ECG Strip Interpretation with Certified Solutions

ECG Strip Interpretation with Certified Solutions Normal PR segment length 0.12 - 0.2 sec 3 - 5 small boxes Normal QRS interval 0.06 - 0.1 sec 1 - 3 small boxes Normal P amplitude & duration < 0.12 sec (3 small boxes) < 0.25 mV (2.5 small boxes) causes of arrhythmias HISDEBS: hypoxia, ischemia/irritability, SNS, drugs, electrolytes, bradycardia, stretch (hypertrophy/enlargement) symptoms of arrhythmias none, "palpitations," light-headedness, syncope, angina, HF, sudden death Arrhythmias - 4 quick questions 1. Normal P waves? 2. Wide QRS? (> 0.12 sec indicates pacemaker below Bundle of His) 3. One P for every QRS? 4. Normal rate & rhythym? Sinus arrhythmia Appearance is ALMOST NORMAL: Respiratory - Circulatory interaction Rate INCREASES with INSPIRATION (IN=IN) Sinus arrest - criteria Rate: Regular or Bradycardia P wave: Normal QRS: Normal Conduction: Normal Rhythm: Irregular: length of pause ≠ multiple of normal rate (random) Junctional Escape Beat/Rhythym - criteria Rate: Bradycardia P wave: Absent or Inverted P; if present, may occur during or after the QRS QRS: Normal Conduction: Escape beat: P-R interval < 0.12 seconds (if P present) Rhythm: Irregular when it occurs (late) If occurs 3 or more times in a row, is considered junctional escape rhythm Sinus exit block - criteria Rate: Regular or Bradycardia P wave: Normal QRS: Normal Conduction: Normal Rhythm: Irregular: length of pause = multiple of normal rate (Signal blocked leaving SA node; block is exactly equal to multiple of rate - one or more impulses "missed") PACs (premature atrial contractions/atrial premature beats) - criteria Rate: Regular underlying rate P wave: Abnormal - they originate from an ectopic pacemaker QRS: Normal Conduction: Normal (except for PACs) Rhythm: Irregular when PACs occur (early) PJCs (Premature Junctional Contractions) AKA: Junctional Premature Beats Rate: Regular underlying rate P wave: Absent or Inverted (like junctional escape) QRS: Normal Conduction: PJC: P-R interval < 0.12 seconds (if P waves are present) Rhythm: Irregular when PJCs occur (early) PSVT (Paroxysmal Supraventricular Tachycardia) AKA: AV nodal Re-entrant Tachycardia Rate: Tachycardia (usually 150 - 200) P wave: Absent or Inverted (like junctional escape) QRS: Normal (may be wide, pseudo R') Conduction: P-R interval < 0.12 seconds (if P) Rhythm: Regular (abrupt onset and termination) Carotid massage: slows or terminates Atrial flutter Rate:Atrial 250-350 Ventricular: 100 -175 P: Irregular or absent, often "saw tooth" QRS: Normal Conduction: AV Block (2:1 > 3:1, 4:1) Rhythm: Regular (usually) - Often underlying cardiac disease Carotid massage: increases block Atrial fibrillation Rate: Atrial 400-650; Ventricular usually 120 - 180 P wave: Not present; often wavy baseline QRS: Normal Conduction: Variable AV conduction Rhythm: Irregularly Irregular - chaotic, unpredictable depolarizations w/i atrium, no atrial kick - CAD, HTN, COPD, etc. Carotid massage: may slow ventricular rate MAT (Multifocal Atrial Tachycardia): Rate: Atrial varies, Ventricular 100-200 P wave: ≥ 3 different 'P' waves QRS: Normal Conduction: AV conduction, P-R intervals vary Rhythm: Irregularly irregular Carotid massage: no effect Etiology: longstanding COPD, etc. PAT (Paroxysmal (episodic) Atrial Tachycardia) Rate: 100 - 200; Ventricular 1:1 (or 2:1, 3:1, 4:1) P wave: Usually present, abnormal QRS: Normal Conduction: P-R interval varies (dt ectopic sites) Rhythm: Regular (warm up &/or cool down) Carotid massage: