ECG Interpretation

Machine-Printed Parameters (top right)

Step-by-Step Analysis

• 164 bpm - this is a significant tachycardia.

• The rhythm appears to be regular with narrow-looking P waves visible before QRS complexes in leads I and II, suggesting a supraventricular origin.
• This is consistent with sinus tachycardia or a supraventricular tachycardia (SVT).

• A QRS of 164 ms is significantly prolonged (normal < 120 ms).
• This suggests either:
  • Bundle branch block (LBBB or RBBB)
  • Ventricular tachycardia (though P waves appear present)
  • Pre-excitation (WPW)
• With a heart rate of 164 bpm and broad QRS, this could represent SVT with aberrant conduction or ventricular tachycardia - the two must be distinguished clinically.

• QRS axis ~38° - normal axis.

• QTc 376 ms - within normal limits (< 440 ms in men, < 460 ms in women).

• RV5 = 2.36 mV, SV1 = 0.77 mV, sum = 3.13 mV
• By the Sokolow-Lyon criterion (SV1 + RV5 > 3.5 mV), this is just below the threshold, so LVH is not definitively met by voltage alone. However, the morphology should be assessed in context.

• Lead I, II: Positive QRS complexes; P waves appear to precede QRS - sinus origin likely.
• aVR: Negative deflection (normal).
• aVL, aVF: Consistent with the reported normal axis.
• Precordial leads (V1-V6): The broad QRS with the morphology seen is important - the pattern of the QRS across precordials helps differentiate LBBB vs RBBB vs VT.

Primary Impression

Wide-complex tachycardia at 164 bpm - the most important finding.

1. SVT (sinus or re-entrant) with bundle branch block / aberrant conduction - more likely if P waves are clearly preceding each QRS with a fixed PR interval.
2. Ventricular tachycardia (VT) - must always be assumed until proven otherwise when QRS > 120 ms + rate >150 bpm.

Clinically Urgent Points

• A heart rate of 164 bpm with a QRS of 164 ms is a medical emergency until proven otherwise.
• If the patient is hemodynamically unstable (hypotension, altered consciousness, chest pain, pulmonary edema) - immediate synchronized DC cardioversion is indicated regardless of the diagnosis.
• If stable - obtain clinical history, 12-lead quality review, and consider adenosine (which will terminate SVT but not VT - and thus also serves as a diagnostic tool).
• The note says "Unconfirmed Report" - this tracing has not been reviewed by a physician yet.

Disclaimer: This interpretation is for educational/supportive purposes only. Clinical correlation is mandatory. A qualified physician must review this ECG in the context of the patient's full clinical picture before any management decisions are made.

Full 12-Lead ECG Interpretation

Known Parameters (from previous strip, same tracing)

• Rate: 164 bpm
• PR interval: 102 ms
• QRS duration: 164 ms (broad)
• QTc: 376 ms
• Axis: P/QRS/T = 56° / 38° / 40° (all normal)

Rhythm

• Regular rhythm at ~164 bpm.
• P waves are visible and upright in leads I, II, aVF - confirming sinus origin.
• Every P wave is followed by a QRS - 1:1 conduction.
• This is sinus tachycardia at 164 bpm (not SVT, not atrial flutter with 2:1 block).

QRS Morphology - Wide Complex (164 ms)

• Lead I: Positive, monophasic broad R wave - no S wave notch
• Lead II / III / aVF: Upright QRS, broad
• aVR: Predominantly negative (deep QS) - normal
• aVL: Small positive deflection

• V1: Small or absent R wave with broad QS pattern - negative
• V2: Low-amplitude with a transition zone pattern
• V3: Transition - becoming positive
• V4, V5, V6: Tall, broad, monophasic R waves - no secondary R' wave, no S wave in lateral leads

ST-T Changes

• In LBBB, ST and T wave changes are expected to be discordant (opposite to the main QRS direction) - this is a normal secondary finding in LBBB and does not necessarily indicate ischemia.
• ST elevation in V1-V2 and ST depression in V5-V6 seen here are consistent with the expected discordant changes of LBBB.

Voltage

• RV5+SV1 = 3.13 mV - borderline, just below the Sokolow-Lyon threshold of 3.5 mV for LVH. However, voltage criteria for LVH are unreliable in the presence of LBBB - LBBB itself distorts QRS amplitude.

Summary / Final Impression

Clinical Significance

• New LBBB + tachycardia is a potentially serious finding. Key questions:
  • Is this LBBB new or old? A new LBBB in the context of chest pain is treated as STEMI-equivalent and warrants urgent cath lab activation (Sgarbossa criteria apply).
  • The sinus tachycardia at 164 bpm suggests the patient may be in pain, distress, hemodynamic compromise, fever, or decompensated heart failure - all must be evaluated.
  • If LBBB is known/chronic, management focuses on the underlying cause of tachycardia.

This ECG requires urgent clinical correlation. "Unconfirmed Report" - a physician must review this with the patient's clinical status immediately.

⚠️ This analysis is educational only. All ECG interpretations must be confirmed by a licensed physician in the context of the full clinical scenario.