Answer to Question 1
A dysrhythmia interrupts the normal contraction sequence of the heart. If the contraction is shortened, the force exerted by the contraction will be less. Less force results in less blood pumped, thereby decreasing the cardiac output.
Answer to Question 2
A natural pacemaker is a node of tissue in the heart that sets the pace of the contractions (the heart beat). It does so by initiating an electrical impulse that spreads throughout the heart muscle. An implantable (artificial) pacemaker is a medical device that is surgically placed in the chest wall and attached to the heart to control the initiation of electrical impulses when the natural pacemaker is not functionally normally.
Cardiac catheterization.
Cardiac damage in rheumatic fever.
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