Prediction of Pulmonary Arterial Pressure in Chronic Obstructive Pulmonary Disease by Radionuclide Ventriculography
Chronic obstructive pulmonary disease is one of the chief causes of disability and death in Europe and in the United States. Pulmonary hypertension triggers the development of right ventricular hypertrophy which may lead to right ventricular failure with a high mortality rate. The measurement of PAP requires right heart catheterization. Although this technique is widely available, its routine use is limited by costs and associated risks. Therefore, less invasive methods have been developed to detect and assess the severity of pulmonary hypertension. One of these methods is the determination of RVEF by technetium-99m radionuclide ventriculography. Studies, however, show that the ventricular ejection fraction lacks in specificity and poorly correlates with pulmonary arterial pressure.
During the last few years, however, radionuclide techniques have improved considerably and some curve parameters have shown a better sensitivity than RVEF in assessing pulmonary arterial pressure. An improved method for the evaluation of the RVEF by krypton-8lm (81mKr) has also been developed.* The aim of this study was to evaluate whether 81mKr RVEF and parameters derived from equilibrium tech-netium-99m red blood cells (99mTc RBC) right ventricular curve allow a better estimation of pulmonary arterial pressure.
Material and Methods
Fifty seven patients with stable and severe chronic obstructive pulmonary disease were subjected to right heart catheterization to measure pulmonary arterial pressure and estimate right ventricular function. There were 53 men and four women (group 1: 64 ±3 years; group 2: 61 ±1 years). No patient had any clinical or electrocardiographic evidence of systemic hypertension, valvular heart disease or coronary artery disease. The patients’ characteristics and lung (unction data are given in Table 1. All the patients have given informed consent to the study, which was approved by the Human Investigation Committee of our institution.
Table 1—Patients Characteristics and Lung Function Data
|N*||Age, yr||Male/Female||FEV, ml*s||FEVj/FEVj,%||FaOg, mm Hg||p^co2,mm Hg|
|Croup 1||16||64 ±3||16/0||953 ±122||40±3||64±4||44±2|
|Croup 2||41||61 ±1||37/4||912 ±63||39 ±6||64±2||43± 1|