Right Chest Electrocardiographic Patterns in Normal Subjects: DISCUSSION

In this study of 110 healthy young male subjects, the prevalence of a rS pattern decreased from V3R to V6R. For example, 89 percent of our subjects showed this pattern in V3R but only 37 percent of them showed it in V6R. However, the opposite was the case for a rSr pattern with a prevalence of 10 percent in V3R and 36 percent in V6R. These findings are similar to those reported by Andersen et al in 109 normal subjects and by Morgera et al3 in 82 normal subjects. Again, similar to the experience of Andersen et al, the amplitudes of the r wave, S wave and secondary r (qr, rSr) wave in our subjects progressively decreased from V3R to V6R (from a mean value of 3.0 to 1.0 mm for r wave, 5.9 to 1.7 mm for S wave and 2.0 to 1.6 mm for secondary r wave) (Tables 3 through 5, Fig 1).

The frequency of a qr, qS, r and qrS pattern in our subjects increased from V3R to V6R and this is similar to the findings of Andersen et al4 (Fig 1). However, the actual prevalence of each pattern in the majority of the leads in our subjects differed markedly from that reported by Andersen et al. For example, the following was the prevalence of a qr and qS pattern in our subjects—0 and 1 percent, respectively, in V3R; 1 and 1 percent, respectively, in V4R; 6 and 1 percent, respectively, in V5R; and 14 and 2 percent, respec­tively, in VeR. The corresponding figures in the study by Andersen et al showed a considerably higher prevalence of qr and qS pattern—1 and 1 percent, respectively, in V3R; 4 and 4 percent, respectively, in V4R; 17 and 11 percent, respectively, in V5R; and 28 and 16 percent, respectively, in V6R. The amplitudes of the Q waves in our subjects were also much smaller than those reported by Andersen et al. For example, the mean Q wave amplitudes in our subjects and the Andersen subjects were as follows—1.4 and 4.4 mm, respectively, in V4R; 0.9 and 2.7 mm, respectively, in V5R; and 0.8 and 2.2 mm, respectively, in VeR. Apcalis Oral Jelly

FIGURE 1. Right-sided ECG patterns in three subjects. The ECGs were recorded at a paper speed of 25 mm/s and a calibration of 1 mV = 10 mm. ftinel A, rS pattern and inverted T waves from V3R through VeR. The amplitudes of the r and S waves decrease from V3R through V6R. Rinel В, rS pattern in V3R; rSr pattern in V,R through VeR. Panel C, rS pattern in V3R; Rs pattern in V4R; qRs pattern in V5R and VeR.

The reasons for the difference in the prevalence of the qr and qS complexes and the amplitudes of the Q waves is unclear and difficult to explain. One possibil­ity is that the profile of our study population was quite different from that of the study by Andersen et al. In our study, all 110 subjects were normal healthy young men of three different ethnic groups who were under­going medical examination before national service military training. They were diagnosed as having no cardiovascular or pulmonary disease after clinical evaluation, a chest x-ray film and a 12-lead ECG test. It is very likely that the prevalence of undetected cardiac disease (particularly coronary artery disease) and pulmonary disease in this cohort of young subjects was either extremely low or none at all. On the other hand, the study population of Andersen et al was considerably more heterogenous, consisting of 40 women and 69 men with a mean age of 41 years (ranging from 18 to 80 years old). The criteria for admission to their study included an absence of a history of heart or lung disease and a normal physical examination, chest x-ray film and 12-lead ECG. How­ever, since a large proportion of the subjects were older than 40 years, it may be difficult to confidently exclude coronary artery disease without other labo­ratory investigations such as exercise stress testing.
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