Ethics approval is already obtained. Consented patients will be screened for ISH in the pre-surgical clinic, utilizing BP automated machine. Patients with ISH or normal diastolic function (control group) will be enrolled. During and after surgery, they will be monitored for changes consistent with myocardial ischemia. A special heart monitor, called ambulatory ECG monitor (Holter monitor), will be used to record, document and count any episodes of myocardial ischemia. A designated research coordinator will be assigned to the study for the recruitment, screening, daily tracking and data collection. The heart monitoring for each patient in the study will be reviewed by the research group. Data will be collected and analysed.
This is the first study looking exclusively at ISH as a risk factor around the time of surgery. Studies suggest that investigators may be labelling surgical patients at risk of a heart attack as "low risk" when in fact the bulk of those heart attacks are in patients labeled "low risk". The finding that ISH patients have a higher incidence of myocardial ischemia will provide evidence for the next level of research. If ISH is in fact a risk factor for heart attacks around the time of surgery, the investigators will identify a group of patients in whom the investigators can lower this risk by instituting appropriate management.
