Cardiovascular diseases Flashcards
1. Overview of the cardiovascular system 2. Knowledge of the pathogenesis of: - hypertension - atherosclerosis - angine - myocardial infarction - infective endocarditis - heart failure 3. Knowledge of their clinical features and management 4. Knowledge of the relevance to dental care and management of patients 5. Recognise and carry out emergency management of cardiac emergencies including angina, MI, cardiac arrest in dental care
What is cardiovascular disease
Disease of the heart and circulation
Incidence is increasing due to higher prevalence of obesity
What is hypertension
Sustained elevation of resting systolic and diastolic BP; >140/90mmHg and this can be primary or secondary
What is primary hypertension
Most common type due to multiple factors including hereditary; environment plays a factor in genetically susceptible people
What is secondary hypertension
It is less common and associated with renal and endocrine diseases
What renal diseases are associated with secondary hypertension
- renal parenchymal disease (chronic glomerulonephritis, pyelonephritis, polycystic renal disease and post transplant)
- renovascular diseases
What endocrine diseases are associated with secondary hypertension
- hyperaldosteronism
- pheochromocytoma
- cushings syndrome
- congenital adrenal hyperplasia
- hyperthyroidism
What can cause secondary hypertension
- Contraction of the aorta (stricture)
- Excessive alcohol intake
- Drugs; oral contraceptives, sympathomimetics, NSAIDs, corticosteroids, cocaine
Outline the clinical features of hypertension
- Asymptomatic until developed in cardiovascular system, brain and kidneys
- Dizziness, facial flushing, headache, fatigue, epistaxis, nervousness, retinal changes
What can severe/prolonged hypertension increase the risk of
- Coronary artery disease or myocardial infarction
- Heart failure
- Stroke (haemorrhagic)
- Renal failure
- Death
Outline the complications that can occur with hypertension
- Generalised arteriosclerosis (arterioles in eye and kidney)
- Reduced kidney lumen increased total peripheral resistance
- Increased after load causing left ventricular hypertrophy and dilated cardiomyopathy leading to heart failure
- Thoracic aortic dissection (layers of aorta become torn)
- Abdominal aortic aneurysms
What is an abdominal aortic aneurysm
When the aorta bulges out and so stagnant blood will collect leading to instant death
What special investigations are taken for hypertension
Multiple BP readings using a sphygmomanometer
- ambulatory BP monitoring needed if higher than 140/90mmHg (14 readings over 24hrs to ensure it is not caused by white coat syndrome)
- urinalysis and urinary albumin/creatine ratio
- blood tests; fasting glucose, lipid profile, creatine, potassium, sodium, thyroid function
- ECG
How is hypertension managed
- Weight loss and exercise
- Smoking cessation
- Diet; more fruit and veg, less salt and alcohol
- Medication
List the types of antihypertensive agents given
- Alpha-adrenergic blockers
- Angiotensin-converting enzyme inhibitors
- Angiotensin II receptor blockers
- Beta-adrenergic blockers
- Calcium-channel blockers
- Diuretics
- Sympatolythics
- Vasodilatory
Give examples of alpha-adrenergic blockers and what is the dental relevance
Doxazosin
Prazosin
Indoramin
Xerostomia
Give examples of ACE inhibitors and what is the dental relevance
Captopril
Enalapril
Iisinopril
Ramipril
- burning sensation/ulceration/loss of taste
- angioedema
- xerostomia
- lichenoid lesion
Give examples of ARBs and what is the dental relevance
Candesartan
Iosartan
Irbestatan
- facial flushing, taste disturbance, gag reflex
- xerostomia
- lupoid reaction
Give examples of beta-adrenergic blockers and what is the dental relevance
Atenolol
Propranolol
Bisoprolol
- xerostomia
- lichenoid lesion
- paraesthesia
Give examples of calcium channel blockers and what is the dental relevance
Amlodipine
Nifedipine
Verapamil
Diltiazem
- gingival hyperplasia (with nifedipine)
- salivation (with nicardipine)
- angioedema
