From the Guidelines
To identify atrial fibrillation (Afib) with ventricular pacing, look for irregular R-R intervals, absence of distinct repeating P waves, and irregular atrial activity on an electrocardiogram (ECG), as these characteristics are indicative of Afib, according to the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1. When examining an ECG for Afib with ventricular pacing, key features to note include:
- Irregular R-R intervals, which occur due to the uncoordinated atrial activation and ineffective atrial contraction characteristic of Afib 1
- Absence of distinct repeating P waves, as the atrial activity is irregular and does not follow a consistent pattern 1
- Irregular atrial activity, which can manifest as a quivering or fibrillatory pattern on the ECG 1 In the context of ventricular pacing, the ECG will also show regular, wide QRS complexes with a pacemaker spike preceding them, indicating that the ventricular contractions are being controlled by the pacemaker. The ventricular paced beats will appear wide (typically >120ms) with a left bundle branch block pattern and have a visible pacing spike immediately before each QRS complex. It is essential to evaluate patients with suspected Afib and ventricular pacing for symptoms of hemodynamic compromise, such as dizziness, shortness of breath, or chest pain, as they may require adjustment of their pacemaker settings or anticoagulation therapy 1.
From the Research
Identifying Afib Ventricular Rate
To identify Afib ventricular rate, it is essential to understand the management strategies for atrial fibrillation (AF). The following points highlight the key aspects:
- Atrial fibrillation is a common cardiac arrhythmia associated with higher risk of cardiovascular morbidity and mortality 2.
- Rate control is a widely used management strategy for AF, which can modulate ventricle rate, alleviate adverse associated symptoms, and improve quality of life 2, 3.
- The clinical target of rate control should be a ventricular rate below 80-90 bpm at rest 3.
Management of Afib Ventricular Rate
The management of Afib ventricular rate involves various treatment options, including:
- Beta-blockers, which are almost always required to achieve rate control in patients with AF and heart failure (HF) 4.
- Digoxin, which may be useful in the presence of hypotension or an absolute contraindication to beta-blocker treatment 4, 5, 6.
- Non-dihydropyridine calcium channel blockers, which are often contraindicated when AF is associated with HF with systolic dysfunction 4.
- Intravenous beta blockers and calcium channel blockers, which are equally effective in rapidly controlling the ventricular rate in acute AF 5.
Assessment of Efficacy
The assessment of efficacy in managing Afib ventricular rate involves:
- Exercise testing and 24h-Holter monitoring to evaluate the appropriateness of different drugs 3.
- Clinical assessment, including assessing the presence of underlying heart disease and haemodynamic impairment 3.
- Identification of reversible and often concealed forms of left ventricular dysfunction, which can permit effective management by rate (or rhythm) control 3.