Blood Pressure and Cardiovascular Disorders March 7, 2017

Try to find several of these! Pulse Points Areas where can easily feel pulse Also act as pressure points. Compressing these points will reduce downstream blood flow useful when dealing with major wounds. Try to find several of these!

Blood Pressure Blood pressure is the pressure the blood exerts against the inner walls of the blood vessels. Usually, we refer to the pressure of the arteries.

Blood Pressure Blood pressure is the pressure the blood exerts against the inner walls of the blood vessels. Usually, we refer to the pressure of the arteries. Why does blood pressure drop so low in the capillaries? Because there are so many more capillaries So that the flow of blood will slow to facilitate exchange of materials

Blood Pressure Blood pressure is the pressure the blood exerts against the inner walls of the blood vessels. Usually, we refer to the pressure of the arteries. Why do we record blood pressure as two numbers? Blood pressure in the arteries fluctuates with the cardiac cycle.

Blood Pressure Systolic pressure occurs due to ventricle contraction Diastolic pressure occurs when ventricles relax

Measuring Blood Pressure A sphymomanometer is placed over the brachial artery. The cuff is inflated to ~150 mmHg (above systolic pressure) Air pressure is slowly released from cuff while a stethoscope is used to listen for Korotkoff sounds in the artery. Correct responses: 118 /72 – normal 124/74/0 – absent 5th phase, so 4th phase is used for diastolic. This can occur in pregnant women, people with arteriovenous fistulas (a direct connection between an artery and a vein) – which sometimes just develops in the legs, but is also sometimes surgically created for hemodialysis, and /or in people with aortic insufficiency – a leaky aortic semilunar valve

Measuring Blood Pressure Test yourself! Korotkoff sounds Cuff pressure > systolic pressure there is no blood flow through artery  NO SOUNDS Cuff pressure = systolic pressure blood begins to flow turbulently through artery  TAPPING SOUND BEGINS Cuff pressure = diastolic pressure blood begins to flow smoothly  SOUNDS DISAPPEAR #1 159/90, #2 161/94 #3 80/62

Factors which affect BP Increased cardiac output (heart rate & stroke volume) increases blood pressure Exercise Stress / Sympathetic nervous system Increased peripheral resistance (friction of blood traveling through vessels) increases BP Atherosclerosis Constriction of blood vessels (due to sympathetic nervous system, cold, chemicals such as nicotine) Number of vessels (body size / fat / pregnancy) Increased blood volume increases blood pressure Kidney problems Book says “for each lb of fat, miles of additional blood vessels are needed” Which factors will decrease BP?

Resting Blood Pressure Hypotension is low blood pressure. May cause dizzy spells, especially when rising Not problematic among young, healthy people Acute hypotension may indicate shock Pulse pressure = difference between systolic and diastolic. High pulse pressure often indicates heart disease, while low pulse pressure often indicates an ineffective heart (such as leaky valves)

Resting Blood Pressure Hypertension can be a positive feedback cycle – why? Hypertension is high blood pressure. Damages blood vessels, which may lead to clots and atherosclerosis Causes heart to work harder, leading to enlarged heart that will eventually weaken Pulse pressure = difference between systolic and diastolic. High pulse pressure often indicates heart disease, while low pulse pressure often indicates an ineffective heart (such as leaky valves). Other causes of high pulse pressure are overactive thyroid and iron deficiency anemia

Myocardial Infarction (aka heart attack) A myocardial infarction (or heart attack) occurs when one of the blood vessels that supplies the heart with oxygen becomes blocked suddenly due to a clot and/or atherosclerosis. The heart tissue begins to die due to lack of oxygen (cardiac ischemia), often over a period of several hours. More than a million americans have a heart attack every year A blood clot forms over a plaque in a partially obstructed artery then breaks off and gets trapped somewhere, stopping blood flow Watch me!

