To recent years, the important role of right-sided chest lead ECGs in the detection of RV infarction in patients suffering from inferior myocardial infarction of the left ventricle has been fully recognized.Several authors have stated that the presence of Q waves and elevated ST segments in right-sided chest leads, especially in V4R, are highly sensitive and specific indicators of RV infarction. However, to be confident that this ECC abnormality has a high specificity for RV infarction, the spectrum of the right- sided ECG pattern in the normal population must be known. Since there have been very few reports so far describing right-sided ECG patterns in normal subjects, we decided to study 110 normal healthy male subjects who were about to undergo active, rigorous military training as part of their national service commitment.
Materials and Methods
Pre-enlistees for national service were evaluated by the two cardiology residents at the Medical Classification Centre of the Singapore Armed Forces. Singapore is a multiracial society and the three major ethnic races are (1) Chinese, (2) Indian and (3) Malay. Every fifth pre-enlistee, according to ethnic race, was enrolled in the study if the following criteria were fulfilled: (a) no previous history of cardiac or pulmonary disease; (b) normal physical examination (including a normal blood pressure reading) after a complete clinical evaluation of the heart and lungs; (c) normal biplane chest x-ray film; (d) normal conventional 12-lead ECC; and (e) no recent use of drugs. levitra 20 mg
All the ECGs were performed by the same technician with a Hewlett Packard 4745 ECG machine using conventional gain and the standard positions for left-sided (Vj to Ve) and right-sided chest leads (V3R to VgR). The paper speed was recorded at 25 mm/s. The ECGs were performed with the subjects in the supine position at least 2 h postprandially and after lying quietly on the bed for at least 15 min.
All the ECGs were read by one of the authors (Dr. Chia). The results were tabulated and recorded in a Mcintosh SE computer. Data analysis was performed using a microprocessor-based statistical package (Stat work TM).