Atrial fibrillation (AFib) and premature ventricular contractions (PVCs) are two of the most common heart rhythm disorders, and they frequently occur together. Both conditions involve disruptions in the heart’s electrical signaling system, leading to an irregular heartbeat, or arrhythmia. While AFib affects the upper chambers of the heart and PVCs affect the lower chambers, their combined presence can complicate diagnosis and alter the overall health outlook. Understanding the combined risks of these dual electrical disturbances is important for effective management.
Understanding the Dual Electrical Disturbance
Atrial fibrillation involves a chaotic, rapid firing of electrical signals in the heart’s upper chambers, the atria. This causes the atria to quiver, or “fibrillate,” instead of contracting effectively, which disrupts the consistent flow of blood to the lower chambers.
Premature ventricular contractions are isolated extra heartbeats that originate lower down in the ventricles. A PVC occurs earlier than the next expected regular beat, often creating the sensation of a forceful or “skipped” beat followed by a pause. These two arrhythmias often coexist because they share underlying causes, such as structural changes in the heart muscle, hypertension, or elevated neurohormonal activity. Furthermore, a frequent PVC can sometimes act as a trigger for an AFib episode by initiating the chaotic rhythm.
Shared Symptoms and Diagnostic Methods
The co-occurrence of AFib and frequent PVCs can lead to overlapping symptoms. Patients may experience palpitations, which can feel like a fluttering, racing, or pounding sensation in the chest. Other symptoms include lightheadedness, fatigue, shortness of breath, or anxiety. The irregular rate of AFib can sometimes mask the characteristic skipped beat feeling of a PVC, or the PVCs can exacerbate the discomfort felt during an AFib episode.
Diagnosis begins with an electrocardiogram (ECG or EKG), which measures the heart’s electrical activity over a short time. Because both AFib and PVCs can be intermittent, continuous monitoring is often necessary to capture the events. A Holter monitor, worn for 24 to 48 hours, or an event recorder, used for up to 30 days, helps quantify the frequency of PVCs and the duration of AFib episodes. Additional tests, such as an echocardiogram, assess the heart’s structure and function, while blood tests check for contributing factors like electrolyte imbalances or thyroid issues.
Assessing the Risk of Complications
For patients with AFib, the primary risk is an ischemic stroke, which occurs when blood pools in the quivering atria and forms clots that travel to the brain. Physicians use the standardized CHA₂DS₂-VASc score to estimate stroke risk and guide the need for blood-thinning medication. This score tallies points for risk factors like congestive heart failure, hypertension, age, diabetes, and prior stroke.
The risk associated with PVCs is directly related to their frequency, known as the PVC burden. When PVCs account for a high percentage of total heartbeats, typically above 10% to 15%, they can eventually lead to PVC-induced cardiomyopathy. This condition involves a weakening and enlargement of the heart muscle due to the constant, inefficient pumping action of the extra beats. The combination of the two arrhythmias complicates the prognosis, as frequent PVCs are independently associated with an increased risk of developing heart failure, stroke, and all-cause mortality.
Tailored Management and Treatment Approaches
Stroke prevention is paramount, primarily achieved through the use of oral anticoagulants, including warfarin and direct oral anticoagulants (DOACs). The decision to prescribe these medications is based on the patient’s individual CHA₂DS₂-VASc score to ensure the benefit of stroke reduction outweighs the risk of bleeding.
Treatment also focuses on controlling the heart rate and restoring a normal rhythm. Medications such as beta-blockers and calcium channel blockers can help slow the heart rate during AFib and may also reduce the frequency of PVCs. Interventional procedures like catheter ablation may be considered. Ablation involves isolating the electrical triggers of AFib and separately targeting the specific site where the PVCs originate to eliminate the abnormal beats. Lifestyle modifications are an important complement to medical therapy, including avoiding known triggers such as excessive caffeine, alcohol, and stress.