Relias Assessments Assistance Material DYSRHYTHMIAS

Relias Assessments Assistance Material DYSRHYTHMIAS EKG interpretation One of the most useful and commonly used diagnostic tools is electrocardiography (EKG) which measures the heart's electrical activity as waveforms. An EKG uses electrodes attached to the skin to detect electric current moving through the heart. These signals are transmitted to produce a record of cardiac activity. Arrhythmia or dysrhythmia are disturbances in the normal cardiac rhythm of the heart which occurs as a result of alterations within the conduction of electrical impulses. These impulses stimulate and coordinate atrial and ventricular myocardial contractions that provide cardiac output. Sinus Tachycardia Sinus tachycardia is a heart rate greater than 100 beats per minute that originated from the sinus node. Rate: 100 to 180 beats per minute P Waves precede each QRS complex PR interval is normal QRS complex is normal Conduction is normal Rhythm is regular Causes of sinus tachycardia may include exercise, anxiety, fever, drugs, anemia, heart failure, hypovolemia and shock. Sinus tachycardia is often asymptomatic. Management however is directed at the treatment of the primary cause. Carotid sinus pressure (carotid massage) or a beta blocker may be used to reduce heart rate. Sinus Bradycardia Sinus bradycardia is a heart rate less than 60 beats per minute and originates from the sinus node (as the term "sinus" refers to sinoatrial node). It has the following characteristics Rate is less than 60 beats per minute P Waves precede each QRS complex PR interval is normal QRS complex is normal Conduction is normal Rhythm is regular Causes may include drugs, vagal stimulation, hypoendocrine states, hypothermia, or sinus node involvement in MI. This arrhythmia may be normal in athletes as they have quality stroke volume. It is often asymptomatic but manifestations may include: syncope, fatigue, dizziness. Management includes treating the underlying cause and administering anticholinergic drugs like atropine sulfate as prescribed. Premature Atrial Contraction Premature Atrial Contraction are ectopic beats that originates from the atria and they are not rhythms. Cells in the heart starts to fire or go off before the normal heartbeat is supposed to occur. These are called heart palpitations and has the following characteristics: Premature and abnormal-looking P waves that differ in configuration from normal P waves QRS complex after P waves except in very early or blocked PACs P waves often buried in the preceding T wave or identified in the preceding T wave. Causes includes coronary or valvular heart diseases, atrial ischemia, coronary artery atherosclerosis, heart failure, COPD, electrolyte imbalance and hypoxia. Usually there is no treatment needed but may include procainamide and quinidine administration (antidysrhythmic drugs) and carotid sinus massage. Atrial Flutter Atrial flutter is an abnormal rhythm that occurs in the atria of the heart. Atrial flutter has an atrial rhythm that is regular but has an atrial rate of 250 to 400 beats/minute. It has sawtooth appearance. QRS complexes are uniform in shape but often irregular in rate. Normal atrial rhythm Abnormal atrial rate: 250 to 400 beats/minute Sawtooth P wave configuration QRS complexes uniform in shape but irregular in rate Causes includes heart failure, tricuspid valve or mitral valve diseases, pulmonary embolism, cor pulmonale, inferior wall MI, carditis and digoxin toxicity. Management if the patient is unstable with ventricular rate of greater than 150 bpm, prepare for immediate cardioversion. If patient is stable, drug therapy may include calcium channel blocker, beta-adrenergic blockers, or antiarhythmics. Anticoagulation may be necessary as there would be pooling of blood in the atria. Atrial Fibrillation Atrial fibrillation is disorganized and uncoordinated twitching of atrial musculature caused by overly rapid production of atrial impulses. This arrhythmia has the following characteristics: Atrial Rate: 350 to 600 bpm Ventricular Rate: 120 to 200 bpm P wave is not discernible with an irregular baseline PR interval is not measurable QRS complex is normal Rhythm is irregular and usually rapid unless controlled. Causes includes atherosclerosis, heart failure, congenital heart disease, chronic obstructive pulmonary disease, hypothyroidism and thyrotoxicosis. Atrial fibrillation may be asymptomatic but clinical manifestation may include palpitations, dyspnea, and pulmonary edema. Nursing goal is towards administration of prescribed treatment to decrease ventricular response, decrease atrial irritability and eliminate the cause. Premature Junctional Contraction Premature Junctional Contraction (PJC) occurs when some regions of the heart becomes excitable than normal. It has the following characteristics. PR interval less than 0.12 seconds if P wave precedes QRS complex QRS complex configuration and duration is normal P wave is inverted Atrial and ventricular rhythms irregular Causes of PJC may include myocardial infarction or ischemia, digoxin toxicity, excessive caffeine or amphetamine use. Management includes correction of underlying cause, discontinuation of digoxin if appropriate.