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nursing 2 cardiac
cardiac/ecg
Question | Answer |
---|---|
Depolarization | electrical activation of cell caused by influx of sodium into cell while potassium exits cell |
Repolarization | return of cell to resting state caused by re-entry of potassium into cell while sodium exits |
Effective refractory period | phase in which cells are incapable of depolarizing |
Relative refractory period | phase in which cells require stronger-than-normal stimulus to depolarize |
Stroke volume | amount of blood ejected with each heartbeat |
Cardiac output | amount of blood pumped by ventricle in liters per minute Changes in cardiac output can be affected by changes in either stroke volume or heart rate, so a low heart rate can decrease cardiac output, Stroke Volume x Heart Rate |
Preload | the amount of blood presented to the ventricle just before systole |
Contractility | the force of the contraction, is related to the status of the myocardium |
After load | the amount of resistance to the ejection of blood from the ventricle |
Ejection fraction | percent of end diastolic volume ejected with each heart beat |
Control of heart rate (2) | Autonomic nervous system, baroceptors |
Baroreceptors | specialized nerve cells in the aortic arch and in both right and left internal carotid arteries. Sensitive to changes in BP. High BP, transmit impulses to decrease HR. Low BP, transmit impulses to increase HR. |
Control of stroke volume (3) | Preload, After load, Contractility |
Where does the nurse auscultate the apex of the heart? | Fifth intercoastal space |
Cardiac biomarkers | myocardial cells that become necrotic from prolonged ischemia or trauma and release specific enzymes |
CK, CK-MB | cardiac biomarker |
Myoglobin | cardiac biomarker |
Troponin T and I | cardiac biomarker |
Lipid profile | cholesterol, triglycerides, lipoproteins |
Brain (B-type) natriuretic peptide | neurohormone that helps regulate BP and fluid volume |
C-reactive protein | a protein produced by the liver in response to systemic inflammation – thought to play a role in development and progression of atherosclerosis |
Homocysteine | an amino acid linked to development of athersclerosis |
Cardiac Catherization | Invasive procedure study used to measure cardiac chamber pressures, assess patency of coronary arteries Requires ECG, hemodynamic monitoring; emergency equipment must be available |
Dysrhythmias | Disorders of formation or conduction (or both) of electrical impulses within heart |
Normal Sinus Rhythm (NSR) | rate = 60-100 bpm in adult. Rate is regular. QRS is usually normal, but can be regularly abnormal. P-wave is normal, consistent in shape and always in front of the QRS. PR interval between 0.12 – 0.20 sec |
Sinus Bradycardia | Looks like NSR, but rate is less than 60 in an adult |
Sinus Tachycardia | Looks like NSR, but rate >100, but usually <120 in adult |
Sinus Arrhythmia | Rate 60-100 in adult. Irregular rhythm. QRS usually normal, may be regularly abnormal. P-wave normal and consistent shape. PR interval 0.12-0.20. |
Premature Atrial Complexes (PAC) | P-wave may be early or hidden in the QRS. PR interval shorter than normal. |
Atrial Flutter | Atrial rate 250-400 and regular, Ventricular rate 75-150 and can be regular or irregular. QRS usually normal, may be abnormal. P-wave is saw-toothed shape. PR interval – multiple waves make it difficult to determine |
Atrial Fibrillation | Atrial rate 300-600, ventricular rate 120-200, both highly irregular. QRS usually normal, may be abnormal. No discernable P-wave. PR interval cannot be measured |
paroxysmal | starting and stopping suddenly and occurring for a very short time |
Premature Ventricular Contraction (PVC) | an impulse that starts in a ventricle and is conducted through the ventricles before the next normal sinus impulse. |
Ventricular Tachycardia | Ventricular rate 100-200, usually regular. QRS is 0.12 sec or more, bizarre, abnormal shape. P-wave very difficult to detect. PR interval very irregular if can even see P waves. |
Ventricular Fibrillation | The most common dysrhythmia in patients with cardiac arrest. Ventricular rate >300 and extremely irregular. QRS irregular and undulating. There is always an absence of an audible heartbeat. This rhythm is fatal if not treated immediately |
Asystole | Flatline. Absent QRS complexes. No heartbeat. No palpable pulse. No respirations. Without immediate treatment, it is fatal. |
Percutaneous Coronary Intervention | Balloon used to open the occluded coronary artery |
Coronary Artery Bypass Grafts | Greater and lesser saphenous veins are commonly used for bypass graft procedures |
Cardiopulmonary Bypass System | The procedure mechanically circulates and oxygenates blood for the body while bypassing the heart and the lungs |
Myocardial Infarction | An area of the myocardium is permanently destroyed. Usually caused by reduced blood flow in a coronary artery due to rupture of an atherosclerotic plaque and subsequent occlusion of the artery by a thrombus. |
Angina Pectoris | A syndrome characterized by episodes or paroxysmal pain or pressure in the anterior chest caused by insufficient coronary blood flow. |
Myocardial Ischemia | The most common symptom of myocardial ischemia is chest pain, atypical symptoms such as weakness, dyspnea, and nausea more common in women and in persons who are older, or who have a history of heart failure or diabetes. |
Cardiovascular disease | the leading cause of death in the United States for men and women of all racial and ethnic groups. |
Coronary artery disease (CAD) | the most prevalent cardiovascular disease in adults. |
