Holter
The electrocardiographic tracing was continuously recorded for 24 h in leads CMt and CM5 by a Holter recorder model Oxford MR 14. The tapes were analyzed for arrhythmias by a high-speed (60 mm/min) automatic analyzer (Medilog MA 14) under visual control of the tracings. The hourly trends of heart rate and ST-T segments also were obtained automatically.
Ventricular arrhythmias were classified according to Myerburg et al. This classification was preferred to the classic classification of Lown and Wolf since it provides a quantitative and qualitative judgment of VPC. The degree of ventricular arrhythmias was expressed by an original score applied to the classification of Myerburg et al (Table 2). For each patient, the total score, suitable for statistical analysis, represents the sum of two numbers which provides an evaluation both of frequency and form of VPC. This score was developed after some attempts to identify possible correlations between ventricular arrhythmias expressed as VPC per hour and clinical-functional conditions had failed. Using this score, the same numerical value may identify different classes of arrhythmias.  However, only a few of all the possible combinations giving the same result in a 5 x 5 table are likely to happen in a sample of arrhythmic patients so that only subjects with comparable degrees of ventricular arrhythmias can be scored by the same number. buy flovent inhaler
Atrial arrhythmias were expressed as APC per hour. The APC have been included in this study, although they lack any prognostic meaning, since they represent a very common finding in COPD patients.

Table 2—Myerburg et al Classification of Ventricular Arrhythmias and the Derived Score 

Hierarchy of Frequencies

A score

Hierarchy of Forms

B score

Class 0-nil

1

A-uniform morphology, unifocal

1

Class 1-rare (<1 VPC/h)

2

B-multiform,

multifocal

2

Class 2-infrequent (1 to 9 VPC/h)

3

C-repetitive forms couplets, salvos repetitive responses (3-5 CVC)

3

Class 3-intermediate (10 to 29 VPC/h)

4

D-nonsustained VT (>6 CVC to runs <30 s)

4

Class 4-frequent (>30 VPC/h)

5

E-sustained VT (runs of ventricular complexes >30 s)

5