This ECG most likely shows atrial flutter with 2:1 AV conduction:

A very regular rate close to 150 bpm is characteristic of atrial flutter with 2:1 conduction, although a clearer full-quality ECG and clinical assessment are needed to confirm it. The ECG characteristics of typical flutter include negative flutter waves in II, III and aVF and upright flutter waves in V1, as described in Fuster and Hurst's The Heart, section on atrial flutter. A regular narrow-complex rhythm at about 150 bpm is also a classic clue for 2:1 flutter conduction, as summarized by the ECG flutter reference.

If this is new, or the person has chest pain, shortness of breath, fainting, severe dizziness, or ongoing palpitations, they should seek urgent medical care now.

This tracing appears to show sinus rhythm with mild sinus bradycardia, at about 59 bpm:

So, compared with the prior ECG, this one looks much slower and organized in sinus rhythm, rather than a regular tachyarrhythmia around 150 bpm.

Photo quality, paper folds, and partial lead visibility limit assessment of subtle ST-T or QT changes. A clinician should review the original full ECG, particularly if there were symptoms or this was obtained after treatment for a fast rhythm. If there is chest pain, breathlessness, fainting, or persistent palpitations, seek urgent assessment.

I do not see a new ECG image attached to your last message. Please upload it, ideally a clear photo of the whole 12-lead tracing including the printed measurements, and I will compare it with the prior two.

This ECG also appears most consistent with atrial flutter with 2:1 AV conduction, producing a regular narrow-complex tachycardia at about 124 bpm (the machine printout shows 124).

Key features:

The rate can vary in flutter depending on the atrial rate and how many atrial impulses conduct through the AV node. In the context of the other tracings, this supports intermittent atrial flutter/tachyarrhythmia, with the ECG at 59 bpm appearing to show a return to sinus rhythm.

This needs formal review by a clinician or cardiologist, particularly because atrial flutter can recur and may require assessment for rate/rhythm management and stroke-risk prevention. Seek urgent care if there is chest pain, shortness of breath, fainting, low blood pressure, or ongoing severe palpitations.

Impression: Sinus tachycardia at approximately 124 bpm. No definite acute ischemic ST-elevation changes visible on this photo.

I would correct the earlier interpretation: this particular ECG is not definitively atrial flutter from the image. The visible preceding P waves and rate of 124 favor sinus tachycardia, though the original ECG printout should be reviewed by a clinician for confirmation.

Impression: Atrial fibrillation with a fast ventricular rate, with possible frequent PVCs.

This is different from sinus tachycardia and warrants prompt clinical assessment, particularly to control the heart rate and assess stroke prevention needs. If there is chest pain, breathlessness, fainting, confusion, low blood pressure, or severe ongoing palpitations, seek emergency care immediately.