III. Assessment of right ventricular function in chronic chest diseases
1. Physical examination It is difficult to distinguish chronic lung disease from associated PH and RV dysfunction. Increased exertional dyspnea may arise from new RV dysfunction or progression of the underlying parenchymal lung disease. Symptoms associated with advanced RV dysfunction (leg edema, ascites) may not be present, or may develop independent of RV dysfunction (Macnee, 2010).
2. Noninvasive measurements
Electrocardiogram (ECG) In the presence of RV hypertrophy the forces of depolarization increase, and if the hypertrophy is severe these forces may dominate on the electrocardiogram. ECG is a relatively insensitive indicator of the presence of right ventricular hypertrophy, and in mild cases of right ventricular hypertrophy the trace will be normal. A dominant R wave in lead V1 is observed. The increased rightward forces are reflected in the limb leads, in the form of right axis deviation. Secondary changes may be observed in the right precordial chest leads, where ST segment depression and T wave inversion are seen. In COPD the electrocardiographic signs of right ventricular hypertrophy may be present, indicating the presence of cor pulmonale (Harrigan and …show more content…
Chest X-rays also play an important role in the diagnosis of other diseases, such as those that impair the lung parenchyma and can cause dyspnea (Hoette et al., 2010).
On chest CT, enlargement of the main pulmonary artery to a diameter of 29 mm or greater was associated with a high sensitivity (84%), specificity (75%), and positive predictive value (95%) in a heterogeneous group of patients with chronic lung disease (Tan et al., 1998). However, CT findings may be less reliable in patients with interstitial pulmonary fibrosis (IPF) (Zisman et al.,
1. Physical examination It is difficult to distinguish chronic lung disease from associated PH and RV dysfunction. Increased exertional dyspnea may arise from new RV dysfunction or progression of the underlying parenchymal lung disease. Symptoms associated with advanced RV dysfunction (leg edema, ascites) may not be present, or may develop independent of RV dysfunction (Macnee, 2010).
2. Noninvasive measurements
Electrocardiogram (ECG) In the presence of RV hypertrophy the forces of depolarization increase, and if the hypertrophy is severe these forces may dominate on the electrocardiogram. ECG is a relatively insensitive indicator of the presence of right ventricular hypertrophy, and in mild cases of right ventricular hypertrophy the trace will be normal. A dominant R wave in lead V1 is observed. The increased rightward forces are reflected in the limb leads, in the form of right axis deviation. Secondary changes may be observed in the right precordial chest leads, where ST segment depression and T wave inversion are seen. In COPD the electrocardiographic signs of right ventricular hypertrophy may be present, indicating the presence of cor pulmonale (Harrigan and …show more content…
Chest X-rays also play an important role in the diagnosis of other diseases, such as those that impair the lung parenchyma and can cause dyspnea (Hoette et al., 2010).
On chest CT, enlargement of the main pulmonary artery to a diameter of 29 mm or greater was associated with a high sensitivity (84%), specificity (75%), and positive predictive value (95%) in a heterogeneous group of patients with chronic lung disease (Tan et al., 1998). However, CT findings may be less reliable in patients with interstitial pulmonary fibrosis (IPF) (Zisman et al.,