A Fib

A good teaching ECG, showing clearly elevated ST segments in V1 through V4.  This patient had an LAD occlusion.  In addition, he has new-onset atrial fib at a rate of about 120/min.  Atrial fib has decreased cardiac output because of the loss of P waves prior to the QRS complexes, and a resultant decreased ventricular filling pressure.  In addition, this fast rate contributes to increased myocardial oxygen demand and damage.  An early priority, along with getting this patient to PCI, is slowing the rate.

This 31 year old man presented to the Emergency Dept. complaining of chest pain, shortness of breath, and nausea. His heart rate on admission was 120 - 130 bpm and irregular, and the monitor showed atrial fibrillation. His rate slowed with the administration of diltiazem. His 12-lead ECG shows the classic ST elevation of inferior wall M.I. in Leads II, III, and aVF. This patient also had JVD, bibasilar rales, orthopnea, and exertional dyspnea, signs of CHF. He had no history of acute M.I., CHF, or atrial fibrillation. He offered no history of drug use or medications.

This ECG is very useful for the basic student, in that the ST elevations are readily seen, and the atrial fib is definitely irregularly-irregular. For the more advanced student, the ST depression in V2 indicates posterior wall injury, while the flat ST segment in V1 indicates that, while the posterior wall is trying to depress the ST segment, the right ventricle is trying to elevate it, resulting in flattening. This should be confirmed with a V4 right, or all chest leads done on the right side.

Also, this ECG can start a very instructive discussion on the relationship between acute M.I., acute CHF, and new-onset Atrial Fibrillation. That could be an entire class by itself!
This patient was transferred to a nearby interventional cath lab, and his outcome is unknown.<br />