CARDIAC + CCRN Questions cardiac

Acute Coronary Syndrome (definition) - answer-Syndrome of acute myocardial ischemia caused by atherosclerotic plaque rupture and thrombus formation Acute Coronary Syndrome (etiology) - answer-Same as Coronary Artery Dz, Angina Pectoris, and Myocardial Infarction Coronary Artery Disease (definition) - answer-A progressive disease of the coronary arteries that results in their narrowing of obstruction CAD (pathophysiology) - answer-1.Arteriosclerosis: a group of diseases characterized by thickening and loss of elasticity (calcification) of arterial walls 2. Atherosclerosis: the most common form of arteriosclerosis. a. A chronic disease process characterized by the build-up of fatty plague along the subintimal layer of arteries leading to a decrease in arterial luman. 3. Decreased blood flow and oxygen supply to the myocardium lead to imbalance between oxygen supply and oxygen demand. a. Gradual or partial occlusion: ischemia causing angina b. Sudden or complete occlusion: necrosis causing MI Pathologic Consequence of Atherosclerosis and Arteriosclerosis - answer-1. Angina pectoris 2. MI 3. Heart failure 4. Dysrhythmias caused ischemia 5. Sudden death Angina Pectoris (etiology) - answer-Factors that decrease supply a. Arteriosclerosis/atherosclerosis b. Coronary artery spasm c. Aortitis d. Dysrhythmias e. Anemia f. Shock Factors that increase demand: a. HTN b. Aortic valve dz c. Tachydysrhythmias d. HF e. Hyperthyroidism Angina Pectoris (clinical presentation - subjective) - answer-1. Subjective a. Substernal chest discomfort that usually lasts 1 to 4 minutes and subsides with rest and/or nitro use. 1. Discomfort may be described as burning, squeezing, tightness, pressure, heaviness, indigestion, or aching. 2. Pain may radiate to shoulders, back, arms, jaw, neck, and epigastrium b. Dyspnea c. N/V d. Anxiety e. Weakness Angina Pectoris (objective) - answer-a. Tachycardia b. Hypotension or HTN c. Tachypnea d. Pallor e. Diaphoresis g. S4 Angina Pectoris (Diagnostic) - answer-a. Serum 1. Isoenzymes: negative for cardiac damage 2. Fasting glucose: to identify DM or glucose intolerance as a risk factor b. ECG 1. ST segment depression in unstable angina 2. ST segment elevation in variant angina 3. Ventricular dysrhythmias may be present c. Cardiac cauterization: coronary artery occlusion 75% or greater; may be negative in variant angina but develop occlusion from spasm Types of Angina - answer-Stable and Unstable Angina Stable Angina (signs and symptoms) - answer-- Unchanging frequency, duration, and severity - Predictable to the patient - ST segment depression may occur during pain Angina Pectoris (Collaborative Management) - answer-1. Relieve chest pain a. Nitro b. Calcium channel blockers (especially for variant angina) c. Morphine sulfate may be required for unstable angina 2. Increase oxygen demand a. nasal canula 5L/min during ischemic pain unless contraindicated by lung dz. b. Blood transfusion if angina caused by anemia c. Platelet aggregation inhibitors (e.g., aspirin or ticlopidine to prevent platelet aggregation; heparin may be prescribed to prevent clotting or extension of clot d. IABP - may be used in unstable angina; IABP increases coronary artery perfusion pressure (CAPP) 3. Decrease oxygen demand a. Removal of provoking factors 1. Activity cessation immediately when chest pain occurs 2. Bed rest during pain; semi-Fowler position usually most comfortable b. NTG as prescribed 1. NTG in doses less than 1 mcg/kg/min is a predominately venous dilator (decreases after load and preload as well); it decreases myocardial workload and myocardial oxygen consumption by decreasing preload. Percutaneous Coronary Intervention (procedures) - answer-PTCA (percutaneous transluminal coronary angioplasty): inflation of a balloon-tipped catheter in an area of coronary artery