Caroline's Hypertension Flashcards
What are the side effects of angiotensin receptor blockers?
Hypotension, affects renal function
Which layers of the heart are sensitive and via which nerves?
Parietal and visceral pericardium via phrenic nerves
Which alpha or beta receptors will adrenaline work at?
A1, B1, B2
What is the vertical ridge running from the superior to inferior vena cava in the right atrium?
The crista terminalis
Name a A1 blocker
Prazonin
What do papillary muscles do?
Anchor chordae tendineae to the ventricular wall
What do chordae tendineae do?
Attach to atrio-ventricular cusps to open and close when the papillary muscles contract
What does vasopressin (ADH) do?
Causes water reabsorption in the collecting duct and general vasoconstriction
What is a positive inotrophic effect?
Increasing heart contractility
When are K+ channel agonists used and why?
Only in hypertensive emergency situations as a large and rapid rise in BP can cause damage to kidneys, eyes etc
What are the layers of the heart?
Fibrous pericardium, parietal pericardium, pericardial cavity, visceral pericardium, epicardium, myocardium, endocardium
What is pressure equal to in terms of flow and resistance?
Pressure = flow x resistance therefore blood pressure = CO x TPR
Which substances generally cause vasoconstriction?
Noradrenaline, histamine, angiotensin II, vasopressin (ADH), adrenaline, endothelin, leukotrienes
What does heart sound S1 represent?
Initiation of ventricular systole, closure of AV valves
What is the difference, structurally, between an artery and a vein?
Veins have a thin tunica media with sparse smooth muscle as they are more dilatory than constrictating
Which nerve innervates the baroreceptors in the carotid sinus?
The glossopharyngeal nerve, IX
Name a B1 selective blocker
Atenolol
Which substances generally case vasodilation?
Nitric oxide, histamine, prostaglandins (PGE1 or 2) bradykinin, adenosine and adrenaline
Where is the mitral valve?
Between the left atrium and left ventricle
What would happen if you stimulated an A1 receptor?
Vasoconstriction
What is the moderator band?
The bundle passing from septum to anterior papillary muscle in the right ventricle, part of the heart conducting system
Which second messenger is nitric oxide associated with leading to vasodilation of vascular cells?
cGMP, which opens K+ channels in the cell membrane causing hyperpolarisation of the cell and relaxation as Ca2+ leaves
What are the adverse affects of calcium channel blockers?
Tachycarida, peripheral oedema, headache due to vasodilation in brain, bradycardia, negative inotrophy when non selective.
What is the infundibulum?
Smooth part of the right ventricle often fails to develop properly in foetus leading to a hole in the heart or ventricular septal defect
What is a positive chronotrophic effect?
Increasing the heart rate
Where is the tricuspid valve?
Between the right atrium and ventricle
How does calmodulin initiate smooth muscle contraction?
Calmodulin binds to Ca2+ which activates myosin light chain kinase, phosphorylating myosin to initiating contraction
Why can conduction of the heart not leave the heart and spread to other cells of the body?
The cardiac skeleton is non conductive and prevents this from happening
Which alpha or beta receptors will noradrenaline work at?
A1 and B1
What are the MAP values for head, thorax and feet?
60mmHg in head, 90mmHg in thorax, 180 mmHg in feet
Who are ACE inhibitors used on?
First line treatment for white patients younger than 55
What does heart sound S2 represent?
Closure of semi lunar valve and atrial filling
Name a drug which blocks B1 but stimulates B2 receptors
Pindolol
Where is the SAN?
Upper end of crista terminalis in right atrium, lying superficially
What is the blood supply of the pericardium and where does it arise from?
Pericardiacophrenic and musculophrenic arteries from the internal thoracic arteries
What is cardiac output at rest and during exercise?
6L/min at rest compared to 24L/min during exercise
What defines coronary dominance?
Which vessel, left or right coronary artery, gives supply to the posterior descending (interventricular) artery
Where does the sympathetic input to the heart arise from?
The three cervical ganglia (superior, middle, inferior) and T1-T4
How do nerves reach the heart?
Via the cardiac plexus
What is hypertension?
When systolic and/or diastolic blood pressure exceeds 140/90
What do calcium channel blockers do?
Inhibit arteriole constriction by agonists (e.g. NA or ang II) by blocking voltage gated Ca2+ channels therefore decreasing TPR
Name a B1 and A1 blocker
Carvedilol
How do noradrenaline, nitric oxide and angiotensin II reach the blood, respectively?
NO and ang. II via blood whereas NA is released by sympathetic nerves at the blood vessel
Name a calcium channel antagonist which is vascular selective and one which is non-selective
Vascular selective: amlodipine
Non selective: verapamil
Where can the aortic valve be heard on the skin with a stethoscope?
Medial end of 2nd right intercostal space
What do K+ channel agonists do?
