From the Guidelines
Bigeminy should be managed by addressing the underlying cause and symptom severity, with a focus on avoiding triggers and using beta-blockers or calcium channel blockers for symptomatic patients, as the use of antiarrhythmic medications has not been shown to reduce mortality and may increase the risk of death in certain populations 1.
Definition and Causes
Bigeminy is a cardiac rhythm pattern where every normal heartbeat is followed by a premature beat, creating a repeating pattern of two beats. This typically occurs when premature ventricular contractions (PVCs) or premature atrial contractions (PACs) alternate with normal beats. The presence of PVCs, which are common and increase in frequency with age, has been associated with increased cardiovascular risk and mortality 1.
Management
Management of bigeminy depends on the underlying cause and symptom severity. For asymptomatic patients without heart disease, reassurance and avoiding triggers like caffeine, alcohol, and stress may be sufficient. Symptomatic patients might benefit from:
- Beta-blockers like metoprolol (25-100 mg twice daily)
- Calcium channel blockers such as diltiazem (120-360 mg daily) For persistent, symptomatic bigeminy, treatment should focus on addressing the underlying condition, such as heart failure or electrolyte abnormalities, rather than relying on antiarrhythmic medications, which have not been shown to reduce mortality and may increase the risk of death in certain populations 1.
Key Considerations
- The detection of PVCs, particularly if multifocal and frequent, is generally considered a risk factor for adverse cardiovascular outcomes 1.
- Treatment of PVCs with antiarrhythmic medications has not been shown to reduce mortality and, in the post-MI population, treatment with class I sodium channel–blocking medications increases the risk of death 1.
- Beta blockers, such as those used in the management of bigeminy, can help prevent recurrent arrhythmias and are a preferred treatment option 2.
From the Research
Definition and Mechanisms of Bigeminy
- Bigeminy is a type of arrhythmia where there is an alternating pattern of normal and premature heartbeats 3, 4.
- The rule of bigeminy is commonly explained by a reentrant mechanism, but it may also be caused by premature ventricular complexes (PVCs) due to early afterdepolarizations in patients with prolonged ventricular repolarization 3.
- Bigeminy can be caused by various mechanisms, including common and uncommon ones, and awareness of these possibilities is essential for accurate diagnosis and quality patient care 4.
Clinical Characteristics and Diagnosis
- Bigeminy is often associated with a long corrected QT interval, relatively fixed coupling interval, and onset after a short-long RR sequence 3.
- Patients with bigeminy may have slower heart rates, longer QT intervals, and more prominent U waves compared to those without bigeminy 3.
- MRI can be used to image premature ventricular contractions (PVCs) in bigeminy, and the contraction pattern of PVCs can provide valuable information for localizing the site of origin of the arrhythmia 5.
Treatment and Management
- Flecainide associated with beta-blockers can be an effective and safe treatment for arrhythmogenic right ventricular cardiomyopathy (ARVC) patients with ventricular arrhythmias, including bigeminy 6.
- Treatment with flecainide and beta-blockers can reduce premature ventricular contraction burden and improve VA-free survival in ARVC patients 6.
- Catheter ablation and implantable cardioverter-defibrillator therapy may also be considered for treating bigeminy and other ventricular arrhythmias in certain patients 6.