Biomedical subjects

J VanHaecke

Publications and source records attributed to J VanHaecke.

3 recordsLinked to original sources

PubMed1997

PET scan predicts recovery of left ventricular function after coronary artery bypass operation.

BACKGROUND: Viable but hypocontractile myocardium can show functional improvement after revascularization (hibernation). It is sometimes difficult, however, to predict viability and recovery in patients with severe left ventricular function. This study sought to identify possible predictive factors of recovery of cardiac function after revascularization in patients with three-vessel disease. METHODS: Positron emission tomography (fluoro-18-deoxyglucose uptake for metabolism; nitrogen 13-labeled ammonia for flow) and equilibrium-gated nuclear angiography (for the global ejection fraction) were performed in 59 patients with three-vessel disease before and after undergoing coronary artery bypass grafting. The positron emission tomographic data were expressed as match normal (flow and metabolism normal), mismatch (low flow, high metabolism), match viable (moderate decrease in flow and metabolism), and match necrosis (low flow and metabolism). RESULTS: Stepwise logistic regression analysis showed that only mismatch regions played a significant role in predicting postoperative improvement in function (p = 0.019). There were 1.7 +/- 1.5 mismatch regions in 31 patients who showed an improvement in their ejection fraction (0.47 +/- 0.14 versus 0.58 +/- 0.11; mean +/- standard deviation) versus 0.8 +/- 1.0 mismatch regions (p = 0.017) in patients who did not show recovery. There was more pronounced functional improvement with increasing numbers of mismatch regions, and patients with at least one mismatch region had a high likelihood of recovery (p < 0.001). In patients with a very low preoperative ejection fraction and two or more mismatch regions, there was early significant recovery (0.27 +/- 0.08 versus 0.46 +/- 0.06; p = 0.009). CONCLUSIONS: At least one mismatch region must be present for there to be a postoperative functional benefit. When a low left ventricular ejection fraction is associated with mismatch, early recovery is substantial.

Adult↗

PubMed1996

Prevention of bone loss in cardiac transplant recipients. A comparison of biphosphonates and vitamin D.

Bone mineral density is already abnormally reduced at the moment of cardiac transplantation and bone loss occurs at an impressive rate in the first postoperative year. The aim of the study was to compare two prophylactic medical regimens as to their efficacy in mitigating bone loss after transplantation. Forty-eight consecutive recipients were randomized to receive either alternating calcium carbonate and disodium etidronate (group A) or a daily supplement of calcium carbonate and alphacalcidol (group B). Bone mineral density measurements were performed immediately before hospital discharge and 6, 12, and 24 months after surgery using dual energy X-ray absorptiometry. Clinical events were recorded and roentgenograms of the spine were performed postoperatively and 1 and 2 years later. In both treatment groups bone loss remained significant at the level of the lumbar spine in the first postoperative year (P<0.005) and at the level of the femoral neck in the first (P<0.005) and the second (P<0.06) year after transplantation. Six months after transplantation, however, patients receiving alphacalcidol had a significant reduction in bone loss at the level of the lumbar spine (P=0.047) and at the level of the femoral neck (P=0.043). At the level of the femoral neck this decrease in bone loss was even more pronounced in the second postoperative year (P<0.001). In the group of patients treated with disodium etidronate, 4 recipients needed additional hospitalizations for treatment of symptomatic fractures at the level of the lumbar spine or the femoral neck. No such events happened in recipients receiving vitamin D supplements. Prophylactic administration of calcium carbonate and alphacalcidol after cardiac transplantation reduces bone loss and seems to decrease osteoporotic complications.

Calcium↗

PubMed1991

Left ventricular function changes during pharmacological and physiological interventions and routine activities monitored in healthy volunteers by a portable radionuclide probe (VEST).

A miniaturized radionuclide cardiac probe incorporated in a semi-rigid plastic chest garment has made ambulatory left ventricular (LV) function evaluation possible, with gated nuclear data being stored on tape together with electrocardiographic data, for subsequent off-line processing. After red blood cell labelling with 555 MBq (15 mCi) 99mTc and standard gated blood pool imaging in 45 degrees LAO, we performed a continuous monitoring of LV function in 20 healthy male volunteers (age range: 22-25 years), in resting control conditions as well as during activities (standing, walking, climbing stairs) and after interventions (isosorbide dinitrate intake, Trendelenburg position, inflation of cuffs around the thighs). VEST-monitoring proved to be a reliable method that gave reproducible results: changes of ejection (EF) in basal conditions were lower than 5% in 95% of the patients. Changes in LV function caused by daily activities were easily demonstrated. While standing effected no significant EF changes, walking and climbing increased EF by 6.9% (p less than 0.05) and 21.2% (p less than 0.05) respectively. Changes in LV volumes caused by alterations in venous return were also demonstrated. Compared with baseline, Trendelenburg increased end-diastolic volume (EDV) by 2.9% while isosorbide dinitrate and inflation of cuffs decreased it by 5.7% and 2.2% respectively.

Adult↗