Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Sep 13;3(6Part A):681-687.
doi: 10.1016/j.hroo.2022.09.001. eCollection 2022 Dec.

Rate or Rhythm Control in CRT (RHYTHMIC): Study rationale and protocol

Mark K Elliott  1   2 , Felicity de Vere  1   2 , Vishal S Mehta  1   2 , Nadeev Wijesuriya  1   2 , Marina Strocchi  1 , Ronak Rajani  1   2 , Steven Niederer  1 , Christopher A Rinaldi  1   2
Affiliations

Rate or Rhythm Control in CRT (RHYTHMIC): Study rationale and protocol

Mark K Elliott et al. Heart Rhythm O2. .

Abstract

Background: Atrial fibrillation (AF) has several detrimental effects on heart failure patients treated with cardiac resynchronization therapy (CRT). These include suboptimal biventricular pacing and the loss of atrioventricular (AV) synchrony. AV node ablation improves biventricular pacing and clinical outcomes in large observational studies. However, restoration of sinus rhythm with AF ablation may have additional benefits.

Objectives: To compare the effects of AV node ablation and AF ablation on echocardiographic and symptomatic outcomes in patients with CRT and suboptimal biventricular pacing.

Methods: RHYTHMIC is a multicenter prospective randomized controlled trial. Seventy patients will be recruited and randomized to each ablation strategy in a 1:1 ratio. Key inclusion criteria include a previous CRT implant (with atrial lead) for dyssynchronous heart failure, and biventricular pacing <95% secondary to AF. Patients with permanent AF will be excluded.

Results: Patients will undergo baseline assessment including transthoracic echocardiography (TTE), device check, blood tests, electrocardiogram (ECG), 6-minute walk test, and symptom questionnaire. They will then undergo either AV node ablation or AF ablation according to their allocated group. Follow-up will occur at 1 week (TTE and ECG) and at 6 months (repeat of baseline investigations). The primary endpoint will be change in left ventricular ejection fraction on TTE.

Conclusion: This is the first randomized controlled trial comparing AV node ablation and AF ablation in patients with CRT. We anticipate it will provide valuable insight into the management of this frequently encountered clinical scenario in a challenging patient cohort.

Keywords: Atrial fibrillation; Atrial fibrillation ablation; Atrioventricular node ablation; Atrioventricular synchrony; Biventricular pacing percentage; Cardiac resynchronization therapy.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Flow diagram of study protocol. AF = atrial fibrillation; AV = atrioventricular; ECG = electrocardiogram.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Elliott M.K., Mehta V.S., Martic D., Sidhu B.S., Niederer S., Rinaldi C.A. Atrial fibrillation in cardiac resynchronization therapy. Heart Rhythm O2. 2021;2:784–795. - PMC - PubMed
    1. Lyons K.J., Ezekowitz J.A., Liang L., et al. Impact of current versus previous cardiac resynchronization therapy guidelines on the proportion of patients with heart failure eligible for therapy. JACC Heart Fail. 2017;5:388–392. - PubMed
    1. Maisel W.H., Stevenson L.W. Atrial fibrillation in heart failure: epidemiology, pathophysiology, and rationale for therapy. Am J Cardiol. 2003;91(6 SUPPL. 1):2–8. - PubMed
    1. Carlisle M.A., Fudim M., DeVore A.D., Piccini J.P. Heart failure and atrial fibrillation, like fire and fury. JACC Heart Fail. 2019;7:447–456. - PubMed
    1. Mustafa U., Atkins J., Mina G., et al. Outcomes of cardiac resynchronisation therapy in patients with heart failure with atrial fibrillation: a systematic review and meta-analysis of observational studies. Open Heart. 2019;6:1–12. - PMC - PubMed