Preservation of ischemic myocardium through activity management

Myocardial ischemia results from an imbalance between oxygen supply and demand. This balance may be restored by medications, procedures to reperfuse the myocardium (eg, angioplasty or thrombolytic therapy), or a reduction of oxygen demand. Studies that have quantified the energy costs of physical activity (eg, toileting methods, bathing, range of motion exercises, and ambulation) by measuring oxygen consumption have confirmed that early mobilization causes no deleterious increase in myocardial oxygen demand in MI patients. The care of patients who have undergone reperfusion by thrombolytic therapy or angioplasty within hours of MI raises special considerations with regard to activity management and length of hospitalization. Although activity progression following MI has been shown to be relatively risk free, the authors recommend individualization of protocols and close monitoring of physiologic parameters to evaluate activity tolerance. Because MI is becoming increasingly more common in groups other than middle-aged men, additional research should be focused on specific subgroups (ie, elderly patients, women, patients who have sustained multiple MIs, and those who have had reperfusion therapies).