Left ventricular volume overload, incomplete right bundle branch block
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Small initial q waves followed by tall R waves and T waves with an upsloping ST segment in lateral leads (V4-6) are suggestive of left ventricular volume overload (diastolic overload) pattern. There is an incomplete right bundle branch block (IRBBB) pattern in V1 (rSr’ pattern). The deep negative P wave in V1 should usually suggest left atrial overload. But the sharp intrinsicoid deflection (downward deflection after the small initial positive deflection) would make one suspect whether this is a pseudo left atrial overload pattern sometimes seen in atrial septal defect with right atrial overload. The negative P wave in left atrial overload has a rounded contour with a less sharp atrial intrinsicoid deflection. The T waves are quite tall in lateral leads, even making one suspect associated hyperkalemia, which is an important cause of tall tented T waves. But the two limbs of the T wave are asymmetrical (upslope less slanting than downslope).