The heart is divided by partitions into four chambers. What are they? (Answer: right and left atria, and right and left ventricles)
Review the remainder of blood circulation. Venous capillaries merge to form larger veins. Blood returns to the heart via vena cava; enters the right atrium. Right atrium contracts; forces blood into right ventricle. Right ventricle contracts, forces blood to lungs. Blood is oxygenated and returned again to left atrium. What are differences between arteries and veins?
Review the exception: The pulmonary artery carries unoxygenated blood. Review the exception: The pulmonary vein carries oxygenated blood. Discuss the components of the heart that are affected by cardiac medications. Consider muscle contraction, chamber filling, electrical conduction, and rhythm.
Why do these conditions require medication? Explain the effect position and rate of flow of blood has on the client with heart failure.
What types of patients are vulnerable to heart failure?
Review the rationale for various drug classes that affect the heart.
Weight should be obtained daily, early in morning before eating or drinking; the bladder should be empty.
An inotropic drug such as digoxin may be combined with an ACE inhibitor, a beta-blocking agent, and/or a diuretic.
When would a prescription for digoxin immune Fab be used? With digitalis therapy, the rate of heart contraction is slowed. Normal heart rate is 60 to 80 beats per minute.
These medications assist in the treatment of hypertension by suppressing the formation of angiotensin II. The first dose may induce a severe hypotensive reaction. The patient should be closely monitored. The physician may discontinue diuretic agents 2 to 3 days before beginning ACE inhibitor therapy.
ACE inhibitors are excreted through the kidney. These medications may cause a severe decrease in blood pressure and an increase in serum potassium level. These medications should be used with caution for patients with renal compromise or pregnancy-induced hypertension.
Beta-blocking agents can be used alone or in combination with other agents to treat hypertension.
A low incidence of side effects exists with angiotensin II receptor–blocking agents. What are some side effects? (Answer: skin rash, facial edema, insomnia, and myalgia)
These medications are also useful in treating diabetic nephropathy and are usually well tolerated. Valsartan (Diovan) is the only one of the listed medications approved to treat heart failure. The remainder are used to treat hypertension and diabetic nephropathy. If the patient is receiving other drugs for hypertension or heart failure, the physician may decrease the dose or eliminate those drugs.
Aldosterone inhibitor agents include spironolactone, a potassium-sparing diuretic agent. Aldosterone inhibitor agents should not be used for patients with elevated serum potassium levels or decreased renal function. Aldosterone is suspected of causing myocardial remodeling after myocardial infarction. This limits the efficient function of the heart. By inhibiting aldosterone, the heart responds more efficiently and the risk for heart failure is decreased.
Discuss normal sinus rhythm and its rate. Rate for bradycardia: <60 Rate for tachycardia: >100
What disorders or conditions require the use of vasoconstricting agents? (Answer: shock, rhinorrhea, allergic reaction)
Epinephrine is available as an EpiPen.
Vasodilating agents are common medication for home management of angina. Vasodilating agents are often first-line treatment for chest pain in the emergency department. What are the routes of administration? (Answer: sublingual, sustained-release oral tablets and capsules, transdermal, spray, intravenous)
Some medications target the dilation of arteries, increasing cardiac output and tissue perfusion. Some medications target the dilation of veins, easing the work of the ventricles. Some medications target both. Common side effects include postural hypotension, reflex tachycardia, and fluid retention. Nearly one third of patients do not take antihypertensive agents properly.
Most patients have “essential” hypertension (no cause is identified). Other lifestyle issues include the following: obesity, diabetes, arthritis (may affect likelihood of exercise), time constraints Review with students the current American Heart Association blood pressure guidelines (available on the organization’s website). If diet and exercise are not effective, single-drug therapy is begun. If this is not effective, combination therapy is begun with several drugs.
Through vessel dilation, these medications reduce the blood flow and workload of the vessels and the heart. Why is orthostatic hypotension a common side effect for this class of drugs?
Clonidine also may be used to control impulsivity in the hyperactive child or the child with attention deficit disorder. It does not increase school performance. Side effects of Aldomet are drowsiness, impotence, and gynecomastia.
