T3 L7: Ischaemic heart disease Flashcards
What is the Framingham heart study?
Started in 1948, it’s a longitudinal study over 3 generation of participants now. Before the study, risk factors for IHD were not clear
Describe some major findings of the Framingham heart study
1957: High cholesterol and high BP linked to CHD
1961: Risk factors introduced
1962: Smoking linked to CHD
1967: obesity and inactivity linked to CHD
1972: diabetes linked to CHD
What is atherosclerosis?
Fatty deposit build up in arteries (hardening of arteries)
Name 3 acute coronary syndromes
Unstable angina, NSTEMI, STEMI. They are characterised by the development of a thrombosis. Are not relieved with sublingual GTN
What is the difference between stable and unstable angina?
Stable angina is caused by a fixed atheromatous stenosis but unstable angina is caused by a dynamic obstruction due to plaque rupture
What are the 3 characteristics of typical angina?
Substernal chest discomfort of characteristic quality and duration, provoked by exertion or emotional stress, relieved by rest or nitrites within minutes
How do beta-blockers treat angina?
They slow heart rate so reduce the oxygen demand of the heart
How do Ca2+ blockers treat angina?
Causes less Ca2+ to enter vessels which causes them to relax and allows the heart to get more oxygen
What is Ivabradine and how does it work?
A hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blockers. It works by slowing the heart rate so the heart can pump more blood through the body each time it beats
What is Nicorandril and how does it work?
A potassium-channel activator. It works by relaxing and widening your blood vessels, which increases the supply of blood and oxygen to your heart
What is Ranolazine and how does it work?
Reduces the flow of sodium ions into the heart muscle cells. This interferes with the sodium-dependent calcium channels through which calcium ions normally enter the cells therefore improving blood flow
What is Trimetazidine and how does it work?
A cytoprotective drug that normalizes metabolic disturbances in low-flow ischemia by inhibiting fatty acid oxidation
What are long-acting nitrites and how do they work?
They widen your blood vessels to increase blood flow to the heart. Long acting-nitrates are in tablet form and are different to GTN spray.
What is GTN spray?
Glyceryl trinitrate (GTN) is a spray used to relieve angina. It’s a long-acting nitrite
What is the clinical significance of Troponin in the blood?
It’s released following injury to the heart and is used a diagnostic marker for MI. It can remain in the blood stream for 2 weeks
What type of angina doesn’t cause elevated Troponin levels?
Unstable angina
How are MI, STEMI, and NSTEMI differentiated?
By their characteristic abnormalities on an ECG
What does an ST elevation on an ECG indicate about the occlusion?
That it’s a complete coronary occlusion
What does an ST depression and variable T wave on an ECG indicate about the coronary occlusion?
An incomplete occlusion
What are the 3 steps of platelet activation?
Adherence, activation, and aggregation
What is the function of thrombin?
It causes platelet aggregation
What are the symptoms of the elderly and diabetic with acute coronary syndromes?
Breathlessness, Nausea or vomiting, sweating and clamminess
What is the dosage of Aspirin given for management of acute coronary syndromes?
300mg at first and then a 75mg maintenance dose
What is Clopidogrel and how does it work?
A P2Y2 receptor antagonist. It makes platelets less ‘sticky’ by decreasing the amount of tissue factor produced so the coagulation cascade can’t happen
What is prasugrel and how does it work?
A P2Y2 receptor antagonist that prevents coagulation
What is Ticagrelor and how does it work?
A P2Y2 receptor antagonist that prevents coagulation
What are secondary prevention tharapies?
It’s what the patient leaves the hospital with. includes medication like statins and life style changes
Which is more of an emergency, a STEMI or an NSTEMI?
A STEMI because it’s a complete occlusion
Why is a coronary artery bypass surgery never performed on those with ST elevation?
Because they’re not stable enough
Which 2 vessels can be used for a coronary artery bypass surgery?
The internal mammary artery from chest or the saphenous vein from the leg
