocking the heart back into normal rhythm
DNR definition
Do Not Resuscitate
when the consequences of CPR is greater than the potential benfits
heartblocks definition
abnormal heart rhythm where heart beat too slowly and the electrical signals are blocked between atria / ventricles
STEMI vs NSTEMI
Non-ST-elevation myocardial infarction - partial obstruction of the blood flow
ST-elevation myocardial infarction - sudden complete blockage of the blood flow to heart
ECG STEMI vs NSTEMI
STEMI - ST elevation
NSTEMI - ST depression
MI risk factors
age - atherosclerosis
gender - men
family history
obesity - increase blood cholesterol / blood pressure
diabetes - nerve damage = silent heart attack
Types of heart block (x4)
1st degree
Wenckebach
Mobitz
3rd degree
1st degree heart block
No symptoms
PR interval prolongation
Wenckebach (Mobitz I) heart block
No symptoms Varying PR (progressively prolonged) intervals
Mobitz II heart block
Dizziness
Blocked P wave with constant PR intervals
Third degree heart block
P waves (atrial depolarizations) being completely unrelated to the QRS complexes (ventricular depolarizations) ― meaning the P waves occur at one rate and the QRS complexes at another. Ventricles begin to depolarise themselves
Chest electrode placement
V1 right 4th intercostal space V2 left 4th intercostal space V3 midway between V1/2 V4 5th intercostal space (middle) V5 left auxiliary line (height of V4) V6 left mid auxiliary line
acebutolol
beta blocker
T = high blood pressure / angina / irregular heartbeats
SE = tiredness / stomach upset / vomiting / headache
DT = asthma / adrenal gland tumour / diabetes
ivabradine
sinus node inhibitor (decrease HR)
T = angina / heart failure
SE = blurred vision
DT = kidney or liver probs / pacemaker / recent stroke or MI
atenolol
beta blocker
T= high blood pressure / arrhythmias / angina / post heart attacK
SE= stomach upset / dizziness / cold extermities
DT= asthma / kidney probs / sugar diabetes / psoriasis
verapamil
calcium channel blocker
T - abnormal heart rhythm / high blood pressure / angina
SE = constipation
DT = no grapefruit juice / liver failure / porphyria / hyPOtension / heart failure
nicorandil
potassium channel activator (vasodilation)
T= angina
SE= headaches
DT= low blood pressure / heart attack / pulmonary oedema
low dose aspirin
anti-platelet (secondary prevention)
T = heart attack / angina / stroke / peripheral arterial disease
SE = bleeding in stomach
DT = asthma
statins (atrovastatin / fluvastatin)
enzyme inhibitor (in cholesterol production)
T = high cholesterol / atheroma
SE = headaches / nausea / diarrhoea
DT = liver disease no grapefruit juice
amlodipine
calcium channel blocker
T = high blood pressure / angina
SE = headaches / peripheral oedema / nausea
DT = liver problems
heparin
anticoagulant - prevents further blood clots / stroke
warfarin
anticoagulant - prevents further blood clots / stroke
T = atrial fibrillation
SE = hair loss / blood in stool / diarrhoea / jaundice
DT = hypertension / bacterial endocarditis / stroke / stomach ulcer
(Digoxin) lanoxin
digitalis
T = atrial fibrillation / flutter and heart failure
SE = nausea / rash / blurred or yellow vision
DT = kidney or thyroid problems / asthma
nitroglycerin tablets
vasodilator
T = angina
SE = headache / fast heartbeat
DT = liver/kidney problems / glaucoma / heart attack / anemia
