Perfusion PrepU
Drugs given with coronary artery stent
Because of the risk of thrombus formation within the stent, the patient receives antiplatelet medications, usually aspirin and clopidogrel. Aspirin should be continued indefinitely and clopidogrel is continued for 1 year following stent placement
A client with known coronary artery disease reports intermittent chest pain, usually on exertion. When teaching the client about nitroglycerin administration, which instruction should the nurse provide? "Be sure to take safety precautions because nitroglycerin may cause dizziness when you stand up." "Replace leftover sublingual nitroglycerin tablets every 9 months to make sure your pills are fresh." "A burning sensation after administration indicates that the nitroglycerin tablets are potent." "You may take a sublingual nitroglycerin tablet every 30 minutes, if needed. You may take as many as four doses."
Correct response: "Be sure to take safety precautions because nitroglycerin may cause dizziness when you stand up." Explanation: Nitroglycerin commonly causes orthostatic hypotension and dizziness. To minimize these problems, the nurse should teach the client to take safety precautions, such as changing to an upright position slowly, climbing up and down stairs carefully, and lying down at the first sign of dizziness. To ensure the freshness of sublingual nitroglycerin, the client should replace tablets every 6 months, not every 9 months, and store them in a tightly closed container in a cool, dark place. Many brands of sublingual nitroglycerin no longer produce a burning sensation. The client should take a sublingual nitroglycerin tablet at the first sign of angina. He may repeat the dose every 5 minutes for up to three doses; if this intervention doesn't bring relief, the client should seek immediate medical attention.
A client asks the purpose of an exercise stress test. What is the nurse's best response? "This will help you endure exercise." "This is to assess your tolerance of isometric exercise." "This test is necessary prior to starting medication therapy for obesity." "The test is used to measure functional status during stress."
Correct response: "The test is used to measure functional status during stress." Explanation: The exercise stress test is used to measure aerobic fitness. It does not help the client endure exercise or assess tolerance of isometric exercise. It is not done prior to starting medication therapy for obesity.
A client asks why he has not had major heart damage since his cardiac catheterization revealed he has 98% blockage of the right coronary artery. The nurse's best response is: "You must have been taking a blood thinner for a long time." "You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." "You are just a lucky person since most people would have had a massive heart attack by now." "With this amount of blockage, your red blood cells get through the vessel one by one and supply oxygen to the muscle."
Correct response: "You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." Explanation: Collateral circulation is a mechanism for the long-term regulation of local blood flow. In the heart, anastomotic channels exist between some of the smaller arteries. These channels permit perfusion of an area by more than one artery. When one artery becomes occluded, these anastomotic channels increase in size, allowing blood from a patent artery to perfuse the area supplied by the occluded vessel. For example, persons with extensive obstruction of a coronary blood vessel may rely on collateral circulation to meet the oxygen needs of the myocardial tissue normally supplied by that vessel. There is no indication that the client is on a blood thinner.
The nurse is teaching a client with suspected acute myocardial infarction about serial isoenzyme testing. When is it best to have isoenzyme creatinine kinase of myocardial muscle (CK-MB) tested? 30 minutes to 1 hour after pain 2 to 3 hours after admission 4 to 6 hours after pain 12 to 18 hours after admission
Correct response: 4 to 6 hours after pain Explanation: Serum CK-MB levels can be detected 4 to 6 hours after the onset of chest pain. These levels peak within 12 to 18 hours and return to normal within 3 to 4 days.
To be effective, percutaneous transluminal coronary angioplasty (PTCA) must be performed within what time frame, beginning with arrival at the emergency department after diagnosis of myocardial infarction (MI)? 30 minutes 60 minutes 9 days 6 to 12 months
Correct response: 60 minutes Explanation: The 60-minute interval is known as "door-to-balloon time" in which a PTCA can be performed on a client with a diagnosed MI. The 30-minute interval is known as "door-to-needle time" for the administration of thrombolytics after MI. The time frame of 9 days refers to the time until the onset of vasculitis after administration of streptokinase for thrombolysis in a client with an acute MI. The 6- to 12-month time frame refers to the time period during which streptokinase will not be used again in the same client for acute MI.
The nurse administers propranolol hydrochloride to a patient with a heart rate of 64 beats per minute (bpm). One hour later, the nurse observes the heart rate on the monitor to be 36 bpm. What medication should the nurse prepare to administer that is an antidote for the propranolol? Digoxin Atropine Protamine sulfate Sodium nitroprusside
Correct response: Atropine Explanation: Sheath removal and the application of pressure on the vessel insertion site may cause the heart rate to slow and the blood pressure to decrease (vasovagal response). A dose of IV atropine is usually given to treat this response.
A middle-aged client presents to the ED reporting severe chest discomfort. Which finding is most indicative of a possible myocardial infarction (MI)? Chest discomfort not relieved by rest or nitroglycerin Intermittent nausea and emesis for 3 days Cool, clammy skin and a diaphoretic, pale appearance Anxiousness, restlessness, and lightheadedness
Correct response: Chest discomfort not relieved by rest or nitroglycerin Explanation: Chest pain or discomfort not relieved by rest or nitroglycerin is associated with an acute MI. The other findings, although associated with acute coronary syndrome or MI, may also occur with angina and, alone, are not indicative of an MI.
