The purpose of this investigation was to determine the severity of pure restrictive
ventilatory impairment that results in right ventricular (RV) dilatation, increased
RV wall thickness, and pulmonary hypertension. Two dimensional (2-D) echocardiography,
Doppler measurements of pulmonary flow, and spirometry were performed on 26 unselected
patients (17 female, 9 male) with a pure restrictive ventilatory impairment. A restrictive
ventilatory impairment was defined as a forced vital capacity (FVC) < or = 80 percent
predicted with a normal FEV1/FVC ratio (FEV1 = 1 s forced expiratory volume). The
patients were grouped according to the severity of the restrictive ventilatory defect:
mild (FVC, 65 to 80 percent predicted), moderate (FVC, 51 to 64 percent predicted),
and severe (FVC < or = 50 percent predicted). An increased RV area (> 20.4 cm2) was
shown in 0 of 10 (0 percent) patients with a mild impairment, 6 of 12 (50 percent)
patients with moderate restriction, and 2 of 4 (50 percent) patients with severe restriction.
Increased RV wall thickness (> 0.5 cm) was observed in 0 of 10 (0 percent) patients
with mild restrictive impairment, 3 of 12 (25 percent) with moderate impairment, and
1 of 4 (25 percent) with severe restrictive impairment. Doppler evidence of pulmonary
hypertension (ACT/ET ratio < 0.32) (ACT = acceleration time, ET = ejection time) was
shown in 0 of 10 (0 percent) patients with a mild restrictive impairment, 8 of 12
(66 percent) patients with moderate restriction, and 4 of 4 (100 percent) patients
with severe restriction (p < 0.01 mild vs moderate and mild vs severe). The RV area
by 2-D echocardiography correlated well with the FVC percent predicted (r = 0.90,
p < 0.001). The ACT/ET ratio also correlated well with the FVC percent predicted (r
= 0.73, p < 0.001). In conclusion, RV enlargement and pulmonary hypertension were
seen only in patients with a moderate or severe restrictive ventilatory impairment.
These data may be useful in the assessment of the likelihood of subtle RV enlargement
in patients with occupational pleuropulmonary disease.