Scenario: This ECG was obtained in a 79-year-old woman admitted to the intensive care unit for acute exacerbation of chronic obstructive pulmonary disease and pneumonia treated with erythromycin. The bedside monitor alarmed for “V Tach.” The nurse could not assess the patient’s mental status because the patient was intubated and sedated with propofol. The patient’s blood pressure was 109/48 mm Hg and her pulse oximeter reading was 93%. The rhythm spontaneously returned to normal sinus rhythm after 30 seconds.
Interpretation: The strip begins with a ventricular triplet. These complexes are further labeled as multiform because of the different QRS morphologies. The fourth beat is a normal sinus beat with a long QT interval (0.64 seconds). This beat is followed by an R-on-T premature ventricular contraction (PVC) inducing torsades de pointes (TdP).
Torsades de pointes is a French term meaning “twisting of the points.” TdP is a form of polymorphic ventricular...