Prevalence of atrial FDG uptake and association with atrial arrhythmias in patients with cardiac sarcoidosis.

BACKGROUND: There is increasing evidence that a proportion of patients with cardiac sarcoidosis (CS) have atrial arrhythmias (AA). Although 18F-fluorodeoxy-glucose (FDG) uptake in the ventricle on positron emission tomography/computed tomography (PET/CT) is well studied, FDG uptake in the atrium has not been elucidated in detail. OBJECTIVES: To evaluate FDG uptake in the atrium and its relationship with AA in patients with CS. METHODS: We retrospectively investigated 62 CS patients. All patients underwent echocardiography and PET/CT. Serum angiotensin converting enzyme (ACE) and soluble IL-2 receptor (sIL-2R) levels, plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations were also evaluated. ECG, Holter monitoring and device interrogations were used to detect AA. RESULTS: Of the studied population, 25 patients (40.3%) had AA, of which 2 patients had atrial tachycardia (AT) and 23 patients had atrial fibrillation (AF). Eighteen patients with AA had atrial FDG uptake on PET/CT, whereas 14 patients without AA had atrial FDG uptake (72.0% vs 37.8%, P = 0.017). Multivariate analysis revealed a significant association between AA and age (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 1.01-1.31, P = 0.040), atrial FDG uptake (odds ratio [OR]: 7.23; 95% confidence interval [CI]: 1.91-27.36, P = 0.004), and left atrial diameter (OR: 1.08; 95% CI: 1.01-1.16, P = 0.027). Meanwhile, gender, serum ACE and BNP levels, and left ventricular ejection fraction were not associated with AA. CONCLUSIONS: Atrial FDG uptake was common in patients with CS and strongly associated with AA.

Serial assessment of left ventricular performance at rest and during bicycle exercise by ECG-gated myocardial perfusion SPECT.

UNLABELLED: The present study evaluates left ventricular performance during exercise by ECG-gated myocardial perfusion SPECT with short-time data collection. METHODS: The study population consisted of 10 healthy volunteers (Group N) and 9 patients with ischemic heart disease (Group I). Seven patients in Group I had a history of prior myocardial infarction. Rest ECG-gated SPECT was performed 40 min after an injection of Tc-99m-tetrofosmin (555-740 MBq). After resting data acquisition, Group N underwent up to two 5-min stages of exercise (75 and 125 watts) on a detachable bicycle ergometer. The Group I patients all underwent symptom-limited, maximal testing on the ergometer. ECG-gated SPECT data were acquired from both groups for 3 min at rest and during the last 3 min of each exercise stage. RESULTS: Significant increases occurred in LVEF from rest to peak stress in both groups (from 55.4 +/- 5.8 to 66.6 +/- 4.1% in group N, p < 0.0001; from 49.0 +/- 12.8 to 56.7 +/- 13.8% in Group I, p < 0.001). The LVESV values significantly decreased to peak stress in Group N (from 49.9 +/- 13.1 to 37.8 +/- 10.0 ml, p < 0.0001), whereas LVEDV did not change (from 110.6 +/- 18.9 to 112.0 +/- 19.0 ml). In contrast, the LVESV values at rest and under peak stress were similar in Group I (from 52.6 +/- 23.9 to 51.7 +/- 31.4 ml) and LVEDV in Group I at peak exercise tended to increase (from 102.8 +/- 36.7 to 111.3 +/- 39.0 ml). The changes in LVESV from rest to peak stress were significantly different between Groups N and I (-12.1 +/- 6.3 vs. -0.9 +/- 11.6 ml, p < 0.02). CONCLUSION: ECG-gated SPECT with short-time data collection can assess left ventricular function during exercise and may offer useful information for evaluating patients with ischemic heart disease.