What response to exercise should be further assessed? Client's heart rate increases from 70 to 100 beats per minute. Client's respiratory rate increases from 12 to 24 breaths per minute. Client's blood pressure decreases from 130/90 to 80/50 mm Hg. Client's venous return to the heart is increased.
Correct response: Client's blood pressure decreases from 130/90 to 80/50 mm Hg. Explanation: Blood pressure should increase with exercise as the increased sympathetic activity constricts the resistance vessels. The decrease in blood pressure needs to be assessed further as this is not an expected response to exercise. The other assessments are expected with exercise.
A client had a percutaneous transluminal coronary angioplasty (PTCA). What medication will the nurse administer to prevent thrombus formation in the stent? Clopidogrel Isosorbide mononitrate Metoprolol Diltiazem
Correct response: Clopidogrel Explanation: Because of the risk of thrombus formation following a coronary stent placement, the patient receives antiplatelet medications, such as clopidogrel or aspirin. Isosorbide mononitrate is a nitrate used for vasodilation. Metoprolol is a beta blocker used for relaxing blood vessels and slowing heart rate. Diltiazem is a calcium channel blocker used to relax heart muscles and blood vessels.
A nurse is caring for a client who experienced an MI. The client is ordered to received metoprolol. The nurse understands that this medication has which therapeutic effect? Decreases resting heart rate Decreases cholesterol level Increases cardiac output Decreases platelet aggregation
Correct response: Decreases resting heart rate Explanation: The therapeutic effects of beta-adrenergic blocking agents such as metoprolol are to reduce myocardial oxygen consumption by blocking beta-adrenergic sympathetic stimulation to the heart. The result is reduced heart rate, slowed conduction of impulses through the conduction system, decreased blood pressure, and reduced myocardial contractility to balance the myocardial oxygen needs and amount of oxygen available. This helps to control chest pain and delays the onset of ischemia during work or exercise. This classification of medication also reduces the incidence of recurrent angina, infarction, and cardiac mortality. In general, the dosage of medication is titrated to achieve a resting heart rate of 50-60 bpm. Metoprolol is not administered to decrease cholesterol levels, increase cardiac output, or decrease platelet aggregation.
The nurse is administering a calcium channel blocker to a patient who has symptomatic sinus tachycardia at a rate of 132 bpm. What is the anticipated action of the drug for this patient? Decreases the sinoatrial node automaticity Increases the atrioventricular node conduction Increases the heart rate Creates a positive inotropic effect
Correct response: Decreases the sinoatrial node automaticity Explanation: Calcium channel blockers have a variety of effects on the ischemic myocardium. These agents decrease sinoatrial node automaticity and atrioventricular node conduction, resulting in a slower heart rate and a decrease in the strength of myocardial contraction (negative inotropic effect).
A client comes to the emergency department reporting chest pain. An electrocardiogram (ECG) reveals myocardial ischemia and an anterior-wall myocardial infarction (MI). Which ECG characteristic does the nurse expect to see? Prolonged PR interval Absent Q wave Elevated ST segment Widened QRS complex
Correct response: Elevated ST segment Explanation: Ischemic myocardial tissue changes cause elevation of the ST segment, an inverted T wave, and a pathological Q wave. A prolonged PR interval occurs with first-degree heart block, the least dangerous atrioventricular heart block; this disorder may arise in healthy people but sometimes results from drug toxicity, electrolyte or metabolic disturbances, rheumatic fever, or chronic degenerative disease of the conduction system. An absent Q wave is normal; an MI may cause a significant Q wave. A widened QRS complex indicates a conduction delay in the His-Purkinje system.
Which is the most important postoperative assessment parameter for a client recovering from cardiac surgery? Inadequate tissue perfusion Mental alertness Blood glucose concentration Activity intolerance
Correct response: Inadequate tissue perfusion Explanation: The nurse must assess the client for signs and symptoms of inadequate tissue perfusion, such as a weak or absent pulse, cold or cyanotic extremities, or mottling of the skin. Although the nurse does assess blood glucose and mental status, tissue perfusion is the higher priority. Assessing for activity intolerance, while important later in the recovery period, is not essential in the immediate postoperative period for clients undergoing cardiac surgery.
The nurse notes that the post cardiac surgery client demonstrates low urine output (< 25 mL/hr) with high specific gravity (> 1.025). What will the nurse anticipate the health care provider will order? Increase intravenous fluids Decrease intravenous fluids Irrigate the urinary catheter Prepare the client for dialysis
Correct response: Increase intravenous fluids Explanation: Urine output of less than 25 mL/hr may indicate a decrease in cardiac output. A high specific gravity indicates increased concentration of solutes in the urine, which occurs with inadequate fluid volume. The health care provider may increase intravenous fluids. Irrigating the urinary catheter will be done if there is a suspected blockage. Dialysis is not indicated by urinary volumes.
