What do ST depression and atrial flutter on ECG mean?

Question

Hi doctor,

I am just wondering about the interpretation of an ECG. There is ST depression and atrial flutter. Please go through my two ECGs.

Please help.

Answer 1

Hi,

Welcome to icliniq.com.

I can understand your concern.

I cannot see the ECG (electrocardiogram) images here, so I will answer you the same way I would in the clinic when someone brings a tracing for interpretation.

Atrial flutter usually shows regular, narrow QRS complexes. Ventricular rate around 150 beats per minute in a 2:1 block. Saw tooth flutter waves, especially in leads II, III, and aVF. In case the heart rate is not close to 150 in the ECG and you observe normal P waves prior to each QRS complex, atrial flutter is unlikely.As for the ST segment depression, it is no less than 1 mm horizontally and downsloping. It is seen in two contiguous leads and sometimes associated with symptoms such as chest pain.

In a healthy 20-year-old male with no cardiac symptoms, true ischemic ST depression would be uncommon, unless there is a specific underlying condition. Mild upsloping changes or slight baseline variation are often misinterpreted by automated systems.

Early repolarization syndrome is very common in young healthy males. It typically shows J point elevation, concave ST elevation, rather than depression, and notching or slurring at the end of the QRS. Most prominent in precordial leads, it does not cause ST depression. So if anything, early repolarization produces mild ST elevation, not depression.

For the second ECG, without seeing it, I would assess heart rate rhythm, regular or irregular, presence of P waves, before every QRS width, ST segment pattern, and T wave symmetry.

At your age, common normal variants include sinus arrhythmia, early repolarization, and high voltage QRS due to a thin chest wall.

Your height and weight suggest a lean build, and that alone can produce prominent voltages that look dramatic but are normal.

Was this ECG done because of symptoms such as chest pain, palpitations, dizziness, or fainting, or was it just routine? Automated ECG interpretations are frequently wrong, especially in young adults.

The final interpretation should always be made by a physician reviewing the tracing directly. If you can describe the heart rate on the ECG, whether the rhythm was regular, and what the printed interpretation said exactly, I can help you reason through it clinically.

I hope this information will help you.

Thanks.

Answer 2

Hi,

Welcome back to icliniq.com.

I reviewed the uploaded image (attachments removed to protect the patient’s identity).

The heart rate of 130 beats per minute indicates tachycardia, while regular rhythm with visible pointed P waves in leads II and III is consistent with sinus tachycardia rather than atrial flutter. 2:1 atrial flutter should demonstrate heart rate closer to 150 bpm with constant flutter waves; also, the presence of normal P waves excludes the diagnosis.

As for ST segment interpretation, ischemic depression should reach at least 1 mm in two contiguous leads, measured from the J point. Early repolarization is typical in young, lean male with J point elevation; therefore, this condition should not explain ST depression.

Taking into account your age, lean body type, normal past ECGs, and musculoskeletal symptoms, sinus tachycardia seems the most probable cause, which could be related to anxiety or pain.

Do not forget about the symptoms such as palpitations, lightheadedness, or dyspnea, since their absence significantly decreases the risk of arrhythmias. Taking into account two normal ECGs and absence of risk factors for heart disease, cardiac ischemia is very improbable in your case.

I hope this helps you.

Thank you.