W12 57 cardiology for dentists Flashcards
What do heart diseases affect?
Heart blood supply, muscles, valves
What are some common signs and symptoms of heart diseases?
Chest pain - SOCRATES, common in ischaemic heart disease but can be unspecific
Dyspnoea - exertional, orthopnoea, paraoxysmal nocturnal dyspnoea
Palpitation - arrhythmia eg atrial flutter, AF
Oedema - eg heart failure
Clubbing - eg infective endocarditis
Syncope - eg heart block, AF
What is orthopnoea?
Shortness of breath upon lying flat
What is paroxysmal nocturnal dyspnoea?
Short breath while sleeping
What is dyspnoea?
Shortness of breath
What is clubbing?
Ask pt to put fingers together, if you see a diamond then no clubbing. Big nail beds = clubbing. Clubbing is also seen in lung diseases, lung cancers or liver diseases.
What is syncope?
When the heart does not supply enough blood to the brain
What is a P wave in an ECG? (PG402)
P wave represents depolarisation of the atria. Atrial depolarisation spreads from the SA node towards the AV node, and from the right atrium to the left atrium.
What is the PR interval in an ECG? (PG402)
PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. This interval reflects the time the electrical impulse takes to travel from the SA node through the AVN.
What is the QRS complex in an ECG? (PG402)
The QRS complex represents the rapid depolarisation of the right and left ventricles. The ventricles have a large muscle mass compared to the atria, so the QRS complex usually has a much larger amplitude than the P wave.
What is the ST segment in an ECG? (PG402)
The ST segment connects the QRS complex and the T wave; it represents the period when the ventricles are depolarised.
What is a T wave in an ECG? (PG402)
The T wave represents the repolarisation of the ventricles.
Briefly how does an electrical impulse move through the heart?
Activity starts from the SAN and spreads to the atrium to form the P wave
From the atrium down to whole ventricles through Bundle of His forms the QRS complex
When ventricular depolarisation happens that forms the T wave
What is the 12 lead ECG? (PG403)
10 electrodes, 4 on limbs and 6 on chest wall
Forms 12 different circuits
What other heart investigations can be done?
Chest x-ray
Echocardiography
24hr ambulatory taped ECG
CT/CT angiogram - to assess vessels in heart
Cardiovascular magnetic resonance - to assess vessels in heart
Exercise ECG - when or has chest pain on exertion
What will chest x-ray show in heart failure and what can it rule out?
Patients with heart failure you’ll see a big heart in chest x-ray, normally more than 50% the length of the diaphragm.
Can help rule out pneumonia - will see white patches (consoligations) in lung fields
What is an echocardiograph and what is it good for?
Ultrasound scan of blood flow in the heart
Useful for patients with vulval disease such as aortic or mitral regurgitations
When might you use a 24hr ambulatory taped ECG?
Useful when you think pt has atrial fibrillation or any irregular heartbeats but unable to capture this in 1 time 12 lead ECG. Measure over 24hrs and forms a report.
What can you see on a 12 lead ECG that you can’t see on a single ECG?
Single lead ECG can tell you if you are in atrial fibrillation but not if you are in MI
What is ischaemic heart disease?
An imbalance between the supply of oxygen to cardiac muscle and myocardial demand
What are some causes of ischaemic heart disease?
Ischaemia - coronary artery atheroma leading to a fixed obstruction of blood flow or coronary artery thrombosis/spasm/arteritis
Increase oxygen demand - thyrotoxicosis, myocardial hypertrophy (eg from aortic stenosis or hypertension)
What is thyrotoxicosis?
Thyroid gland releases too much thyroid hormone increasing metabolic rate of the heart
What are the risk factors for ischaemic heart disease?
Hyperlipidaemia
Smoking
Hypertension
Metabolic factors - eg uncontrolled diabetes
Lifestyle: diet, exercise, alcohol
What would pain history be if angina was occurring?
Central chest, sudden onset, sharp pain, radiates to left arm and jaw, associations are sweat syncope and shortness of breath, worse with stress and exercise but GTN spray helped, pain score 10/10
Angina is a medical emergency! What would you do?
A-E approach - airway breathing circulation disability exposure
15L oxygen through a non-rebreathable mask if shortness of breath
GTN spray 1-2 activations, sublingually (will help relieve pain and improve blood supply to heart)
Dispersible Aspirin 300mg to chew
What happens if the pt does not respond to your angina treatment?
