Welcome to the presentation on hypertension and dyslipidemia. All exam questions on this content will be derived from the objectives listed here. We’ll begin by discussing hypertension, or high blood pressure As you know, when your blood pressure is read, you get two numbers, one number over another. The top number is the systolic blood pressure, or when the heart contracts and forces blood into systemic circulation. This number is essentially a measure of the force generated by the squeeze of the heart. The bottom number is the diastolic blood pressure or when the heart is relaxed and the chambers are full of blood. Hypertension is the clinical term for elevated blood pressure of either the bottom or top numbers. The optimal blood pressure is <120/80mmHg. This means the patients systolic blood pressure is below 120mmHg and the diastolic blood pressure is below 80mmHg. The current guidelines, published at the end of 2017, have identified three classes of hypertension. The first is elevated blood pressure. As you can see, this is when only the systolic is above optimal. Next, is stage 1 hypertension with a systolic between 130-139 mmHg or a diastolic between 80 to 89 mmHg. Stage 2 hypertension is defined as a systolic greater than or equal to 140 mmHg or a diastolic greater than or equal to 90 mmHg. Finally, note that if only one of the patient’s numbers (either systolic or diastolic) is elevated, it is still considered hypertension and staging is determined by the most elevated number. For example, a patient with a blood pressure of 139/92 mmHg has stage 2 hypertension because of the diastolic falls into the highest stage. There are a large number of medications in many different classes that treat HTN. We will cover 4 medications in this class. Since there are so many medications to choose from, how does a prescriber decide what to start with? There are guidelines available such as JNC-8, which you researched in your learning activity, that give some guidance. Also some HTN medications can help patients with other conditions. For example, we will cover lisinopril later in this presentation. Lisinopril is actually preferred in patients with diabetes as it can help prevent the nephropathy, or kidney damage that can be caused by poorly controlled diabetes. The first and probably most commonly used medication for hypertension is hydrochlorothiazide or HCTZ. It is in the class of diuretics, specifically a thiazide diuretic. It works by preventing sodium reabsorption in the kidneys. This means that the body gets rid of more sodium in the urine and since in general, where sodium goes, water follows, this medication causes increased urination. This is called diuresis. In this process, blood pressure is decreased because there is less fluid in the vessels, resulting in decreased pressure. The urine contains higher than normal levels of sodium, potassium, and chloride. Side effects include dizziness, low potassium levels and muscle cramps. Which are all side effects related to low electrolytes. Lisinopril, marketed under the brand name of Zestril is also a commonly used medication for the treatment of hypertension. Lisinopril is a member of a class of drugs called ACE inhibitors. ACE inhibitors work by inhibiting the angiotensin converting enzyme. This enzyme is responsible for constricting the blood vessels, which makes them narrower, resulting in increased blood pressure. By inhibiting the enzyme, lisinopril prevents vasoconstriction which results in decreased blood pressure. It also works by preventing sodium and water retention. This results in a decreased blood volume, which also decreases blood pressure. ACE inhibitors work in a different part of the kidney as diuretics and they actually cause increased potassium levels, unlike diuretics. Lisinopril has additional benefits other than decrease blood pressure. There are benefits in the heart and kidneys, especially in patients with diabetes. ACE inhibitors do have some side effects. One of the most serious side effects is angioedema. This is a very rare and potentially life-threatening side effect associated with ACE inhibitors and it is the swelling of the lips and face. A picture of this is on the right. Another, much more common side effect of ACE inhibitors is a dry cough. This is a dry, non-productive, chronic cough. It is not like a cough associated with a cold. This is not a harmful side effect, but it may be incredibly bothersome to patients. ACE inhibitors can also cause high potassium levels and dizziness. They can also sometimes cause kidney dysfunction in some patients, which can be confusing because we use them to protect kidney function in diabetic patients. Norvasc or amlodipine is another medication used to treat hypertension. It belongs to a class of medications known as calcium channel blockers. They work by blocking calcium channels in smooth muscles located in arteries. This decreases blood pressure by decreasing the constriction on the arteries. Dizziness and fatigue are common side effects of most blood pressure medications because having a lower blood pressure can make you feel dizzy and tired. However, it