Give examples of diuretics and what is the dental relevance
Bendroflumethiazide Amiloride Furosemide Indapamide Spironolactone
- xerostomia
- erythema multiformis
- lichenoid lesion
Give examples of sympatolytics
Methyldopa
Clonidine
Give examples of vasodilators and what is the dental relevance
Minoxidil
Hydralazine
- ulceration
What is atherosclerosis
Patchy intimal plaques encroaching on the lumen of arteries - these contain lipids, inflammatory cells, smooth muscle cells and connective tissue and is initiated by endothelial injury
What are the risk factors of atherosclerosis
hyperlipidemia, diabetes, cigarette smoking, family history, sedentary lifestyle, obesity, hypertension
What is a stable plaque
One which regresses, remains static or grows slowly
When slow growing this can causes stenosis or occlusion
What is an unstable plaque
These are vulnerable to spontaneous rupture, erosion or fissuring and the plaque content triggers acute thrombosis
What does acute thrombosis of an unstable plaque lead to
- thrombus becomes incorporated into existing plaques
- thrombus rapidly occludes vascular lumen
- thrombus may embolise (detach)
- plaque may fill with blood, balloon out and occlude artery
- plaque contents may embolise, occluding vessels downstream
What are the clinical features of atherosclerosis
- initially asymptomatic
- stable plaque reduces arterial lumen causing stable exertionl anginga, TIAs, intermittent claudication
- unstable plaque ruptures and acutely occludes major arteries causing unstable angina, MI, ischaemic stroke and rest pain in limbs
- sudden death without preceding angina, aneurysms and arterial dissection
What special investigations are done for atherosclerosis
CT angiography Blood tests; lipid profile, plasma glucose, HbA1c Catheter based imaging testing - intravascular ultrasonography - angiography - plaque thermography - optical coherence tomography - elastography/immunoscintigraphy
How can atherosclerosis be managed
Lifestyle changes
- diet = less sat/trans fat, more fruit and veg, more fibre
- smoking cessation, regular exercise
Drugs
- hyperlipidaemia = statins
- hypertension = ACE inhibitors and beta-blockers
- diabetes = metformin, glicazide
- antiplatelet drugs = aspirin, clopidogrel, prasugrel
What is angina pectoris
Precordial discomfort or pressure due to transient myocardial ischaemia without infarction
The cardiac workload and myocardial oxygen demand exceeds supply of oxygenated blood via narrow coronary arteries (due to atherosclerosis, spasm, embolism)
What is stable angina
Predictable, increased workload leads to ischaemia
What is unstable angina
Chest pain at rest, increase frequency/intensity of episode
What are the clinical features of angina pectoris
- triggered by strong exertion or emotion
- persists for more than a few minutes and subsides with rest
- discomfort beneath the sternum
- radiates to left shoulder, inside arm, back, throat, jaw and teeth
- atypical angina causes abdominal distress, gas, bloating, indigestion
- nocturnal angina
What are the special investigations for angina
- ECG
- stress testing with ECG or echocardiograph
- coronary artery angiography
- intravascular ultrasonography
What drug treatments are used for angina pectoris
Relieve acute symptoms = sublingual nitroglycerin
Prevent ischaemia = anti platelets, beta-blockers
Prevent future ischaemic events = Ca channel blockers and nitrates
What is myocardial infarction
Myocardial necrosis resulting from acute obstruction of a coronary artery characterised by pain similar to angina pectoris but more severe and long-lasting with dyspnoea, diaphoresis, nausea and vomiting
Other features = pale clammy skin, cyanosis, thready pulse, syncope
It is only temporarily relieved by nitroglycerine (unlike angina)
What are the special investigations for MI
Initial and serial ECGs = STEMI/NSTEMI
Serial cardiac markers = troponin I/ troponin T and CK
Coronary angiography
What treatments are given for patients with MI
Prehospital = oxygen, nitrates, aspirin, opioids
