Beta-blockers and mechanical dyssynchrony in heart failure assessed by radionuclide ventriculography.

BACKGROUND: Radionuclide ventriculography (RNVG) can be used to quantify mechanical dyssynchrony and may be a valuable adjunct in the assessment of heart failure with reduced ejection fraction (HFrEF). The study aims to investigate the effect of beta-blockers on mechanical dyssynchrony using novel RNVG phase parameters. METHODS: A retrospective study was carried out in a group of 98 patients with HFrEF. LVEF and dyssynchrony were assessed pre and post beta-blockade. Dyssynchrony was assessed using synchrony, entropy, phase standard deviation, approximate entropy, and sample entropy from planar RNVG phase images. Subgroups split by ischemic etiology were also investigated. RESULTS: An improvement in dyssynchrony and LVEF was measured six months post beta-blockade for both ischemic and non-ischemic groups. CONCLUSIONS: A significant improvement in dyssynchrony and LVEF was measured post beta-blockade using novel measures of dyssynchrony.

The introduction of a chest pain nurse and fast-track troponin service reduces the length of stay of patients presenting with chest pain.

BACKGROUND: Troponin I (TnI) measurement is important in decision making and management of patients who present with chest pain. Undetectable levels of TnI in these patients are associated with a low risk of death or myocardial infarction at 30 days, and may allow early discharge from hospital. METHODS: An audit was performed tracking patients who presented with chest pain and had a TnI blood test requested. Routine clinical service was audited for three months. A "fast-track" troponin service and chest pain specialist nurse was then introduced to assist in the management of patients. This was continued for three months to assess the impact on length of stay. RESULTS: 446 patients were admitted during the first three month period and 511 patients admitted during the second monitoring period when the new measures were introduced. The time from chest pain onset until the TnI blood test was taken reduced from 23.0 hours to 20.3 hours. The percentage of patients admitted to hospital wards from the Acute Medical Receiving Unit (AMRU) fell from 62% to 53% (p < 0.001). The new measures resulted in a reduction in admission time from 73.1 hours to 51.0 hours. CONCLUSION: A fast-track troponin and specialist nurse achieved a reduction of nearly 24 hours in length of stay in patients presenting with chest pain. This would result in a saving of approximately 2000 bed-days per annum, releasing 5-6 acute beds per day.

Downscatter correction and choice of collimator in 123I imaging.

(123)I imaging is increasingly used in nuclear medicine but downscatter from high (>300 keV) energy emissions degrades the image and introduces variation in sensitivity with depth when imaging with a low energy collimator. A dual windowing technique using a matched window immediately above the principle window to correct for the effects of downscatter is described. The technique is shown to correct for the variation in sensitivity with depth and to reduce outlying scatter. Quantitative imaging of (123)I using a low energy collimator should always employ downscatter correction.