Cardiovascular disease Flashcards
Frequency of self-reported CV disease in perio pts
20%
85% of referred pts to hospital could have been managed by GDP with more confidence
What could go wrong in CV pts in the dental chair?
Develop chest pain -angina or MI Develop a tachycardia -get palpitations or breathlessness Develop a bradycardia -get dizzy, blackout Develop heart failure -breathlessness, sometimes very acute and very severe Suddenly die -ventricular tachycardia or fibrillation Get endocarditis -don’t worry, they’ll be out of your surgery by then
Questions you should ask when faced with pts with definite/ possible CV disease
Will they tolerate my treatment?
-almost always yes
Will my treatment complicate their condition or treatment?
-very rarely
Will their condition or treatment complicate my treatment?
-often, particularly bleeding risk
Should I tell anyone about them?
-yes, if you uncover cardiac symptoms (chest pains, breathlessness, blackouts, dizziness) or signs (irregular pulse, high/ low BP, swelling)
Consequence of malfunction: myocardium (pump of the heart)
Heart failure
Consequence of malfunction: valves (so blood only goes the way it is supposed to)
Heart failure
Endocarditis
Consequence of malfunction: conduction system (electrical system)
Arrhythmia (tachycardia, bradycardia, sudden death)
Consequence of malfunction: coronary blood supply (the arteries that take blood to your heart, these develop narrowings)
Angina
Myocardial infarction
Heart failure
When the pump isn’t effective it causes heart failure
Conditions that affect efficiency of pump (< cardiac output) cause heart failure
Common causes of heart failure
Previous heart attacks (MI) High BP Genetic causes Drugs (chemotherapy) Idiopathic
Standard assessment of pump function
Transthoracic endocardiography (ultrasound) -dilated with impaired function (cardiomyopathy) Can show what ventricles and valves are like. Right ventricle shown near the top, left ventricle lower with aorta on the right.
Symptoms of heart failure
Breathlessness (> fluid p in lungs) -if it gets worse with less exertion could be a heart problem Swelling (> fluid p in venous system) Dizziness Tiredness Weight loss
Left and right heart failure
< cardiac output increases fluid p in lungs (left heart failure), < venous return to the heart via vena cava (right heart failure) and compensatory responses cause fluid retention and vasoconstriction
Clinical signs of heart failure
Low BP High pulse rate Crepitations in lungs > jugular venous p Pitting ankle oedema/ ascites
When the valves go wrong (reguritant or stenosed) it causes
The same symptoms as heart failure
-aortic stenosis: valve becomes thicker and doesn’t open as it should
Causes of valve disease
Degeneration (i.e. it just happens) Rheumatic fever Congenitally abnormal valve Endocarditis Papillary muscle rupture after MI
Infective endocarditis symptoms
Like a really bad systemic infection -night sweats -fever -rigors -weight loss But with bonus of infected lumps flying around blood stream -causing embolic complications And your heart valves being eaten away -causing valve regurgitation and heart failure
Who is at risk of infective endocarditis
More likely in artificial valves or abnormal valves
Elderly
IV drug abusers
In people with previous endocarditis
Possible infective endocarditis organisms
Large range, usually Streptococcal or staphylococcal
Infective endocarditis causes valve damage and embolisation
Cerebral abscesses Aortic and mitral vegetations -lumps on valves caused by emboli Retinal emboli (Roth spots) Digital emboli -same cause as splinter haemorrhages, Janeway lesions etc. -not that common
Arrhythmia
Proper cardiac function orchestrated by electrical conduction system of heart
Most rhythm abnormalities are too fast or too slow
-tachycardia >100bpm
-bradycardia <60bpm
-both are treated very differently
How are cardiac rhythm and conduction examined?
Electrocardiogram
Usually measured from the surface of the body
More detailed intracardiac ECGs are used in Electrophysiology studies
12-lead ECG
12-Lead ECG
Limb leads I, II, III
Chest leads V1-V6
All leads record the same sequence
-P, QRS, T wave
P wave
Atrial depolarisation
QRS complex
Ventricular depolarisation
T wave
Ventricular repolarisation
Effect of faster heart rate on an ECG
The closer together the QRS complexes, the faster the heart rate
Narrow complex tachycardia ECG
Narrow QRS
Fast rate
Broad complex tachycardia ECG
Wide QRS
Fast rate
Could be associated with fatality unless shocked
Effect of a slower heart rate on an ECG
The further apart the QRS complexes, the slower the heart rate.
