An arrhythmia is an irregular heartbeat — too fast, too slow, or uneven. Atrial fibrillation (AFib) is a common type of arrhythmia, caused by chaotic electrical activity in the upper chambers of the heart. When you experience AFib, one of the characteristic symptoms is shortness of breath.
At Northwest Houston Heart Center, expert cardiologists Dr. A. Adnan Aslam and Dr. Roy Norman offer state-of-the-art diagnosis and advanced treatments to correct AFib at their offices in Tomball, Cypress, Magnolia, and The Woodlands, Texas. As they want their patients to be able to recognize the signs of this unstable beat, they’ve put together this guide to get you in the know.
Matters of the heart
The heart is the organ that pumps oxygenated blood to the rest of the body. During each heartbeat, the upper two chambers, called the atria, contract. After that, the two lower chambers, called the ventricles, contract. When the heart is working normally, the timing of the contractions is precise, making for an efficient pump. The timing is directed by the heart’s internal electrical system.
The electrical impulse starts in the right atrium, in a region called the sinoatrial node (SA node), which normally adjusts the rate depending on how much activity you’re doing. For example, the SA node increases impulse rate during exercise and decreases the rate while you’re asleep.
When the SA node initiates an impulse, the electrical activity spreads through the right and left atria in a coordinated manner, causing them to contract. This forces blood into the lower ventricles.
The impulse then travels to the atrioventricular (AV) node, which is located near the middle of the heart in a region called the septum. The AV node is the only bridge that allows impulses to travel from the SA node in the atrium to the ventricles. The signal moves through the ventricles’ walls, causing them to contract, which pumps blood out of the heart. The right ventricle sends blood to the lungs to pick up oxygen, and the left ventricle sends oxygenated blood to the body.
This well-coordinated rhythm is called “normal sinus rhythm,” and the normal heart beats this way between 60 and 100 times per minute while you’re at rest.
What is atrial fibrillation?
AFib is the most common irregular heart rhythm, and it starts in the atria. The initial electrical impulse doesn’t come from the SA node; instead, many nerves fire at once, causing a fast but chaotic rhythm that doesn’t allow the atria to contract forcefully and pump blood into the ventricles.
As all the impulses spread through the atria at the same time, they compete for the opportunity to go through the AV node. What impulses do get through aren’t coordinated and cause the ventricles to contract irregularly, causing a rapid, unsteady heartbeat.
There are two types of atrial fibrillation: paroxysmal, or intermittent, and continuous, or persistent.
The symptoms of atrial fibrillation
It’s possible to have AFib without any symptoms, but if they’re present, you may experience:
- Heart palpitations: a pounding, fluttering, or racing feeling in the chest
- Lack of energy or feeling over-tired
- Dizziness or lightheadedness
- Pain, pressure, or discomfort in the chest
Shortness of breath, in which you have difficulty breathing during normal activities or at rest, is also a major symptom. Since the heart isn’t pumping blood efficiently, your body isn’t receiving enough oxygen to fuel its activities, and the lack of oxygen can make you gasp for breath to compensate.
AFib can also lead to complications, such as the development of clots that lead to stroke or a pulmonary embolism (blocked airway), weakened heart muscles, heart failure, and death. That’s why you need to see a cardiologist regularly, to ensure that any problem is caught early so it can be treated appropriately. AFib is easily detectable on an electrocardiogram (EKG), a painless, noninvasive test of heart function.
If you’re experiencing shortness of breath or any of the other symptoms of AFib, or if you notice your heart “skips” a beat more often than not, it’s time to come into Northwest Houston Heart Center for an evaluation and treatment. Give us a call at any of our locations to schedule a consultation with one of our cardiologists, text us at 832-402-9518, or book online with us today. We can help.