ECG Case of the Month: ECG in a 20-Year-Old Woman with Dyspnea. Sinus tachycardia (104 beats/minute), slight right axis deviation of the QRS (+92°), an R/S ratio greater than 1 in lead V1 with ST depression and T wave inversion in leads V1 - V4, and a prominent S wave in lead I, Q wave in lead III, and inverted T wave in lead III(S1 Q3 T3). These findings suggest right ventricular hypertrophy or strain and are consistent with pulmonary emboli.

A 20-year-old Hispanic woman presented to the emergency department complaining of six months of progressive dyspnea on exertion associated with intermittent palpitations. Her only past medical history was a stillbirth at 32 weeks gestation about two years ago. Her vital signs in the emergency department were a heart rate of 120 beats/minute, a blood pressure of 145/86 mmHg, and an arterial oxygen saturation of 98 percent with her breathing air. Significant laboratory values included a blood hemoglobin of 14.5 gm/dL, a hematocrit of 49 percent, a brain naturetic peptide (BNP) level of 177 pg/mL, a D-dimer level of 330 ng/ml, a prothrombin time of 12.85 s with an INR of 1.2, and a partial thromboplastin time of 45.7s. Urine pregnancy test was positive, and serum beta-human chorionic gonadotropin level was 81 MIU/mL consistent with a fetus of 3-4 weeks gestational age. An electrocardiogram was recorded.