Determine the impact if the connection between the sinoatrial (sa) node and the atrioventricular (av) node becomes blocked. determine the impact if the connection between the sinoatrial (sa) node and the atrioventricular (av) node becomes blocked. the ventricles will beat more slowly. the ventricular rhythm will not change. the ventricles will beat faster. the atria will contract more forcefully.

The correct answer will be option- the ventricles will beat more slowly.

Explanation:

Two types of autorhythmic nodes are present in the heart which are the sino-atrial node or SA node and the atrioventricular node or AV node.

The SA node is present in the upper wall of the right atrium which acts as a natural pacemaker to the heart as it generates the electrical impulses which cause contraction of the chambers.  The AV node is present in the lower portion of the atrium and acts as a relay station of the impulse and transmits them to the ventricles.  

If SA- AV node pathway gets blocked then it will cause the slow heart rhythm as the impulse will not be transmitted to the ventricles and ventricle will beat more slowly.

Thus, the selected option is the correct answer.