What Researchers Did
Researchers used in-chamber transthoracic echocardiography to evaluate cardiac changes in 11 patients and 9 staff members during hyperbaric oxygen therapy administered at 243 kPa.
What They Found
During hyperbaric oxygen therapy, heart rate significantly decreased from 70 bpm to 65 bpm (P = 0.002), leading to a reduced cardiac output of 5.3 L·min⁻¹ from 5.9 L·min⁻¹ (P = 0.003). While left ventricular outflow tract dimension increased from 2.23 cm to 2.30 cm (P = 0.0003) and velocity time integrals decreased, stroke volume remained similar at 61 ml versus 65 ml (P = 0.5).
What This Means for Canadian Patients
This study suggests that hyperbaric oxygen therapy induces specific cardiac changes like reduced heart rate and cardiac output, but appears safe for patients without active cardiac disease. Canadian patients undergoing HBO therapy can be reassured that significant adverse cardiac effects are unlikely based on these findings.
Canadian Relevance
This study was not conducted in Canada and has no direct Canadian connection.
Study Limitations
A limitation of this study is its small sample size and focus on subjects without active cardiac disease, which may limit generalizability.