They are in MI, call 999
What investigations are done after angina turns into MI in secondary care?
ECG
Blood test - cardiac markers: troponin I or T - these elevate when there are ischaemic heart events that cause cardiac muscle damage
Coronary angiography - identify the presence and location of coronary artery vascular blockage
What is unstable angina?
Myocardial ischaemic at rest or in minimal exertion in the absence of acute cardiomyocyte injury/necrosis.
Prolonged (>20mins) angina at rest
New onset of severe angina
Angina that is increasing in frequency, longer in duration, or lower in threshold
Angina that occurs after a recent episode of myocardial infarction
What is myocardial infarction?
Necrosis of myocardial tissue following occlusion of a coronary artery and subsequent ischaemia
What are the 2 types of MI (depending on the ECG changes)?
ST-segment elevation myocardial infarction (STEMI) - complete and persisting blockage of the artery
Non-ST-segment elevation myocardial infarction (NSTEMI) - partial or intermittent blockage of the artery
How is the diagnosis of NSTEMI made?
A combination of: clinical history, abnormal troponins, the absence of ST-elevation on ECG
In patients with STEMI you see an ST elevation. What might be seen in NSTEMI? (PG406 WAVES!)
In NSTEMI you might see depressant of T wave inversion.
The ST wave is differential between STEMI a and NSTEMI, but what things definitely indicate an MI?
Positive history and abnormal troponins
What is the management of MI?
Percutaneous coronary intervention
Coronary artery bypass grafting
Medical treatment
Statins (meds to prevent future heart attacks)
What medical treatment is given to manage MI?
Antiplatelets - eg aspirin, clopidogrel
Anticoagulation - heparin/low-molecular weight heparin in hospital eg DOACs like apixaban, rivaroxaban. Warfarin.
Antianginals - nitrate, beta blocker, calcium channel blockers
What are complications of MI?
Acute heart failure
Chronic heart failure
Post-infarction angina
Stroke
Depression
Dressler’s syndrome (post MI periocarditis, inflammation response in heart)
Sudden death
What should be checked in dental practice about a patient with history of MI?
If they’re on their usual treatment, e.g. GTN spray
Risk of bleeding (from anticoagulation/antiplatelets)
Managing potential triggers eg dental anxiety, pain
If prolonged chest pain or unwell, consider MI and call 999
What is heart failure?
Unable to function as a pump and maintain cardiac output to meet the demands of the body
What are the main causes of heart failure?
Ischaemic heart disease
Cardiomyopathy (dilated) - heart chamber esp ventricles are bigger than before so does not pump properly
Hypertension - resistance too high so does not function properly.
What are some other causes of heart failure?
Cardiomyopathy (hypertrophic, restrictive)
Valvular heart disease - regurgitation or stenosis in heart, affecting blood flow
Congenital heart disease (atrial or ventricular septal defect)
What is the difference between hypertrophic and restrictive cardiomyopathy?
Hypertrophic = heart walls too thick so heart has less capacity to contract
Restrictive = heart muscles are too rigid to contract
What are the clinical symptoms of heart failure?
Exertional dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnea
Fatigue
What are the clinical signs of heart failure?
Cardiomegaly - big heart on chest x ray
Tachycardia
Hypotension
Ankle oedema
Ascites and tender hepatomegaly
How do you diagnose heart failure?
Clinical signs and symptoms
Measure N-terminal pro-B-type natriuretic peptide level - a protein produced when cardiac muscle is damaged due to heart failure
Arrange a 12-lead ECG to assess conductivity
Other testing eg chest x ray, blood tests, urine dipstick, lung function test. Assess for underlying causes.
What lifestyle changes can be made to manage heart failure?
Smoking, alcohol, exercise, dietary
What medication can be taken to manage heart failure?
A loop diuretic eg furosemide - symptoms of fluid overload
ACE inhibitor and a beta blocker - vasodilator therapy
Consider antiplatelets for atherosclerotic arterial disease, and statins
What non-pharmacological things can manage heart failure?
Revascularisation, cardiac resynchronisation therapy, implantable cardioverterdefibrillator heart transplant
What are some complications of heart failure?
Cardiac arrhythmias - AF
Depression
Cachexia (wasting)
Anaemia
Kidney - chronic kidney disease and acute kidney injury (either due to low perfusion state or meds to treat HF)
Sexual dysfunction
Sudden death
What is end-stage heart failure?