Complete heart block ECG
No relationship between P waves and QRS Slow rate -atria and ventricles doing different things -pt dizzy/ blacked out/ not their best -need to be treated to prevent death
Types of tachycardia
Atrial fibrillation Atrial flutter Supraventricular tachycardia (SVT) Ventricular tachycardia Ventricular fibrillation Ectopic beats (not really a tachycardia)
Atrial fibrillation ECG appearance
No P waves, irregular QRS rate
Causes of atrial fibrillation
Hypertension Heart failure Valve disease Alcohol Age Obesity Lung disease Hyperthyroidism
Symptoms of atrial fibrillation
Often asymptomatic
Palpitations
Breathlessness
Dizziness
Atrial fibrillation risk
Increases risk of stroke
Atrial flutter ECG appearance
Rapid abnormal P waves
-often 2 per QRS
Causes of atrial flutter
Hypertension Heart failure Valve disease Alcohol Age Obesity Lung disease Hyperthyroidism (as atrial fibrillation)
Symptoms of atrial flutter
Often asymptomatic Palpitations Breathlessness Dizziness (as atrial fibrillation)
Risk of atrial flutter
Increases risk of stroke
Supraventricular tachycardia (SVT) ECG appearance
Narrow QRS complex tachycardia, often absent P waves
Causes of supraventricular tachycardia
Can probably happen to anyone, few presisposing factors
Can be born with accessory pathway that increases chances
Symptoms of SVT
Mainly palpitations
Risk from SVT
Rarely dangerous but affects QoL
Ventricular tachycardia ECG appearance
Broad QRS tachycardia
Causes of ventricular tachycardia
Anything that can cause heart failure
- drugs (incl. anaesthetics)
- genetic disorders
- idiopathic
Symptoms of ventricular tachycardia
Palpitations
Dizziness
Sudden death/ syncope
Risk from ventricular tachycardia
Dangerous!
Ventricular fibrillation ECG appearance
Coarse fibrillation waves with no organised QRS
Ventricular fibrillation causes
Anything that can cause heart failure -drugs (incl. anaesthetics) -genetic disorders -idiopathic (as ventricular tachycardia)
Symptoms of ventricular fibrillation
Sudden death
Risk from ventricular fibrillation
Lethal if untreated promptly
Ectopic beats ECG appearance
Extra occasional narrow or broad isolated QRS complexes
Causes of ectopic beats
Common in normal people
More common in any heart disease
Symptoms of ectopic beats
Palpitations
Skipped/ missed beats
Risk from ectopic beats
Rarely significant
Types of bradycardia
Sinus bradycardia Slow atrial fibrillation/ flutter 2nd degree heart block Complete (3rd degree) heart block Asystole
Sinus bradycardia ECG appearance
Normal ECG but slow
Slow atrial fibrillation/ flutter ECG appearance
Normal ECG but slow
Sinus bradycardia causes
Drugs
Fitness
Conduction disease
Hypothyroidism
Symptoms of sinus bradycardia
Often asymptomatic
Tiredness
Risk from sinus bradycardia
Little/ none
Slow attrial fibrillation/ flutter causes
Drugs Fitness Conduction disease Hypothyroidism (as atrial fibrillation)
Symptoms of slow atrial fibrillation/ flutter
Tiredness
Dizziness
Breathlessness
Risk from slow atrial fibrillation/ flutter
Increases risk of stroke
2nd degree heart block ECG appearance
Intermittent failure to conduct between P wave and QRS
Causes of 2nd degree heart block
Drugs
Conduction disease (age)
Surgery
Aortic endocarditis
Symptoms of 2nd degree heart block
Often none
Dizziness
Risk from 2nd degree heart block
May worsen to complete heart block
Complete heart block ECG appearance
No relationship between P waves and QRS, slow QRS rate
Complete heart block causes
Drugs
Conduction disease (age)
Surgery
Aortic endocarditis
Symptoms of complete heart block
Tiredness/ dizziness/ breathlessness
Sudden death/ syncope
Risk from complete heart block
Dangerous! Heart can stop at any time
Asystole ECG appearance
Flatline
Causes of asystole
Anything that can cause heart failure; drugs (inc anaesthetics), genetic disorders, idiopathic
Conduction disease
Symptoms of asystole
Sudden death
Risk from asystole
Lethal if untreated promptly
Risk factors for coronary artery disease
Smoking High cholesterol High blood pressure Diabetes Overweight Poor diet Lack of physical activity Other atherosclerotic conditions (stroke, peripheral vascular disease) Family history Genetics Male sex Age
Angina
When coronary artery disease becomes obstructive, this can cause angina
“Plaque/s” that cause angina are stable; a strong fibrous cap protects the blood from exposure to the lipid core of the lesion, preventing thrombosis
Angina symptoms
Recurrent feeling of chest pressure/ heaviness/ pain/ indigestion
Sometimes radiates to arm, neck or back
Rarely lasts more than 10 mins
Precipitation of angina
Exertion or stress
-circumstances where heart needs > blood supply
Rarely is at rest
Is angina dangerous
No but “unstable angina” is a sign of risk and warrants immediate assessment
-could be > frequency, duration, or onset at rest
Myocardial infarction (MI)
Occurs when an atherosclerotic plaque in a coronary artery ruptures, triggering thrombus formation
-causes permanent death of some myocardium (unlike angina)
MI symptoms
Usually causes chest discomfort similar to angina; it is not always severe
MI pain tends to last longer than angina
When can MI occur?