Alpha-blocking agents include prazosin hydrochloride (Minipress), terazosin hydrochloride (Hytrin), and doxazosin mesylate (Cardura). Alpha-blocking agents are also used to treat benign prostatic hypertrophy (BPH) or hyperplasia.
These medications affect peripheral arterioles, arteries and arterioles of the heart, and cardiac muscle. They have no effect on the veins. These medications also affect the sites of the electrical conduction of the heart: the SA and AV nodes.
These medications must be used carefully with digoxin. How does the action of beta-blocking agents differ from calcium channel–blocking agents? Common side effects include bradycardia, AV block, exacerbation of heart failure, reflex tachycardia, dizziness, and peripheral edema.
Calcium salts include calcium gluconate, calcium chloride, and calcium lactate.
Drugs include the following: Phytonadione (vitamin K 1 oxide), (Mephyton) Phytonadione injection (AquaMEPHYTON) Administered by the oral or intravenous route. Intravenous administration may cause a severe adverse reaction. Vitamin K injection is administered at birth because infants are bone deficient in vitamin K and are at risk for neonatal hemorrhage.
Prothrombin time (PT) is used to evaluate the effectiveness of warfarin and guard against overdose. International normalized ratio (INR) is a system of standardizing the PT values. What is meant when patients say they take a “blood thinner”? How does an anticoagulant agent “thin” the blood?
Subcutaneous administration is seldom used because of the risk for bruising and bleeding. Heparin is used for prevention and treatment of pulmonary embolism, arterial emboli, and treatment of consumption coagulopathies (like disseminated intravascular coagulation [DIC]). Heparin encourages the antithrombin activity by altering the thrombin part of the clotting cascade.
The lab value activated partial thromboplastin time (aPTT) is used to monitor response to therapy and coagulation. Normal aPTT is approximately 40 seconds. Treatment range for aPTT is usually between 60 and 80 seconds (depends on the patient situation). Review the patient situations that would require heparin treatment. What are the signs and symptoms of the side effects of heparin?
Advantages over unfractionated heparin agents: May be given by subcutaneous injection Have a longer half-life, and thus may be administered less frequently Lower incidence of antiplatelet formation and HIT May be given on a fixed schedule. No need to monitor aPTT because of the low molecular weight. Low–molecular-weight heparin is more expensive than heparin, but many patients can remain at home and self-administer this treatment.
The dose is based on body weight. This medication may be given as prophylaxis to prevent deep vein thrombosis. It may be used to treat an active deep vein thrombosis. Review with students the patient teaching regarding subcutaneous administration, home care, and use of this medication.
Lepirudin directly inhibits thrombin formation. It is used to reverse HIT while maintaining the anticoagulation in the patient. Common side effects include back pain, nausea, hypotension, and hemorrhage.
Heparin must be given for initial treatment while coumarin is being started. Neither large loading doses nor administration using the intramuscular or intravenous route hastens antithrombotic action.
Dose may be adjusted by using the PT or INR.
This therapy is used for acute myocardial infarction, deep vein thrombosis, and massive pulmonary emboli. For myocardial infarction treatment, therapy must be administered within 4 to 6 hours of symptom presentation. Common side effects include hemorrhage, antibody production, fever, and hypotension.
These medications prevent thrombus formation in the arteries. An anticoagulant agent is used to prevent thrombus formation in the veins. They are useful for the prevention of a myocardial infarction (either initial or recurring). They are useful for decreasing the risk for stroke for patients with history of transient ischemic attacks (TIAs).
These medications increase the risk of gastrointestinal bleeding and also increase the risk of hemorrhage and hemorrhagic stroke.
Present guidelines recommend obtaining a complete lipoprotein and triglyceride profile every 5 years beginning at age 20. A low blood cholesterol level is unattainable for many patients using diet alone. Atherosclerosis is the fatty streak in the arterial wall. Atherosclerosis encourages fibrin formation and subsequent thrombi.
Many lipid-lowering drugs must be taken later in the day, with the evening meal. Some drugs decrease production of cholesterol. Others increase the removal of cholesterol from the bloodstream.
Lab testing of lipid levels and liver enzymes is necessary.