Woman with Metabolic Syndrome
ANSWER
The correct interpretation of this ECG includes sinus rhythm with frequent premature ventricular complexes (PVCs), a T-wave abnormality suggesting lateral ischemia, and a prolonged QT interval.
PVCs occur when conduction of the ventricular myocardium occurs without involving the normal His-Purkinje system. They are responsible for the patient’s irregular pulse.
A prolonged QT interval is evidenced by a QTc interval > 440 ms. The QTc is calculated from Bazett’s formula, which states the QTc = QT interval divided by the square root of the previous R-R interval. The normal range for a QTc is generally considered to be 350 to 440 ms.
Inverted T waves in leads V3 to V6 are suggestive of lateral ischemia. However, they are also seen in subacute or old pericarditis and myocarditis, so clinical correlation is required. The patient has had no recent or remote episodes of chest pain or chest discomfort in the past year.