Pacemaker therapy

The type of bradycardia determines the type of pacemaker implanted and how its settings should be adjusted. The pacemaker usually eliminates symptoms caused by bradycardia at rest and often recovers the heart's ability to cope with exercise. A pacemaker is implanted under local anaesthetic, with additional sedatives administered when necessary. The pacemaker is implanted through a small incision in the chest wall and the pacemaker wires are guided along the veins into the atria and ventricles, under X-ray guidance. The pacemaker is adjusted and the saved data collected using an external programming device. The condition of the pacemaker is regularly checked at the pacemaker outpatient clinic.

Heart failure and pacemaker therapy

Pacemaker therapy alleviates severe heart failure in patients whose conduction pathway has been injured, causing left bundle branch block. This shows on an ECG. Bundle branch block delays contraction of the peripheral left ventricle, which can be corrected using two pacer wires. This heart resynchronisation therapy restores the pumping action of the heart and may also decrease the size of cardiac dilation.

Implantable cardioverter defibrillator (ICD)

An implantable cardioverter defibrillator (ICD) is placed in the same way as a pacemaker
to treat bradycardia. Its effectiveness in treating an arrhythmic attack is tested when the device has been implanted. An ICD monitors the pulse rate and stops ventricular tachycardia by sending rapid electrical pulses or giving an electrical shock to the ventricle. Electric shock therapy is applied within 10 to 20 seconds to stop ventricular fibrillation. During the delay, the patient may lose consciousness for a short period of time. An ICD is implanted when life-threatening arrhythmia is likely to recur. An ICD may also be implanted as a preventative measure in patients with a severe heart condition who have not yet had serious arrhythmia. An ICD may also be implanted to treat bradycardia in a similar way to a pacemaker. Some ICDs integrate the feature of delivering resynchronisation therapy to alleviate heart failure.