Cardiovascular system part 1 (Heart disease) Flashcards
List the 4 major coronary arteries & their locations
- Right coronary artery (Back of the heart)
- Left main coronary (divided into 2 branches, leftanteriordescending
& left circumflex artery) –> Any blockage here will affect the left ventricular
Which term refers to the amount of blood pumped by each ventricle in 1 min?It’s the product of stroke volume. (Volume/min)
List the which 2 variables affect this term (formula)
& what is the normal value of said term?
Cardiac output
- Cardiac output= Stroke volume x Heart rate* e.g. 4800ml = 60ml x 80 per/min
- Normal CO = 4.2 – 7 L/min
Which term refers to the the amount amount of blood pumped in 1 heart rate (Volume/beat)
An increase in said term results in…
& what is the normal value of said term?
Stroke volume
- An increase I stroke volume results in an increase in cardiac output & vice versa.
- Normal stroke volume is 60-100 ml/beat
Which term refers to number of beats in 1 min? (beats/min)
An increase in said term results in an increase in…
What is the normal value for said term?
Heart rate
- An increase I heart rate results in an increase in cardiac output & vice versa
- Normal heart rate is 70 beats per min
Which term refers to how the ventricles don’t eject all of the blood in one beat, in a typical example the ventricle is filled with about 100ml of blood but only 60ml is ejected during contraction, resulting in…? Or can be described as the measurement of the percentage of blood leaving your heart each time left ventricle contracts.
Where the 100 ml in the example being the..?
And the 40ml in the example being..?
What the formula involving these 2 variables and the stroke volume?
Ejection fraction (EF)
- An ejection fraction of 60%
- End-diastolic volume (EDV), meaning at the end of diastole/filling
- End-systolic volume (ESV), meaning at the end of systole/contraction.
- Stroke volume = EDV -ESV
(Factors that influence stroke volume)
Which factor that influences stroke volume refers to the force of the contraction of the heart muscle, where the more forceful the contraction, the more blood it ejects?
Which factor that influences stroke volume is related to end-diastolic volume, and is the degree of stretch of cardiac myocytes at the end of ventricular filling, but since this parameter is not readily measurable in patients, EDV is used instead? & describe the balloon analogy
Which factor that influences stroke volume refers to the resistance that the ventricle must overcome to eject blood? It contains 2 major components, (1) which is the pressure in the left ventricle must be greater than the systemic pressure for the aortic valve to open. Similarly, the pressure in the right ventricle must exceed pulmonary pressure to open the pulmonary valve. & provide an example. & (2) ___
- Contractility:
- Preload: Just like a balloon, the more air it contains, the more stretched it becomes. According to the Frank-Starling mechanism, the greater the stretch, the greater the force of contraction. In the balloon analogy, the more inflated the balloon, the more forceful it releases air when deflated
- After load: (1) Vascular pressure, where in hypertension for example higher vascular pressures make it more difficult for the valves to open, resulting in a reduced amount of ejected blood. & (2) Damage to the valves, such as stenosis, also presents higher resistance and leads lower blood output.
(Factors that influence stroke volume)
Increased preload results in…?
Increased afterload results in..?
Increased in contractility/inotropy results in..?
- Increased SV (increased EDV)
- Decreased SV (Increased ESV)
- Increased SV (Decreased EDV)
Which term refers to the leading cause of death in Canada, and is related issues with the small coronary arteries that supply the cardiac tissue?
& what is the main issue/cause of said condition?
Coronary Artery Disease
- Atherosclerosis, due to the characteristics of the coronary arteries being very small and spiralling.
List some modifiable and non-modifiable risk factors for coronary artery disease
Modifiable: Dyslipidemia, hypertension, cigarette smoking, diabetes mellitus, obesity, sedentary lifestyle, atherogenic diet
Non-modifiable: Age, gender, & family history
(Myocardial ischemia) Which term refers to an angina that is coming and going, usually occurring during exertion, due to the gradual narrowing of the coronary arteries; such as during exercise where you experience pain but when you rest the pain goes away?
& provide an example
Stable angina
- You usually drive to work, but I change my routine and go for a 30 min run, which is out of norm; the heart is under stress, the heart load work goes up, and the perfusion doesn’t go up, and you feel pain
(Myocardial ischemia)
Which term refers to if an angina happens all of a sudden & can happen during rest, or waking up in the morning, & It is not during exertion? Its also not unpredictable as its not related to any activities?
Unstable angina
(Myocardial ischemia) Which term refers to an angina that happens due to the spasm of the coronary arteries not a blockage? Nicotine can cause this when smoking, or when you’re very angry due to psychological stress, or even in cold. Can happen in rest, it comes and goes.
Prinzmetal angina
(Myocardial ischemia) Which term refers to an angina that is asymptomatic, without any specific manifestations, where it doesn’t present as a typical angina, common with people with diabetes?
This type of ischemia is the most dangerous, since they are not treated. Happening mostly in ppl with diabetes, since they don’t feel pain. They don’t feel chest pain due to neuropathy, a complication of diabetes. They have fatigue, shortness of breath, sweating (non-specific signs & symptoms). Causing them to not come to the hospital.
Silent ischemia
Which term refers to gradual narrowing of stable plaques, activated by physical exertion or stress where the narrowing does not allow enough coronary blood flow?
These patients experience referred pain, such as substernal chest discomfort where they feel sensations of heaviness or pressure, this may radiate to the neck, lower jaw, left arm, & shoulder.
Risk factors include:
-Uncontrolled Diabetes, dyslipidemia, obesity
- Hypertension
- Increased LDLs (low density lipoproteins)
- Decreased HDLs (High Density Lipoproteins )
- Sedentary lifestyle
- High BMI
- Genetics
Stable angina pectoris
Which term also known as variant angina, can presents no evidence of coronary artery disease, and is unstable, unpredictable, & can occur at rest? Where the main cause is vasospasm of coronary arteries with or without atherosclerosis.
It usually occurs at night, where it can cause dysrhythmias
It is also associated with decreased vagal activity, hyperactivity of the SNS
How is it treated?
Prinzmetal angina
- Calcium channel blockers
Which term refers to condition without typical symptoms, including fatigue, dyspnea, feeling of unease & can occur alone or with angina?
What is the % of myocardial ischemia are symptomatic & asymptomatic?
What are the causes for said conditon?
Silent ischemia
- 40% are silent ischemia
- Diabetes mellitus, cardiac transplant, mental stress, surgical denervation
List some signs & symptoms of angina
Also, diabetics, older people, and women may not show typical signs & symptoms of angina.
Traditionally women don’t show signs & symptoms. Whereas men typically have the classical presentation
Substernal chest discomfort, sensation of heaviness or pressure, pain may radiate to neck, lower jaw, left arm and shoulder, pallor, diaphoresis, & dyspnea
What is the leading cause of death among Canadian women?
Since, women present with atypical symptoms such as palpations, anxiety, weakness, & fatigue - 42% of women do not experience chest pain! Where they are presented with more fatigue & right sided chest pain Briefly read chart on p.g. 17 of notes
Heart disease & stroke