From the Guidelines
Atrial fibrillation with rapid ventricular response (AFib with RVR) is primarily caused by the loss of normal atrial electrical activity, resulting in chaotic, rapid impulses that overwhelm the AV node and lead to a fast ventricular rate, with common causes including hypertension, coronary artery disease, heart failure, valvular heart disease, hyperthyroidism, alcohol consumption, pulmonary embolism, and acute illness or surgery, as well as other contributing factors such as advanced age, obesity, sleep apnea, diabetes, chronic lung disease, and electrolyte abnormalities 1.
Causes of AFib with RVR
The causes of AFib with RVR can be categorized into several groups, including:
- Structural heart diseases, such as hypertension, left atrial enlargement, coronary artery disease (CAD), heart failure (HF), valvular heart diseases, and myocardiopathies 1
- Non-cardiac diseases, such as diabetes mellitus, hyperthyroidism, obesity, asthma, obstructive sleep apnea, and chronic kidney disease 1
- Acute temporary causes, including excessive alcohol intake, surgery, pericarditis, myocarditis, hyperthyroidism, and pulmonary embolism 1
- Drug-induced atrial fibrillation (DIAF), which can be caused by a variety of cardiovascular, non-cardiovascular, and anticancer drugs 1
Mechanism of AFib with RVR
The rapid ventricular response occurs because the AV node becomes overwhelmed by the numerous atrial impulses, allowing more impulses to conduct to the ventricles than would normally occur, resulting in heart rates that typically exceed 100 beats per minute and can reach 150-200 beats per minute in severe cases, potentially leading to hemodynamic compromise if left untreated 1.
Clinical Implications
AFib with RVR is associated with symptoms, diminished functional capacity and quality of life, and increases the rate of all-cause hospital admissions and the risk of cardiovascular complications, including heart failure and stroke 1. Therefore, it is essential to identify and manage the underlying causes of AFib with RVR to prevent these complications and improve patient outcomes. The management of AFib with RVR should focus on controlling the ventricular rate, preventing thromboembolism, and correcting underlying causes, with beta blockers being the preferred agents for achieving rate control unless otherwise contraindicated 1.
From the Research
Causes of Atrial Fibrillation with Rapid Ventricular Response
- Atrial fibrillation (AF) is a common dysrhythmia associated with significant morbidity and mortality, and it can lead to stroke, heart failure, and death 2
- When AF occurs in the context of a rapid ventricular rate/response (RVR), this can lead to complications, including hypoperfusion and cardiac ischemia 2
- The exact cause of AF with RVR is not explicitly stated in the provided studies, but it is mentioned that AF may lead to stroke, heart failure, and death, and that RVR can lead to complications 2
Risk Factors and Associated Conditions
- Heart failure (HF) is a significant comorbidity in patients with AF, and the management of AF with RVR in HF patients can be challenging 3, 4
- Patients with concomitant HF and AF with RVR may require careful consideration of treatment options, including the use of intravenous medications such as metoprolol or diltiazem 3, 4
- The American Heart Association and other clinical groups note that non-dihydropyridine calcium channel blockers (CCB) should be avoided in patients with heart failure with reduced ejection fraction (HFrEF) due to their potential negative inotropic effects 4
Treatment and Management
- Rate control using beta blockers or calcium channel blockers is a common approach for managing AF with RVR 5, 2, 6
- The choice of medication for rate control may depend on individual patient factors, including comorbidities and clinical situation 5
- Emergent cardioversion is indicated in hemodynamically unstable patients, while elective cardioversion may be a safe option for select patients 2, 6