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Heart Rhythm Problems

Heart rhythm problems, also called arrhythmias, are a disorder of the heart rate or heart rhythm. Arrhythmias occur when the heart that beats too fast (called tachycardia), too slow (called bradycardia), or irregularly.

The heart has an electrical system that helps it heart pump blood out of the coronary arteries to the rest of the body. This system of electrical impulses–the heart’s natural pacemaker–makes sure that the heart contracts in an orderly way.

Problems that occur within this electrical conduction system cause arrhythmias. Various arrhythmias result depending on where along the conduction system the problem occurs. Arrhythmias increase the risk for problems such as heart failure, stroke, or sudden cardiac arrest.

How does molecular imaging help people with arrhythmias?

Images and information provided by myocardial perfusion imaging, a nuclear functional study and other molecular imaging procedures help physicians:

  • assess the potential for sudden cardiac death and other cardiac events in patients with heart rhythm problems
  • select patients for automatic internal cardiac defibrillators (AICDs).

To prevent SCD, a device called an automatic internal cardiac defibrillator (AICD) may be surgically placed under the skin in the chest or abdomen. When the AICD detects an irregular arrhythmia, the device uses electric pulses or shocks to restore the heart’s normal rhythm.