Arrhythmia can lead to heart failure, and heart failure can lead to arrhythmia

The heart acts as a pump, sending oxygen-rich blood out to the body and oxygen-depleted blood to the lungs. To execute its duties, it must contract with sufficient power at a regular rate throughout our lives. In the average lifetime, the heart beats about 3 billion times. That’s a lot of work for one muscle.

Sometimes, the heart can lose its power and start to fail. When that happens, the condition is called heart failure. Other times, haywire signals make the heart contract out of sync or beat too fast or too slowly, which is called arrhythmia. The two conditions often occur together or one after the other. This is because a failing heart muscle can affect rhythm, and an uneven or badly paced rhythm can tax a hardworking heart muscle.

The basics of heart failure

The term “heart failure” describes when heart muscle function has faded to the point it’s unable to pump out enough blood. Heart failure occurs in one of two ways:

• When the ventricles (lower chambers) become incapable of contracting normally, so the heart can’t pump hard enough to push blood around your body
• When the ventricles become incapable of relaxing normally, so the heart can’t fill with blood like it should

One effect of a failing heart muscle and weaker pumping is fluid backup. Fluid can build up in the lungs, or you might experience swelling in your feet, hands, abdomen or neck veins. Shortness of breath or swelling can signal heart failure, says Saumil R. Shah, MD, a cardiologist who specializes in abnormal heart rhythms with Virginia Arrhythmia Consultants at Chippenham Hospital in Richmond, Virginia.

Heart failure can set the stage for a heart to beat out of sync, or to become arrhythmic.

The basics of arrhythmia

There are multiple kinds of arrhythmias. When the heart beats too slowly, it's called bradycardia. When the heart beats too quickly, it's called tachycardia. Tachycardias that originate above the ventricles are supraventricular tachycardias. When a tachycardia originates in the ventricles themselves, it can be quite dangerous and requires immediate medical attention.

A heart that beats at an irregular pace is not keeping a normal, or sinus, rhythm. One common and usually benign example is a premature or "extra" heartbeat, which is associated with the feeling that your heart has "skipped a beat."

People with arrhythmias may not be aware that they have one. They may not know the signs, or their arrhythmia might not cause obvious symptoms. When symptoms are milder, they can include a slow heartbeat, an irregular heartbeat or perhaps heart palpitations, which often feel like your heart is racing, thumping or skipping beats. When arrhythmias are more serious, you may feel fatigue, dizziness, shortness of breath or even chest pain. Eventually, you may notice something that occurs only occasionally, or your symptoms may become more frequent over time.

In certain cases, arrhythmias may be life-threatening. Some can cause the heart to stop pumping blood, which is called cardiac arrest. Others may allow clots to develop and make their way to the brain, causing a stroke.

The link between heart failure and arrhythmia

People who have heart failure often will develop arrhythmia, and vice versa, suggesting that each can be a risk for the other.

Heart failure patients experience "a lot of strain," says Dr. Shah. This strain can lead to a type of arrhythmia called atrial fibrillation (AFib), in which the heart beats irregularly. "The heart is not pumping well, and the fluid can back up into the left atrium (upper chamber of the heart), which is where a lot of AFib starts," he explains.

In the reverse case, AFib can weaken the heart muscle, leading to heart failure. "When the heart beats too rapidly for a prolonged period, the muscle can weaken, leading to cardiomyopathy and congestive heart failure," Shah says. Cardiomyopathy is a disease of the heart muscle that may cause heart failure.

Because of this association, Shah says that people with heart failure should be aware of arrhythmia symptoms like a racing or irregular pulse. To investigate these symptoms, your healthcare provider (HCP) may perform an electrocardiogram (EKG)--which displays the heart's rhythms and electrical signaling in different regions--or ask you to wear a heart monitor.

Another time someone with heart failure should ask about arrhythmia is if their heart failure has been stable and well managed and something suddenly changes, Shah says. "That's another time to look for AFib to be sure that what's changed is not the rhythm," he says.

As for patients with an arrhythmia, hints of heart failure are related to its usual symptoms, including shortness of breath and fluid retention, says Shah. "It presents with the same symptoms" with or without AFib, he says.

Your treatment options

Treatments for heart failure and arrhythmia when they occur together are similar to treating them separately. The focus is on getting the heart rate and rhythm into normal range.

Although medications might achieve this goal, sometimes, a patient may need a procedure called an ablation, Shah says. With this approach, the cardiologist targets the areas of the heart where the offrhythm signals originate. They then use either radiofrequency or very cold temperature to make little scars and silence the abnormal signals.

Regardless of treatment approach, the key is to identify both the heart failure and the arrhythmia, says Shah. “The take-home is that patients should be evaluated for AFib if they have heart failure and vice versa,” and be appropriately treated, he says.