Review Chapter 42 and answer the following questions:
You are the nurse in a cardiologist’s office. Describe how you would explain to a new cardiac patient the conduction system of the heart. Be sure to include the correlation between the normal ECG with cardiac electrical activity.
The cardiac conduction system is made up of the sinoatrial (SA) node, the atrial bundles, the atrioventricular (AV) node, the bundle of His, the bundle branches, and the Purkinje fibers. During conduction, the cells in the SA node generate an impulse that is transmitted through the AV node before being sent down to the bundle of His into the ventricles. When the cardiac muscle cells are stimulated, contraction occurs. An electrocardiogram (ECG) measures the electrical activity of the heart. A normal ECG is made up of five waves: the P wave, the QRS complex, and the T wave. The P wave precedes the contraction of the atria. The QRS complex precedes the contraction of the ventricles. The T wave precedes the relaxation of the ventricles.
What are the mechanisms that control blood pressure? How do they influence blood pressure?
Blood pressure is maintained by the stimulus from the sympathetic nervous system and reflex control of blood volume and pressure by the renin-angiotension system and the aldosterone-ADH system. Hypotension and hypertension are the two main alterations of blood pressure and these two systems work to keep the cardiovascular system balanced.
Review Chapter 43 and answer the following questions:
Identify the 3 normal controls of blood pressure and how angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), calcium channel blockers, and vasodilators affect these controls. What are common concerns of using these different types of medications across the lifespan? You may use a table format if you wish.
Blood pressure in the cardiovascular system is determined by heart rate, stroke volume, and total peripheral resistance.
Drug Class Effects Concerns
Angiotensin-Converting Enzyme Inhibitors Decrease in BP and cardiac workload associated with decrease in peripheral resistance and blood volume. Caution should be used in patients with heart failure. Contraindicated during pregnancy. Effects decrease if taken with food.
Angiotensin II Receptor Blockers Decrease in BP by blocking vasoconstriction. Caution should be used in presence of hepatic or renal dysfunction. Contraindicated during pregnancy.
Calcium-Channel Blockers Decrease BP, cardiac workload, and myocardial oxygen consumption. Caution should be used in presence of hepatic or renal dysfunction. Contraindicated during pregnancy. Should not be taken with grapefruit juice.
Vasodilators Decrease BP and causes muscle relaxation and vasodilation. Caution for patients with peripheral vascular disease, CAD, HF, or tachycardia. Contraindicated during pregnancy.
Access the NIH (National Institutes of Health) website and access information about the National Heart, Lung, and Blood Institute information, specifically information pertaining to patient teaching on hypertension and pick 5 items that are pertinent to a patient with hypertension and write them up.
Receive routine follow-up care.
Monitor own conditions.
Plan for pregnancy with primary care provider.
Prevent worsening high blood pressure by making heart-healthy lifestyle changes.
Learn the warning signs of serious complications and have a plan.
Review Chapter 44 and answer the following questions:
Compare and contrast the 3 drugs digoxin, inamrinone, and digoxin immune fab. You may use the Internet and a table format if you wish.
Digoxin decreases myocardial workload and relieves HF. Digoxin is an antidote for overdose of digoxin. Inamrinone is used for patients who have not responded to digoxin alone.
A patient is taking a carditonic agent. Why is the patient taking this drug? What nursing interventions and assessments are important when caring for this patient? What teaching points are necessary for the patient prior to discharge from the hospital?
Cardiotonic drugs affect the intracellular calcium levels in the heart, leading to increased contractility. This leads to increased cardiac output and overall decrease in heart workload. Patients should learn to take their own pulse and keep track of rate and regularity on a calendar. Patients should also monitor their own weight to monitor for fluid retention.
Describe the pathophysiology of heart failure. What are the clinical signs and symptoms of heart failure? Be sure to include information on the compensatory mechanisms for heart failure to maintain cardiac function and what happens if these mechanisms begin to fail.
HF is when the heart fails to pump blood around the body effectively. Any failure of the muscle to pump blood out of the heart can result in backup of blood, which doesn’t allow the body’s cells to get oxygen and nutrients. If left side is inefficient, this results in pulmonary edema, rales, wheezes, blood-tinged sputum. If right side is inefficient, this results in lover congestion, edema in legs and feet. Decreased cardiac output stimulates baroreceptors, causing a sympathetic stimulation, which causes an increase in HR, BP, and rate and depth of respirations as a compensatory mechanism. If these mechanisms fail the heart begins to become overworked. Causing hypertrophy.
List 3 essential nursing measures required to be implemented when using digoxin in pediatric patients. List 3 essential nursing measures required to be implemented when using digoxin in geriatric patients.
Children: carefully calculate dosage, monitor for signs of impending digitalis toxicity, monitor serum digoxin levels.
Geriatric: reduce dosage is renal dysfunction, monitor for toxic effects, check drug regimen and drug-drug interactions.
Review Chapter 45 and answer the following questions:
What nursing measures are essential when giving antiarrhythmic drugs to adults? What teaching points are important for the nurse to provide to the patient taking antiarrhythmic drugs?
Assess neurological status, assess cardiac status, monitor respiratory rate and depth, obtain baseline ECG.
Teach patient name of drug, prescribed dosage, measure to avoid adverse effects, warning signs of problems, and need for periodic monitoring and evaluation with primary care provider.
Compare and contrast the prototype drugs lidocaine, propranolol, amiodarone, and diltiazem. Describe similarities and differences and the therapeutic effect of each drug.
Drug Antiarrhythmic Class Indications Actions
Lidocaine Class I Manages acute ventricular arrhythmias during cardiac surgery or MI. Decreases depolarization, decreases automaticity of ventricular cells, increases ventricular fibrillation threshold.
Propanolol Class II Treatment of cardiac arrhythmias, treatment of ventricular tachycardia induced by digitalis. Blocks beta-adrenergic receptors in the heart and kidney, decreases influence of sympathetic nervous system.
Amiodarone Class III Treatment of life-threatening ventricular arrhythmias. Acts directly on heart cells to prolong repolarization and refractory period, acts on peripheral smooth muscle to decrease peripheral resistance.
Diltiazem Class IV Treatment of paroxysmal supraventricular tachycardia, atrial fibrillation, atrial flutter. Blocks movement of calcium ions across cell membrane, depressing generation of action potentials, delaying phases 1 and 2 of repolarization, slowing conduction through AV node.
Review Chapter 46 and answer the following questions:
Explain the pathophysiology of coronary artery disease and describe the signs and symptoms of coronary artery disease.
In CAD, lumen of blood vessels become narrowed so that blood does not flow freely to muscle cells. Narrowing of vessels is caused by atheromas (fatty tumors) building up in arteries through a process called atherosclerosis. S;S: angina pectoris, acute myocardial infarction.
Describe the differences between stable and unstable angina.
Stable angina is pain due to the imbalance of myocardial oxygen supply and demand; pain is relieved by rest or stoppage of activity.
Unstable angina is episode of myocardial ischemia with pain due to imbalance of myocardial oxygen supply and demand when person is at rest.
What is Prinzmetal’s angina?
It is the drop in blood flow through the coronary arteries cause by a vasospasm in the artery, not by atherosclerosis.