Segmentary coronary reserve in hypertensive patients with echocardiographic left ventricular hypertrophy, gamma-graphic ischaemia and normal coronary angiography.

Stress thallium scintigraphies are frequently positive in patients with systemic hypertension (SHT), especially in the presence of left ventricular hypertrophy (LVH). In order to determine whether positive thallium perfusion scans in patients with LVH secondary to SHT and normal coronary angiographies are due to segmentary reduction of coronary reserve (CR), we have studied 10 out of 60 consecutive cases of SHT with echocardiographic LVH, using intracoronary Doppler. We compared coronary blood flow velocity at rest and post-papaverine (PP), and CR in at least two major coronary vessels, always including the one corresponding to the ischaemic segment. In the vessel with the least CR at rest, a new determination of CR was made under intracoronary nitroglycerin. A group of five normal patients acted as controls. The mean CR of the controls and patients, respectively, was 6.2 +/- 1.4 vs 2.7 +/- 0.9 (P < 0.001). In patients with positive thallium perfusion scans, the coronary arteries corresponding to the ischaemic segments had less CR (2.5 +/- 0.6) than arteries from non-ischaemic segments (3.4 +/- 1, P < 0.05). These differences were greater when the ischaemia was anterior. There was no correlation either between CR and left ventricular mass (r = 0.23) or rest coronary blood flow velocity (r = 0.07). Only one patient exhibited functional behaviour indicating reduced CR; this rose from 1.9 to 7.5 after nitroglycerin 300 micrograms. In conclusion, CR determined by intracoronary Doppler and papaverine shows segmentary differences both in normal patients and in patients with LVH and normal coronary angiograms. This could be the cause of segmental ischaemia detected by means of radionuclide stress tests.