ECG Interpretation

Machine-Reported Data

Rhythm

• Sinus tachycardia — rate ~101 bpm, regular rhythm with upright P waves in L1, L2, aVF (P axis 54° — normal)
• PR interval 120 ms — at the lower limit of normal (borderline short, but not pre-excitation)

Conduction

• QRS 105 ms — borderline prolonged (upper limit of normal is 100–110 ms); suggests possible incomplete bundle branch block or non-specific intraventricular conduction delay
• No clear RBBB or LBBB morphology from the tracing visible

Intervals

• QTc 458 ms — borderline prolonged (normal upper limit: 440 ms in men, 460 ms in women)
  • This warrants attention, especially if the patient is on QT-prolonging medications or has electrolyte abnormalities

Axes

• P axis: 54° — normal
• QRS axis: 24° — normal (no axis deviation)
• T axis: 51° — normal, concordant with QRS

Waveform Analysis

Key Concerns (Despite "Normal Limits" Machine Read)

1. QTc 458 ms — marginally prolonged; check:
   • Electrolytes (K⁺, Mg²⁺, Ca²⁺)
   • QT-prolonging drugs (antibiotics, antipsychotics, antiarrhythmics)
   • Hypothyroidism, cardiac disease
2. Sinus tachycardia — not a normal resting finding; investigate:
   • Pain, fever, sepsis, anemia, hypovolemia, anxiety, hyperthyroidism, PE
3. QRS 105 ms — borderline; monitor for development of frank bundle branch block

Summary

Sinus tachycardia at 101 bpm with borderline prolonged QTc (458 ms) and borderline QRS duration (105 ms). Axes and intervals are otherwise within acceptable limits. The machine Minnesota Code reads "within normal limits," but the QTc and tachycardia warrant clinical correlation.