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Aims To evaluate the accuracy of echocardiography in conjunction with quantitative high-dose dipyridamole technetium-99m sestamibi tomography (SPECT) in detecting coronary allograft vasculopathy.Methods and Results Seventy-eight consecutive heart transplant recipients underwent echocardiography while at rest and high-dose dipyridamole SPECT within 48h of a yearly angiogram. Resting wall motion abnormalities were considered significant if present in two or more segments. SPECT was considered abnormal in the presence of reversible/fixed defects. The coronary angiogram was normal in 53, showed non-significant coronary allograft vasculopathy in 13 and significant (≥50% stenosis) coronary allograft vasculopathy in 12 cases. Resting wall motion abnormalities were observed in nine cases and perfusion defects in 20. Echocardiography and SPECT were concordant in 59 cases (five positive and 54 negative); in these, accuracy was 100% for significant coronary allograft vasculopathy and 83% for any coronary allograft vasculopathy. Over 6·5±2 years, 17 patients suffered coronary allograft vasculopathy-related events, including death in six and retransplantation in three. Resting wall motion abnormalities, SPECT perfusion defects and angiographic coronary allograft vasculopathy were significant predictors of cardiac events.Conclusion Normal resting wall motion at echocardiography coupled to normal stress myocardial perfusion, rules out the presence of significant coronary allograft vasculopathy in many heart transplant recipients. Conversely, resting wall motion abnormalities and perfusion defects strongly predict cardiac events. Therefore, a strategy which reserves angiography for patients with resting wall motion abnormalities and/or perfusion defects may be safe and cost-effective. [ABSTRACT FROM PUBLISHER]

Silent ischaemia has been widely investigated limiting the diagnostic approach to the left ventricle. To date, no systematic study on silent ischaemia in patients with demand-induced right ventricular dysfunction has been reported. The occurrence of painless ischaemic episodes was evaluated by atrial pacing and radionuclide angiography in 20 consecutive patients with single right coronary artery stenosis and without previous myocardial infarction. At the peak pacing rate all patients showed transient myocardial dysfunction (reduction of ejection fraction and/or development of wall-motion abnormalities) localized to the right, the left, or to both ventricles in 9, 1 and 10 patients, respectively. Eight patients experienced chest pain (group 1) and 12 were asymptomatic (group 2) at the maximal pacing rate. Basal left ventricular ejection fraction (55 ± 4% vs. 55 ± 5%), basal right ventricular ejection fraction (48 ± 4% vs. 46 + 8%), peak pacing left (52 ± 9% vs. 50 ± 11%) and right (38 ± 7% vs. 37 ± 9%) ventricular ejection fractions, and maximal pacing pressure rate product (17 289 ± 2880 vs. 19 244 ± 3806) were not significantly different in the two groups. This study demonstrates a high prevalence of silent ischaemia in patients with single right coronary artery stenosis and pacing-induced dominant right ventricular dysfunction. Painful episodes do not appear to be related to the magnitude of changes in ejection fraction. [ABSTRACT FROM PUBLISHER]

The effect of various doses of intracoronary verapamil on the diameter of angiographically normal left coronary artery segments was investigated in 22 patients with and without coronary atherosclerosis by quantitative angiography. Very low doses (50 μg) were given in 3 patients; doses of 250 μg, 350 μg and 500 μg were administered in 7,6 and 13 patients, respectively. A single dose was administered in 15 patients, while two increasing doses of verapamil were tested in 7. The effect of verapamil was compared in each patient with that of nitroglycerin (NG; 0.6 mg), administered sublingually in all as the last step of the study. An additional group of 8 patients served as the control. These patients received 4 intracoronary injections of contrast medium without drugs and a fifth injection following 0.6 mg of sublingual NG. In the control group no significant changes in coronary artery diameter were observed following the four control injections of contrast medium, while a 18±9% increase in vascular diameter was observed following NG. When verapamil was injected a dose-dependent vasodilation was observed, which began to be significant with doses higher than 250 μg. Mean percent variations of coronary artery diameter relative to control were –0·2±3.6%, 4.6±5.5%, 11.4±7.5% and 19.9±10.7%, in response to verapamil doses of 50, 250, 350 and 500 μg, respectively. Subsequent nitroglycerin induced a 21.5±10.7% mean percent coronary artery dilation (NSvs verapamil 500 μg and vs NG in the controlgroup). Thus, verapamil induced a dose-dependent coronary vasodilation which at a dose of 500 μg was comparable to that induced by NG. Both with verapamil and NG the smallest vessels exhibited the greatest vasodilation. It is concluded that at the doses used in this study, injection of verapamil into the left coronary artery is safe and markedly decreases tone in the large coronary arteries. This finding supports the use of verapamil in clinical conditions in which the role of coronary vasoconstriction proven or thought to be relevant. [ABSTRACT FROM PUBLISHER]