Cardiac Assessment PDF

Cardiac Assessment I might have to wait for a phone call from the hospital again, as usual. Um, my mom is going to be discharged today. You totally know that, right? And totally, she got the opportunity to maybe not meet her, but she knows that she was on her floor. So, um, hoping that could happen...

Cardiac Assessment I might have to wait for a phone call from the hospital again, as usual. Um, my mom is going to be discharged today. You totally know that, right? And totally, she got the opportunity to maybe not meet her, but she knows that she was on her floor. So, um, hoping that could happen as well. Haven’t heard anything so far, but—so party it says we all need to party. So, your learning outcomes for all this are going to be describing, at a time, the physiological determinants as part of the vascular system. View the components related to cardiac output, explain that in the parameters incorporated into the history and physical of a cardiac examination. Add the implications of selected diagnostic studies related to the cardiac lesson itself. So, right—how are you? I just kept on some options of the heart, um, exceptions, and cardiac output we're gonna talk about. So, the primary function of the heart is to deliver oxygen to tissues. They, um, return deoxygenated blood to the heart via veins. The pulmonary artery and pulmonary veins are the only two that function oppositely. Do you guys remember what that means? Well, we all do. The pulmonary artery and the pulmonary vein are the only two that are opposite of each other. Everything else, when you're sending it out from the left side of the heart, is oxygenated blood. It actually starts with the vein and goes out. When it comes in, it goes in from the right side of the heart and through an artery into the lungs. That’s the only difference. Everything else consists of veins coming into the right side of the heart, and arteries going out. Does that make sense? After being oxygenated in the lungs, did I mention this to you guys the other day about the tree? When I envision the pulmonary system, there's a tree of vessels branching out, and I thought about this last time—it looks just like the lungs. It really does. All its branches and little extensions resemble the lung structures. Just as you were pulling out of the parking lot here, you can visualize that. So anyway, just remember that the pulmonary artery and vein are the only two that are reversed, okay? It's actually due to the function of the heart, pushing blood through the pulmonary vein into the pulmonary system via the contraction of the heart. Now, we're going to talk about the arterial system and the venous system. The arterial system consists of high pressure, thick walled muscular vessels that carry oxygenated blood from the heart to the tissues. As these vessels gradually decrease in size, they branch further. The venous system, in contrast, is a low pressure system containing valves that push blood upwards, assisting its return to the heart. These valves also allow for IV infusion products to be introduced into the blood. That’s why certain medications cannot be administered into an artery but must go into a vein. Capillary beds are where the exchange of nutrients and oxygen occurs, as well as the removal of cellular waste. The waste products are transported through the bloodstream, processed by the liver, and eliminated. We have an extensive network of blood vessels that can constrict or dilate according to the metabolic needs of the body. Now, let’s discuss the anatomy of the heart. We all know it’s about the size of a fist, right? It is located behind the mediastinal space and the sternum. The heart is covered by the pericardium, which contains a fluid layer that provides lubrication, reducing friction during pumping. This allows the heart to contract and relax smoothly without excessive stretching. The chambers of the heart include the atria and the ventricles. The atria are the upper chambers. Blood enters the right atrium from the body and then moves into the right ventricle. From there, it is pushed into the pulmonary arteries—remember, this is an artery, not a vein—where it travels to the lungs. Once reoxygenated, the blood returns to the heart via the pulmonary veins, entering the left atrium. It then moves into the left ventricle before being pumped out to the rest of the body. I thought there were some pictures in here to help visualize this. You can see the superior vena cava, which brings in deoxygenated blood from the body. It empties into the right atrium. The heart has multiple valves: the pulmonary valve, tricuspid valve, mitral valve, and aortic valve. You all remember this from physiology, right? This is just a refresher. The pulmonary artery pushes blood out, and we follow it through the left ventricle and the aorta. Now, about the heart valves—let’s talk about their function. The tricuspid valve is between the right atrium and ventricle, and the mitral (bicuspid) valve is between the left atrium and ventricle. When open, these valves allow blood flow into the ventricles. When they close, they prevent