common cardiac conditions Flashcards
describe briefly the electrical activity of the heart
SA node generates the electrical impulse causing the atria walls to contract
signal then passes to the AV node, which delays it by about 0.1 seconds
the bundle branches carry signals from the AV node to the heart apex
purkinje fibres and bundle of his conduct the electrical impulses and cause ventricles to contract
how can arrhythmias occur?
when cells outside of normal pathways conduct impulses or there is a block in an existing channel
what are the components of a normal ECG?
-P wave - atrial depolarisation
-QRS complex
-ventricular contraction
-T wave - ventricular repolarisation
-ventricular filling phase
what is sinus bradycardia?
when heart rate is less than 60bpm
-can be normal in athletes or during sleep
what is sinus tachycardia?
heart rate between 100-180 bpm
normal response to stressor eg anxiety, exercise or due to fever
what is atrial fibrillation
an irregular and often rapid heart rhythm
what is an atrial flutter?
It occurs when a short circuit in the heart causes the upper chambers (atria) to pump very rapidly.
what is supra ventricular tachycardia?
rapid heart rhythm that originates above the heart’s ventricles (the lower chambers) in the atria or the atrioventricular (AV) node
what is premature atrial contractions?
-early heartbeats that originate in the atria, the upper chambers of the heart.
-interrupt the heart’s regular rhythm by causing an extra beat, which can feel like a “skipped” or “extra” beat
-common and generally harmless
what is heart block?
Heart block is a condition where the electrical signals from the atria to the ventricles are delayed or blocked
what are the different types of heart blocks?
-first degree AV block
-2nd degree heart block
-complete heart block / third degree
what is a first degree AV block?
-mildest form and is usually benign.
-prolonged PR interval
-but all signals still successfully reach the ventricles.
explain difference between mobitz type 1 and mobitz type 2 2nd degree heart block
-mobitz type 1- progressive lengthening of the PR interval with each heartbeat until one of the beats (a QRS complex) is “dropped,” meaning that the electrical signal fails to reach the ventricles.
-mobitz type 2- more serious & higher risk of progressing to 3rd degree… some of the p waves fail to reach the ventricles
what causes the cardiac sounds S1 and S2?
S1- classic club sound - AV valve closure
S2- semilunar valves closure produces the dub sound
what is the baroreceptor reflex?
the ability to control acute changes in BP
(note may be slower in the older person)
what are examples of common cardiac conditions?
-hypertension/ hypotension
-ischaemic heart disease/ coronary artery disease
-peripheral artery disease
-valve disorders
-heart failure
-cardiac arrhythmias
what are examples of investigations for cardiac conditions?
-12 lead ECG
-echo (structure of heart, valves, assessment of pumping function)
-EST
-DCCV
-ablation
-bloods eg electrolytes, troponin BNP
what is important to note about the levels of troponin in the blood?
-troponin is released with myocardial ischemia
what is BNP?
B-type natriuretic peptide
can be released with myocardial stretch, increased with worsening HF
what are the ‘big 5’ that can lead to cardiovascular disease?
-tobacco (smoking)
-poor diet
-sedentary behaviour
-obesity / overweight
-alcohol
define atherosclerosis
narrowing of the arteries - occurs when deposits of cholesterol and other fatty substances cause the build up of plaque on the inner lining of the arteries
what is plaque made up of?
-fat, cholesterol, calcium and other substances found in the blood
what can the rate of plaque build up depend on?
-smoking
-BP
-cholesterol levels
-genetics
what is hypotension generally defined as?
-systolic BP less than 90mmHg
-diastolic BP less than 60mmHg
what are examples of meds that can help with increasing BP?
fludrocortisone and midodrine
what are examples of medications that treat hypertension?
-ACE inhibitors (angiotensin converting enzyme)
-alpha blockers
-angiotensin II antagonists
-beta blockers
-calcium channel blockers
-diuretics
what is ischaemic heart disease (IHD)?
-characterised by reduced blood supply to the heart muscle
-caused by narrowing of the coronary arteries that supply blood to the heart
what are the recommendations for physical activity for hypertension?
-regular medium to high intensity aerobic activity may lower the blood pressure for hypertensive patients
-isometric (static) activity may also lower the blood pressure in the same patients to a similar degree
what can happen when atherosclerosis develops in the coronary arteries?
-decrease in blood supply to the heart muscle
-decrease in oxygen and nutrients to reach the heart muscle
-chest pain (angina)
what could happen if the atherosclerotic plaques in the lining of the coronary arteries rupture?
-a clot or thrombus can develop at the site of rupture
-totally blocking the blood supply to that part of the heart
-heart attack - MI
what are examples of non modifiable risk factors of IHD?
-family history
-age and sex (men more likely)
-ethnic origin
what are examples of modifiable risk factors for IHD?
-tobacco smoke
-high cholesterol
-diet (high in saturated fat)
-physical inactivity
-obesity- excess body fat (especially at the waist)
-diabetes mellitus- esp if uncontrolled
what are examples of signs and symptoms of IHD?
-angina pectoris (chest discomfort)
-pain in the arms, upper central abdomen, back, neck and jaw
-breathlessless
-sweating
-nausea
-decreased exercise tolerance
-arrhythmias
what is an example of an anti-angina medication?
-glyceryltrinitrate (GTN)
what is an ambulatory electrocardiogram?
records the electrical activity of the heart throughout the day during daily activities
what is a coronary angiogram?
-examines the hearts blood vessels using x rays- dye is visible by x ray injected into the blood vessels using a catheter
what is an echocardiogram?
ultrasound of the heart to look at the hearts size, valves, structure and motion
how can IHD be diagnosed?
