6. The hallmark of cardiovascular dysfunction
with submersion injury is shock (33).
Systemic and pulmonary vascular
resistances are raised with hypothermia and
sympathetic activity associated with the
diving reflex. With these processes,
ventricular end-diastolic pressures are
raised, as are atrial pressures, with resultant
congestion of central and pulmonary veins.
Myocardial contractility is diminished with
hypoxemia. Poor myocardial contractility, in
combination with raised systemic vascular
resistance, results in lower cardiac output.