Symptoms at rest and exacerbated by any physical activities
What might you consider for heart failure patients in dental practice?
Unlikely to impact treatment in a stable patient
Avoid prolonged periods of lying flat
Might need to refer for secondary care for unstable patients
What is hypertension?
Systolic BP >=140mmHg and/or diastolic BP >=90mmHg
(140/90)
What are the conditions to measure hypertension?
At least 2 readings on separate occasions
Alternatively a 24hr ambulatory BP measurement average of >=130/80mmHg or a home BP measurement average of >=135/85mmHg
What is white-coat syndrome?
When BP is higher in front of doctors due to nervousness
What is the difference between primary and secondary hypertension?
Most patients have no underlying causes = primary hypertension
Due to another disease = secondary hypertension
What is the aetiology of primary hypertension (no underlying causes)?
Genetic
Lower birth weight
Obesity
Lifestyle:excess alcohol intake, high salt diet
Metabolic syndrome
What are some aetiological causes of secondary hypertension?
Renal disease
Endocrine disease (eg hyperthyroidism, increased metabolic rate so raised BP)
Pre-eclampsia in pregnancy - will affect baby and mum, raised BP can cause seizure
Medications eg steroids, NSAIDs, etc
What are the symptoms of hypertension?
Mainly asymptomatic
But when there’s a sudden spike in BP, some uncommon ones: headache, visual changes, dyspnoea, chest pain, sensory or motor deficit
What are the lifestyle management options for hypertension?
Reduce the risk - avoid smoking, reduce alcohol intake, healthy diet and increase daily exercise
What is the medication management for hypertension?
ABCD:
A - ACE inhibitor or ARB
B - beta-blockers (also lower HR)
C - calcium channel blockers (eg amlodipine)
D - diuretics (like thiazides)
How does uncontrolled hypertension affect dentistry?
Bleeding risk - eg after invasive procedures
Pain and anxiety can cause hypertension - so adequate pain relief and LA are important
What can calcium channel blockers cause in dent?
Gingival hyperplasia (rare). Can cause periodontal disease and bone loss. Usually will resolve after stopping meds.
What is arrhythmia?
Irregular heartbeat, eg bradycardia, tachycardia
What is bradycardia?
Heart rate is slow <60/min
What is sinus bradycardia?
Sinus means the electric signal passing through the heart is generated by the sinus node SAN and spread down the AVN. On ECG, P wave is seen before each QRS complex = sinus rhythm.
Sinus bradycardia is seen in young fit adults who exercise a lot etc, people with good cardiac strength.
What is tachycardia?
Heart rate is fast >100/min
What is sinus tachycardia?
Common in people exercising, or stress, causing natural increase of HR.
What are the different types of arrhythmia?
Sinus arrhythmias
Atrial myocardium (muscle)
Heart blocks
Ectopic beats
Ventricular myocardium (muscle)
What are sinus arrhythmias?
Normal variation, quicker during inspiration and slower during expiration
What is atrial myocardium?
Atrial fibrillation (AF) or atrial flutter
(Actual signals in the atria causing turbulent flow down the heart can increase risk of stroke)
What are heart blocks?
When there is a problem between SAN and AVN and AVN down to ventricles/Bundle of His, patient can have heart blocks of ectopic beats.
In heart blocks the SAN sends a signal down to the AVN. Due to the Bundle of His problem, the VTE file signal might not contract in the right pace or might miss a beat. Easy syncope episodes.
What is ventricular myocardium?
Ventricular tachycardia
Ventricular fibrillation (VF) - extremely dangerous because the ventricles contract in a different pace compared to the entire heart, so reduced CO resulting in cardiac arrest.
How are arrhythmias shown on an ECG? (PG411 ECG!)
Just go to pg411 and look and read
What is atrial fibrillation?
The most common arrhythmia. AV node conducts a proportion of the atrial impulses to produce an irregular ventricular response. An irregularly irregular pace. Increases embolism of a thrombus in atrium and stroke risk.
What is the management of AF?
Stroke and thrombus prevention
Control the rate of AF (when clinically unwell)
Control rhythm in younger patients
How do you prevent stroke and thrombus?
Antiplatelets and anticoagulants
How do we control rate of AF?
