Pediatric emergency medicine trisk 1527 1527

FIGURE 77.1 A diagnostic approach to tachycardia. a Altered mental status, diaphoresis,
hypertension. b See Chapter 10 Shock . HR, heart rate; EKG, electrocardiogram; SVT,
supraventricular tachycardia; ARF, acute rheumatic fever.

Pericardial effusion may occur after blunt chest trauma, viral infection, or as a
component of inflammatory diseases such as systemic lupus erythematosus.
Small effusions may be detected as a friction rub. Large effusions often cause
cardiogenic shock and may lead to muffling of heart sounds and EKG changes,
such as low-voltage or T-wave flattening with “strain” pattern in leads V1
through V6, but are nonspecific. Pericardial effusions are best identified using
ultrasound. Patients with evidence of significant circulatory impairment should