Myocardial Infarction (aka heart attack) Risk Factors Warning Signs Atherosclerosis High blood pressure High cholesterol Obesity Diabetes Smoking Genetics / family history Sedentary lifestyle Angina = chest pain

Myocardial Infarction (aka heart attack) Treatment The immediate goal of treatment is to restore blood flow and reduce the stress on the heart. Drugs used: Aspirin and other blood thinners – reduces blood clotting Antiplatelets – reduce formation of platelet plug Thrombolytics – enzymes that dissolve blood clots Nitroglycerin – dilates blood vessels Betablockers – relax heart muscle, reducing damage ACE inhibitors – lower blood pressure and reduce stress on heart

Myocardial Infarction (aka heart attack) Treatment Surgical Options: Coronary angioplasty and stenting A long thin tube (catheter) in inserted into an artery in the leg and thread through to the blockage in the heart. A balloon in the tube then inflates at the site of the blockage to open up the artery. A mesh stent (tube) may also be inserted to keep the artery open long term. Coronary artery bypass surgery Doctors sew in new arteries or veins to bypass a blockage, restoring blood flow to the heart. Watch me! When possible, doctors would prefer to do the surgical methods after the heart has had time to heal from the MI as a way to reduce further chances. But, if drugs don’t seem to be working will do as emergency surgeries Watch me!

Myocardial Infarction (aka heart attack) Prognosis Fast treatment is the key to a good prognosis. The longer the heart is starved for oxygen, the more damage will result. 25 % of people die on the way to the hospital Survivors often have lasting heart damage due to tissue death, including: heart failure, irregular heart rhythm, aneurysm, enlarged (and ineffective) heart cavity, other clots, etc. Full recovery possible Aneurysm = enlarged, weakened artery

Common heart conditions review Why might you need a pacemaker? What does it do? What are the causes and consequences of each of the following condition? Atheroscelerosis Hypertension Hypotension Heart murmur Pulse pressure = difference between systolic and diastolic. High pulse pressure often indicates heart disease, while low pulse pressure often indicates an ineffective heart (such as leaky valves). Other causes of high pulse pressure are overactive thyroid and iron deficiency anemia

Common heart conditions review Why might you need a pacemaker? What does it do? If your heart’s internal conduction system doesn’t work (SA node not working or blockage in conduction system) you might need a pacemaker. A pacemaker will stimulate contraction of the heart. What are the causes and consequences of each of the following condition? Atheroscelerosis – Atherosclerosis is the narrowing of the arteries due to the accumulation of plaque. The plaque accumulates partly due to damage of the arteries. Risk factors include: diabetes, high blood pressure, high cholesterol, smoking, obesity, poor diet, lack of exercise, and family history / genetics. Consequences: May cause heart attack or stroke Pulse pressure = difference between systolic and diastolic. High pulse pressure often indicates heart disease, while low pulse pressure often indicates an ineffective heart (such as leaky valves). Other causes of high pulse pressure are overactive thyroid and iron deficiency anemia

Common heart conditions review Hypertension High blood pressure may be caused by atherosclerosis, obesity, smoking, stress, lack of exercise, poor diet, and family history / genetics. Hypertension damages the blood vessels, putting you at risk for heart attack, stroke, blindness, and kidney damage. Hypotension Low blood pressure may be acute due to blood loss, chronic but not serious (young women), or may be due to poor blood circulation in elderly. Fainting and dizziness may result. Heart murmur Heart murmurs are unusual heart sounds, usually due to a problem with the heart valves. Sometimes, these problems make the heart less efficient which could lead to heart enlargement and heart failure. Pulse pressure = difference between systolic and diastolic. High pulse pressure often indicates heart disease, while low pulse pressure often indicates an ineffective heart (such as leaky valves). Other causes of high pulse pressure are overactive thyroid and iron deficiency anemia

Closure What was our objectives, and what did we learn? What was our learner profile trait and how did we demonstrate it? How does what we did today tie to our unit question? http://www2.sunysuffolk.edu/pickenc/Capillary%20Exchange.swf MI