Left Axis Deviation in Electrocardiogram with Normal QRS Duration in Ambulatory Adults without Cardiac Symptoms: A Possible Marker of Glucose Intolerance

We are increasingly noticing isolated left axis deviation (LAD) in electrocardiogram in younger people with diabetes without obvious heart disease and association of LAD with glucose intolerance has not been explicitly raised before. We planned a study of ambulatory adults with borderline (0o to –30o) and moderate-to-marked (<–30o to –90o) LAD looking into their possible association with glucose intolerance with fasting plasma glucose (FPG) ≥100mg/dL. Methods: We consecutively enrolled adults aged 30 or more, with electrocardiogram normal duration QRS axis between 0o to –90o, without cardiac symptoms, not on any medication, attending outdoor-clinics for health checkup. Results: Out of 100 participants enrolled, about 90% were aged between 30 and 60 and 47% had borderline and 53% moderate-to-marked LAD. Moderate-to-marked LAD group had higher frequencies of abnormal blood pressure (BP), FPG, and lipids than borderline LAD group even after conditioning effects of age and sex (p≤0.03) and of FPG after conditioning effects of BP (p=0.02). The frequencies of glucose intolerance were 48.9% even in borderline LAD with 84.9% in moderate-to-marked LAD group. In moderate-to-marked LAD group mean values of BP, FPG, and lipid profiles were higher (p<0.001) and abnormal. In borderline LAD group though mean BP and lipid values were normal, FPG was impaired. Conclusions: Impaired mean FPG values and high frequencies of glucose intolerance in both borderline LAD group with normal BP and moderate-to-marked LAD group with conditioning of effects of BP in relatively younger ambulatory adults without cardiac symptoms indicate possible association between LAD and glucose intolerance. Keywords: diabetes; ecg; glucose intolerance; left axis deviation.