Ivabradine is an effective treatment for focal atrial tachycardia. However, it may also be effective for re-entrant atrial arrhythmia. An 85-year-old woman with a history of underlying ischaemic cardiomyopathy complained of worsening symptoms of heart failure because of rapid atrial tachycardia that was resistant to several rate-controlling drugs, but responded well to ivabradine. An electrophysiology study demonstrated a roof-dependent macro-re-entrant tachycardia of the left atrium. Linear ablation of the left atrial roof resulted in termination of the tachycardia. Thus, ivabradine can be an effective treatment for re-entrant atrial tachycardia.

OBJECTIVE: To explore the effect of controlling the heart rate on the heart failure index and on heart function in patients with heart failure and atrial fibrillation.
METHODS: 82 patients with heart failure and atrial fibrillation were divided into a control group (n=41) and a study group (n=41). The patients in the control group underwent conventional treatment. In addition to the conventional treatment, the patients in the study group were administered metoprolol to actively control their heart rates and to decrease their resting heart rates down to 55-60 beats/min as the target heart rate. After three months of treatment, the heart function, the levels of N terminal pro B type natriuretic peptide (NT-proBNP), and the inflammatory factors were compared between the two groups. At the same time, the readmission rates and prognoses were calculated.
RESULTS: After the treatment, the left ventricular ejection fraction (LVEF) and the cardiac output (CO) levels in the two groups were increased, and the levels in the study group were higher than the levels in the control group; there were opposite trends in the left ventricular end-systolic diameter (LVESD) levels, the left ventricular end-diastolic dimension (LVEDD) levels, and the NT-proBNP, serum CRP, TNF-α and IL-6 levels (all P<0.05). After a six month follow up, the readmission and heart failure rates, and the incidence of adverse events in the study group were lower than they were in the control group (all P<0.05).
CONCLUSIONS: The effective control of the ventricular rate can more significantly benefit the heart failure symptoms and atrial fibrillation, alleviate the inflammatory response, and thus improve the heart function and prognoses of heart failure patients with atrial fibrillation.

The optimal level of heart rate (HR) control in patients with atrial fibrillation (AF) is unknown. To assess the effect of rate control on cardiopulmonary exercise capacity and quality of life (QoL) in permanent AF.
One hundred forty-three patients with permanent AF were enrolled in this study. All patients received rate control medications and were followed up for 1 year. After 1-year therapy, the exercise capacity and QoL were evaluated by cardiopulmonary exercise testing (CPET) and 36-item Short-Form Health Survey, respectively. Data were compared by dividing the patients according to the following criteria: (1) whether the resting HR was ≤80 or > 80 bpm; (2) whether the exercise HR during moderate exercises on CPET was ≤110 or > 110 bpm; and (3) whether the resting HR was ≤80 bpm and exercise HR was ≤110 bpm.
No significant differences in peak oxygen uptake, peak metabolic equivalent, and anaerobic threshold were found between the strict control and lenient control groups. Both physical component summary (PCS) and mental component summary (MCS) were significantly higher for the strict rate control group than for the lenient control group. The single-factor correlation analysis revealed a negative correlation between resting HR and both PCS and MCS. The multivariable linear regression analysis indicated that both exercise HR and duration of AF linearly correlated with PCS and MCS.
Therefore, in patients with permanent AF, exercise capacity may not be affected by the stringency of rate control, and strict rate control may be associated with better QoL.