Article Types

Circulation publishes multiple different types of manuscripts, and authors should pay particular attention to the instructions for each type of article. Please note that all manuscripts must conform to one of the below article types. We do not consider articles such as Case Reports for publication. A brief description of each type follows:

Original Research Articles

Circulation considers for publication all types of original research articles related to cardiovascular science and medicine, including studies conducted in humans or analyses of human data, as well as preclinical studies that have direct clinical correlation or relevance. Preclinical studies will be considered that are novel and significantly advance the field. In terms of basic, discovery science, the editors are especially interested in disease-related studies that are ultimately informative and translatable to human disease and are conducted in vertebrate models. Circulation receives more than 5,000 submissions per year, and the acceptance rate for original research articles is approximately 7%. Acceptance for publication is based on originality, scientific quality, impact on cardiovascular science and the practice of cardiology, and the topical balance of the journal. Decisions are communicated by email, generally within six weeks.

Submitting an Original Research Article

We will consider initial Original Research Article submissions that are not formatted according to Circulation standards. However, the initial Original Research Article submission must include a complete list of authors entered into the online submission portal and include all submission files necessary for review. Those papers that are revised or ultimately accepted will be required to be formatted by the authors according to specific Circulation requirements (ie, title page, abstract, references, tables and figures, and disclosures). At that stage, please refer to the journal's Revised & Accepted Manuscripts instructions. Note that submissions in other article categories besides Original Research Article should meet the specified number of words, references, and figures/tables of that category upon initial submission.

General Requirements

Maximum length: ≤5,000 words
The 5,000 word limit does not include the title page, abstract, references, tables, and figure legends.
Maximum number of references: 50
Maximum number of figures and tables: 8
Structured abstract of ≤350 words, to include the following sections: Background, Methods, Results, Conclusions

Please refer to the journal's Manuscript Preparation Instructions when submitting an original research article

State of the Art Review Articles

Please note that most review articles are invited by the editors; however, unsolicited material may be considered for publication. If you wish to submit a review article to the journal, please do so via our submission site, https://circ-submit.aha-journals.org.

Invited articles, if accepted, are eligible to have page charges waived and to include color figures at no charge to the author, as long as color is essential to comprehend the figure. If color is non-essential, the figure may appear grayscale in print and color online.

All invitations are issued by a member of the Circulation team, generally the Editor-in-Chief, Executive Editor, or an Associate Editor, via email. Please note that informal discussion regarding a submission does not necessarily reflect a formal invitation with the associated privileges laid out above. Authors are welcome to contact the editorial office to confirm invitation status.

In Depth Review: Articles will focus on topics of contemporary interest to the cardiovascular clinician and/or scientist. The In Depth Review series is designed to provide a comprehensive and definitive review of a timely topic of high relevance to the cardiovascular community. Overviews of disease mechanisms, natural history, epidemiology, diagnostic strategies, and treatment approaches will be included in this series.

Length: ≤7,500 words
Word count does not include title page, abstract, references, tables, and figure legends.
References: ≤100
Maximum number of figures and tables: 8
An unstructured abstract is required: 200-350 words

Primer: The Primer series will provide a focused review of an important area that can be adequately covered in a relatively succinct format, as compared with an In Depth Review.

Length: ≤3,000 words
Word count does not include title page, abstract, references, tables, and figure legends.
References: ≤50
Maximum number of figures and tables: 6
An unstructured abstract is required: ≤250 words

New Drugs and Devices: This series will provide a timely and in-depth review of new diagnostic or treatment modalities for cardiovascular disease and will include reviews of medications, biologics, and devices. Newly approved therapies will be highlighted, in particular, in this series.

Length: ≤7,500 words
Word count does not include title page, abstract, references, tables, and figure legends.
References: ≤100
Maximum number of figures and tables: 8
An unstructured abstract is required: 200-350 words

Consensus Reports: Submissions will be reports commissioned by the editors from a group of thought leaders to inform our readership on topics where the evidence base is incomplete or controversial. These reports are intended to reflect a committee’s consensus following deliberations and include findings, conclusions, and recommendations based on available scientific evidence. Information in these articles is expected to include expert opinion on topics where robust data are lacking.

Length: ≤7,500 words
Word count does not include title page, abstract, references, tables, and figure legends.
References: ≤100
Maximum number of figures and tables: 8
An unstructured abstract is required: 200-350 words

White Papers: These are authoritative reports that inform readers about a complex issue and present the authors’ philosophy on the matter, supported by available evidence and expert opinion. They may suggest a new framework or paradigm for thinking about a topic or disease entity. They are intended to help readers understand a complex issue, solve a problem, or make a decision.

