A genetic disorder that leads to abnormal cardiac contractility results in sudden cardiac death

A genetic disorder that leads to abnormal cardiac contractility results in sudden cardiac death. Mutations within a voltage-gated Na+ channel, Nav1.5, underlies 20 % of cases in patients that present with this disease. These channels show decreased peak Na+ currents.

Please draw an action potential in a cardiac pacemaker AND a cardiac muscle cell from one of these patients. LABEL EACH AXIS. Which one is more adversely affected by this mutation? Point out these differences on your graphs.

What would happen to the stroke volume of the heart in patients with this mutation compared to healthy controls? Why?