Cardiology Nursing 1 Humber Final Exam Questions with Correct Answers

Sinus rhythm Correct Answer regular rhythm Set by SA node at 60 to 100 bpm P waves normal Normal qrs PR 0.12 - 0.2 Normal qrs less than 0.10 Wide qrs is Correct Answer greater than 0.12 Sinus Tachycardia Correct Answer 100-160 bpm SA node Reduced time for ventricle filling Assess for SOB or chest pain A prolonged QT interval Correct Answer more prone to arrhythmia NSR reflects the heart's Correct Answer normal electrical activity, providing synchrony between the atria and the ventricles. Sinus tachycardia occurs when the Correct Answer sinus node discharges impulses too fast (100 - 160 beats/minute). All other parameters are normal Facts about sinus tachycardia Correct Answer Normal response of heart in certain circumstances (for example exercise) •Begins and ends gradually in contrast to other tachycardias •Usually benign arrhythmia that goes away when underlying cause is treated •Common causes: Anxiety, hypoxia, hypovolemia, hypotension, heart failure, pain, drugs that increase sympathetic tone (epinephrine, norepinephrine, dopamine, dobutamine, isoproterenol, nitroprusside), and drugs that decrease parasympathetic tone (atropine) •Persistent sinus tachycardia may result in decreased cardiac output due to a decrease in stroke volume. Cardiac output = stroke volume ×heart rate. A decrease in either stroke volume or heart rate may result in a decrease in cardiac output. Sinus bradycardia occurs when Correct Answer the sinus node discharges impulses too slow (40 - 60 beats/minute). All other parameters are normal. Sinus bradycardia features Correct Answer regular rhythm, rate 40-60 bpm Normal p waves PR interval normal 0.12 to 0.2 QRS normal less than 0.1 Facts about sinus bradycardia Correct Answer Normal response of heart in certain circumstances (for example relaxation, sleep) •Most common arrhythmia associated with acute inferior wall myocardial infarction •Other causes: Reperfusion rhythm following myocardial reperfusion procedures (thrombolytic administration, angioplasty); vagal stimulation; sleep apnea; hyperkalemia; increased intracranial pressure; disease of SA node; and administration of drugs, such as digitalis, calcium channel blockers, and beta blockers •Persistent bradycardia may result in decreased cardiac output due to a decrease in heart rate. Cardiac output = stroke volume ×heart rate. A decrease in either stroke volume or heart rate may result in a decrease in cardiac output. Treatment of sinus bradycardia Correct Answer No treatment is necessary if patient is asymptomatic. •Symptomatic bradycardia is initially treated with oxygen and atropine IV push. If unsuccessful, external pacing or transvenous pacing may be used. •Chronic sinus bradycardia may require a permanent pacemaker. Sinus arrhythmia occurs when Correct Answer the sinus node discharges impulses irregularly. The heart rate may be normal range or slow. All other parameters are normal. Sinus arrhythmia ECG features Correct Answer irregular rhythm Rate normal or slow P waves normal PR interval normal 0.12 to 0.20 QRS normal less than 0.1 Facts about sinus arrhythmia Correct Answer Normal phenomenon usually associated with phases of respiration (heart rate increases with inspiration and decreases with expiration) •Most commonly observed in infants, children, and young adults, although it may occur in any age-group •Frequently occurs along with sinus bradycardia, in which case it is usually called sinus arrhythmia with a bradycardic rate