Cardiac Arrhythmias and Left Ventricular Function in Respiratory Failure from COPD (Part 4)
The patients were studied while in the supine position using a left anterior oblique projection optimized to obtain the best separation between both ventricles and atria. After the injection of 1.6 mg of stannous chloride (Cis-Sorin, TCK 7) followed by 700 MBq of Tc-pertechnetate 15 to 20 min later, 16 frames per cardiac cycle were recorded in frame mode. A standard Anger camera was equipped with an all-purpose parallel-hole collimator was connected on line to a dedicated minicomputer (Philips PDS P/855 M). Individual frames contained over 250,000 counts requiring a total acquisition time of 4 to 5 min. The data for the left ventricle were processed by totally operator-independent software (Philips U1) in order to obtain the following indices: LVEF, PER, PFR. The velocity indices, ie, PER and PFR, were normalized on end-diastolic counts and thus expressed in EDV/s units. The PER reflects the peak of the left ventricular performance in the ejection phase, whereas PFR explores the early diastolic myocardial relaxation. asthma inhalers
Angiocardiography was always performed 6 h after the administration of inhaled bronchodilators to minimize the potential effects of beta-agonists on the heart function.
A clinical evaluation of RF was obtained using a score based on six common signs and symptoms: dyspnea at rest, productive coughing, sweating, edema, muscular twitching and diurnal hyper somnia. One point was assigned to the presence of each sign or symptom so that RF was identified by a number ranging from 0 to 6.