# Single Ventricle Circulation

> Interactive simulation of single ventricle circulation stages and surgical palliation. (iPhone/iPad app by Tim Conover.)

- Source: https://appshunter.io/ios/app/single-ventricle-circulation/id1055039025 (this page in markdown: same URL + `.md`)
- Developer: [Tim Conover](https://appshunter.io/developer/1055039024)
- Category: Education, Medical
- Price: Free
- Rating: 5.00/5 from 3 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.3 · 3 MB
- Languages: American English
- Released: 2019-08-19
- Data updated: 2026-06-01
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/single-ventricle-circulation/id1055039025/reviews.md

## What is Single Ventricle Circulation?

This app presents a model of circulation throughout the three stages of surgical palliation for patients with single ventricle physiology, known as the Fontan sequence.  An educational tool designed for medical students and anyone interested in congenital heart defects, the app allows the user to experiment with several different common surgical procedures and medical treatments, to observe the effects on clinical measures like blood pressures and oxygen delivery both at rest and during exercise, and to predict immediate post-surgical outcomes. The app displays both tabular results, and time-based blood pressure and flow waveforms and ventricular pressure-volume loops.

This app accompanies our JTCVS paper(1), which describes the circulation models used, abbreviations and settings. The paper includes details of the model mechanics, and a partial validation of model outputs vs. clinical measurements from 47 patients. This is the hand-held device app mentioned in that paper. The app provides default values for the circulation, which the user can can be customize to investigate clinical situations or patient-specific predictions. Details on the basis of the circulation model are cited in the JTCVS paper (1). 

(1) Conover, T., Hlavacek, A.M., Migliavacca, F. et al. An interactive simulation tool for patient-specific clinical decision support in single ventricle physiology. J Thorac Cardiovasc Surg. 2018; 155: 712–721

## Key features

- Model of circulation for surgical palliation
- Experiment with surgical procedures
- Observe effects on clinical measures
- Predict immediate post-surgical outcomes
- Display tabular results and waveforms
- Customize circulation model values

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/single-ventricle-circulation/id1055039025/reviews.md

### 5/5 — Useful tool

*2022-08-19, version 1.0*

Should be a useful tool for any med student, especially those leaning towards cardio

### 5/5 — Insightful

*2021-01-08, version 0.8.4*

Very clever and useful in my clinical activities and learning

## Frequently asked questions about Single Ventricle Circulation

### What is Single Ventricle Circulation?

Single Ventricle Circulation is an educational tool that presents a model of circulation throughout the three stages of surgical palliation for patients with single ventricle physiology, also known as the Fontan sequence. It allows users to experiment with different surgical procedures and medical treatments.

### Who is the target audience for Single Ventricle Circulation?

This app is designed for medical students and anyone interested in learning about congenital heart defects and single ventricle physiology. It provides an interactive way to understand complex circulatory models.

### What kind of outcomes can be predicted with Single Ventricle Circulation?

The app allows users to observe the effects of various surgical procedures and medical treatments on clinical measures like blood pressures and oxygen delivery. It also helps in predicting immediate post-surgical outcomes.

### What data is displayed by Single Ventricle Circulation?

The app displays both tabular results and time-based blood pressure and flow waveforms, as well as ventricular pressure-volume loops. This provides a comprehensive view of the circulatory model's performance.

### Is Single Ventricle Circulation based on any published research?

Yes, this app accompanies a JTCVS paper that describes the circulation models used, abbreviations, and settings. The paper includes details on model mechanics and validation of model outputs against clinical measurements.

### Can I customize the circulation model in Single Ventricle Circulation?

Yes, the app provides default values for the circulation, which users can customize to investigate specific clinical situations or patient-specific predictions. This feature enhances its utility for detailed study.

### What devices does Single Ventricle Circulation support?

Single Ventricle Circulation is available on Mac, iPhone, iPad, and iPod. This broad compatibility ensures accessibility for a wide range of users.

### How often is Single Ventricle Circulation updated?

The latest version of Single Ventricle Circulation is 1.0, and it was last updated on August 18, 2022. This indicates a stable release with potential for future updates based on research advancements.

## Version history (last 4 releases)

### 1.0 — 2022-08-18

In Version 1.0 the interface as been completely overhauled for Universal compatibility to run on both iPad and iPhone.  This version also runs on Apple Silicon Macs.  There is also a version for Intel Macs running Mac OS 10.15+.
• New color scheme also supports Dark Mode.
• Minimum required iOS 12.3, still supports original iPad Air and iPhone 5S.  Future versions will require iOS 13+.
• User needs to "agree" to the disclaimer only once, on the first launch after install.
• New user's manual pages on the Single Ventricle Circulation Home web site.
• iPhone version has pinch-zooming feature for best visibility of plots.
• iPhone version has a scroll-locking mechanism on the inputs and results tables to improve readability.
• Updated TCPC pump model using new H-Q vs. RPM data.  Also, new calculation of caval pressure and TCPC gradient for results, and a new visual indicator of the TCPC pump impeller.
• New, more-consistent treatment of collaterals and coarctation in modified runs retaining baseline resistances.
• Some corrections of the exercise model to match the Kung model as-published. 
• Install with confidence - user cases entered in the previous version are preserved on your device (unless, of course, you do a clean install).

### 0.8.5 — 2022-02-20

This is a patch release.  Newer versions of iOS have a stricter requirement on alert dialogs, causing a crash in Single Ventricle Circulation version 0.8.4.  This fixes that bug.

### 0.8.4 — 2019-08-31

In modified runs, the inputs for all three collateral flows have a new default option, which is "baseline."   In this case the original collateral resistance is kept, and collateral flow will vary according to system pressures.  This fixes some previously confusing behavior in the simulation.

### 0.8.3 — 2019-08-19

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*