PT  - JOURNAL ARTICLE
AU  - D Pagano
AU  - F Fath-Ordoubadi
AU  - K J Beatt
AU  - J N Townend
AU  - R S Bonser
AU  - P G Camici
TI  - Effects of coronary revascularisation on myocardial blood flow and coronary vasodilator reserve in hibernating myocardium
AID  - 10.1136/heart.85.2.208
DP  - 2001 Feb 01
TA  - Heart
PG  - 208--212
VI  - 85
IP  - 2
4099  - http://heart.bmj.com/content/85/2/208.short
4100  - http://heart.bmj.com/content/85/2/208.full
SO  - Heart2001 Feb 01; 85
AB  - OBJECTIVE Previous studies have suggested that resting myocardial blood flow is within normal limits in most chronically dysfunctional left ventricular segments which improve function after coronary artery revascularisation (hibernating myocardium). The aim of this study was to assess myocardial blood flow and coronary vasodilator reserve in hibernating myocardium before and after coronary revascularisation.PATIENTS AND METHODS 30 patients with multivessel coronary disease undergoing coronary revascularisation (21 patients with bypass grafting and nine with coronary angioplasty), and 21 age and sex matched healthy volunteers (controls). Myocardial blood flow (MBF, ml/min/g) was measured by positron emission tomography using oxygen-15 water at rest and after dipyridamole (MBFdip, 0.56 mg/kg in four minutes). Coronary vasodilator reserve was calculated as MBFdip/MBF. Regional wall motion was assessed with echocardiography.RESULTS Before revascularisation there were 48 remote and 275 dysfunctional myocardial segments, of which 163 (59%) improved function after revascularisation (hibernating). In hibernating segments coronary vasodilator reserve before revascularisation was significantly lower than in remote segments (1.97 (0.7), p < 0.0001) and controls (3.2 (1.5), p < 0.0001). In hibernating segments, myocardial blood flow remained unchanged after revascularisation (0.94 (0.3)v 0.95 (0.3) ml/min/g, p = 0.3) while coronary vasodilator reserve increased (1.47 (0.7)v 1.98 (1.0), p < 0.0001). Myocardial blood flow was similar in remote, hibernating segments before and after revascularisation and in controls.CONCLUSIONS This study confirms that myocardial blood flow at rest in hibernating myocardium is within normal limits in most segments, and that hibernating myocardium is characterised by an impaired coronary vasodilator reserve which improves significantly after coronary revascularisation.