Heart block is a condition in which the heart beats more slowly or irregularly. It is caused by an issue with the electrical pulses that control how fast your heartbeats. The symptoms vary depending on the type of heart block you have. The mildest type, 1st-degree heart block, may not cause any symptoms. While 2nd-degree heart block can occasionally cause troubling symptoms that require treatment, 3rd-degree heart block, the most severe type, can be a medical emergency. Heart Block Facts and Figures According to the Heart and Stroke Foundation of Canada, anyone can have a heart block but it most commonly occurs in older adults and those who have a history of heart disease. Some facts and statistics about heart block have been listed below: Incidence of Heart Block0.10% Common inAdults and Older Adults At-Risk GenderMales  Average Age for Diagnosis30 to 60 years Problems related to Heart BlockLow blood pressure, damage to internal organs, fainting  Specialists Who Treat Heart BlockCardiac Surgeon