the backward flow of blood. This mechanism also occurs throughout the venous system, preventing blood from flowing in the wrong direction. We’ll discuss this more when we get to conditions like congestive heart failure (CHF), peripheral vascular disease (PVD), and coronary artery disease (CAD), as these conditions often involve issues with blood flow regulation. The valves are connected to the ventricular muscles by chordae tendineae, which prevent them from bulging or inverting. Additionally, some valves are located between the ventricles and their respective arteries. The pulmonary valve is situated between the right ventricle and the pulmonary artery, while the aortic valve is between the left ventricle and the aorta. Understanding the difference between the pulmonary artery and pulmonary vein is crucial. This concept will appear on tests—so be prepared! These are straightforward, concrete questions about how blood flows through the heart. Now, let's talk about the semilunar valves. These valves are located between the ventricles and their respective arteries. They open and close in response to pressure changes during ventricular contraction and relaxation. During diastole, which is the relaxation phase, the heart refills with blood. Does everyone remember what happens during diastole? It's the resting phase of the heart. Blood flows into the ventricles, and the pressure is lower. Which pressure is higher—systolic or diastolic? Systolic is higher, and diastolic is lower. As the ventricles fill, the valves close to prevent backflow. When the ventricles contract (systole), the semilunar valves open, allowing blood to be ejected into the pulmonary and systemic circulation. Now, let’s discuss the coronary arteries. The left coronary artery branches into the left anterior descending (LAD) artery and the circumflex artery. You can see the circumflex arteries here—these branches supply blood to different areas of the heart muscle. This is an extremely important area to understand, especially when discussing cardiac disease. If a blockage occurs due to plaque or an embolism, the affected arteries will no longer deliver oxygen to the heart muscle. What do you think will happen? A myocardial infarction (MI), or heart attack, can occur. In severe cases, the blockage can be fatal, especially if it affects a large portion of the heart. This is why one of the most critical blockages is known as the “widowmaker.” It refers to a major blockage in the LAD artery, cutting off blood supply to a significant portion of the heart muscle, often leading to sudden death. I want to share a story. I used to tutor anatomy and physiology in nursing school. There was a young woman struggling with the heart's anatomy. No matter how many times we went over it, she wasn’t understanding—until I realized the problem. She didn’t know the heart had its own blood supply. She thought it was just a muscle pumping blood to the body. Once I explained that the coronary arteries supply oxygen to the heart itself, it clicked for her. That moment stuck with me throughout my career. So, I just want to make sure everyone here understands: The heart has its own blood supply. This is crucial because if these arteries become narrowed or blocked, conditions like myocardial infarction, angina (chest pain), and heart failure can occur. We're gonna get to that. So, um, both ventricles, the interventricular system, is located right here. You have your left atrium and the posterior wall of the left ventricle. Here’s your left, here’s your right— pretty simple. It took a long time to find one good picture. So, um, very ugly. The right coronary artery supplies the right atrium and the sinoatrial (SA) node. We have the right marginal branch, located about here in this area. Then, of course, you've got the lateral aspects of the right atrium, which are all in this area, and the posterior aspects of both ventricles and the interventricular septum, which is in this area. The coronary circulation consists of the major vessels that supply blood to the heart—the left and right coronary arteries. These are the first arteries branching off the aorta as it leaves the left ventricle, originating in the cusps of the aortic valve. The arteries branch into arterioles and capillaries, merge into capillary veins, exchange oxygenated blood, and then empty into the right atrium, where the cycle starts all over again. Remember, the heart has its own blood supply, so it goes straight back into the atrium. Does that make sense? The Conduction System This is the fun part—everyone thinks of the heart as a hollow organ that does what it's supposed to do, keeps us alive, and keeps going, right? But how does the system work? The heart functions using specialized cardiac muscle cells, and the cardiac electrical conduction system is necessary for its electrical activity. Everyone remembers the electrical conduction of the heart, right? Cardiac cells have specific characteristics that facilitate electrical conduction: they are automatic, excitable, and conductive. The heart's main function is to move blood through your body, delivering oxygen