2010 BC Guide in Determining Fitness to Drive

Episodic impairmentThe potential episodic impairment is a partial or complete loss of consciousness thatincapacitates the driver. This may be caused by a variety of cardiovascular events such as: bradyarrhythmias tachyarrhythmias myocardial disease (massive myocardial infarction) left ventricular myocardial restriction or constriction pericardial constriction or tamponade aortic outflow tract obstruction aortic valvular stenosis, or hypertrophic obstructive cardiomyopathy.Persistent impairmentIndividuals with congestive heart failure may develop persistent cognitive impairment, loss ofstamina or general debility as a result of a reduction of oxygen to the brain, organs and tissues.Cardiac arrest may also cause persistent cognitive impairment where a loss of blood to the braincauses brain damage.Neurocognitive deficits can occur in individuals undergoing intracardiac procedures (e.g. valvesurgery) or extracardiac procedures (e.g. coronary artery bypass graft (CABG) surgery).However, the majority of studies investigating cognitive decline have focused on individualsundergoing CABG surgery. The results of those studies indicate that a significant number ofindividuals experience post-operative cognitive decline (POCD) for several months after surgery,with documented declines in memory, attention, speed of processing, and executive functioning.Studies indicate that between 20% and 79% of individuals experience POCD between 6 weeksand 6 months of CABG surgery, with a majority of the studies showing a rate of 45% or higher.In those studies that have followed individuals for more than 6 months post-surgery, the resultsindicate that up to 35% of individuals will show POCD one year after surgery. The currentunderstanding is that POCD is the result of a number of factors associated with cardiactreatment, rather than a single factor such as the use of cardiopulmonary bypass.163