Senile heart block

The cardiac conduction system is composed of the sinoatrial node, atrioventricular node, atrioventricular bundle (bundle of His), left and right bundle branches, and their subdivisions. It is responsible for cardiac pacing and impulse conduction, ensuring coordinated contraction of the atria and ventricles. Conduction block can occur at any site along the cardiac conduction system. When it occurs between the sinoatrial node and the atria, it is called sinoatrial block; between the atria and ventricles, atrioventricular block; within the atria, intra-atrial block; and within the ventricles, intraventricular conduction block. In elderly patients with atrioventricular block, symptoms depend not only on the underlying heart disease and cardiac functional status but also on the degree and site of the block. In second-degree type II atrioventricular block, symptoms such as bradycardia, dizziness, fatigue, chest tightness, shortness of breath, and decreased cardiac function may occur. Some patients present with atypical symptoms, such as generalized weakness, fatigue, or a hypotensive state. Further examination is required to confirm the diagnosis.