Cardiac arrhythmias may be caused by
A) disturbances in the normal conduction system of the heart.
B) ischemia and drugs.
C) failure of the sinoatrial (SA) node.
D) all of the above.

Question

Quizplus · Accepted Answer

Arrhythmias can arise from disturbances in the normal conduction system of the heart, including the pacemaker (the SA node), the atrioventricular (AV) node, the bundle branches, and the Purkinje fibers (see Figure 10-35). Ischemia and drugs cause many arrhythmias. Failure of the SA node may be responsible. Table 10-1 lists the causes of arrhythmias. Heart block occurs when the impulses from the SA node become slow or irregular at or below the AV node.

Cardiac Arrhythmias May Be Caused by