Opens K+ channels in vascular smooth muscle cells causing hyperpolarisation and relaxation
How long is P-R on an ECG?
120 ms
How long is Q-T?
300 ms
When are A1 blockers used?
4th line drug used in combination with others
Which body system contributes most to TPR?
Muscle due to large vascular bed
What does heart sound S4 represent?
Atrial systole, only heard if EDP is increased
What would happen if you stimulated a B1 receptor?
Increased heart rate and contractility.
Where can the mitral valve be heard on the skin with a stethoscope?
5th intercostal space at the mid clavicular line
What is the fossa ovalis?
The remnant of the foramen ovale of the fetus, a pit in the right atrium left from a closed up hole
What is the auricle of the left atrium?
The only thing in the left atrium that disturbs its smooth walled appearance, reflects the invasion of endothelium of pulmonary veins during development
Name a thiazide type diuretic.
Bendroflumethiazide
Where is there a lot of ACE in the body and why is it there?
In the lungs because it is produced on endothelium and the lungs have a lot of endothelium due to need for gas exchange
How do thiazide type diuretics work?
Increased water and sodium excretion by kidneys so decrease blood volume therefore pressure
Which nerve innervates the baroreceptors in the aortic arch?
The vagus nerve, X
Where can the pulmonary valve be heard on the skin with a stethoscope?
Medial end of 2nd left intercostal space
Name an ACE inhibitor
Ramapril
What would happen if you stimulated a B2 receptor?
Bronchodilation, vasoconstriction of skin and diversion of blood flow from skin and viscera to skeletal muscle
What is endothelin?
A vasoconstrictor which antagonises nitric oxide and is produced in the lungs
Name a K+ channel agonist.
Minoxidil
What is pressure naturesis?
Increased pressure in renal artery leading to increased excretion of Na+ and water
When do coronary arteries fill with blood?
During diastole
Name a non-selective B blocker
Propanolol
What are the sinus venarum and musculi pectinati?
The sinus venarum is the smooth wall of the right atrium behind the crista terminalis whereas the musculi pectinati is the muscular, comb like wall in front of the crista terminalis
Where can the tricuspid valve be heard on the skin with a stethoscope?
5th intercostal space either side of the sternum
Where is the heart in terms of surface anatomy?
Upper right border: 3rd costal cartilage
Lower right border: 6th costal cartilage
Upper left border: 2nd intercostal space
Lower left border: 5th intercostal space
The heart reaches the mid clavicular line on the left
How is mean arterial blood pressure (MAP) calculated?
[Diastolic pressure + (systolic-diastolic)] divided by 3
Where does the right coronary artery supply?
The ‘right heart’ myocardium, SAN and AVN
What are A1 blocker side effects?
Postural hypotension, ankle oedema, drowsiness
What is the parasympathetic input to the heart?
Vagus nerve
What do ACE inhibitors do?
Block production of angiotenion II and inhibit bradykinin breakdown
Where does the left coronary artery supply?
The ‘left heart’ myocardium and intra ventricular septum
What are the four layers of an artery?
1) Endothelium
2) Tunica intima (contains elastic lamina)
3) Tunica media (SM cells connected by gap junctions)
4) Tunica adventitia (nerves, blood vessels, fibroblasts)
How does oxidative stress interfere with the ability of blood vessels to dilate?
Reactive oxygen species react with NO preventing it from mediating vasodilatation
What percentage of the general population, and the over 50s have hypertension?
25% of general population and 50% of over 50s
Which blood pressure represents TPR?
Diastolic
What are the adverse affects of ACE inhibitors?
Chronic dry cough, hypotension, affects renal function
What are trabecular carneae?
The highly muscular ridges of myocardium in the ventricles
Name an angiotensin receptor blocker.
Losartan
What could a diastolic murmer indicate?
Stenonis of the AV valves as they are open during diastole
What does heart sound S3 represent?
Opening of AV valves and rapid filling
Who should propanolol not be used on?
Asthmatics as it blocks B2 receptors as well as B1 and blocking B2 causes bronchoconstriction
When are thiazide type diuretics used?
In patients over 55 when calcium channel blockers are not suitable
How is membrane depolarisation initiated in smooth muscle contraction?
Na+ and Ca2+ influx via a G protein coupled receptor gated ion channel. Once the ion concentration reaches threshold Ca2+ voltage gated channels open and Ca2+ floods in adding to depolarisation
What are the side effects of thiazide type diuretics?
Hypokalemia and high plasma cholesterol
What is vascular remodelling?
Where the artery wall gets thicker in response to sustained hypertension, increasing TPR
When are calcium channel blockers used?
First line for black patients of any age, or white patients over 55
Where is the AVN?
Near the atrio-ventricular junction, lying deep
How long is QRS on an ECG?
80 ms
