Search PubMed⌕ Search

Biomedical subjects

B T Kim

Publications and source records attributed to B T Kim.

39 records · Page 3Linked to original sources

Iodine-123 MIBG imaging before treatment of heart failure with carvedilol to predict improvement of left ventricular function and exercise capacity.

BACKGROUND: We examined whether cardiac sympathetic imaging with iodine-123 metaiodobenzylguanidine (MIBG) would predict improvement of left ventricular (LV) function and exercise capacity in patients with heart failure after treatment with carvedilol. METHODS AND RESULTS: Eighteen patients with heart failure and 5 control subjects underwent I-123 MIBG imaging. Heart-to-mediastinum ratios at 20 minutes and 3 hours and myocardial washout rates (WR) were measured. Of the 18 patients, 11 were randomized to receive carvedilol medication, whereas the remaining 7 received a placebo. Only the carvedilol group demonstrated a significant improvement in both heart failure functional class and LV ejection fraction (EF) 1 year after the start of medication. Within the carvedilol group, MIBG WR showed a significant inverse correlation with improvement in LVEF (rho = -0.74, P =.02). The diagnostic accuracy of WR for predicting EF response to carvedilol was 91%. WR also appeared to be inversely related to the peak oxygen consumption rate (rho = -0.65, P =.08), although this did not reach statistical significance. CONCLUSION: I-123 MIBG imaging appears useful in predicting which patients with heart failure are likely to show the most improvement in LV function and exercise capacity after carvedilol treatment. Further studies in this area appear to be warranted.

3-Iodobenzylguanidine↗

Dipyridamole myocardial SPECT with low heart rate response indicates cardiac autonomic dysfunction in patients with diabetes.

BACKGROUND: Because dipyridamole is used to assess heart rate (HR) variability, we investigated whether a low HR response during dipyridamole single photon emission computed tomography (SPECT) in patients with diabetes indicates the presence of cardiac autonomic neuropathy (CAN). METHODS AND RESULTS: Subjects were 61 non-insulin-dependent diabetes patients without perfusion defects, myocardial infarction, or arrhythmia who underwent thallium 201 SPECT imaging. The control group comprised 28 subjects without diabetes. HR was measured during infusion of dipyridamole at a rate of 0.14 mg/kg/min, and peak-baseline ratios of 1.20 or less were defined as low. CAN severity was classified by standard autonomic function tests as severe (n = 22), mild (n = 19), or none (n = 20). HR ratios were significantly attenuated in patients with diabetes compared with those in control subjects (1.22 +/- 0.12 vs 1.32 +/- 0.12, P <.001). Among the patients with diabetes, HR ratios decreased as CAN severity increased from none (1.32 +/- 0.10) to mild (1.23 +/- 0.12, P <.05) to severe (1.13 +/- 0.08, P <.005). There was good correlation between HR ratio and R-R interval ratio to deep breathing and to Valsalva, and patients with low HR ratios showed an attenuated response to both tests (all P <.001). The sensitivity and specificity of HR ratios in the detection of CAN were 77% and 74% for severe CAN and 63% and 90% for mild-to-severe CAN, respectively. CONCLUSIONS: In patients with diabetes who have normal dipyridamole SPECT results, an attenuated HR response observed during stress indicates a high likelihood of CAN. Further work that assesses these results in diabetes patients with coronary artery disease is warranted.

Autonomic Nervous System Diseases↗