Definition of Arrhythmias
Arrhythmias are disturbances in the normal rhythm of the heart, either in frequency (beats too fast or slow), amplitude (beats too strong or weak), regularity (beats without a definable rhythm), or most commonly in all three areas. Arrhythmias reflect abnormal electrical activity in the heart muscle and can be caused by congenital abnormalities, genetic factors, environmental stresses, infections, injuries, ingestion of toxins, underlying heart disease, breed predisposition and many other factors. Some dogs live a normal life with heartbeat irregularities and never show signs of discomfort, while others are severely affected. When signs do appear, they can be subtle. Owners complain that their dogs tire easily, pant and cough more than normal and have breathing difficulties even at rest. Dogs with arrhythmias from serious heart conditions may faint and have abdominal discomfort, severe breathing problems, extreme fatigue, exercise intolerance and sudden death. Arrhythmias may go undetected for years. Fortunately, they often can be well-managed with medication and lifestyle changes.