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
. 2007 Feb;4(2):138-44.
doi: 10.1016/j.hrthm.2006.10.017. Epub 2006 Oct 20.

Regional left atrial voltage in patients with atrial fibrillation

Gregory M Marcus  1 , Yanfei Yang, Paul D Varosy, Karen Ordovas, Zian H Tseng, Nitish Badhwar, Byron K Lee, Randall J Lee, Melvin M Scheinman, Jeffrey E Olgin
Affiliations

Regional left atrial voltage in patients with atrial fibrillation

Gregory M Marcus et al. Heart Rhythm. 2007 Feb.

Abstract

Background: Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis.

Objectives: The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium.

Methods: Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude.

Results: The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05).

Conclusion: Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls.

PubMed Disclaimer

Conflict of interest statement

There are no potential conflicts of interest to disclose

Figures

Figure 1
Figure 1
Mean voltage differences (in mV) for the entire left atrium and by region for the atrial fibrillation and atrial tachycardia groups. Y-error bars denote standard deviations.
Figure 2
Figure 2
Linear regression coefficients of voltage in the septum, posterior wall and lateral walls compared to voltage in the anterior wall for atrtial fibrillation and focal atrial tachycardia patients. Y-error bars denote 95% confidence intervals. * denotes p < 0.05; ** denotes p < 0.001.
Figure 3
Figure 3
Odds ratios for the presence of a low voltage point (<0.5 mV) in the septum, posterior wall, and lateral wall compared to the anterior wall for atrial fibrillation and focal atrial tachycardia patients. Y-error bars denote 95% confidence intervals * denotes p < 0.05; ** denotes p < 0.001.
Figure 4
Figure 4
Electroanatomic maps of left atria using the CARTO (Biosense) system, illustrating homogeneous normal voltage in the septum (A) and lateral wall (B) of an atrial tachycardia patient. The atrium of an AF patient exhibits significantly lower voltage in the septum (C) than the lateral wall (D). As demonstrated by the color coded key, purple represents voltage > 0.99 mV.
Figure 5
Figure 5
Local electrogram from the same point taken from the endocardium of a canine ventricular preparation using a 4 mm tipped ablation catheter (left) and an 8 mm tipped ablation catheter. The 8 mm tipped catheter recorded a larger peak to peak voltage.
See this image and copyright information in PMC

Comment in

  • Substrate mapping and the aging atrium.
    Tedrow U, Stevenson WG. Tedrow U, et al. Heart Rhythm. 2007 Feb;4(2):145-6. doi: 10.1016/j.hrthm.2006.11.007. Epub 2006 Nov 17. Heart Rhythm. 2007. PMID: 17275747 No abstract available.

References

    1. Kumagai K, Nakashima H, Urata H, Gondo N, Arakawa K, Saku K. Effects of angiotensin II type 1 receptor antagonist on electrical and structural remodeling in atrial fibrillation. J Am Coll Cardiol. 2003;41(12):2197–2204. - PubMed
    1. Li D, Fareh S, Leung TK, Nattel S. Promotion of atrial fibrillation by heart failure in dogs: atrial remodeling of a different sort. Circulation. 1999;100(1):87–95. - PubMed
    1. Verheule S, Wilson E, Everett T, 4th, Shanbhag S, Golden C, Olgin J. Alterations in atrial electrophysiology and tissue structure in a canine model of chronic atrial dilatation due to mitral regurgitation. Circulation. 2003;107(20):2615–2622. - PMC - PubMed
    1. Boldt A, Wetzel U, Lauschke J, Weigl J, Gummert J, Hindricks G, Kottkamp H, Dhein S. Fibrosis in left atrial tissue of patients with atrial fibrillation with and without underlying mitral valve disease. Heart. 2004;90(4):400–405. - PMC - PubMed
    1. Hassink RJ, Aretz HT, Ruskin J, Keane D. Morphology of atrial myocardium in human pulmonary veins: a postmortem analysis in patients with and without atrial fibrillation. J Am Coll Cardiol. 2003;42(6):1108–1114. - PubMed