and nutrients to all cells. The heart controls rhythm and speed, which we call heart rate, and maintains blood pressure. It works with the nervous system and endocrine system, as hormones tell the blood vessels to contract or relax, affecting blood pressure. The cardiac cycle is defined as the sequence of events that produce muscular contraction, ejecting blood from the right ventricle into the pulmonary circulation and the left ventricle into systemic circulation. Cardiac Conduction Automaticity: The ability to generate impulses independently and rhythmically. Excitability: The ability to respond to stimulation and generate an impulse. Conductivity: The ability to transmit impulses to neighboring connected cells. We have our SA node, also known as the heart’s natural pacemaker, right up here in this corner. Then, we have our AV node. The impulse spreads over the atria through the intermodal pathways, right in here. The SA node fires, the impulse travels to the AV node, then moves down to the Bundle of His, also known as the atrioventricular bundle. The impulse is delayed at the AV node to allow for atrioventricular contraction and ventricular filling. This all happens in a fraction of a second. The impulse then moves through the right and left bundle branches, traveling down the interventricular septum to the Purkinje fibers, which extend the impulse into the ventricular tissue, facilitating ventricular contraction. The Cardiac Cycle and Blood Pressure The cardiac cycle is again defined as a series of events that push blood from point A to point B, circulating it to feed muscles, organs, and tissues—all of which require oxygen to survive. The cycle works in coordination with the electrical conduction system. Diastole: The heart relaxes, and the chambers fill with blood. This is the lowerpressure phase of blood pressure. Systole: The heart contracts, pushing blood out to the body. This is where Starling’s law and cardiac output are measured. During systole, once filling is complete, the ventricles contract. Increased pressure in the ventricles causes the AV valves to close. Eventually, the pressure exceeds that of the aortic and pulmonary circuits, forcing the semilunar valves open and ejecting blood. Blood pressure reflects the pressure generated during the cardiac cycle. It represents the force exerted against vessel walls by blood flow. Factors affecting blood pressure include: The amount of blood ejected during systole (cardiac output). The resistance to blood flow in the peripheral vessels (afterload). Cardiac output is calculated as: Heart Rate × Stroke Volume = Cardiac Output Heart rate: The number of contractions per minute, influenced by the autonomic nervous system. Stroke volume: The amount of blood ejected per ventricular contraction. Preload: The amount of blood in the ventricles at the end of diastole. Afterload: The resistance the ventricles must overcome to eject blood. The size and volume of blood vessels determine the resistance and pressure within them. Major Risk Factors for Cardiovascular Disease Assessing a patient’s complete physical and medical history is critical. The history should include: Family history of cardiovascular disease, diabetes, kidney disease, or hypertension. Hyperlipidemia (high cholesterol). Current health status—not just past diagnoses, but whether conditions like hypertension or heart disease are currently present. For example, my mother, who is currently in a cardiac unit, insists there’s nothing wrong with her heart— even though she has congestive heart failure and atrial fibrillation. Many elderly patients believe that if they feel fine, they don’t have a problem. However, conditions like hypertension are controlled by medication—stopping medication would cause blood pressure to spike again. Signs and Symptoms of Cardiac Issues Key complaints to assess: Chest pain: Frequency, intensity, location, radiation. Shortness of breath: Resting or exertional? Palpitations: Fast or irregular heartbeats? Fatigue and dizziness: Signs of decreased cardiac output. Right vs. Left Sided Heart Failure Left sided failure: Blood backs up into the lungs, leading to pulmonary congestion, shortness of breath, and potential respiratory distress. Right sided failure: Blood backs up into the body, leading to swollen legs (peripheral edema) and fluid retention. To treat fluid overload, we use Lasix (furosemide), monitoring:  Strict input/output measurements. Weight daily—as 1 gallon of fluid = 8 lbs. Potassium levels—since Lasix depletes potassium, a potassium supplement (potassium rider) may be necessary. Physical Assessment of a Cardiac Patient Skin color: Pale, grayish, cyanotic? Diaphoresis (sweating): Common in myocardial infarction (MI). Edema: Swelling in legs (right sided heart failure) or lungs (left sided heart failure). Jugular vein distention (JVD): Sign of fluid overload. Clubbing of fingers/toes: Indicates chronic hypoxia. Heart Sounds S1: Closing of AV valves, beginning of systole ("lub"). S2: Closing of semilunar valves, beginning of diastole ("dub"). S3 (ventricular gallop): May indicate heart failure if heard in adults. S4 (atrial gallop): May indicate decreased ventricular compliance. Cholesterol and Cardiovascular Risk Cholesterol is necessary for hormone synthesis and cell walls, but high cholesterol levels contribute to arterial plaque buildup and cardiovascular disease. The liver produces cholesterol, but dietary intake from animal products can increase bad cholesterol levels. We will cover good vs. bad cholesterol in the coronary artery disease (CAD) lecture on Monday. Everybody here has heard of HDLs and LDLs, correct? Well, LDLs are the bad cholesterol, and HDLs are the good cholesterol. We all agree on that. The good cholesterol (HDL) attaches itself to the bad cholesterol (LDL), carries it to the liver, and excretes it through the feces, right? That’s how it works. But when LDLs are too high, there aren’t enough HDLs to get rid of that extra cholesterol, and then it starts building up. Can you have too much good fat? Good fats? That’s a different question. Do you mean HDLs? Well, I don’t know if you can have too much HDL. I’ve yet to see anybody get higher than the high normal. You know, the range is about 45 to 65 mg/dL, I believe. That’s a good number to be at. Again, if you can increase your good cholesterol (HDL) to bring down the bad cholesterol (LDL), that would be great. Unfortunately, that’s why we have medications to do that—because the body isn’t always able to do it effectively on its own. So, when bad cholesterol (LDL) levels rise, we have to take medications to help the body get rid of it. By the way, I know I said I’d talk more about this next week, but let me mention one thing now. When you give medication for cholesterol, such as statins, it needs to be taken at night. Does anyone know why? Go ahead, tell me. Because the liver makes cholesterol at night—yes! That’s why we take cholesterol medication at night to control it. It makes me crazy when I walk in and see someone getting it in the morning. Why? They don’t need it in the morning! Your body doesn’t start making cholesterol until nighttime, so that’s when we need the medication to be working. Alright, I just wanted to make sure I covered everything in my notes. And we all know that elevated cholesterol levels can lead to arterial disease if left unchecked. Our total cholesterol should be less than 200 mg/dL, and LDL (bad cholesterol) should be less than 100 mg/dL—that’s ideal. What did I say earlier—45 to 65? Well, actually, HDL (good cholesterol) should be between 40 and 60 mg/dL, so I was off by five. Triglycerides should be less than 150 mg/dL. A lipid panel includes: Total cholesterol Low-density lipoproteins (LDL bad cholesterol) High-density lipoproteins (HDL good cholesterol) Triglycerides This is what your lipid panel will look like when taken at the doctor’s office or hospital. Cholesterol & Lipoproteins Cholesterol is a fat (lipid). It also synthesizes hormones and helps form cell walls, making it essential for the body. It is obtained from animal products (meat, dairy, eggs) and is also synthesized in the liver. However, cholesterol is not watersoluble, so it binds with proteins to form lipoproteins: LDLs (bad cholesterol) primarily transport cholesterol into cells but can also deposit it on arterial walls. HDLs (good cholesterol) remove excess cholesterol and transport it to the liver for excretion. LDL buildup in arteries leads to atherosclerosis, increasing the risk of: Heart attack Stroke Pulmonary embolism (if plaque dislodges and travels to the lungs) Diagnostic Studies & Cardiac Markers Markers of Acute Cardiac Damage 1. Creatine Kinase (CK) A general marker of cellular injury. Released from the brain, skeletal muscle, and cardiac tissue after muscle damage. Not cardiacspecific, so it is not widely used today. 2. CKMB (Creatine KinaseMB) Specific to cardiac tissue. Released when myocardial damage occurs. Increases within 3 hours, but only lasts 36 hours in the blood. Limitation: If a patient does not seek medical help right away, CKMB levels may return to normal, making detection difficult. 3. Troponins (Troponin I & T) The gold standard for detecting heart attacks. Levels elevate within 4 hours of an MI and remain elevated for up to 10 days. Troponin tests are taken every 3 to 6 hours to monitor the progression of a heart attack. Unlike CKMB, troponins stay elevated longer, making them more reliable. Important: A heart attack does not happen instantly—it takes time. Troponin levels continue to rise throughout the entire heart attack event, providing a clear timeline of myocardial damage. 4. Myoglobin Another cardiac marker but not specific to the heart. Released with muscle damage (including skeletal muscle). Can be elevated from exercise or muscle injury. 