RT Journal
A1 Katz DF, Varosy PD, Nguyen DT, et al
T1 THe irregular tachycardia that was not atrial fibrillation
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 2011
FD December 12
VO 171
IS 22
SP 1985
OP 1985
DO 10.1001/archinternmed.2011.577
UL http://dx.doi.org/10.1001/archinternmed.2011.577
AB 
A 49-year-old woman was admitted to the inpatient cardiology service with complaints of palpitations, fatigue, and dyspnea on exertion. During a previous hospitalization she was noted to have a paroxysmal, irregular tachycardia with largely the same left bundle branch block that was seen during normal sinus rhythm; this arrhythmia was believed by her physicians to represent atrial fibrillation. At that time, findings from echocardiography were consistent with rheumatic mitral valve disease. Her outpatient medical regimen consisted of metoprolol tartrate and warfarin sodium for presumed valvular atrial fibrillation. An electrocardiogram (ECG) was obtained at the time of readmission (Figure 1).