Reperfusion is useful for (AIIMS May 2011)
|C||Non ischemic viable myocardium|
|D||Mixed ischemic myocardium|
1. "LV dysfunction can be due to non-contractile or hypo contractile segments that are viable but are chronically ischemic (hibernating myocardium).
2. As a consequence of chronic reduction in myocardial blood flow these segments down regulate their contractile function.
3. These can be detected by using radionuclide scans of myocardial perfusion and metabolism, PET, CMR imaging, or delayed scanning with thallium-201 or by improvement of regional functional impairment, provoked by low-dose dobutamine.
4. " In such patients, revascularization improves myocardial blood flow, can return function, and can improve survival."
5. Stunned myocardium can be differentiated from hibernating myocardium by three clinical parameters, namely, LV wall motion, myocardial perfusion, and myocardial metabolism.
6. Stunned myocardium has abnormal wall motion that tends to normalize in response to inotrope and postextrasystolic potentiation.
7. Perfusion is adequate and metabolism is also adequate. Hibernating myocardium also has abnormal wall motion, which normalizes after nitrates, inotrope, post extrasystolic potentiation (PESP), PTCA, or CABG.
8. Myocardial perfusion is reduced but can be reversed with PTCA or CABG and metabolism is adequate.
Extra Edge: Recent Advances:
Following are the methods to reperfuse the myocardium
1. Thrombolytic therapy
2. Mechanical method:
3. Coronary artery bypass graft (CABG)