Drug treatment = anti platelets, antianginal, anticoagulants, ACE inhibitors, statins, beta-blockers
Reperfusion therapy = fribrinolytics, angiography with percutaneous coronary intervention or coronary artery bypass
Post discharge rehabilitation = exercise, diet, weight loss, stop smoking; Drugs - anti platelet, beta-blockers, ACEi and statins
What is infective endocarditis
Rare condition associated with microbial infection of the endocardial surface of the heart occurring after bacteraemia in patients with predisposing cardiac lesions
Which patients are at high risk of IE
Those with
- prosthetic heart valves
- proviso IE
- acquired valvular heart disease with stenosis or regurgitation
- congenital heart defect
What is acute bacterial endocarditis
Aggressive within 7 days of bacteraemia
- common in elderly and IV drug users
- Staphylococcus aureus is most common offending organism
What is sub-acute bacterial endocarditis
Insidious onset within 2-3 weeks of bacteraemia
- Streptococcus viridian’s is most common offending organism
What are the clinical symptoms of IE
Flu-like symptoms, fever, anorexia, malaise, weight loss, night sweats, embolic phenomena, stroke, haematuria
Splinter haemorrhages (underneath nails), conjunctival petechiae, Osler’s nodes, Janeway’s lesions
What are Osler’s nodes
Tender, subcutaneous nodules in the pulp of the digits
What are Janeway’s lesions
Nontender, erythematous, hemorrhagic, pustular lesions on the soles or palms
Why is there no prophylaxis for IE
Because there is no evidence that antibiotics prevent IE and there could be adverse reactions from drugs given as well as increasing bacterial resistance
What are the causes of left ventricular heart failure
- Coronary artery disease
- DM and obesity
- Hypertension
- Valvular heart disease
- Hyperthyroid disease
- Substance abuse
Outline the pathogenesis of left ventricular failure
Decreased cardiac output triggers compensatory mechanisms (SNS and RAAS) which increases after load leading to further myocardial deterioration and worsening of myocardial contractility
Pulmonary venous pressure increases so pulmonary capillary pressure exceeds oncotic pressure of plasma proteins so fluid extravasates from capillaries into interstitial space and alveoli affecting gaseous exchange
This means there is less pulmonary compliance and increased workload of breathing and decreased systemic arterial oxygenation causing myocardial deterioration
What are the clinical features of left ventricular failure
- Restlessness, confusion and fatigue
- Orthopnea
- Tachycardia, cyanosis
- Exertional dyspnea, paroxysmal nocturnal dyspnea
- Elevated pulmonary capillary wedge pressure
- Pulmonary congestion; cough, crackle, wheeze, tachypnea, bloody-sputum
What are the causes of right ventricular failure
Previous LV failure, severe lung disorder (cor-pulmonale), multiple pulmonary emboli and RV infarction
What is the pathogenesis of RV failure
RV dysfunction causes systemic venous pressure increase so fluid extravasation and oedema in dependant tissues and abdominal viscera causing fluid accumulation in the peritoneal cavity
What are the clinical features of RV failure
- Heaptomegaly, splenomegaly
- Abdominal distension (acites) and weight gain
- Elevated jugular venous pressure
- Nausea, vomiting and fatigue
- Chronic venous congestion in the viscera (anorexia and malabsorption of nutrients)
- Dependant peripheral oedema
- Nocturnal diuresis
- Swellings of fingers and hands
- Anorexia and complains of GI distress
What are the special investigations for heart failure
FBC, electrolyte and urea, thyroid function test, ECG, chest radiography, echocardiography, coronary angiography, cardiac MRI
Outline the treatments for heart failure
Symptomatic relief
- Diuretics; loop diuretics = furosemide
- Nitrates; isosorbide nitrate (dilates blood vessels)
- Digoxin
Long term management
- ACE inhibitors; ramipril, catopril
- Beta-blockers; atenolol, bisoprolol
- Aldosterone antagonists; spironolactone
- Angiotensin II receptor blockers; losartan