At any time: -at rest -on exertion -while asleep etc. Can be immediately fatal or lead to lifelong heart failure
Investigation and treatment of CV disease
MI –> angina, arrhythmia, heart failure, valve disease
Valve disease –> endocarditis, arrhythmia, hear failure
Heart failure –> arrhythmia, valve disease
Endocarditis –> valve disease, heart failure, arrhythmia
Arrhythmia –> angina, heart failure
How can we tell if someone has coronary artery disease?
Exercise ECG -easy but inaccurate Myocardial perfusion scan -slightly more accurate Angiography -either by CT or invasive angiography -investigation of choice
Treatment of coronary artery disease
Lifestyle modification
Cholesterol lowering (usually statin treatment)
Antiplatelets lowers MI risk (usually aspirin)
Address other risk factors; BP, diabetes
These improve prognosis but do not reduce angina frequency
Lifestyle modification for treatment of coronary artery disease
Stop smoking Take more exercise Eat heart healthy diet -5-6 veg/ fruit per day -low processed food -oily fish -olive oil -nuts/ seeds Lose weight
If CAD is causing angina what treatment would be necessary
Lifestyle modification
Cholesterol lowering (usually statin treatment)
Antiplatelets lowers MI risk (usually aspirin)
Address other risk factors; BP, diabetes
these improve prognosis but not angina frequency
No need to treat further if not bothersome
Medication to < angina attacks
If medication not working/ side effects; stenting or coronary artery bypass grafting
these improve angina but do not improve prognosis
Is it MI? Or is it trapped wind?
Two key investigations: ECG and serum troponin measurement
- if ECG shows ST elevation it is an ST elevation MI
- if ECG is normal or shows other changes it may be a non-ST elevation MI (NSTEMI), or trapped wind
- in both STEMI and NSTEMI serum troponin will be raised, but may take some hours to rise, so often treat as MI until results known
What changes in an ECG could indicate an NSTEMI
Normal
ST depression
T wave inversion
Management of STEMI and NSTEMI
Immediate dual antiplatelet therapy and pain relief
-paramedics usually give the aspirin and opiates
-oxygen should be avoided and nitrates are useless for MI
Anticoagulation for 24-72 hours
Both should have angiography and if possible stenting
-STEMI immediately
-NSTEMI within 72 hours or sooner if complications
Secondary prevention
Cardiac rehabilitation
Immediate dual antiplatelet therapy (DAPT)
Aspirin plus Ticagrelor, Prasugrel or Clopidogrel
Anticoagulation for 24-72 hours
Heparin
Fondapariux or similar
Secondary prevention of STEMI and NSTEMI
DAPT for a year then Aspirin alone Statin Betablocker for a year ACE inhibitor Treatment of any complication (heart failure, arrhythmia, etc)
Cardiac rehabilitation
Exercise
Education
Diet
Smoking cessation
Investigation of heart failure
Mainstay is transthoracic echocardiography (ultrasound) to detect ventricular impairment
Also newer test for elevated serum B-type Natriuretic Peptide (BNP)
-goes up if you have heart failure
Other tests include cardiac MR
Treatment of heart failure
Predominantly medical (drugs) -ACE inhibitors -betablockers -aldosterone antagonists (spironolactone or eplerenone) -diuretics -ivabradine Correction of other causes -anaemia -thyroid dysfunction Management of complications (arrhythmia) Some heart failure pts benefit from cardiac resynchronisation therapy (CRT - special form of pacemaker)
Investigation of valve disease
Diagnosis usually by transthoracic echocardiography (ultrasound)
Transoesophageal echocardiography gives better images particularly of mitral valve but is not pleasant for pt
Treatment of symptomatic (usually breathlessness) valve disease
Valve surgery probably appropriate
-done by cardiothoracic surgeon, not cardiologist
Valve can be replaced with metallic prosthesis, biological prosthesis (tissue from animal or human donor) which requires open heart surgery
For aortic stenosis we now sometimes use TAVI (transcatheter aortic valve implantation)
Metallic valves warning
Require lifelong warfarin, and this can only be stopped if bridged with Heparin. (Anticoagulation for e.g. AF can often be stopped without bridging Heparin).
