Heart pacemaker

  • Definition
    • A pacemaker is a small, battery-operated device that senses when your heart is beating irregularly or too slowly. It sends a signal to your heart that makes your heart beat at the correct pace.

  • Alternative Names
    • Cardiac pacemaker implantation; Artificial pacemaker; Permanent pacemaker; Internal pacemaker; Cardiac resynchronization therapy; CRT; Biventricular pacemaker

  • Description
    • Newer pacemakers weigh as little as 1 ounce. Most pacemakers have 2 parts:

      • The generator contains the battery and the information to control the heartbeat.
      • The leads are wires that connect the heart to the generator and carry the electrical messages to the heart.

      A pacemaker must be implanted under the skin. This procedure takes about 1 hour in most cases. You will be given a sedative to help you relax. You will be awake during the procedure.

      A small incision (cut) is made, most often on the left side of the chest below your collarbone. The pacemaker generator is then placed under the skin at this location. The generator may also be placed in the abdomen, but this is less common.

      Using live x-rays to see the area, the doctor puts the leads through the cut, into a vein, and then into the heart. The leads are connected to the generator. The skin is closed with stitches. Most people go home within 1 day of the procedure.

      Two kinds of pacemakers -- transcutaneous and transvenous pacemakers -- are used only in medical emergencies. They are not permanent pacemakers.

  • Why the Procedure Is Performed
    • Pacemakers may be used for people who have heart problems that cause their heart to beat too slowly. A slow heartbeat is called bradycardia. Two common problems that cause a slow heartbeat are sinus node disease and heart block.

      When your heart beats too slowly, your body and brain may not get enough oxygen. Symptoms may be light-headedness, tiredness, fainting spells, and shortness of breath.

      Some pacemakers can be used to stop a heart rate that is too fast (tachycardia) or that is irregular.

      Other types of pacemakers can be used in severe heart failure. These are called biventricular pacemakers. They help coordinate the beating of the heart chambers.

      Most biventricular pacemakers implanted today can also work as implantable cardioverter defibrillators (ICD), which restore a normal heartbeat.

  • Risks
    • Possible complications of pacemaker surgery are:

      • Abnormal heart rhythms
      • Bleeding
      • Punctured lung. This is rare.
      • Infection
      • Puncture of the heart, which can lead to bleeding around the heart. This is rare.

      A pacemaker senses if the heartbeat is above a certain rate. When it is above that rate, the pacemaker will stop sending signals to the heart. The pacemaker can also sense when the heartbeat slows down too much. It will automatically turn back on and start pacing the heart again.

  • Before the Procedure
    • Always tell your health care provider what drugs you are taking, even drugs or herbs you bought without a prescription.

      The day before your surgery:

      • Shower and shampoo well.
      • You may be asked to wash your whole body below your neck with a special soap.

      On the day of the surgery:

      • You may be asked not to drink or eat anything after midnight the night before your procedure. This includes chewing gum and breath mints. Rinse your mouth with water if it feels dry, but be careful not to swallow.
      • Take the drugs you have been told to take with a small sip of water.

      Your health care provider will tell you when to arrive at the hospital.

  • After the Procedure
    • You will probably be able to go home after 1 day. You should be able to return to your normal activity level quickly.

      Ask your provider how much you can use the arm on the side of your body where the pacemaker was placed. You may be advised not to lift anything heavier than 10 to 15 pounds and to avoid pushing, pulling, or twisting your arm for 2 to 3 weeks. You may also be told not to raise your arm above your shoulder for 6 weeks.

      When you leave the hospital, you will be given a card to keep in your wallet. This card lists the details of your pacemaker and has contact information for emergencies. You should always carry this wallet card with you.

  • Outlook (Prognosis)
    • Pacemakers can help keep your heart rhythm and heart rate at a safe level for you. The pacemaker battery lasts about 6 to 15 years. Your provider will check the battery regularly and replace it when necessary.

  • References
    • Epstein AE, DiMarco JP, Ellenbogen KA, Estes NA 3rd, Freedman RA, Gettes LS, et al. 2012 ACCF/AHA/HRS focused update incorporated into the ACCF/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation. 2013 Jan 22;127(3):e283-352

      Swerdlow CD, Zipes DP. Pacemakers and implantable cardioverter-defibrillators. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 36.