Ischaemic heart disease, heart failure, hypertension Flashcards
What is ischaemic heart disease?
Heart disease due to insufficient perfusion of cardiac tissues. It includes angina pectoris, acute coronary syndromes and myocardial infarction.
Lecture 9/1/18
What is angina pectoris?
Central chest tightness or heaviness due to myocardial ischaemia, brought on by exertion and relieved by rest
(OHCM)
How does Poisueille’s law relate to angina symptoms?
Radius affects blood flow to the 4th power, so diameter has to fall by 75% before a person experiences symptoms.
What is Prinzmetal’s angina?
Arteries go into vasospasm which increases resistance and causes reduction in blood flow.
(9/1/18 lecture)
Give a non-modifiable risk factor for angina.
Age, sex
Give a modifiable risk factor for angina.
Smoking, exercise, weight
What is unstable (crescendo) angina?
Angina of increasing frequency or severity, occurring on minimal exertion or at rest, with normal troponin. (OHCM)
What are the 3 key characteristics of angina pain?
- Heavy, central, tight chest pain, radiation to arms, jaw and neck
- Precipitated by exertion
- Relieved by rest/ sublingual GTN. (9/1/18 lecture)
How does GTN spray work?
It dilates arteries.
What would you see on an ECG in angina?
ECG is often normal but there may be signs of IHD such as ST depression, T wave inversion and bundle branch block. (lecture 9/1/18)
What would the treadmill test show with angina?
The person walks on a treadmill which gets incrementally steeper. Look for ST segment depression on ECG. This is no longer on the NICE guidelines but can still be used.
What is the gold-standard diagnostic test for angina?
Invasive angiogram, which shows the luminal narrowing.
How does CT angiography work and why is it used?
A contrast-rich dye is injected into the arteries and CT scanning produces detailed images. It has a higher NPV than PPV so it is good for excluding CAD in young, low-risk patients. There are lots of false positives.
What is a stress echo?
A functional test which uses dynamic imaging with and without pharmacological stress, looking for regional wall motion abnormalities. Requires expertise so not done as often as it could be. (9/1/18 lecture)
What is a SPECT and what is it used for?
SPECT = Single photon emission CT. Radio labelled tracer taken up by metabolising tissues, to give an idea of the degree of ischaemic myocardia. AKA myoview.
What factors affect choice of investigation for angina?
Patient choice, pre-test probability of CAD, invasive or non-invasive, allergies, intolerances, clinician preferences.
What is primary prevention of angina?
Exercise, stop smoking, antihypertensive, good control of diabetes.
What are the first-line anti-anginal drugs and how do they work?
Beta-blockers such as bisoprolol and atenolol reduce oxygen demand and work of the heart.
Nitrates are venodilators, reduce preload and vasospasm.
Lecture 9/1/18
Give a side-effect of beta-blockers.
Bradycardia, worsening of asthma and coronary spasm.
What is PCI and why would it be used? What are the risks?
Percutaneous coronary intervention/ stenting to remove narrowing and restore blood flow. Used for patients with troponin elevation or unstable angina. Risks of restenosis and thrombosis, but less invasive than CABG. (lecture 9/1/18)
What might a blood test show in angina?
Anaemia
Is angina more common in men or women?
5% men, 4% women.
What investigation could you use to check the pulmonary vessels and heart size?
Chest X ray
What drug can be used to treat angina if a person has asthma?
Calcium channel blockers.
What is an example of a second-line anginal drug and how does it work?
Ivabradine - cardiotonic; reduces cardiac pacemaker activity, so it slows HR selectively and allows more time for blood to flow to the myocardium. This makes it a good drug for HFREF.
What is a CABG and what are the advantages and disadvantages?
Surgical intervention to divert blood around narrow or clogged arteries to major arteries. Good prognosis but longer recovery. Contraindicated in frail patients. (PTS)
What are acute coronary syndromes?
A spectrum of disease progressing from unstable angina to STEMI, with the main underlying pathology of plaque buildup and rupture leading to thrombosis and inflammation.
What is troponin and what is it used for?
Regulator of actin-myosin contraction. Sensitive marker of cardiac injury. Used to diagnosed NSTEMI, not specific for ACS (also positive in sepsis, heart failure etc)
What can cause ST elevation, tall T waves and possibly a new LBBB?
STEMI
How is NSTEMI diagnosed?
Retrospectively using troponin. ST depression seen on ECG. (PTS)
What changes would be seen on an ECG in someone with ischemia?
ST-T changes: The ST segment can be depressed or elevated, and the T wave can be up (hyperacute T wave), down (flattening) or inverted.
https://ecgwaves.com/topic/ecg-myocardial-ischemia-ischemic-changes-st-segment-t-wave/
What features of chest pain may suggest MI?
Chest pain - unremitting, usually severe, at rest; associated with sweating, breathlessness, nausea and vomiting.
What is the difference between Q wave and non-Q-wave MI - what might you see on ECG?
Non-Q-wave: Poor R wave progression, STE, biphasic T wave. Q-wave - pathological Q waves.
What is a silent MI?
MI without ECG signs or symptoms. Seen in elderly and diabetics. lecture 9/1/18; PTS
Who is at higher risk of death from ACS?
Increasing age, diabetes, renal failure, LVSD (lecture 9/1/18)
What is the initial management of MI?
AMONA: Ambulance (admission) Morphine (analgesia) Oxygen if hypoxic Nitrates Aspirin 300mg If STE, primary PCI Bed rest Lecture 9/1/18