None of the patients had a history of or electrocardiographic findings of angina pectoris, myocardial infarction, coronary artery bypass grafting or previous use of cardioactive drugs. Isolated T wave inversion in right precordial leads and/or ST segment depression in inferior leads were not criteria of exclusion from the study, since these ST-T changes are known to develop quite frequently during decompensated COPD. Actually, such ECG findings were present in six patients during decompensated RF and disappeared after improvement in RF, which seems to confirm their close relationship with the respiratory conditions.
We use the following standardized therapy: oxygen delivered by Venturi mask at concentrations ranging from 24 to 31 percent according to individual needs; intravenously administered ampicillin for ten days; intravenously administered corticosteroids for four days, progressively tapered within 10 to 15 days; inhaled salbutamol (200 fig four times a day). After clinical improvement, a condition characterized by arterial blood gas levels very close to the values “usual” for each patient for at least five consecutive days was defined as stabilized RF.
Methods
The study design is summarized in Table 1. Each patient underwent Holter recording, equilibrium radionuclide angiocardiography, clinical examination, blood gas analysis, chest x-ray film and pulmonary function tests by a FVC maneuver. Serum potassium and magnesium concentrations were both normal at the time of the Holter study.

Table 1—Study Design 

Decompensated

Stabilized

RF

RF

Angiocardiography

+

Holter recording

+

‘ +

Blood gas analysis

+

+

Pulmonary function tests

+

Clinical examination

+

+