Understanding Arrhythmia: Types, Triggers and Risks
It’s common to feel an occasional fluttering or racing of your heart. There are several heart arrhythmia types, from harmless to serious. Some arrhythmias need no treatment, while others require immediate care.
Knowing which type of arrhythmia you have is key to understanding its severity and your treatment options. “If your healthcare provider says you have an irregular heartbeat, you should get further testing. That’s how we determine whether it’s life-threatening and if we need to take action right away,” says Demetrio Castillo, MD, an electrophysiologist (EP) at Memorial Cardiac and Vascular Institute (MCVI).
Irregular Heart Rate
Typically, an irregular heart rate goes undetected. “It’s the minority of people who actually feel palpitations or have chest pain,” says Daniel Benhayon Lanes, MD, an electrophysiologist at MCVI. “The majority are unaware that they have arrhythmias. Although they may feel general symptoms like fatigue, they often adapt and start doing less.” But some people do notice when their heart does the following:
- Beats too slow: When your heart beats too slowly, it’s called bradycardia. You may feel weak, lightheaded or short of breath.
- Beats too fast: Tachycardia is the medical term for when your heart beats too fast. It feels like your heart suddenly speeds up or is pounding in your chest.
- Beats too soon or has extra beats: Usually, your heart has a steady, consistent rhythm. An extra or premature beat occurs when the electrical signals misfire, triggering your heart to contract. This can feel like fluttering in your chest or your heart beating in your throat.
Arrhythmia Types & Risks
The type of arrhythmia depends on the irregularity it causes and in what part of your heart — the upper (atria) or lower (ventricular) chambers. The more the arrhythmia affects blood flow, the more severe the condition.
Atrial fibrillation (AFib)
The most common arrhythmia in adults is atrial fibrillation. About two out of every 100 people in the United States have AFIB. It occurs when the upper heart chambers contract too fast and have an irregular rhythm. This throws the timing off between the upper and lower heart chambers. An AFib episode reduces blood flow by about 10 percent.
The condition increases stroke risk, especially if you have other heart concerns or health problems. Frequently, patients with atrial fibrillation will need to take a blood thinner. To manage the condition, your healthcare provider may recommend other medications or a minimally invasive procedure.
Your risk of AFIB increases with the following factors:
- Age > 60
- Untreated obstructive sleep apnea
- Excessive alcohol use
- High blood pressure
- Underlying heart disease such as congestive heart failure, valve problems, and hypertrophic cardiomyopathy.
Atrial flutter isn’t as common as AFib, though they have similar risk factors and treatments. Both increase the risk of stroke. Some people with atrial flutter also have episodes of AFib.
Supraventricular tachycardia (SVT)
Supraventricular tachycardia causes your heart to suddenly speed up. The condition is usually not dangerous, but can cause frequent symptoms. Specialists typically recommend either medication or a minimally invasive procedure called cardiac ablation. SVT occurs at all ages, including children and adults.
Types of SVT include:
- AVNRT (AtrioVentricular Nodal Reentrant Tachycardia): An electrical short circuit exists inside a part of the heart called the AV node. This is fairly common across all age groups and is typically managed with either medication or a low-risk procedure, depending on the patient’s preference.
- AVRT (AtrioVentricular Reciprocating Tachycardia): This is the type of SVT that patients with Wolf-Parkinson-White (WPW) develop—they are usually diagnosed in childhood, but occasionally the diagnosis is made as an adult. Here, the electrical short circuit involves an abnormal band of muscle that patients are born with. For this type of SVT, a procedure is generally preferred over medication.
- ATACH (Atrial Tachycardia): This SVT is less common in younger patients and becomes more common with age. Like AVNRT, this is managed with either medication or a procedure depending on the patient’s preference.
Premature contractions are often felt as heart palpitations. They’re extra heartbeats that disrupt your heart’s normal rhythm. Often, patients will perceive the pause that follows the extra beat and will describe “missing beats.” It’s very common to have this type of arrhythmia.
When premature beats happen in the upper heart chambers, they’re called premature atrial contractions (PACs). Those that start in the lower heart chambers are premature ventricular contractions (PVCs).
Ventricular tachycardia (VT)
Less common than other arrhythmias, ventricular tachycardia causes a rapid heart rate in the lower heart chambers. Whether this is a dangerous heart rhythm depends on whether a patient has an otherwise normal heart. Patients with ventricular tachycardia will typically undergo further cardiac testing such as an echocardiogram (ultrasound imaging of the heart), and sometimes an MRI of the heart or a cardiac catheterization (angiogram).
“If your heart is otherwise completely normal, VT is usually not life threatening,” says Dr. Castillo. “It’s much more serious when it is complicating other forms of heart disease.”
Get a Heart Evaluation
If you’ve been diagnosed with an irregular heartbeat, it’s important to find out what type of arrhythmia you have. You can learn more about heart and vascular services at MCVI. To schedule an appointment with a cardiologist, electrophysiologist or vascular specialist at Memorial, call 855-400-6284.