Arrhythmia Flashcards
Sinus arrhythmia can occur naturally in
athletes and children
Sinus arrhythmia
Conditions unrelated to respiration may also produce sinus arrhythmia, including inferior wall myocardial infarction (MI), advanced age, use of digoxin (Lanoxin) or morphine, and conditions involving increased intracranial pressure.
Sinus bradycardia is?
sinus rate below 60 beats/minute and a regular rhythm.
Sinus bradycardia may occur normally in
during sleep or in a person with a well-conditioned heart—an athlete, for example
Sinus bradycardia also occurs normally during sleep due to decreased metabolic demands.
If sinus bradycardia had no symptoms should it be treated ?
Usually, sinus bradycardia produces no symptoms and is insignificant. Unless the patient shows symptoms of decreased cardiac output, no treatment is necessary. (See the appendix ACLS algorithms.)
Causes of sinus bradycardia?
noncardiac disorders, such as hyperkalemia, increased intracranial pressure, hypothyroidism, hypothermia, sleep, and glaucoma
• conditions producing excess vagal stimulation or decreased sympathetic stimulation, such as sleep, deep relaxation, Valsalva’s maneuver, carotid sinus massage, and vomiting
cardiac diseases, such as sinoatrial node disease, cardiomyopathy, myocarditis, and myocardial ischemia, immediately following an inferior wall myocardial infarction
• certain drugs, especially beta-adrenergic blockers, digoxin (Lanoxin), calcium channel blockers, lithium (Lithobid), and antiarrhythmics, such as sotalol (Betapace), amiodarone (Cordarone), propafenone (Rhythmol), and quinidine.
Sinus bradycardia in ECG looks like ?
the atrial and ventricular rhythms are regular, as are their rates, except that they’re both under 60 beats/ minute.
other characteristics appear normal. You’ll see a P wave preceding each QRS complex and a normal PR interval, QRS complex, T wave, and QT interval.
Treatment of sinus bradycardia
If the patient is asymptomatic and his vital signs are stable, treatment isn’t necessary
If the patient is symptomatic, treatment aims to identify and correct the underlying cause
transcutaneous pacing
Treatment of symptomatic sinus bradycardia
Atropine is given as a 0.5 mg dose by rapid injection. The dose may be repeated every 3 to 5 minutes up to a maximum of 3 mg total.
If atropine proves ineffective, administer an epinephrine infusion at a rate of 2 to 10 mcg/minute.
If low blood pressure accompanies bradycardia, administer a dopamine infusion at 2 to 10 mcg/kg/minute.
Treatment of chronic, symptom-producing sinus bradycardia requires insertion of a permanent pacemaker
Stop drug causing it
Symptoms of sinus bradycardia
hypotension
- cool, clammy skin
- altered mental status
- dizziness
- blurred vision
- crackles, dyspnea, and an S 3 heart sound, which indicate heart failure
- chest pain
- syncope.
Sinus tachycardia is
sinus rate of more than 100 beats/minute
Causes of sinus tachycardia
Sinus tachycardia may be a normal response to exercise, pain, stress, fever, or strong emotions, such as fear and anxiety. It can also occur:
- in certain cardiac conditions, such as heart failure, cardiogenic shock, and pericarditis
- as a compensatory mechanism in shock, anemia, respiratory distress, pulmonary embolism, sepsis, and hyperthyroidism
- when taking such drugs as atropine, isoproterenol (Isuprel), aminophylline, dopamine, dobutamine, epinephrine, alcohol, caffeine, nicotine, and amphetamines.
Sinus TACHYCARDIA on ECG
atrial and ventricular rhythms are regular.
Both rates are equal, generally 100 to 160 beats/minute. ( regular rhythm )
the P wave is of normal size and shape and precedes each QRS, but it may increase in amplitude.
As the heart rate increases, the P wave may be superimposed on the preceding T wave and difficult to identify.
The PR interval, QRS complex, and T wave are normal.
The QT interval normally shortens with tachycardia.
