ECG of the Month: ECG in a 30-Year-Old Woman

Sinus rhythm; an atrial premature complex; sagging ST-segments, low T-waves, and prominent U-waves suggesting hypokalemia. The ST-T and U-wave changes described above are characteristic of hypokalemia. When the serum potassium level is between 3.0 and 3.5 mEq/L, one or more of the findings may be present. All three are common when the serum potassium level is below 2.5 mEq/L. At the lowest serum potassium levels the T-wave becomes a notch on the upstroke of a giant U-wave, as occurs here in the ECG of this woman with a serum potassium of 1.7 mEq/L.1,2 This configuration is occasionally mistaken for the ST-segment depression and long QT interval of myocardial ischemia.3 Atrial premature complexes are common with hypokalemia, and atrial fibrillation may occur. This patient's potassium was repleted, and the following day her ECG was essentially normal (Figure 2) and virtually unchanged from an ECG recorded two years earlier.

ECG Case of the Month: Unexpected Atrioventricular Conduction in High-Grade Atrioventricular Block. Sinus rhythm; high-grade second degree atrioventricular block with a junctional escape rhythm and three capture complexes, each with right bundle branch block aberration; possible septal myocardial infarct of indeterminate age; ST-T and U wave changes suggesting hypokalemia

A 90-year-old man with a history of high blood pressure, a cerebrovascular accident without focal residua, dementia, and stage 3 chronic kidney disease went to the emergency department because of dizziness and near syncope. His medications were aspirin 81 mg qd, clopidogrel 75 mg qod, escitalopram oxalate 10 mg qd, Seroquel 25 mg qd, and memantine hydrochloride 10 mg qd. He had orthostatic hypotension with supine blood pressure of 173/77 mm Hg falling to 116/68 on standing, while pulse increased from 66 to 84 beats/ min. He received IV fluid and returned home. Two days later he saw his primary care physician because of episodes of dizziness and confusion. The figure shows an electrocardiogram recorded during that visit.

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.

ECG Case of the Month. Out-of-Hospital Cardiac Arrest. DIAGNOSIS: Atrial fibrillation with a rapid ventricular response (150 beats/minute) and right bundle branch block

A muscular-appearing 50-year-old man was found down in his home by family members. Paramedics documented pulseless electrical activity and began cardiopulmonary resuscitation that included placement of an endotracheal tube. The resuscitation was continued in the hospital emergency department (ED), and after 20 minutes, an arterial pulse returned. An electrocardiogram (ECG) was obtained (Figure 1). Meanwhile, a past history established that the patient was a personal trainer who seemed fit and healthy until 10 days earlier, when he came to the ED because he had begun to lose his balance and fall frequently. Computed tomography (CT) at that time revealed lytic lesions in the fifth lumbar vertebra and extensive retroperitoneal lymphadenopathy involving the aortic, iliac, and obturator chains and the perirectal region. Arrangements had then been made for outpatient workup of a presumed malignancy.

ECG of the Month. Unexpected Atrioventricular Conduction in High-Grade Atrioventricular Block. DIAGNOSIS: Sinus rhythm; high-grade second-degree atrioventricular block with a junctional escape rhythm and three capture complexes, each with right bundle branch block aberration; possible septal myocardial infarct of indeterminate age; ST-T and U wave changes suggesting hypokalemia

A 90-year-old man with a history of high blood pressure, a cerebrovascular accident without focal residua, dementia, and stage 3 chronic kidney disease went to the emergency department because of dizziness and near syncope. His medications were aspirin 81 mg qd, clopidogrel 75 mg qod, escitalopram oxalate 10 mg qd, quetiapine fumarate 25 mg qd, and memantine hydrochloride 10 mg qd. He had orthrostatic hypotension with supine blood pressure of 173/77 mmHg falling to 116/68 on standing, while pulse increased from 66 to 84 beats/min. He received IV fluid and returned home. Two days later, he saw his primary care physician because of episodes of dizziness and confusion. The Figure shows an electrocardiogram recorded during that visit.