Prognostic value of thallium-201 myocardial scintigraphy after atrial transoesophageal pacing in patients with suspected coronary artery disease

Fifty-five patients with suspected coronary artery disease underwentplanar thallium-201 myocardial scintigraphy after atrial transoesophagealpacing. Coronary angiography was carried out in all patients.Eighteen patients had no myocardial infarction, but a greaterthan 50% narrowing of at least one main vessel: initial hypoperfusionwith redistribution at 4 h occurred in 16 patients (sensitivity89%). Twenty-one patients had had a previous myocardial infarction:a reversible thallium defect was observed in 12 patients andan irreversible defect in the nine remaining patients. Sixteenpatients had normal coronary arteries: a reversible thalliumdefect was observed in three patients (specflcity 81%). Aftera mean follow-up of 22±13 months (range 6 to 40), 23cardiac events occurred: cardiac death in one patient, unstableangina in three, and revascularization procedures for recurrentangina despite medical therapy in 19 (coronary artery bypasssurgery in 7 and coronary angioplasty in 12). By univariateanalysis, the predictors of future cardiac events were a historyof previous myocardial infarction (odds ratio 55, P<0.02)multivessel coronary artery disease (odds ratio 9.6, P<0.0002),angina during atrial pacing (odds ratio 5.1, P<0.05), abnormalscintigraphy (odds ratio 17.1, P<0.001) and reversible perfusiondefect after pacing (odds ratio 7.9, P<0.002). By multivariateanalysis, multivessel disease (P<0.004) and reversible perfusiondefect after pacing (P<0.02) were the only independent predictorsof future cardiac events. In conclusion, thallium-201 myocardial scintigraphy after transoesophagealatrial pacing is accurate for the diagnosis and prognosis ofpatients with suspected coronary artery disease, and may beundertaken in patients unable to perform exercise stress testing.     

Influence of age on rectal tone and sensitivity to distension in healthy subjects

Hypersensitivity to rectal distension is frequently observed in patients with irritable bowel syndrome (IBS). However, few data are available about the influence of age on rectal sensory thresholds and tone. The aim of this study was to measure rectal sensory thresholds and tone with a barostat in 12 healthy subjects (aged 86 +/- 4 years, eight females, four males) as compared with 12 young healthy male controls (26 +/- 1 years). Isobaric phasic distensions were performed in the fasted state (increment of 4 mmHg, steps of 5 min, interval of 5 min). Rectal tone changes were then measured as changes in volume of the barostat bag, the pressure being kept constant. After a baseline recording of 1 h, a 1000-kcal meal was served and the tone recorded until return to baseline. Rectal sensory thresholds were significantly higher in aged subjects. First sensation, sensation of urge to defaecate and sensation of pain were triggered at 21.1 +/- 3.2 mmHg, 30.4 +/- 5.4 mmHg and 40.5 +/- 5.0 mmHg, respectively, in aged subjects, vs 13.3 +/- 4.6 mmHg (P < 0.05), 20.7 +/- 1.0 mmHg (P < 0.001) 31.3 +/- 1.7 mmHg (P < 0.001) in controls. Rectal compliance was not significantly different between the two groups. Mean barostat bag volume was 104 +/- 13 mL in fasting aged subjects and 125 +/- 23 mL in controls (NS). After the meal, the barostat bag volume decreased by 69 +/- 11% during 85 +/- 17 min in aged subjects and 75 +/- 14% during 89 +/- 15 min in young controls (NS). Rectal sensory thresholds triggered by distension are increased in aged healthy subjects while compliance and tone are not different. Age should be considered as a confounding factor when studying rectal sensitivity and further studies in aged patients with IBS should include a group of control subjects within the same range of age as studied patients.