• Slow heart rate is called Brachycardia
• Excessively slow heart rates frequently cause symptoms of fatigue, lethargy, or dizziness
• Heart rates less than 35/min may cause fainting or near fainting episodes
• When the heart rate is less than 20/min patients generally cannot stand upright

    Abnormally heart rhythms causing excessively slow heart rates are much more common in elderly patients. Frequently, the onset of a slow heart rate in an elderly patient is gradual and insidious and is often unrecognized by the patient’s family. The elderly patient may exhibit loss of energy and stamina and may become listless and inactive. Some elderly patients with markedly reduced heart rates develop episodes of confusion, forgetfulness, or impaired ability to walk.

    Alternatively, the onset of slow heart rates in elderly patients may be sudden and can occur without any warning. Some disorders of the heart rhythm cause sudden profound slowing of the heart rate or prolonged pauses. This may cause sudden loss of consciousness. Patients who are standing when they experience a sudden fall in heart rate are much more likely to faint than are patients who are lying supine. However, when the heart stops beating for more than ten seconds, patients almost always lose consciousness, whether they are standing upright or supine.

    Until the introduction of permanent pacemakers 50 years ago, there was no effective treatment for patients with symptoms caused by slow heart rhythms. Modern implantable dual chamber pacemakers have revolutionized the care of elderly patients.