5. Brain Natriuretic Peptide (BNP) Released from overstretched ventricular tissue. Elevated in congestive heart failure (CHF) or cardiomyopathy. A key marker for heart failure. Normal Lab Values (Every hospital has different "normal" values based on their lab calibrations, but these are general guidelines.) CKMB: 0 3 ng/mL Troponin: < 0.04 ng/mL Myoglobin: 0 85 ng/mL BNP: < 100 pg/mL If I ask a question, I will use these values. Electrocardiogram (ECG/EKG) An ECG (electrocardiogram) is a basic cardiac assessment used routinely in hospitals. It is often performed yearly during physicals. An ECG measures the heart’s electrical activity. Sometimes, it can reveal an old heart attack (silent MI) that a patient didn’t even know they had. Leads: The placement of ECG leads is labeled on the ECG pack. Terminology: It used to be called an EKG (electrokardiogram) but is now commonly referred to as an ECG (electrocardiogram). Chest XRay & Cardiac Imaging Chest X-rays evaluate heart size and shape. They cannot diagnose heart disease but can detect: Cardiac enlargement Pulmonary congestion (fluid in the lungs) Echocardiogram (ECHO): Uses ultrasound to assess heart function. Measures ejection fraction (how much blood the heart pumps). Can be done at the bedside in larger hospitals. Transesophageal Echocardiogram (TEE): Involves inserting an ultrasound probe down the throat. Provides clearer images of heart structures. Uncomfortable but useful for detailed heart evaluation. Cardiac Stress Testing Evaluates heart function under stress. Treadmill Test: Patient walks while ECG, blood pressure, and vitals are monitored. Pharmacologic Stress Test (for those unable to exercise): Medication is injected to stimulate heart rate. More invasive than the treadmill test but necessary for some patients. Cardiac Catheterization Invasive procedure to evaluate heart function and coronary arteries. Right vs. Left Heart Cath: Right heart cath: Through a vein. Left heart cath: Through an artery. Can be used to: Removed clots Place stents Assess Valve Function The catheter is advanced to the right side through the inferior vena cava. The left heart catheterization is done through the superior aorta, again via the femoral, radial, or brachial artery. The catheter is advanced through the aorta and into the heart. As I mentioned earlier, a stent can be placed to open up an artery or vein, depending on what needs to be addressed—especially for the revascularization of an area. While performing a cardiac catheterization, they typically capture around 15 images of the area being examined. Physiological Changes in the Cardiovascular System with Aging As a person ages, changes occur in their cardiovascular system. These may include: Left ventricular atrophy Decreased elasticity of the aorta Increased rigidity of heart valves I’ve mentioned this to you all many times, especially since last term. Being in oncology, ICU, and working in intensive care for as long as I have, I’ve seen it firsthand. When an 85yearold patient says, "I walk five miles a day, and I do this and that, so I’m going to be fine!" Well, guess what? You might be fine, and that’s great—you’re keeping yourself healthy. But your organs are still 85 years old. No matter how well you take care of your body, aging still happens. And unfortunately, these changes happen more rapidly as you get older. For example: Hypertension (high blood pressure): You could have never had hypertension before, and suddenly, it develops. Why? Agingrelated changes, such as hardening of the arteries (arteriosclerosis) and plaque buildup (atherosclerosis). No matter how healthy you are, your body still experiences wear and tear over time. I can’t tell you how many people have been avid runners for 25+ years, only to suffer a cardiac event during a marathon. They did everything right, but we’re still human—aging is inevitable. Aging & Physical Deconditioning As we age, physical deconditioning occurs. We don’t move as easily as we once did. We lose flexibility and endurance over time. Hypertension is common with aging due to: Stiffening of the arteries Stenosis (narrowing) of heart valves Increased fibrosis (hardening) of the arteries These are all fancy ways of saying the same thing: The blood vessels become less flexible, increasing the risk of thrombosis (clots). Blood clots can lead to a stroke. Two Types of Stroke 1. Ischemic Stroke (caused by a clot or plaque buildup) This type is easier to treat. TPA (tissue plasminogen activator) can be administered to dissolve the clot and restore blood flow. 2. Hemorrhagic Stroke (caused by a ruptured blood vessel) More difficult to treat. Often requires surgical intervention, such as catheterization to stop the bleeding and open the artery. Cardiovascular Health Issues Associated with Aging Hypertension (HTN) Coronary Artery Disease (CAD) Congestive Heart Failure (CHF) Atrial Fibrillation (Afib) Does anyone know what Atrial Fibrillation is and what causes it? Answer: It’s an irregular heart rhythm. But why? Think back to when we discussed the Bundle of His earlier. Afib is caused by electrical misfiring in the heart, leading to uncoordinated contractions—essentially, the heart is spasming instead of beating in a regular rhythm. That’s it for Cardiovascular Assessment! Oh, God—I’m done! Wait... we still have another hour? Oh no... okay, let’s start hypertension then. Wait, are you actually giving us a break? If I let you out early, it will be at 1:22 PM—so that’s only 20 minutes early. I’m sorry about that—I thought I was further along in my lecture!