A sharkfin waveform on monitor is most consistent with which condition?

• A. Hyperkalemia
• B. Myocardial infarction
• C. Bronchospasm, asthma, COPD
• D. Ventricular tachycardia

Answer: (C)

A sharkfin capnography pattern points to obstructive airway disease causing markedly slowed and uneven exhalation. In conditions like bronchospasm, asthma, or COPD, narrowed airways impede expiratory flow, so the CO2 increases more gradually and the expiratory portion of the waveform becomes curved and triangular rather than a clean, flat plateau. This results in the distinctive sharkfin appearance. It’s a ventilation/airway problem, not a primary ECG issue, so hyperkalemia, myocardial infarction, or ventricular tachycardia wouldn’t produce this waveform. Recognizing this pattern suggests imminent respiratory compromise and the need for bronchodilators and airway support.