Comorbidities: Atrial Fibrillation and Other Arrhythmias

Each day our heart beats more than 100,000 times.¹ For most, the heartbeat is steady and rhythmic. It is normal for the heart rate to change based on circumstances; slower when someone is at rest or faster during exercise, exertion, or excitement.² Sometimes, however, the heart’s internal electrical system short circuits and this results in a disruption in the normal rate or rhythm of the heartbeat. This is called an arrhythmia.^2-3

Arrhythmia

Arrhythmias can develop when something disrupts the electrical impulses that control the pumping rate of the heart. This can cause the heart to beat faster, slower, or irregularly.⁴ When this happens, the heart doesn’t pump blood as effectively and the body may not get enough oxygen to function properly.² Arrhythmias can start in the upper chambers of the heart (atria), or the lower chambers of the heart (ventricles).

Studies have shown that increased heart rate is associated with higher mortality rates for the general population and those with heart failure (HF). For people with HF, an increased heart rate can be an indicator of worsening myocardial dysfunction which can cause heart failure to deteriorate.⁵

There are different kinds of arrhythmias, some of which can be harmless and others that can be life-threatening, including:^2-3

• Tachycardia: a fast heart rate
• Bradycardia: a slow heart rate
• Atrial Fibrillation: electrical signals cause a disorganized contraction of the atria, leading to irregular contractions of the ventricles
• Premature contraction: an early heartbeat (can come from either the atria or the ventricles)
• Ventricular Fibrillation: electrical signals cause a disorganized contraction of the ventricles

Arrhythmias can be caused by diseases of the heart, an overactive thyroid, anemia, excessive use of caffeine, drugs or alcohol, for example, risks of developing arrhythmias are increased by conditions that strain or damage heart tissue.²

Heart rhythm describes the way the heartbeats. Conduction describes the way electrical impulses travel through the heart signaling it to beat. Some conduction disorders can cause arrhythmias, or irregular heartbeats.³

Atrial fibrillation

Atrial fibrillation (AFib) is the most common heart rhythm disorder.¹ It occurs when the atria are beating in a very fast, disorganized way. Only some of the impulses sent from the atria reach the ventricles. This can interfere with the synchronized contractions of the heart. When this happens, blood can pool in the atria, creating risk for complications including blood clots, stroke, and heart failure. Atrial fibrillation can be temporary or persist until treated.²

Types of AFib:

AFib can be characterized as:

• Paroxysmal: sometimes present, sometimes not, and generally goes away by itself.
• Persistent: Lingers for a week or more and can become permanent. Requires treatment to return to a normal rhythm
• Permanent: The normal rhythm cannot be restored.¹

Symptoms

AFib is sometimes referred to as a quivering heart because the atria, the two upper chambers, can quiver. It can feel like your heart is racing, fluttering, or skipping beats. This can cause sensations of breathlessness, dizziness, and exhaustion.^1-2 Yet not everyone experiences AFib symptoms which can make detection more difficult. AFib is frequently identified during an electrocardiogram (ECG) performed during a physical exam.¹

Treatment

Managing AFib is based on the presence of any underlying medical conditions, comorbidities, and each person’s individual contributing factors for AFib. Treatment focus is generally to prevent strokes, using medications to prevent blood clots and control heart rate and rhythm, as well as making lifestyle changes.^1,4,6

There are several surgical and non-surgical approaches to treating AFib. An example of a surgical approach is the placement of an internal pacemaker. A pacemaker is a small electrical device that is implanted inside the body with wires leading into the heart which delivers an electrical signal to regulate the heartbeat.⁷ There is a non-surgical procedure called electrical cardioversion which uses an electrical shock to reset the heart’s natural rhythm. It is similar to defibrillation (used when someone’s heart stops beating) but uses lower levels of electricity.⁸

To best manage AFib it is important to:¹

• Exercise regularly under the guidance of your healthcare team
• Follow a heart-healthy diet that is low in salt, saturated, and trans fats
• Control your blood pressure and cholesterol
• Limit your alcohol and caffeine intake
• Don’t smoke

Remember to tell your healthcare team about any changes in the way you feel or symptoms you experience and seek emergency treatment if you think you may be experiencing a heart attack or stroke.