Beta blockers (Bisoprolol) or calcium antagonists (verapamil, diltiazem)
Digoxin - to increase force of contraction and reduce conductivity within the AVN
How do we control heart rhythm (in pt younger than 65)?
Anti-arrhythmics - eg amiodarone
Cardioversion-p - synchronised DC shock
Ablation to atrial muscle
What do you do in dental practice if there is a procedure with a high bleeding risk?
Haemostatic measures - dressing and sutures
When can you do invasive procedures in patients taking warfarin?
If over 3.5 don’t do invasive procedures.
In emergency situations where treatment is needed and INR is >4, will use vitamin K intravenous infusions to reverse the warfarin effects.
What’s the half life of DOACs?
Anticoagulants - around 12hr half life
Should you worry about aspirin for dental procedures?
Aspirin has effect as long as the platelet life (usually 7-10days)
For small dental extractions don’t need to worry about aspirin. For large operations, patient will need to stop aspirin.
Do you bleed if you have LA with adrenaline?
LA with adrenaline may mask the bleeding temporarily through vasoconstriction. Mainly try and use dressing and sutures to stop the bleeding.
What drug interactions are there with anticoagulants?
NSAIDs and DOAC - avoid ibuprofens for pain relief
Warfarin and metronidazole/miconazole/fluconazole - increased bleeding risk.
What 4 different cardiac arrhythmias can cause cardiac arrest? (Pg413 ECG)
Ventricular tachycardia (VT)
Ventricular fibrillation (VF)
Pulseless electrical activity (PEA)
Asystole
How do you manage resuscitation in the dental practice?
Unresponsive and not breathing normally
Call 999 and ask for an ambulance
30 chest compressions
2 rescue breaths
Continue CPR 30:2
As soon as AED arrives, switch it on and follow instructions
How do pacemakers interact in the dental practice?
Ultrasonic dental scaler associated electromagnetic fields may interrupt pacemakers
When do people have pacemakers?
Indicated in heart block or conditions that affects sinoatrial node causing bradycardia and tachycardia
What are the types of valvular heart disease?
Incompetent (regurgitant) = failure to close completely
Stenotic = failure to open completely
Or both
What are the most common valves affected by valvular heart disease?
Acquired left sided valvular lesions
Eg aortic stenosis/regurgitation or mitral stenosis/regurgitation
What heart valves are there?
PG415 IMG LOOK AT PLS
RHS - tricuspid, pulmonary
LHS - mitral (bicuspid), aortic
What are the causes of valvular heart disease?
Rheumatic fever - affecting all 3 heart layers
Infective endocarditis
Degeneration and calcification
Pulmonary hypertension
Congenital
What is the management for valvular heart disease?
Treat the cause and manage the disease conservatively if mild and asymptomatic
Medical - treat the complications
Surgical - eg valve replacement
Long-term anticoagulation - warfarin for prosthetic mechanical valves (not required if bioprosthetic valves are used)
Are patients with valvular heart disease affected by dental treatment?
Shouldn’t be
Assess risk of developing infective endocarditis (eg in patients with mechanical valves)
Assess the bleeding risk
What is infective endocarditis?
An infection involving the endocardial surface of the heart, including valvular structures, the chordae tendinae, sites of septal defects, or the mural endocardium.
What is the presentation of infective endocarditis?
Presents non-specifically, most commonly with fever and symptoms/signs of embolism.
What are the causes of infective endocarditis?
Native valve endocarditis in the absence of intravenous drug
IVDUs often present with right sided valvular involvement (S aureus!)
Prosthetic valve endocarditis (often by Staph epidermidis)
What cardiac conditions have increased risk of developing infective endocarditis according to NICE?
Acquired valvular heart disease with stenosis or regurgitation
Hypertrophic cardiomyopathy
Previous infective endocarditis
Structural congenital heart disease
Valve replacement
What advise should you give to patients on antibiotic prophylaxis according to NICE?
Explain benefits and risks and why it’s not routinely recommended anymore
Importance of maintaining good oral health
Symptoms that may indicate infective endocarditis and when to seek expert advice
Risks of invasive procedures including non-medical ones
Prophylaxis against IE
Should you give antibiotic prophylaxis?
Not routinely recommended for people undergoing dental procedures.
Chlorhexidine mouthwash should not be offered as prophylaxis to people at risk of IE
Check with cardiologist
