Chief Complaint: 60 year old woman with DMII and obese, experiencing a myocardial infarction. Her blood pressure is 95/55, breathing rate is 30 per min. , and heart rate is 125 BPM.
Background
The anatomy of the heart
Pathway of blood through the heart
Right Atrium
The role of valves and papillary muscles in heart physiology
The normal sounds of the heart and what causes them
The relationship between heart function and blood pressure
The relationship between heart function and respiratory rate
The concepts of heart rate, stroke volume, cardiac output, mean arterial pressure, preload
afterload, peripheral resistance, and others relevant to this case.
Upstream
Downstream
Tricuspid Valve
Right Ventricle
Pulmonary SemiLunar Valve
Pulmonary Trunk
Pulmonary Arteries 2x
Lungs
Pulmonary Veins 4x
Oxygen-Poor Blood
Left Atrium
Bicuspid (Mytral) Valve
Left Ventricle
Aortic Semilunar Valve
Aorta
Body
Inferior Vena Cava
Superior Vena Cava
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Oxygen-Rich Blood
Semilunar Valves
Atrioventricular Valves
Open-- the cusps of the valve will extend into the ventricles. It allows blood to move from the atriums to the ventricles
Close -- the cusps of the AV valve prevents backflow of blood back into the atrium.
Associated with papillary's assistance to secure the cusp from inverting into the atriums.
Open- When the ventricles contract, it the force of the blood pushes the SL valves to open and enters the atrial trunks
Close- the SL valves close when the ventricles relax and the pressure in the ventricles becomes less than the pressure in an atrial trunk. The closure of the SL valves prevents backflow of blood into the ventricles.
Due to ageing, the elasticity and flexibility will weaken causing a blood flow disruption. A heart murmur may be detected.
Papillary Muscles
will secure the tendinous cords that attach to the lower surface of each AV valve cusp, preventing the valves inversion or prolapse these valves on systole.
Lubb-Dupp sounds
Lubb (S1 sound) represents the closing of the AV valves
Dupp (S2 sound) represents the closing of the SL valves
These heart sounds provide clinically important info. about the heart activity and action of heart valves. If an abnormal heart sound, heart murmurs, will indicate a heart valve problem.
Coronary Vessels
Cardiac Output - is the volume of blood pumped out of the right or left ventricle per minute. Stroke Volume x Heart Rate = Cardiac Output.
Stroke Volume- is the volume of blood ejected by each ventricle during a single contraction.
Heart rate- is the number of heartbeats per minute.
Preload - is the degree to which cardiac muscle cells are stretched by the blood entering the heart chambers.
Afterload- is a measure of the pressure that must be generated by the ventricles to force the SL open
The Respiratory Pump assists the movement of the blood within the thoracic cavitiy.
Mean Arterial Pressure (MAP) - is the average measure of the blood pressure forces on the arteries.
Diastolic pressure x 1/3 Pulse Pressure
lower than 60mm Hg may indicate insufficient blood flow.
very high MAP could indicate the delivery of too large of blood flow to body tissues with the possibility of causing edema in the tissues
could also be a risk factor for the development of atherosclerosis
Peripheral Resistance - is the resistance of the arteries to blood flow
Determined by three factors: Autonomic activity: sympathetic activity constricts peripheral arteries.
During inhalation, pressure in the abdominal region increases while pressure in the thoracic cavity decreases.
These pressures act upon the veins passing through theses regions
Blood flows toward the heat as it moves pressure in thoracic region and right atrium.
It is reversed during exhaling, backflow in the veins is prevented by the valves.
Direct: Experience a myocardial infarction. This permantly damage the papillary muscles of the left ventricle. Papillary muscles role is to close the valve so the leaflets do not invert into the atrium.
Effects due to a mitral valve failure
since the mitral valve did not shut entirely, blood was leaked back into the left atrium. (Regurgitation)
Mitral valve regurgitation can be caused by problems with the mitral valve, also called primary mitral valve regurgitation. Diseases of the left ventricle can lead to secondary or functional mitral valve regurgitation.
Endocarditis. The mitral valve may be damaged by an infection of the lining of the heart (endocarditis) that can involve heart valves.
Heart attack. A heart attack can damage the area of the heart muscle that supports the mitral valve, affecting the function of the valve. If the damage is extensive enough, a heart attack can cause sudden and severe mitral valve regurgitation.
Damaged tissue cords. Over time, the tissue cords that anchor the flaps of the mitral valve to the heart wall may stretch or tear, especially in people with mitral valve prolapse. A tear can cause leakage through the mitral valve suddenly and may require repair by heart surgery. Trauma to the chest also can rupture the cords.
Mitral valve prolapse. In this condition, the mitral valve's leaflets bulge back into the left atrium during the heart's contraction. This common heart defect can prevent the mitral valve from closing tightly and lead to regurgitation.
Atrial fibrillation. Atrial fibrillation is a common heart rhythm problem that can be a potential cause of mitral valve regurgitation.
other systems being affected by mitral valve regurgitation
Respiratory System
Urinary System
Nervous System
Dysautonomia
A dysfunction of the nerves that regulate nonvoluntary body functions, such as heart rate, blood pressure, and sweating.
Pulmonary hypertension. If you have long-term untreated or improperly treated mitral regurgitation, you can develop a type of high blood pressure that affects the vessels in the lungs (pulmonary hypertension). A leaky mitral valve can increase pressure in the left atrium, which can eventually cause pulmonary hypertension. This can lead to heart failure on the right side of the heart.
When you have heart disease, your heart may not pump blood in the right way. Your heart may become too full of blood. This causes pressure to build in the main vein connected to your kidneys, which may lead to a blockage and a reduced supply of oxygen rich blood to the kidneys. This can lead to kidney disease.
Indirect: She has many lifestyle factors that associated with her mitral valve failure
Age
Weight
Diabetes Mellitus Type II
Papillary muscles tend to weaken through aging
Since she is obese, her heart may have to work harder to push the blood through out the body causing a strain in the heart.
Abnormal lipid (cholesterol) levels. High levels of LDL cholesterol may lead to narrowing and hardening of the arteries which can impede blood flow from the heart to all the parts of the body.
Higher chance of Atherosclerosis. When plaque builds up in the walls of arteries and narrows them, blood has less room to travel through.
Heart disease risk is elevated with this level of belly fat because it tends to increase levels of LDL (bad cholesterol) and the particular type of blood fat that may be deposited inside your blood vessel walls.
Tricuspid AV Valve
Chambers of the heart
Atriums (Left and Right)
Ventricles (Left and Right
Bicuspid AV valve
Papillary Muscles
Chordnae Tendineae
Aortic SL valve
Pulmonary SL Valve
Heart rate and blood pressure do not necessarily increase at the same rate. A rising heart rate does not cause your blood pressure to increase at the same rate. Even though your heart is beating more times a minute, healthy blood vessels dilate (get larger) to allow more blood to flow through more easily