Improved assessment of inferior left ventricular wall motion using biplane equilibrium radionuclide ventriculography

Analysis of the effects of electroacupuncture at the pericardium 6 acupoint on heart function in patients with angina using equilibrium radionuclide angiocardiography quantity analysis technique

OBJECTIVE

To analyze changes in cardiac function indices after electroacupuncture (EA) at the pericardium 6 (PC-6) acupoint using the equilibrium radionuclide angiocardiography (ERNA) quantity analysis technique.

DESIGN

Analysis of clinical outcomes after EA at PC-6 measured by ERNA.

SETTING

The study was conducted in a hospital.

PARTICIPANTS

31 participants (17 patients with angina and 14 healthy volunteers).

INTERVENTION

The study used ERNA to study outcomes of EA at PC-6 on heart function.

OUTCOME MEASURE

ERNA images were taken before the treatment (T0), at the end of the treatment (T1), and 20 minutes after the treatment (T2) and then processed.

RESULTS

Regional left ventricular ejection fraction (REF) increased after EA in the angina and control groups. REF at T2 was significantly higher than at T1 in the angina group (p<.01). In the control group, REF was higher at T1 than at T0 (p<.01) but did not differ between T1 and T2 (p=.08). The REF deviation among ventricular regions in the angina group was significantly greater than that in the control group at T0 (p<.01) but was reduced to the level of that in control group after EA (p=.52). Peak filling rate was lower in the angina group than in controls at all three time points (all p<.01). After EA, peak filling rate increased markedly in the angina group but not in the control group. The cardiac cycle was shorter in the angina group than in the control group at T0 (p<.01) and increased after EA. The cardiac cycle of the control group did not change.

CONCLUSION

Effects of EA at PC-6 on heart function can be detected and quantified by ENRA.

Non-invasive measurement of left ventricular volumes and function by gated positron emission tomography

To date cardiac positron emission tomography (PET) studies have focussed on the measurement of myocardial blood flow, metabolism and receptors while left ventricular (LV) function and dimensions have been derived from other modalities. The main drawback of this approach is the difficulty of data co-registration, which limits clinical interpretation. The aim of this study was to evaluate whether it is possible to measure absolute cardiac volumes, and consequently LV function parameters such as ejection fraction, and wall motion with gated PET. Nineteen patients underwent a PET scan and planar radionuclide ventriculography (MUGA) within 9+/-9 days. A 9-min scan (16 gates/cardiac cycle) was acquired after inhalation of 3 MBq/ml of oxygen-15 labelled carbon monoxide at the rate of 500 ml/min over 4 min using a multislice PET camera. Noise reduction was performed on the gated image to enhance the definition of the ventricles before reslicing to the short-axis view. A threshold value was used to detect the edge of the LV at each gate. LV volumes at each gate were estimated by summing the volume of voxels within the LV boundary. PET measurements of LV volumes were as follows: LV end-diastolic volume ranged from 72 to 233 ml and LV end-systolic volume ranged from 24 to 203 ml. Phantom experiments supported the validity of this approach for estimating volumes. LV ejection fraction measured with MUGA was 38.4%+/-16.3% (range 15%-71%) and that measured with PET was 39.6%+/-17.7% (range 9%-72%) (P=NS). The LV ejection fraction measurements were highly correlated (r2=0.824). These results indicate that: (1) absolute end-diastolic and end-systolic volumes can be quantified using gated PET and (2) LV ejection fraction can be accurately measured by gated PET simultaneously with the other physiological PET parameters.