Conditions - Ischaemic Heart Disease Flashcards
What are the different types of ischaemic heart disease?
Angina pectoris and myocardial infarction
What is angina pectoris?
Central chest tightness/pain caused by myocardial ischaemia
What is the clinical presentation of angina pectoris?
Symptoms: Dyspnoea, nausea, sweatiness and syncope
What are the different types of angina pectoris?
Stable
Unstable
Decubitus
Prinzmetal
What is stable angina pectoris?
It is induced by effort and relieved by rest
What is unstable angina pectoris?
Increasing severity and frequency. Minimal exertion and there is a high risk of MI
What is decubitus angina pectoris ?
Pain when lying flat
What is prinzmetal angina pectoris?
During rest
What is the pathophysiology of stable, unstable and decubitus angina?
Atheroma obstructing or narrowing coronary artery
What is the pathophysiology of prinzmetal angina?
Coronary artery spasm
What is the aetiology of angina?
Atheroma
What are the diagnostic tests done for angina pectoris?
ECG
What does an ECG of angina pectoris show?
Usually normal
Some ST depression
Flat or inverted T waves
What is the treatment of angina pectoris?
Modify risk factors Aspirin Beta blockers Nitrates Long -acting calcium channel blockers K+ channel activators Statins
What is the action of aspirin in the treatment of angina pectoris?
irreversibly blocks the formation of thromboxane A2 in platelets, producing an inhibitory effect on platelet aggregation
What is the action of beta blockers in the treatment of angina pectoris
blocking the effect of adrenaline on the heart. This has two major beneficial effects in patients with angina: Slowing of the heart rate, in particular during periods of exercise or stress. Reducing the force of heart muscle contraction
What is the action of nitrates in the treatment of angina pectoris?
Nitrates work as venodilators and arterial dilators, and by these actions in patients with angina pectoris can reduce myocardial oxygen demands while maintaining or increasing coronary artery flow
What is the action of calcium channel blockers in the treatment of angina?
The entry of calcium is critical for the conduction of the electrical signal that passes from muscle cell to muscle cell of the heart, and signals the cells to contract.
It also is necessary in order for the muscle cells to contract and thereby pump blood.
In the arteries, the entry of calcium into muscle cells constricts the arteries.
Thus, by blocking the entry of calcium, calcium channel blockers reduce electrical conduction within the heart, decrease the force of contraction (work) of the muscle cells, and dilate arteries.
What is the action of K+ channel activators in the treatment of angina?
Open or prolong the open state duration of potassium channels. Hence they promote potassium efflux, hyperpolarize the cell membrane, thus preventing intracellular penetration of calcium through the voltage-dependent calcium channels
What is a myocardial infarction?
Death of heart tissue due to an ischaemic event
What are the types of MI?
STEMI and NSTEMI
What is the clinical presentation of MI? Give 3 symptoms and signs
Symptoms: Nausea, crushing chest pain, vomiting, dyspnoea, sweating, fatigue, palpitations
Signs: fever, hyper/hypotension, 3th/4th heart sound and signs of congestive heart failure
What is the pathophysiology of MI?
Blockage of the coronary artery by a thrombus. This leads to ischaemia in the cardiac tissue
What is the aetiology of MI?
Atheroma