- bleeding disorder for the rest of their life
- affects childbirth, child at risk of developmental disorders
- dental surgery/ chemotherapy not possible
Investigation of arrhythmias
Diagnosis made by ECG at time of symptoms
-easier said than done - often needs multiple 24hr recordings, home recorders, smartphone apps or implanted loop recorder
Other investigations look for causes
-echo for heart failure, valve disease
-angio for CAD
-family screening/ testing for genetic conditions
Treatment of arrhythmias
Vary according to specific type of arrhythmia
Treatment of atrial fibrillation
Slow rate with beta blockers, digoxin, or calcium channel blockers
Anticoagulate with warfarin or NOAC if high stroke risk
-calculate CHADS2-VASc score
Atrial flutter treatment
Sam as AF:
Slow rate with beta blockers, digoxin, or calcium channel blockers
Anticoagulate with warfarin or NOAC if high stroke risk
-calculate CHADS2-VASc score
Supraventricular tachycardia (SVT) treatment
Attacks can be terminated by vagal manoeuvers, iv Adenosine, DC Cardioversion (electric shock)
Recurrent attacks can be < by regular anti-arrythmic drugs
-betablockers
-Flecainide
-Amiodarone etc.
Can usually be cured by invasive ablation, requires Electrophysiological study
Ventricular tachycardia treatment
Usually requires immediate DC Cardioversion (shock)
Recurrence prevented by regular anti-arrythmic drugs
-betablockers
-Amiodarone. Common to require Implantable Cardioverter Defibrillator unless having acute MI
Ventricular fibrillation treatment
Always requires immediate DC Cardioversion (shock)
Recurrence prevented by regular anti-arrythmic drugs
-betablockers
-Amiodarone Common to require Implantable Cardioverter Defibrillator unless having acute MI
Ectopic beats treatment
Reassurance
Sometimes betablockers
Very rarely ablation
Treatment of bradyarrhythmia
Pacemaker insertion
Devices
Dual Chamber Pacemaker
Implantable Cardioconverter/ Defibrillator
Cardiac Resynchronisation Therapy (CRT)
Dual Chamber Pacemaker
Treats bradyarrhythmia
Does nothing for tachycardia or VF
Implantable Cardioverter/ defibrillator
Treats ventricular tachycardia or VF
Can also pace bradycardias
Cardiac Resynchronisation Terhapy (CRT)
Treats heart failure
Can also pace bradycardia (CRT-P)
CRT-D also has ICD
When should you defer treatment?
Urgent tx rarely warrants deferral; risk of deterioration theoretical in almost all situations
Stable angina not a reason to defer tx
-but > pain/ pain at rest may well be
Stable heart failure (breathless on exertion but can lie flat at night, is on tx) not a reason to defer
-but > breathlessness and/ or oedema may be
Recent MI (within 6 weeks)
-defer until 3-6 months post MI, longer if possible
Frequent attacks of disabling tachycardia
If pts awaiting stents / bypass / valve surgery but are stable, then can proceed with tx
Adrenaline, locals and heart problems
Risk very low Risk arises from systemic administration Could immediately give nitrates to lower BP and reduce possible angina pain MI? Get help
High frequency descaler/ apex locator and pacemakers
High magnetic fields can inactivate/ interfere with function
Need to talk to cardiologist/ pacemaker clinic at local hospital
-write to them or phone them
