Cardiovascular Flashcards
What is normal heart rate?
60-100 bpm
What is the dominant pacemaker of the heart?
SA node
What is the intrinsic rate of the AV node?
40-60bpm
What is the impulse conduction pathway?
Sinoatrial node → AV node → Bundle of His → Bundle branches →
Purkinje fibres
How long is the average AV node delay?
0.12-0.2 S
How long is the average atrial depolarisation?
0.08-0.1 s
How long is the average ventricular depolarisation?
0.06-0.1S
On an ECG, which is the only lead to not show a P wave?
aVR
What does the P wave signify?
Atrial depolarisation
What does the PR interval signify?
Time taken for the atria to depolarise, and electrical activation to get through the AV node
What does the QRS complex signify?
Ventricular depolarisation
What does the ST segment signify?
The interval between depolarisation and repolarisation
What does the T wave signfiy?
Ventricular repolarisation
What is tachycardia?
Increased heart rate
What is bradycardia?
Decreased heart rate
What is dextrocardia?
The heart on the right side of the chest instead of the left
How many seconds is one small box on an ECG?
0.04s
How many mV is a large box on an ECG?
0.5mV
Where is the left ventricle palpated?
5th Intercostal space and mid-clavicular line
What is stroke vol?
The volume of blood ejected from each ventricle during systole
What is cardiac output?
The volume of blood each ventricle pumps as a function of time
How is cardiac output calculated?
Stroke volume (L) x Heart rate (BPM)
What is total peripheral resistance?
The total resistance to flow in systemic blood vessels from beginning of aorta to vena cava - arterioles provide the most resistance
What is preload?
The volume of blood in the left ventricle which stretches the cardiac myocytes before left ventricular contraction - how much blood is in the ventricles before it pumps
What is afterload?
the pressure the left ventricle must overcome to eject blood during contraction
What is contractility?
Force of contraction and the change in fibre length
What is elasticity?
Myocardial ability to recover normal shape after systolic stress
What is diastolic dispensibility?
The pressure required to fill the ventricle to the same diastolic volume
What is compliance?
How easily the heart chamber expands when filled with blood volume
What is Starlings law?
Force of contrition is proportional to the end diastolic length of cardiac muscle fibre - the more ventricle fills the harder it contracts
What is S1?
Mitral and tricuspid valve closure
What is S2?
Aortic and pulmonary valve closure
What is S3?
In early diastole during rapid ventricular filling, normal in children and pregnant women, associated with mitral regurgitation and heart failure
What is S4?
‘Gallop’, in late diastole, produced by blood being forced into a stiff hypertrophic ventricle - associated with left ventricular hypertrophy
What does renin do?
Convert angiotensinogen to angiotensin I
What does ACE do?
Convert angiotensin I to angiotensin II
Where is renin released from?
The kidney’s juxtaglomerulus apparatus in response to a low blood pressure
What are the actions of angiotensin II?
- Causes post pituitary to release ADH
- Vasoconstriction of vessels
- Adrenal release of aldosterone
- Tubular Na+, Cl- reabsorption, and K+ excretion
- Increased sympathetic activity
What is the result of atrial stretch receptors being activated?
Increased ANP synthesis
What percentage of live births have a cardiac defect?
1%
What are the 4 features of tetralogy of fallot?
- Ventricular septal defect
- Pulmonary stenosis
- Hypertrophy of right ventricle
- Overriding aorta
How is Tetralogy of Fallot usually treated?
Compete repair at 3-6 months of age
Name 3 clinical features needed for diagnosis of typical stable angina
- Chest pain that radiates
- Relieved with rest or GTN spray
- Provoked by physical exertion
QRISK is a cardiovascular disease risk predictor used by GPs. Give 3 modifiable and 3 nonmodifiable risk factors for cardiovascular disease that are asked for in a QRISK calculation.
- Modifiable: Smoking, Diabetes, Cholesterol/HDL ratio, Blood Pressure, BMI
- Non-Modifiable: Age, Gender, Ethnicity, Angina/MI 1st degree relative, Diagnosis of: AF, RA, SLE, ED, Sever mental illness,
Give an example of an ACEi and a side effect of this drug?
Example: Ramipril, Lisinopril, Enalapril
SE: Dry Cough, Hyperkalaemia, Fatigue, Headache
Patient arrives to hospital with a suspected MI. ECG shows ST elevation. What would you expect to see on the ECG over the next few hours and the next few days?
- Hours= Tall T waves, ST Elevation.
- Days= T inversion, Pathological Q waves
What are the 3 cardinal symptoms of heart failure?
- Shortness of breath
- Fatigue
- Peripheral oedema
You suspect that a patient has heart failure and perform a chest x-ray. Name 3 signs that would be visible in a patient with heart failure? Clue- ABCDE
- Alveolar oedema (bat wings)
- Kerley B lines (interstitial oedema),
- Cardiomegaly,
- Dilated Prominent Upper Lobe Vessels,
- Pleural Effusion
Name 2 of the 4 features of Tetralogy of Fallot.
- A large, misaligned ventricular septal defect
- An overriding aorta
- Right ventricular outflow tract obstruction
- Right ventricular hypertrophy
What condition is characterised with a concave-upwards (saddle-shaped) ST elevation on ECG?
Pericarditis
What would be the first-line treatment for a 49-year-old Caribbean male with a BP of 148/96?
Calcium channel blocker (E.G. amlidopine)
What is the most likely diagnosis of a patient with the following ECG findings? ECG: F waves, no P waves, QRS irregularly irregular?
