Brief Summary
This comprehensive video covers essential ECG interpretations important for nursing, focusing on various heart rhythms. Key rhythms discussed include normal sinus rhythm, sinus bradycardia, sinus tachycardia, atrial fibrillation, atrial flutter, and ventricular tachycardia, along with their characteristics, causes, and treatments.
- Understand the characteristics and criteria for various heart rhythms.
- Recognise the different treatments required for bradycardia, tachycardia, and arrhythmias.
Normal Sinus Rhythm
Normal sinus rhythm originates from the sinoatrial (SA) node and is characterised by regular rhythm and rates between 60 to 100 beats per minute. Key ECG indicators include upright P waves before each QRS complex, a PR interval of 0.12 to 0.20 seconds, normal QRS complex width of less than 0.12 seconds, a QT interval between 0.36 to 0.44 seconds, and a flat ST segment. Monitoring is essential to ensure the rhythm remains stable and does not deviate towards arrhythmias.
Sinus Bradycardia
Sinus bradycardia originates from the SA node but presents as a slow rhythm with a heart rate of less than 60 beats per minute. Upon analysis, the ECG appears similar to normal sinus rhythm but at a slower rate. P waves are present, and PR intervals fall between 0.12 to 0.20 seconds. Causes of bradycardia include Sick Sinus Syndrome, low thyroid hormone levels, age-related changes, and certain medications like beta-blockers and calcium channel blockers. Treatment is symptom-dependent; if asymptomatic, close monitoring is adequate; if symptoms appear, emergency treatment is necessary.
Sinus Tachycardia
Sinus tachycardia also begins at the SA node, but the heart rate exceeds 100 beats per minute. The ECG presents normal findings except that the atrial and ventricular rates are elevated. QRS complexes remain narrow and regular. Common causes include fever, exercise, anxiety, and medications that prompt increased heart rates. Treatment focuses on identifying the underlying cause rather than treating the tachycardia directly, as it may resolve once the trigger is removed.
Atrial Fibrillation
Atrial fibrillation is characterised by chaotic quivering of the atria, leading to an irregular rhythm with no distinct P waves. Instead, fibrillatory waves (F waves) appear on the ECG. The ventricular rate can be normal or rapid, and complications like blood clot formation can lead to strokes. Causes often include heart surgery, valve issues, and lung conditions like COPD. Treatment depends on the patient's stability and symptoms and may involve anticoagulation, cardioversion, or medications.
Atrial Flutter
Atrial flutter is marked by rapid atrial contractions at around 300 beats per minute, creating flutter waves in a sawtooth pattern on the ECG. The ventricular rate can be regular or irregular. Causes include heart structural issues and hyperthyroidism. Treatment aims to control the heart rate through medications and possibly cardioversion to restore normal rhythm.
Ventricular Tachycardia
Ventricular tachycardia originates from the ventricles and is identified by wide QRS complexes and a rapid heart rate, typically between 100 to 250 beats per minute. Causes include electrolyte imbalances, heart disease, and medication toxicity. Immediate treatment is crucial as it can lead to ventricular fibrillation. Depending on the patient's stability, interventions may include antiarrhythmic medications or synchronized cardioversion.
Ventricular Fibrillation
Ventricular fibrillation is a life-threatening rhythm that presents as chaotic, disorganised electrical activity in the ventricles, resulting in no effective heartbeat or cardiac output. The ECG shows fibrillatory waves without identifiable patterns. Causes include severe heart disease and electrolyte disturbances. Treatment requires immediate CPR and defibrillation to restore a normal rhythm.
Asystole
Asystole is identified by a flat ECG line indicating no cardiac contraction. Causes generally lead to the cessation of the heart's activity, often due to lethal rhythms like V-fib. Treatment involves confirming asystole, activating emergency response, and performing CPR since it is a non-shockable rhythm. Epinephrine may also be administered while investigating potential reversible causes.
Pulseless Electrical Activity (PEA)
PEA presents with organised electrical activity on the ECG that does not translate into an effective pulse. Causes include hypoxia and hypovolemia. Treatment is similar to that for asystole: immediate CPR, activating emergency response, and administering epinephrine. It's critical to determine and address reversible causes during resuscitation efforts.
Heart Blocks
Heart blocks occur due to interrupted electrical conduction, classified into first-degree, second-degree types 1 and 2, and third-degree. Each type has distinct characteristics, primarily affecting the PR interval and the relationship between atrial and ventricular activity. Treatment varies with symptoms and conditions but may involve monitoring or pacing to ensure adequate cardiac output. Third-degree heart block often requires urgent intervention.
