Ventilatory Dynamics in Hypertensive Heart Disease

Small and large airways functions were studied in patients with hypertensive heart disease in slightly ro moderately compromised state functionally. In this study, the forced vital capacity and various flow paramaeters reflecting expiratory flow rate were determined from simultaneously recorded forced expiratory volume and maximal expiretory flow volume curves in 86 cases. The closing volume was measured by a single breath nitrogen mrthod in 57 cases and airway resistance with its related parameters by a body plethysmograph in 11 cases. These results were compared with those obtained from the same numbers of healthy controls matched for sex, age and height.

In the patient group, the forced vital capadity and all the observed values of flow parameters, execpt for the ratio of the first second vital capacity to the forced vital capacity, were significantly reduced than those in the controls. When the remainder of flow parameters was volume-adjusted to the forced vital capacity, however, the mean of the peak expiratory flow rate and the maximal expiratory flow rate at the 75 percent of the vital capacity were not significantly different from that of controls. In contrast, the volume-adjusted values of maximal expiratory flow were remained significantly smaller than those in the controls. The closing volume and its ratio to the vital capacity were significantly larger in the patient group. Airway resistance and its related parameters revealed no significant differences between two groups. These findings suggest that the patients with hypertensive heart disease in a mild to moderate failure are associated with restrictive ventilatory impairment and a small airways obstruction, but with little or no large airway dysfunction.