Atrial Fibrillation
Name 2 clinical features of aortic dissection
- Sudden ‘tearing’ chest pain +/- radiates to back
- Unequal arm pulses and BP
- Acute limb ischaemia
- Paraplegia
- Anuria
What are the four stages of chronic limb ischaemia?
- Stage I: asymptomatic
- Stage II: intermittent claudication
- Stage III: rest pain/nocturnal pain
- Stage IV: necrosis/gangrene
Give 2 causes of secondary hypertension?
Renal Disease e.g CKD, renal artery stenosis, polycystic kidney disease, Cushing’s, Conn’s, Phaeochromocytoma, Coarctation of aorta, Pregnancy, COCP
There are several types or categories of shock, circulatory failure that leads to inadequate organ perfusion, give 3 examples.
Anaphylactic, Cardiogenic, Septic, Haemorrhagic, Neurogenic
Give 2 complications of an aneurysms?
Rupture, Thrombosis, Embolism, Excess pressure on other structures
Describe the electrical pathway/components needed for cardiac contraction.
The sinoatrial node is the pacemaker of the normal heart and is located in the atrium. The SA node signals contraction of the atrium, this signal is passed on to the atrioventricular (AV) node which then passes the signal to the bundle of his and purkinje fibers in the ventricle resulting in contraction of the ventricle.
What is the most common congenital heart defect and describe how it affects cardiac blood flow
Ventricular septal defect (VSD). It is an opening in the wall or septum which separates the right and left ventricle. This hole results in what is called a left to right shunt which means that oxygenated blood from the left ventricle is passed to the right ventricle.
What is the underlying pathophysiology that causes angina and what symptoms do patients with stable angina exhibit?
Coronary artery disease (atherosclerosis) is a build-up of plaques or lesions within the coronary arteries that are fibrous and lipid rich. These plaques cause narrowing of the arterial lumen which results in reduced blood flow.
Stable angina is defined as chest pain (usually described as central or left sided pain radiating down the left arm or to the jaw or abdomen) that occurs on exertion and resolves with rest.
What is the underpinning cause of the significant differences in cardiovascular disease risk between the Sheffield areas of Ranmoor and Netherthorpe?
Social deprivation, health inequality (inequity). Loneliness and social isolation have been linked with higher rates of CVD. Higher percentage of smokers in lower socioeconomic groups. Depression and anxiety linked with higher CVD risk.
Name four risk factors for cardiovascular disease
- Smoking
- Obesity
- high cholesterol
- hypertension
- diabetes
- psychosocial status
- poor diet
- “Stress”
A 55 year old male presents to the Emergency Department with crushing central chest pain. His ECG done in the ambulance shows inferior ST elevations. What is the most important intervention for him?
Percutaneous coronary intervention (PCI) or angiogram. This is when the coronary arteries are visualised using a dye to identify areas of obstruction or reduced blood flow which can be stented open.
In what other conditions besides myocardial infarction does a patient have increased risk of when diagnosed with artherosclerosis?
- Ischaemic stroke or cerebrovascular accident (CVA)
- Critical limb ischaemia
- Sudden cardiovascular death
What medications do we give when treating acute coronary syndrome (ACS)?
- Aspirin (Anti-platelet)
- Fondaparinux (Low Molecular Weight Heparin)
- A statin (lowers cholesterol)
- Beta blocker (Decreased oxygen demand due to the reductions in heart rate, blood pressure, and contractility)
- Morphine (Pain management)
- GTN (Opens coronary arteries improving blood flow)
What risk factors must you consider when assessing a patient for possible PE or DVT and what risk assessment scoring system do we use?
- Recent surgery or immobility
- long haul flight or long car ride
- cancer
- oral contraceptive pill
- hormone replacement therapy
- pregnancy
- inherited thrombophilia
Wells Score
What is the most helpful investigation to identify valvular heart disease?
Echocardiogram
What are the two most common causes of acute pericarditis and what features are needed to make a diagnosis?
Viral infection and autoimmune disease
Diagnosis is based on two of the following:
• chest pain (sharp and pleuritic
• relieved with sitting forward and worse with lying down)
• ECG changes (diffuse sawtooth ST elevation)
• friction rub on examination (pathppneumonic - “crunching snow”)
• pericardial effusion
What medications do we use to help relieve the symptoms of heart failure?
Shortness of breath and peripheral oedema are common symptoms so diuretics are a mainstay of symptom relief. Furosemide and bumetanide are used initially and spironolactone can be added in if required.
What features on physical examination are suggestive of infective endocarditis?
- Splinter haemorrhages
- Osler Nodes
- Janeway lesions
- Roth spots
- Murmer
- Petechiae
What are splinter haemorrhages?
fine, thread-like, blood clots appearing vertically in the bed of the fingernail
What are Osler’s Nodes?
Small, tender, purple subcutaneous lesions on the pulp of the finger tips
What are Janeway lesions?
Erythematous, macular, nontender lesions on the fingers, palms and/or soles of the feet
What are Roth spots?
Retinal haemorrhages with white or pale centers seen on fundoscopy
What is Wells score used for?
Assessment of risk for DVT or pulmonary embolism
What is the QRISK score used for?
Risk of developing cardiovascular disease in the next 10 years
What is the most common arrythmia?
Atrial Fibrillation
What are the major 3 causes of heart failure?
- Ischaemic heart disease
- Dilated cardiomyopathy
- Hypertension
