Comparison of Cardiac Pacing Modes in Patients With Chronic Obstructive Pulmonary Disease – Patient Population
Limitations in exercise tolerance are a common manifestation of patients with chronic lung disease. Compromised pulmonary mechanics limit the ability of the lungs to respond to increasing oxygen demands. This leaves these patients dependent on other mechanisms to deliver available oxygen to the tissues to support the metabolic demands of exercise. Optimizing cardiac output is, therefore, important to provide maximum oxygen delivery. This is no less important for patients with moderate to severe lung disease who develop symptomatic bradycardia and require implantation of a cardiac pacemaker. This study was designed to compare the relative efficacy in optimizing cardiac performance and exercise capacity of two different cardiac pacing modes. The relatively complex dual chamber adaptive rate pacing (DDDR) was compared with the significantly simpler ventricular adaptive-rate pacing (WIR) in patients with lung disease who require pacemaker implantation for symptomatic bradycardia. buy flovent inhaler
A total of 16 patients with DDDR pacemakers were studied. Eight had obstructive lung disease documented by an FEV, and FEF25/75 less than or equal to 67 percent of predicted normal values. Several of the patients in this group also had a restrictive component associated with their lung disease. For purposes of this study, both obstructive and obstructive/restrictive disease will be grouped together. Eight paced patients of age similar to the patients with lung disease but who had normal lung function (NLF) defined as FVC and FEV, greater than or equal to 80 percent of predicted normal values, served as controls. All patients had been previously implanted with DDDR pacemakers for sinus node dysfunction and/or intermittent high-degree atrioventricular (AV) block. As a group, the average patient age was 73 years and ranged from 67 to 81 years; there were 11 men and 5 women. The average patient age of those in the lung disease group was 75 years and ranged from 68 to 81 years. The average patient age of those in the NLF group was 71 years and ranged from 67 to 78 years. The study protocol was in compliance with and approved by the Internal Review Board and an informed consent was obtained from each patient.