-ECG
-ambulatory electrocardiogram
-blood tests
-cardiac stress testing
-coronary angiogram
-echocardiogram
what is the treatment for IHD?
anti-anginal drugs may be used to reduce the rate of occurrence and severity of angina attacks
-prevention - healthy diet and med to control diabetes, cholesterol etc
-addressing risk factors eg control BP, blood sugars (if diabetic), regular exercise, healthy diet, smoking cessation
what are examples of medications that may be used for IHD?
-beta blockers
-calcium channel blockers
-sinoatrial inhibitors
-nitrates
-potassium channel openers
what is an angioplasty?
a balloon threaded up to the coronary arteries
-inflated to widen blocked areas and is combined with a stent to keep artery open
what is a CABG?
coronary artery bypass graft - arteries/ veins harvested and used to bypass blocked artery in heart
what is peripheral artery disease?
a partial or complete obstruction of more than 1 peripheral arteries
-insufficient blood supply to the left that could cause leg pain and dysfunction in the same way that coronary artery disease that could lead to angina
what is intermittent claudication?
characterised as leg pain associated with walking and received by rest
-exercise induced ischemic leg pain, primarily in the calf
what are examples of treatment that can be used for PAD?
-exercise
-medications eg anti platelet, anticoagulants, anti HTN
what is valve stenosis?
when the heart valves become hardened or stiffened which can restrict normal blood flow through the heart
what is valve regurgitation/insufficiency/leaky ?
-when the valve does not close tightly - some blood will leak backwards across the valve
what are causes of valve disease?
-can be congenital or acquired
describe congenital valve disease
-most often affects the aortic or pulmonic valve
-valves may be the wrong size, malformed leaflets etc
what are examples of acquired causes of valve disease?
rheumatic fever - caused by an untreated bacteria infection eg strep throat
-mitral valve prolapse
-MI
-hypertension
-coronary artery disease
what is endocarditis?
occurs when the bacteria enter the bloodstream and attack the heart valves
what are examples of symptoms of valve disease?
-SOB
-swelling of ankles, feet or abdomen
-palpitations
-chest discomfort/pain
-orthopnea
-reduced exercise tolerance
-weakness or dizziness
how is valve disease diagnosed?
-ausc of heart - murmur is the sound made by the blood flowing through a stenotic or leaky valve
-leg oedema
-abdomen swelling
what are examples of treatment for valve disease?
-protecting valve from further damage
-medication
-surgery - heart valve repair or replacement
define heart failure
any structural or functional impairment of ventricular filling or ejection of blood. the cardinal manifestations of HF are SOB, fatigue
-not enough blood getting to body, blood backs up waiting to enter heart, causing blood vessels to leak fluid into surrounding tissues
what are signs and symptoms of heart failure?
-SOB at rest or on exercise
-fatigue
-ankle swelling
-tachycardia, tachyopnea
-pulmonary crepitations
-raised jugular venous pressure (seen in neck)
describe left sided heart failure
-reduced left ventricular function both systolic (unable to contract with enough force) or diastolic (unable to relax and filling is impaired)
-most common type of heart failure
-results in poor systemic circulation, dizziness, confusion, cool extremities
describe right sided heart failure
-failure of right ventricle leads to congestion of systemic capillaries
-often a direct result of left sided failure
-excess fluid accumulation in the body
how is heart failure diagnosed?
ECHO
ECG
haematological investigations
what is an important protein to measure in blood in a patient who may have heart failure?
-B type natriuretic peptide
-higher than normal levels of BNP in blood can be a sign that the heart isn’t pumping enough blood through the body
how is HF treated?
-treat underlying causes
-lifestyle changes
-medications
-surgery
-physiotherapy management- eg critical care, early mob and rehab, improved QOL, patient education
what are examples of implantable devices in heart failure?
-permanent pacemaker (PPM)
-cardiac resynchronisation therapy (CRT)
-implantable cardioverter debrillators (ICDs)
why would a patient have a pacemaker inserted?
-bradycardia at rest
-tachybrady syndrome
-atrial fibrillation
-blunted HR response to exercise
what is the advice given post insertion of device?
-CXR done post to outrun pneumothorax
-shoulder restrictions and precautions for 6/52
-ROM exercises for 6/52
-driving - 1 week to 6 months
-wound care
-education re magnetic fields
-long term - contact sports, repetitive EOR arm mvts
what is a cardiac resynchronisation therapy?
a treatment for HF induced conduction disturbances and ventricular dyssynchrony to reduce symptoms and improve cardiac function by restoring the mechanical sequence
-re - coordinates the contraction
what are implantable cardioverter defibrillators ICDs?
-implanted in patients at risk of SCD (sudden cardiac death) due to ventricular fibrillation etc
-it delivers a brief electrical impulse to the heart when detects cardiac arrhythmia
describe cardiac arhythmias
any abnormal electrical activity in the heart - can be too fast, too slow or irregular
-causes include hypoxia, electrolyte imbalances, physical activity, anxiety etc
what is acute coronary syndrome?
term used to describe a range of conditions associated with sudden, reduced blood flow to the heart
eg unstable angina, myocardial ischemia,
describe STEMI vs NSTEMI
- STEMI- A complete blockage of a coronary artery leading to a significant portion of the heart muscle being affected.
- NSTEMI-A partial blockage or transient clot that causes some damage to the heart muscle but does not present with the same ECG changes as STEMI
what is cardiac arrest?
medical emergency that occurs when the heart suddenly stops beating effectively, leading to an immediate cessation of blood flow to the brain and other vital organs
- can happen due to lots of different conditions eg coronary heart disease, heart attack, arrthymias, cardiomyopathy
what effect can cardiac rehab have on exercise training?
-reduced BP and HR
-reduced cholesterol
-reduced sedentary lifestyle
-increased exercise capacity
-overall reduces risk of further CVD 30-50%