Cardiac Flashcards
What is the definition of acute coronary syndrome?
A collection of disorders due to decreased blood flow in the coronary arteries leading to a decreased oxygen supply to the myocardium.
What is the definition of angina?
A coronary artery disease caused by a narrowing of the coronary artery leading to a decreased blood flow to myocardium. Usually relieved by nitrates.
What is the definition of NSTEMI?
Myocardial infarction caused by a partial occlusion of the coronary arteries. Does not show ST elevation on ECG.
What is the definition of a STEMI?
Myocardial infarction caused by a complete occlusion of the coronary artery. Shows ST elevation on the ECG.
What is the treatment goal for acute coronary syndrome?
To facilitate timely reperfusion of the myocardium, reduce cardiac workload and reduce pain.
What is SVT?
Supraventricular tachycardia is a tachy-arrhythmia caused by a re-entry pathway in the atrial conduction system.
What characterises an SVT rhythm?
Fast, regular rhythm with narrow QRS complex and no p waves (p waves not related to QRS)
What is the rationale behind the valsalva manoeuvre?
Increased intrathoracic pressure leads to decreased venous return. When the pressure is released, a sudden shunt of blood enters the heart. Sudden stretch of aorta leads to profound vagul response. This slows the AV node conduction and will hopefully revert SVT.
What is the process of APO/ LVF?
Left ventricle dysfunction leads to a decrease in stroke volume. This leads to increased Left Venticular End Diastolic Pressure and increased left atrial pressure. This leads to increase pulmonary hydrostatic pressure which forces water into the alveoli washing away surfactant leading to alveoli collapse, decreased gas exchange and respiratory distress.
What is the definition of cardiac output?
Is the volume of blood pumped through the circulatory system in one minute.
What is the definition of stroke volume?
Stroke volume is the volume of blood ejected from heart in one heart beat.
What is the definition of vascular resistance?
Is the resistance that needs to be overcome by the heart to achieve adequate cardiac output. Increased vascular resistance is due to narrowing/ tightening of vessels.
What is blood pressure?
Blood pressure is the amount of pressure exerted on the vessel walls.
What is the relationship between CO, BP, SV, VR, and HR?
CO = SV x HR BP = CO x VR
What is MAP and how do you calculate it?
Mean arterial pressure is the average blood pressure during a full cardiac cycle.
MAP = 1/3 (SBP- DBP) + DBP
What is the process of an atheroma formation?
- Atherosclerosis is a chronic inflammatory process which begins from childhood.
- Lipid proteins called LDLs build up in the intima of the coronary artery.
- LDLs are then engulfed by macrophages leading to the formation of foam cells.
- Eventually the contents protrude in the lumen of the artery eventually leading to formation of a fibrous cap.
- This results in narrowing and hardening of the arteries which decrease blood flow.