A backflow of blood is noted in the left ventricle from the left atrium. The patient is suffering from a defect in which valve? Mitral valve Tricuspid valve Pulmonic valve Aortic valve
Correct response: Mitral valve Explanation: The mitral valve separates the left atrium and left ventricle. This malfunction allows the backflow of blood due to a defect in the mitral valve. The tricuspid valve separates the right atrium and right ventricle. The pulmonic valve separates the right ventricle and pulmonary artery. The aortic valve separates the left ventricle and aorta.
Which discharge instruction for self-care should the nurse provide to a client who has undergone a percutaneous transluminal coronary angioplasty (PTCA) procedure? Cleanse the site with disinfectants and dress the wound appropriately Refrain from sexual activity for 1 month Monitor the site for bleeding or hematoma. Normal activities of daily living can be resumed the first day after surgery
Correct response: Monitor the site for bleeding or hematoma. Explanation: The nurse provides certain discharge instructions for self-care, such as monitoring the site for bleeding or the development of a hard mass indicative of hematoma. A nurse does not advise the client to clean the site with disinfectants or refrain from sexual activity for 1 month.
The nurse is teaching a client diagnosed with coronary artery disease about nitroglycerin. What is the cardiac premise behind administration of nitrates? Preload is reduced. More blood returns to the heart. It increases myocardial oxygen consumption. It functions has a vasoconstrictor.
Correct response: Preload is reduced. Explanation: Nitroglycerin dilates primarily the veins, and in higher dosages, also the arteries. Dilation of the veins causes venous pooling of the blood throughout the body. As a result, less blood returns to the heart, and filling pressure (preload) is reduced. Nitroglycerine is administered to reduce myocardial oxygen consumption, which decreases ischemia and relieves pain.
The nurse is caring for a client following a coronary artery bypass graft (CABG). The nurse notes persistent oozing of bloody drainage from various puncture sites. The nurse anticipates that the physician will order which medication to neutralize the unfractionated heparin the client received? Protamine sulfate Alteplase Clopidogrel Aspirin
Correct response: Protamine sulfate Explanation: Protamine sulfate is known as the antagonist for unfractionated heparin (it neutralizes heparin). Alteplase is a thrombolytic agent. Clopidogrel is an antiplatelet medication that is given to reduce the risk of thrombus formation after coronary stent placement. The antiplatelet effect of aspirin does not reverse the effects of heparin.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? Depolarization of the sinoatrial node Depolarization of the ventricular conduction system Repolarization of the atrium Repolarization of the ventricles
Correct response: Repolarization of the ventricles Explanation: The P wave represents the depolarization of the sinoatrial node. The QRS complex represents the depolarization of the ventricles. The T wave represents repolarization of the ventricles, not the atrium.
Which serum biomarker is highly specific for myocardial tissue? Troponin Creatine kinase White blood cells C-reactive protein
Correct response: Troponin Explanation: The troponin assays have high specificity for myocardial tissue and have become the primary biomarker tests for the diagnosis of myocardial infarction. Creatine kinase is specific for muscle injury but is not as focused as is troponin. White blood cells and C-reactive protein are associated with inflammation.
The client has had biomarkers tested after reporting chest pain. Which diagnostic marker of myocardial infarction remains elevated for as long as 2 weeks? Myoglobin Troponin Total creatine kinase CK-MB
Correct response: Troponin Explanation: Troponin remains elevated for a long period, often as long as 2 weeks, and it therefore can be used to detect recent myocardial damage. Myoglobin peaks within 12 hours after the onset of symptoms. Total creatine kinase (CK) returns to normal in 3 days. CK-MB returns to normal in 3 to 4 days.
The nurse is caring for a client with severe coronary artery disease (CAD) who is experiencing chest pain because the oxygen demand exceeds supply. What forces could potentially be lowered to reduce oxygen consumption? Select all that apply. pulse pressure afterload stretch on the ventricles heart rate preload
Correct response: afterload stretch on the ventricles heart rate preload Explanation: The primary forces that determine the heart's use of oxygen or oxygen consumption include: heart rate (the more the heart has to pump, the more oxygen it requires), preload (the more blood that is returned to the heart, the harder it will have to work to pump the blood around), afterload (the higher the resistance in the system, the harder the heart will have to contract to force open the valves and pump the blood along), and stretch on the ventricles (if the ventricular muscle is stretched before it is stimulated to contract, more actomyosin bridges will be formed, which will take more energy). Pulse pressure does not impact oxygen consumption, though lowering blood pressure reduces afterload.
When describing Starling's law of the heart, the instructor compares this to: moving up and down on a staircase stretching of a rubber band pushing and pulling of a rope flowing of water through a pipe
Correct response: stretching of a rubber band Explanation: Starling's law of the heart is often compared with the stretching of a rubber band, such that the heart returns to its normal size after it is stretched—the further it is stretched, the stronger is the spring back to normal.