Quantitative Computed Tomography of Pulmonary Emphysema and Ventricular Function in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Hypertension

OBJECTIVE: This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT). MATERIALS AND METHODS: Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators. RESULTS: Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume (R2 = 0.340, p = 0.023), RV stroke volume (R2 = 0.406, p = 0.011), and RV cardiac output (R2 = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed. CONCLUSION: The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.

Effects of Propranolol on the Left Ventricular Volume of Normal Subjects During CT Coronary Angiography

OBJECTIVE: The purpose of this study is to determine the effects of propranolol on the left ventricular (LV) volume during CT coronary angiography. MATERIALS AND METHODS: The LV volume of 252 normal Chinese subjects (126 subjects with propranolol medication and 126 age- and gender-matched Chinese subjects without medication) was estimated using 64 slices multi-detector CT (MDCT). The heart rate difference was analyzed by the logistic linear regression model with variables that included gender, age, body height, body weight, systolic blood pressure (SBP), diastolic blood pressure (DBP) and the dosage of propranolol. The following global LV functional parameters were calculated: the real-end diastolic volume (EDV), the real-end systolic volume (ESV) and the real-ejection fraction (EF). RESULTS: The female subjects had a greater decrease of heart rate after taking propranolol. The difference of heart rate was negatively correlated with the dosage of propranolol. The real-EDV, the real-ESV and the real-EF ranged from 48.1 to 109 mL/m2, 6.1 to 57.1 mL/m2 and 41% to 88%, respectively. There was no significant difference in the SBP and DBP between the groups without and with propranolol medication (123 +/- 17 and 80 +/- 10 mmHg; 120 +/- 14 and 80 +/- 11 mmHg, respectively). The real-EDV showed no significant difference between these two groups, but the real-ESV and real-EF showed significant differences between these two groups (69.4 +/- 9.3 and 70.6 +/- 8.9 mL/m2; 23.5 +/- 5.7 and 25.6 +/- 3.7 mL/m2, 66.5 +/- 5.1% and 63.5 +/- 4.6%, respectively). CONCLUSION: The difference of heart rate is significantly influenced by gender and the dosage of propranolol. Propranolol will also increase the ESV, which contributes to a decreased EF, while the SBP, DBP and EDV are not statistically changed.