Coronary Atherosclerosis | the abnormal accumulation of lipid deposits and fibrous tissue within arterial walls and lumen, blockages and narrowing of the coronary vessels reduce blood flow to the myocardium. |
Angina Pectoris | characterized by episodes or paroxysmal pain or pressure in the anterior chest caused by insufficient coronary blood flow. |
Stable Angina | predictable and consistent pain that occurs on exertion and is relieved by rest and/or nitroglycerin |
Unstable Angina | symptoms increase in frequency and severity; may not be relieved with rest or nitroglycerin |
Treatment angina pectoris | The nurse should direct the patient to stop all activities and sit or rest in bed in a semi-fowler’s position to reduce the oxygen requirements of the ischemic myocardium |
Percutaneous Coronary Intervention | Balloon used to open the occluded coronary artery |
Coronary Artery Bypass Grafts | Greater and lesser saphenous veins |
Cardiopulmonary Bypass System | The procedure mechanically circulates and oxygenates blood for the body while bypassing the heart and the lungs |
Heart failure | the inability of the heart to pump sufficient blood to meet the needs of the tissues for oxygen and nutrients characterized by fluid overload or inadequate tissue perfusion. |
Intractable or refractory angina | severe incapacitating chest pain |
Variant angina | (Prinzmetal’s angina) pain at rest with reversible ST-segment elevation; thought to be caused by coronary artery vasospasm |
Silent ischemia | objective evidence of ischemia (such as ECG changes with a stress test), but patient reports no pain |
Nitroglycerin | very unstable, so it should always be carried securely in it original container (i.e. capped dark glass bottle), otherwise it will lose it’s potency |
Beta-adrenergic blocking agents | to reduce myocardial oxygen consumption |
Calcium channel blocking agents | to decrease SA node automaticity and AV node conduction to decrease the workload of the heart |
Antiplatelet and anticoagulant medications | prevent platelet aggregation and subsequent thrombosis |
Myocardial Infarction | An area of the myocardium is permanently destroyed. Usually caused by reduced blood flow in a coronary artery due to rupture of an atherosclerotic plaque and subsequent occlusion of the artery by a thrombus. |
Treatment MI(3) | Oxygen, Morphine Sulphate, and Bed Rest |
Right-sided failure | Right-Ventricle (RV) cannot eject sufficient amounts of blood and blood backs up in the venous system. periperal edema, acites, hepatomegaly |
Left-sided failure | Left-Ventricle (LV) cannot pump blood effectively to the systemic circulation. Pulmonary venous pressures increase. dyspnea, crackles |
Chronic heart failure | frequently biventricular – both right-sided and left-sided |
BNP | key diagnostic indicator of HF |
Angiotensin converting enzyme inhibitors (ACE Inhibitors) | recommended for use in the prevention of Heart Failure in patients who are at risk. Play a pivotal role in the management of systolic HF Vasotec (enalapril) |
Angiotensin II receptor blockers (ARB) | Used for the management of CHF in patients who cannot tolerate ACE Inhibitors Diovan (valsartan) |
Beta-Blockers | Block norepinephrine and epinephrine, Reduce myocardial oxygen consumption by blocking beta adrenergic sympathetic stimulation to the heart, Reduce by slowing SA node and AV node conduction, Side Effects Postural Hypotension Lopressor |
Diuretics | Remove excess extracellular fluid by increasing the rate of urine produced Loop-Lasix(furosemide)Thiazide or Thiazide-Like Esidrix hydrochlorothiazide Aldosterone Blocking (Potassium Sparing)Aldactone (Spironolactone) |
Digitalis | increases the force of the myocardial contraction and slows the conduction through the AV node, improves contractility, increases left ventricular output and enhances dieresis.Therapeutic serum levels 0.5-2 ng/mL. maintenance dose 0.125-0.5 mg/day |
Calcium Channel Blockers | are contraindicated in patients with systolic HF, but may be used in patients with diastolic HF. They decrease SA and AV node conduction, decreasing the workload of the heart.Norvasc (amlodipine) |
Dobutamine | given IV for patients with significant left ventricular dysfunction or hypoperfusion. It acts to increase cardiac contractility |
Pulmonary Edema | Acute event, Left Ventricle cannot handle an overload of blood volume, Pressure increases in the pulmonary vasculature, causing fluid movement out of the pulmonary capillaries and into the interstitial space of the lungs and alveoli, Results in hypoxemia. |
Signs of Pulmonary edema | hacking cough, fatigue, weight gain, development or worsening edema, and decreased activity tolerance |
Cardiogenic Shock | life-threatening condition with a high mortality rate, Decreased cardiac output leads to inadequate tissue perfusion and initiation of shock syndrome. |
Pulmonary embolism | blood clot from the legs moves to obstruct the pulmonary vessels. |
Pericardial effusion | is the accumulation of fluid in the pericardial sac |
Cardiac tamponade | is the restriction of heart function due a decrease in venous return and decreased cardiac output (is a result of pericardial effusion) Cardinal signs falling systolic BP, narrowing pulse pressure, rising venous pressure, distant heart sounds. |
Regurgitation | the valve does not close properly and blood backflows through the valve. |
Stenosis | the valve does not open completely and blood flow through the valve is reduced. |
Valve prolapse | the stretching of an atrioventricular valve leaflet into the atrium during diastole. |