The bloodshot appearance is due to the irritation and dilation of the surface blood vessel in the eye. Other symptoms can accompany the red appearance, like itching, soreness, discharge and even blurred vision. These symptoms could indicate a more serious problem.
The list of possible medications or substances mentioned in sources as possibe causes of Heart block includes: 1  Beta-adrenergic blockers. 2  Digitalis. 3  Flecainide. Flecatab. 4  Flumadine. Quinidine. 5  Rimantidine. Tambocor.
The most common causes of first-degree heart block are an AV nodal disease, enhanced vagal tone (for example in athletes), myocarditis, acute myocardial infarction (especially acute inferior MI), electrolyte disturbances and medication.