cyanotic spell
Acute episodes of severe cyanosis and dyspnea in patients with tetralogy of Fallot and related conditions.
Full Definition
Cyanotic spells, also known as hypercyanotic spells or tet spells, are acute episodes of worsening cyanosis, dyspnea, and sometimes loss of consciousness that occur in patients with tetralogy of Fallot and similar conditions with right ventricular outflow tract obstruction. These spells result from sudden increases in right ventricular outflow tract resistance or decreases in systemic vascular resistance, leading to increased right-to-left shunting. Episodes may be triggered by crying, defecation, or exercise, and are often relieved by squatting or knee-chest positioning. Frequent or severe spells indicate the need for urgent surgical intervention.
Usage
Usage note: Also commonly called 'tet spells' even when occurring in conditions other than tetralogy of Fallot.
In Context
- "The patient experienced increasing frequency of cyanotic spells, prompting early surgical repair." — consultation note
- "Parents reported that squatting position relieves the child's cyanotic spells within minutes." — history and physical