The plot thickens

The approach to clinical conundrums by an expert clinician is revealed through the presentation of an actual patient’s case in an approach typical of a morning report. Similarly to patient care, sequential pieces of information are provided to the clinician, who is unfamiliar with the case. The focus is on the thought processes of both the clinical team caring for the patient and the discussant.

After losing consciousness at a supermarket, a 70-year-old man was brought to the emergency department by paramedics. He subsequently developed chest pain.

Syncope can be difficult to evaluate, but chest pain may help narrow an otherwise broad differential diagnosis. If this patient has aortic stenosis or hypertrophic cardiomyopathy, effort syncope is the culprit. Cardiac dysrhythmia (eg, ventricular tachycardia), complete heart block, and supraventricular tachycardia each can cause syncope along with chest pain. Myocardial infarction and associated ventricular arrhythmia might also explain both chest pain and syncope. The paramedics might have noted an arrhythmia on the cardiac monitor; if possible, the rhythm strip should be reviewed. A pulmonary embolus can cause chest pain and, if large enough to cause right ventricular compromise, syncope.

According to witnesses at the supermarket, the patient dropped to the ground, lost consciousness, and convulsed for 30 seconds. He had no head trauma, tongue biting, urinary incontinence, or confusion afterward. Electrocardiogram (ECG) performed at the scene showed ST elevations in leads V1 to V3 with ST depressions in the inferior leads. On arrival in the emergency department, the patient described nonradiating substernal chest pressure exacerbated by deep inhalation. The pain did not improve with nitroglycerin. He recalled feeling light-headed before the syncope.

He had not received medical care for 20 years and had no known illnesses other than hypertension. He was not taking any medications. He previously worked as a welder and never smoked tobacco, drank alcohol, or used illicit drugs. The patient’s temperature was 36.4°C. Heart rate was 88 beats per minute, blood pressure 128/72 mm Hg, oxygen saturation 100% on room air, and respiratory rate 22 breaths per minute. The patient had conjunctival pallor. There was a grade 3/6 crescendo- decrescendo systolic murmur loudest at the right upper sternal border without radiation to the carotids. There was no jugular venous distention. Lungs were clear to auscultation bilaterally. There was no peripheral edema, rash, or lymphadenopathy.

Convulsive movements commonly occur during episodes of unconsciousness lasting more than 15 seconds—a phenomenon termed convulsive syncope and often is confused with seizures. These movements are usually clonic jerks of the extremities and trunk and slight twitching of the face, and occasionally tonic extension of the trunk and clenching of the jaw. Absence of tongue biting, urinary incontinence, and confusion in this patient’s case makes seizures less likely.

The distribution of ST segment changes on his ECG are concerning for myocardial infarction in the septal and inferior regions. Right-sided ECG should be performed to assess for right ventricular infarction. Although myocardial ischemia is the primary concern, some features warrant consideration of other etiologies of syncope. First, syncope is an unusual presentation of cardiac ischemia or infarct. The complaint of chest pressure exacerbated by deep inhalation is another atypical feature for myocardial ischemia. Although the patient’s oxygen saturation and heart rate are normal, pulmonary embolism remains a possibility.

The prominent crescendo-decrescendo systolic murmur at the right upper sternal border could indicate aortic stenosis; the carotids should be palpated to assess for pulsus parvus et tardus. A high-flow state associated with anemia could also lead to a midsystolic murmur. Conjunctival pallor typically is seen with hemoglobin levels of 6 g/dL or less. This finding may indicate severe anemia, which has the potential to cause myocardial ischemia and syncope.

Laboratory testing revealed a troponin of 0.04 ng/dL, hemoglobin 4.1 g/dL with MCV of 84.7 fL, white blood cell count 6,500/μL and platelet count 179,000/μL. Serum sodium was 130 mEq/L, urea nitrogen 16 mg/dL, creatinine 1.6 mg/dL, calcium 7.8 mg/dL, total protein 11.4 g/dL (reference range, 6.0-8.2), and albumin 2.2 g/dL. Erythrocyte sedimentation rate (ESR) was 20 mm/h. Serum iron was 48 μg/mL, total iron binding capacity 275 μg/dL, percent iron saturation 17% (reference range, 20-55), and ferritin 10 ng/mL (reference range, 30-400). The international normalized ratio (INR) was 1.5, prothrombin time 15.5 sec (reference range, 9.4-11.6), and partial thromboplastin time 24.7 sec (reference range, 22.9-30.6). Hepatitis C and HIV antibodies were negative as was the urine toxicology screen. Urine protein to creatinine ratio was 0.07. His hemoglobin rose to 7.9 g/dL with transfusion of 4 units packed red blood cells (RBC). His chest pain improved and inferior ST depressions resolved on follow-up ECG. Further history revealed multiple episodes of melena and hematochezia in the preceding weeks without nausea, vomiting, or abdominal pain.

The patient has a strikingly large gamma gap: 9.2. A gap larger than 4 is concerning for the presence of paraproteins. Given the possibility of a paraproteinemia (eg, multiple myeloma, plasmacytoma, Waldenström macroglobulinemia), the first step is to check serum and urine protein electrophoresis. The patient’s anemia is significant and reticulocyte index low. The low ferritin level combined with the inappropriately low reticulocyte count could result from iron deficiency anemia, another bone marrow process, or both. The patient’s syncope likely resulted from severe anemia and hypovolemia associated with hematochezia. The prolonged prothrombin time could be caused by a coagulation factor production problem, from vitamin K deficiency or underlying liver disease, or by a consumptive problem, from low-grade disseminated intravascular coagulation. It is controversial whether inhaling welding fumes causes cancer, but the patient’s age alone makes malignancy a definite possibility.