is important that blood pressure does not get too low. Edema is a serious side effect of Norvasc. This is fluid retention causing swelling of the extremities, specifically the legs. Too much fluid retention can put strain on the heart causing heart failure, so patients who have edema should stop taking this medication and contact their doctor right away. The final medication we will talk about is Lopressor or metoprolol. This medication is part of the class of medications called beta blockers. They block the beta receptors in the heart which causes the heart rate to slow and the force of each beat to decrease. These combined effects lower blood pressure. Side effects are dizziness, fatigue and bradycardia or too slow of a heart rate. Patients who plan to do vigorous exercise should be cautious with beta blockers as they prevent the heart rate from increasing in response to exercise. There is no cure for hypertension. Lifestyle modifications such as decreased salt intake and increased exercise are beneficial, but these are lifelong changes. Most patients require life-long drug therapy as well. In some patients, who lose large amounts of weight, such as after gastric bypass surgery, blood pressure medications may be discontinued, but in most cases they are considered lifelong treatment. Now we will transition to discuss dyslipidemia. Sometimes you may hear dyslipidemia referred to as high cholesterol or hyperlipidemia. This is somewhat inaccurate as we are also concerned about low HDL or good cholesterol. Why are we concerned about dyslipidemia? Dyslipidemia is associated with increased risk of heart attack or stroke. The goal is to prevent someone from having a first heart attack or stroke. This is called primary prevention. If the patient has already had an event, we want to prevent them from having more. This is called secondary prevention. What is cholesterol? Cholesterol is a necessary building block for cell membranes and some hormones. However, you need to have the right balance of cholesterol. LDL is known as “bad” cholesterol. This is the type that forms the plaques we are going to discuss on the next slide. You want low LDL. HDL is known as “good” cholesterol. It goes around the body and picks up the LDL and helps prevent the formation of plaque. You want a high HDL. Triglycerides are literally particles of fat in the blood. Having too high of triglycerides can cause artery blockages on its own. Total cholesterol is a number that adds your LDL and HDL, plus 20% of triglycerides. Total cholesterol alone is not a good measure of cholesterol because a person could have a very high HDL, “good cholesterol” and have a high total number. It is much more important to know each component of total cholesterol separately. Having dyslipidemia can also lead to atherosclerosis, which is the narrowing and hardening of arteries. Atherosclerosis itself can lead to heart attacks and strokes. On the top left we have a normal artery. When that artery is damaged, perhaps by high blood pressure, it leaves a small space for plaque to attach. Once there is some plaque, it attracts more of itself and you get narrowing of the artery on the bottom left. If there is a small blood clot or a small piece of plaque that gets dislodged, it can completely clog the artery as you see on the bottom right. This would cause a heart attack or stroke depending on the location of the artery. There are many different classes of cholesterol medications, such as those listed here. Some try to raise HDL, like nicotinic acid derivatives. Some decrease triglycerides, like fibric acid derivatives. Most try to decrease LDL. In this course we will only discuss HMG CoA reductase inhibitors, more commonly known as “statins”. Statins are the only oral medication to reduce cholesterol that have strong evidence of preventing heart attacks and strokes. Our example medication is Zocor or simvastatin. Notice that the generic name ends in –statin. That is a rule that applies to all drugs in this class. These medications work by blocking the enzyme that works to produce cholesterol in the liver. The main effect is a lowering of LDL. Although some medications in this class will raise HDL and lower triglycerides somewhat. Since the primary site of action for simvastatin is the liver, you can predict that the liver is also the site of some of the side effects. Liver toxicity, or liver damage is a side effect of simvastatin that we are worried about. To check for this, patients on statins will have liver function tests (a simple blood test) taken periodically. The other major side effect we are worried about is called rhabdomyolysis. Which is a breakdown of the muscles. This muscle breakdown releases myoglobin in to the blood. When myoglobin is filtered by the kidney, it will damage the kidney causing kidney failure. This can be life threatening. It is treatable if caught early. The early signs are muscle pain and weakness, not related to injury. If a patient experiences muscle pain, they should contact their doctor right away. Also of note, statins are pregnancy category X and are not to be used when breastfeeding either.