Heart Flashcards
What is an ECG?
An electrocardiogram. A visual representation of the ‘electrical activity’ of the heart. Can assess abnormalities in rhythm, conduction and repolarisation.
What does ST segment depression suggest?
Often a sign of myocardial ischemia of which coronary insufficiency is a major cause.
What is PTCA angioplasty?
Percutaneous transluminal coronary angioplasty. A minimally invasive procedure to open up clocked coronary arteries. Goes up through femoral artery and uses a balloon to open the arteries up. Can place in a stent-latticed metal scaffold- within the artery to keep it open.
What is haemoptysis?
Act of coughing up blood or blood stained mucus.
What is Angina Pectoris?
Chest pain due to myocardial ischaemia. Causes a build up of metabolites which activate sensory nerves. Not a disease itself. 3 types: stable, unstable and variant.
What is ischaemia due to?
Increased myocardial oxygen demand which is not met.
Give details on unstable angina.
Attacks are unpredictable. Coronary artery occlusion due to platelet adhesion to ruptured atherosclerotic plaque.
What is ‘coronary steal’?
When the coronary arteries are dilated, this sends more blood to already well perfused areas, but where dilatation cannot occur less blood is delivered because of the fall in input pressure. Termed ‘the reverse Robin Hood effect.’ However, may be useful to dilate coronary arteries in variant angina. Can be a problem with dipyridamole, SNP and adenosine.
What does Ivabradine do?
Recently introduced to treat all forms of angina. Blocks Na+ current that contributes to SA node depolarisation towards threshold. Leads to a decrease in heart rate but not force and so decrease myocardial oxygen demand.
What is after-load?
Force against which the left ventricle contracts. Can be decreased by dilating arteries.
What is pre-load?
Diastolic pressure that distends the relaxed left ventricle. Can be decreased by dilating veins.
What is the Bainbridge (atrial) reflex?
A sympathetic reflex initiated by increased blood in the atria which causes stimulation of the SA node.
What is GTN?
Glyceryl trinitrate. A vasodilator used in the treatment of angina. Taken as a sub-lingual tablet or spray. Not orally active as it is destroyed by first pass metabolism. Rapid onset but short action.
What is amyl nitrate?
A vasodilator used in the treatment of angina. Vials opened and inhaled. Has become a drug of abuse (poppers). Rapid onset but short action.
What is Isosorbide mononitrate?
A vasodilator used in angina that is taken orally. Slower in onset and more prolonged duration than GTN. Used for sustained prophylaxis in all forms of angina.