NURS 3500 - Test 3 – Cardiovascular Review Questions and Correct Answers

Electrical Conduction of Heart- Electrical impulses from myocardium make contractions - SA node, the heart's "natural pacemaker" at top of atrium releases impulse causing atrium to contract - Signal passes through AV node, causing ventricle filling - AV node checks signal and sends it through muscle fibers of ventricles causing them to contract Depolarization- Electrical stimulation Repolarization- Reset & relaxation Sinus Rhythm: P Wave- Atrial depolarization (stimulation) Sinus Rhythm: QRS complex- Depolarization of ventricles (stimulation) - More stimulation needed for ventricles - <.12 seconds Sinus Rhythm: PR Interval- Time it takes for impulse to go from atrial systole to before ventricle systole - Time between stimulation of atrium and stimulation of ventricles - .12-.20 seconds Sinus Rhythm: Q Wave- Atrial repolarization (relaxation) Sinus Rhythm: T Wave- Repolarization of ventricles (relaxation) Chest Radiograph (X-Ray or CXR)- Used to detect size & position of heart and abnormalities of the heart and lungs - Light areas show consolidation or where light is absorbed by body - Dark areas represent x-ray passing through the body Electrocardiogram (ECG or EKG)- Records electrical signals as they travel through the heart - Used to look for patterns among heartbeats and rhythms and to diagnose various heart conditions - Can detect: arrhythmias, blocked or narrow coronary arteries, structural problems in heart chambers, previous heart attack Echocardiogram- Uses sound waves to produce images of heart beating and pumping blood - Images can be used to identify heart disease Nuclear Cardiology- Small amount of radioactive tracer is injected into vein and taken up by heart - Gamma camera then takes pictures and movies when heart is at rest, exercising, medically induced, or stressed - Identify coronary heart disease, the severity of prior heart attacks, and the risk of future heart attacks. Magnetic Resonance Imaging (MRI)- Uses a magnetic field and radio waves to create detailed images of certain organs and tissues in the body - Assesses: size & function of heart chambers, thickness & movement of walls of heart, extent of damaged caused by heart attack or heart disease, inflammation or blockages of vessels, and structural problems to aorta (aneurysm) Computed tomography (CT) Scan- Combines x-ray images taken from different angles and uses computer procession to create cross-sectional images or slices of the bone, blood vessels, and soft tissue - More detailed than plain x-ray - Used to: locate tumor, infection or clot, guide procedures, detect & monitor diseases, monitor effectiveness of treatments, and to detect internal bleeding Holter Monitor- Small, wearable device which keeps track of heart rhythm - Wore normally for 1-2 days, in this time device records all heartbeats - Normally done after ECG if previous test doesn't give Dr enough information - Used to test and monitor for irregular heartbeats (arrhythmias) Cardiac Markers- Biomarkers measured to evaluate heart function - Elevated levels usually indicates myocardial infarction Types of Cardiac Markers- Troponin - is released during MI - High levels of Creatine kinase enzyme can also indicate a heart attack Troponin- Cardiac enzyme/protein released from the heart muscle when it is damaged - The greater the damage to the heart, the higher the level