stenosis from plague; plague is pushed back against the wall of vessel and fractured (controlled trauma) Coronary Artery Stent: Use of a metal that acts as a scaffolding device to support a coronary artery and maintain potency after PTCA Brachytherapy: use of intracoronary irradiation to reduce risk of restenosis Coronary atherectomy: removal of plaque from coronary artery by a high-speed diamond tipped (rotational) or shaving (directional) device PCI (indications) - answer-Unstable or chronic angina Acute or post acute MI Post-CABG with postoperative angina Patient must be surgical candidate (in case of coronary artery dissection) PCI (contraindications) - answer-Left main CAD (unless there is a patent bypass around it, referred to as protected) Stenosis of coronary artery at orifice Variant angina Myocardial Infarction - answer-Death of a portion of the myocardium MI (etiology) - answer-Most are caused by arteriosclerosis and thrombosis Arteriosclerosis/atherosclerosis Coronary artery thrombosis Coronary artery spasm Cocaine-induced: excessive sympathetic stimulation causes tachycardia, HTN, arterial vasoconstriction, and spasm; coronary artery spasm may cause MI, especially non-Q wave infarction MI (patho) - answer-Atherosclerosis with unstable plaque Plaque rupture may be caused by inflammation and/or infection C-reactive protein (CRP) rises rapidly following an inflammatory response Inadequate oxygenation causes anaerobic metabolism - which causes lactic acidoses Prolonged ischemic causes electrical and mechanical death of myocardium Ischemia, injury, and acidosis causes electrical irritability; this potentially leads to PVCs, VT, VF Left main coronary artery Location: ECG leads: Complications: - answer-Extensive anterior V1 - V6 Sudden Cardiac death HF Cariogenic shock Left anterior descending artery Location: ECG leads: Complications: - answer-Septal V1 - V2 Sinus Tachy AF Anterior V3 - V4 Ventricular aneurysm HF Cariogenic Shock Left Circumflex Artery Location: ECG Leads: Complications: - answer-Lateral High: I, aVL Low: V5, V6 Dysrhythmias HF Right coronary artery Location: ECG Leads: Complications: - answer-Inferior II, III, aVF Sinus Brady Junctional Rhythms Blocks (First degree AV block, Second degree type I) Papillary muscle rupture Posterior Reciprocal changes in V1 and V2 indicative of changes in V7-V9 (especially V8-V9 Papillary muscle rupture with acute mitral regurgitation Right Ventricular V4r - V6r (especially V4r) MI (clinical presentation) - answer-Pain: 75% to 85% with MI have pain (knifelike, stabbing, burning, or indigestion). Radiates to left arm, left elbow, left shoulder, or jaw. (if pain is radiating to back, consider dissecting aortic aneurysm). May have diminished breath sounds r/t decreased contractility. May have murmur of systolic murmur of mitral regurgitation (holosystolic murmur loudest at apex that radiates to axilla). Palliation: not relieved by oxygen, rest and/or nitrates. Pain is relieved by narcotics and/or reperfusion (e.g., fibrinolytic drugs or PCI). CK-MB? - answer-Positive serum isoenzyme - greater than 4% is indicative of MI (highly specific test for MI) Typical criteria for prompt reperfusion therapies (e.g., PCI and fibrinolytic drugs) in acute MI include either of the following? - answer-ST segment elevation of greater than 1mm in at least two continuous leads New left bundle branch block (LBBB) IABP deflates and inflates when? - answer-The balloon is inflated during diastole to increase myocardial oxygen supply. Balloon is deflated immediately before systole to decrease myocardial oxygen demand (decreases left ventricular after load by decreasing systolic BP) IABP (assessment paramaters) - answer-BP: decreases in systolic BP, and increase in diastolic BP, and an increase in MAP is desirable. CO/CI: an increase in cardiac output/index is desirable