Length: ≤7,500 words
Word count does not include title page, abstract, references, tables, and figure legends.
References: ≤100
Maximum number of figures and tables: 8
An unstructured abstract is required: 200-350 words

Frame of Reference Articles

While the editors invite most articles in the Frame of Reference section, unsolicited material is encouraged. If you wish to submit a Frame of Reference article to the journal, please do so via our submission site, https://circ-submit.aha-journals.org. Please note that all contributions in this section are designed to be brief discussions rather than extensive reviews of a topic area.

On My Mind: These articles are brief opinion essays covering a wide range of "hot" topics of relevance to the cardiovascular community. In many instances, the topic may be provocative or contentious, and this is encouraged. These articles may briefly introduce a new paradigm or idea, challenge current dogma, or raise a controversial point; this content should stimulate discussion. Most of these articles will be written by only a single author, but we will allow up to three authors. These articles must be no more than 1,000 words in length and have no more than 5 references. A single figure or table is encouraged. If no figure or table is included, the word limit is 1,200 words.

Perspective: These articles are also brief essays focusing on timely topics in cardiovascular medicine; however, they will be more evidence-based and formally structured essays than the opinion-based On My Mind pieces. Some of these articles may represent scientific discussions of important content published in Circulation or in other leading journals, but many will be stand-alone discussions of emerging or important areas of cardiovascular medicine. This section will also include personal perspectives from individuals with career insights of interest to the cardiovascular community. These articles can include no more than three authors, must be no more than 1,000 words in length and have no more than 5 references. A single figure or table is encouraged. If no figure or table is included, the word limit is 1,200 words.

Clinical Implications of Basic Research: These articles will provide a brief overview of an emerging insight or methodology in fundamental molecular research and point to possible implications to cardiovascular clinical medicine. Their intent is to inform clinicians regarding emerging scientific methods and discoveries, thereby fostering dynamic interchange of ideas across the spectrum of cardiovascular research. These articles are limited to 1,000 words with ≤5 references. A single schematic figure should be included that captures the key points for clinicians.

Special Sections

Correspondence: Letters to the Editor that pertain directly to an article published in the journal will be considered for publication. A letter must not exceed 500 words and must be limited to 3 authors and 5 references (one reference should be the cited article). Letters cannot include tables or figures. Letters citing unpublished data will not be accepted. Letters must be submitted within 6 weeks of the print date of the article. Authors of the original article cited in the letter will be invited to reply. Letters to the Editor should be submitted via the online manuscript submission process. The journal will permit no more than 6 yearly letter to the editor submissions from any one corresponding author. Only Letters concerning Original Research Articles will be considered. Note that as with all other article types, Letters to the Editor which are accepted for publication will incur an article publication charge. Letters to the Editor concerning American Heart Association statements and guidelines are handled by the AHA. Submission instructions can be found on the AHA Web site.
Research Letters: Original research articles of a focused nature will also be considered for publication in a special section of Circulation. These focused research letters must not exceed 800 words and 5 references, and can include only 1 figure or table. No supplemental materials or abstract should be included. Research Letters will be peer reviewed in a manner identical to original research articles. Please Note: Supplemental Data is not allowed for this article type.
ECG Challenge: Interesting ECG cases will be considered for this section. Authors will submit a case with an ECG tracing (as an unknown), along with the answer and evidence corroborating the answer (e.g. preceding or subsequent ECG, imaging study, angiogram, intracardiac electrogram). The answer and rationale will then be published on the subsequent page. We will favor cases presented in a focused, succinct manner with emphasis on the ECG itself and its role in facilitating important clinical decisions. The initial case presentation will be limited to 300 words with no references, and the case discussion to 500 words and 3 references, with emphasis on references that support relevant details of the ECG presented. There should be no more than 3 authors listed.
Case Series: Compelling descriptions of a clinical case that convey a unique insight will be published in Circulation Cardiovascular Case Series. This content is intended to be explicitly heuristic, conveying an insight unique to an individual presentation that has implications on a larger scale. These case histories should include a concise description of the patient’s presentation, work up, interventions, and outcome; relevant images should be included. The case presentation should be structured in stages, with expert commentary supplied between stages, in order to aid and educate the reader about key differential diagnostic and therapeutic considerations. View a case series article. At the end, a discussion of the case along with “take home messages” should be given. There should be no more than 3 authors listed. The content will be limited to 2,000 words, up to 4 figures, and no more than 5 references.
Hospitals of History: The purpose of this article type is to document the history of historical hospitals and clinics. Authors, institutions, and societies are invited to submit a high quality image of their historical hospitals and/or clinics. Each submission should include one high quality image/figure as a TIFF, EPS, or PDF file. In addition, a brief caption of no more than 300 words should be included. The caption/figure legend should identify the hospital, include the date or year that the building was inaugurated, and, as space permits, explain its signficance.
Editorials: The editors will solicit all editorials. Instructions pertaining to the writing of an editorial will be included with the request from the editorial office.