Cardiology Nursing 1 - Humber Final Questions And Answers Rated A+

2 types of cardiac cells - Electrical -specialized cells which conduct electrical impulses -these cells start and transmit electrical activity in the heart Mechanical -cells which make up bulk musculature in the heart -these cells contract in response to stimuli from the electrical cells 2 types of cardiac cells - Electrical -specialized cells which conduct electrical impulses -these cells start and transmit electrical activity in the heart Mechanical -cells which make up bulk musculature in the heart -these cells contract in response to stimuli from the electrical cells a cardiac arrhythmia is - is any deviation from the normal pattern of the heartbeat (normal sinus rhythm) a cardiac arrhythmia is - is any deviation from the normal pattern of the heartbeat (normal sinus rhythm) a cardiac cycle on ecg is - PQRST a prolonged QT interval - more prone to arrhythmiaa prolonged QT interval - more prone to arrhythmia Absolute refractory period - Cardiac cells have not repolarized to their threshold potential and are unable to respond to a stimulus Period extends from onset of QRS complex to peak of T wave Absolute refractory period - Cardiac cells have not repolarized to their threshold potential and are unable to respond to a stimulus Period extends from onset of QRS complex to peak of T wave Accelerated junctional rhythm - originates in an ectopic pacemaker site in the AV junction at a rate of 60 to 100 beats/minute. The term accelerated denotes a rhythm that occurs at a rate faster than the inherent junctional rate of 40 to 60 beats/minute, but that isn't fast enough to be junctional tachycardia. Accelerated junctional rhythm is a regular, continuous rhythm characterized by an inverted P wave that may occur before the QRS, after the QRS, or be hidden within the QRS complex; a short PR interval of 0.10 second or less; and a normal QRS complex. afterload - the amount of resistance to ejection of blood from the (left) ventricle - amount of resistance to overcome Altered automaticity - firing rate of the sinus node decreases, resulting in a slower sinus rate and allowing a faster ectopic site the opportunity to take control as pacemaker of the heart. •Automaticity of the ectopic site increases, resulting in a faster ectopic rate which takes control of the heart from the slower-firing SA node. Amount of pressure against which the left ventricle must work during systole to open the aortic valve Clinically measure by systolic blood pressure - afterloadAmount of pressure against which the left ventricle must work during systole to open the aortic valve Clinically measure by systolic blood pressure - afterload An atrial ectopic beat that occurs late instead of early is called an - atrial escape beat. The morphologic characteristics of the late beat are the same as with the PAC. Atrial escape beats usually occur during a pause in the underlying rhythm. Escape beats act as an electrical backup to maintain the heart rate and require no treatment. An ECG tracing provides a view of the heart's electrical activity between two poles (a positive and a negative pole). - • Current flowing toward a positive pole produces a positive deflection • Current flowing toward a negative pole produces a negative deflection • Current flowing away from both poles will produce a biphasic deflection; biphasic deflections may be equally positive and negative, more positive than negative, or more negative than positive. An ECG tracing provides a view of the heart's electrical activity between two poles (a positive and a negative pole). - • Current flowing toward a positive pole produces a positive deflection • Current flowing toward a negative pole produces a negative deflection • Current flowing away from both poles will produce a biphasic deflection; biphasic deflections may be equally positive and negative, more positive than negative, or more negative than positive. Anatomy of the heart - Large, muscular organ consisting of mostly cardiac tissue called the myocardium Surrounded by a sac called the pericardium Consists of 2 sides, right and left, separated by a septum Consists of 4 chambers: 2 atria and 2 ventricles 2 sets of valves: semilunar valves and atrioventricular valves (AV valves)Valves produce the "lub" and "dub" sounds of the heartbeat Atrial arrhythmias originate from - ectopic sites in the atria Atrial fibrillation - is a rapid and highly irregular heart rhythm originating in an ectopic site in the atria, depolarizing at a rate greater than 400 beats/minute. As in atrial flutter, the AV node blocks most of the impulses from entering the ventricles, thus protecting the ventricles from excessive rates. The AV node conducts impulses irregularly, resulting in an irregular ventricular rhythm. When the ventricular rate is less than 100 beats/minute, the rhythm is called controlled atrial fibrillation.When the ventricular rate is greater than 100 beats/minute, the rhythm is called uncontrolled atrial fibrillation. The ventricular rhythm is more irregular with slower rates and less irregular with faster rates