A heartbeat consists of a two-part pump action that takes less than one second, according to the Texas Heart Institute. Normally, the heart follows a distinct beating pattern that properly sends blood through the blood vessels and supplies the body tissues with oxygen. When the heartbeat is abnormal, it is referred to as an arrhythmia. An abnormal heartbeat can cause health problems, including shortness of breath.
Physiology of a Heartbeat
The heart contains its own electrical system that is responsible for controlling the heartbeat. The heart has a natural pacemaker called the sinoatrial, or SA, node. The SA node sends out an electrical signal that triggers the atria, the upper chambers of the heart, to contract. The signal from the SA node then travels from the atria and to the lower heart chambers, called the ventricles. When the electrical signal reaches the ventricles, it causes them to contract. When the electrical systems in the heart are disrupted, it results in an abnormal heartbeat.
Causes of An Abnormal Heart Beat
A number of factors can disrupt the heart’s electrical signal and arrhythmias can range from minor to severe. Minor arrhythmias are usually caused by alcohol abuse, smoking, excessive caffeine intake, increased stress or strenuous exercise. The most common cause of more severe arrhythmias is a specific heart disease, including coronary artery disease, abnormal heart valve function and heart failure, according to the American Academy of Family Physicians. Minor arrhythmias usually only cause shortness of breath during increased physical activity. Severe arrhythmias can cause shortness of breath in the absence of physical exertion.
Blood and Oxygen
Red blood cells contain an iron-rich protein center called hemoglobin. Hemoglobin is responsible for picking up oxygen in the body and binding it to the red blood cell. As the red blood cell moves through the body, it delivers this bound oxygen to all of the body tissues. Normal heartbeats ensure that blood moves through the body smoothly so that the blood can efficiently deliver oxygen to the tissues. When the heartbeat is abnormal, blood moves through the body erratically, and oxygen cannot be delivered to the tissues correctly. This causes the tissues to become starved of oxygen and leads to shortness of breath.
Shortness of breath is treated by correcting the underlying cause of the arrhythmias. Moderate arrhythmias may be treated with medications that correct the heart's electrical system and improve breathing. More severe arrhythmias may require implantation of medical devices, such as an artificial pacemaker, or surgery. An artificial pacemaker is an electronic device that is placed in the chest that takes over the role of the SA node and helps to maintain normal heartbeat. Once normal heartbeat is maintained, breathing should return to normal. Bypass surgery can correct the underlying heart conditions, such as coronary artery disease, that are causing the arrhythmia.
Extreme shortness of breath can lead to light-headedness and possible fainting. If the oxygen supply to the major organs is significantly decreased, it can lead to organ damage as well. Because of this, those with severe arrhythmias should avoid moderate exercise and strenuous activities.