Martin Ugander
@mugander.bsky.social
Physician-scientist, Professor of Cardiac Imaging, U of Sydney, Founder of aecgs.com 🇦🇺🇺🇸🇸🇪 Posts about 🫀 imaging 🧲🔊 ⏺ ☢️ &⚡️ECG #CardioSky #RadSky
www.ugander.com/martin
www.ugander.com/martin
Reposted by Martin Ugander
Accuracy of #AI based measurements on echocardiography www.jacc.org/doi/10.1016/... #cardiosky @jaccjournals.bsky.social
September 23, 2025 at 6:15 PM
Accuracy of #AI based measurements on echocardiography www.jacc.org/doi/10.1016/... #cardiosky @jaccjournals.bsky.social
More about likelihood ratios in diagnostic testing:
Jaeschke R, et al, JAMA, 1994.
www.pubmed.gov/8309035
Jaeschke R, et al, JAMA, 1994.
www.pubmed.gov/8309035
Users' guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based Medicine Workin...
Users' guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based Medicine Workin...
www.pubmed.gov
September 19, 2025 at 1:15 AM
More about likelihood ratios in diagnostic testing:
Jaeschke R, et al, JAMA, 1994.
www.pubmed.gov/8309035
Jaeschke R, et al, JAMA, 1994.
www.pubmed.gov/8309035
Interpretation for both LR+ and ILR- in terms of how conclusive the test changes pretest to posttest likelihood of a positive (or negative) finding:
>10 = large
5-10 = moderate
2-5 = small but sometimes important
<2 = inconclusive
>10 = large
5-10 = moderate
2-5 = small but sometimes important
<2 = inconclusive
September 19, 2025 at 1:15 AM
Interpretation for both LR+ and ILR- in terms of how conclusive the test changes pretest to posttest likelihood of a positive (or negative) finding:
>10 = large
5-10 = moderate
2-5 = small but sometimes important
<2 = inconclusive
>10 = large
5-10 = moderate
2-5 = small but sometimes important
<2 = inconclusive
Inverse negative likelihood ratio (ILR-) = 1/LR- = specificity / (1-sensitivity) = 92.3% / (1-41.2%) = 1.6 = how many more times likely it is that you do NOT have the disease in question thanks to the test
September 19, 2025 at 1:15 AM
Inverse negative likelihood ratio (ILR-) = 1/LR- = specificity / (1-sensitivity) = 92.3% / (1-41.2%) = 1.6 = how many more times likely it is that you do NOT have the disease in question thanks to the test
Positive likelihood ratio (LR+) = sensitivity / (1-specificity) = 41.2% / (1-92.3%) = 5.4 = how many more times likely it is that you have the disease in question thanks to the test
September 19, 2025 at 1:15 AM
Positive likelihood ratio (LR+) = sensitivity / (1-specificity) = 41.2% / (1-92.3%) = 5.4 = how many more times likely it is that you have the disease in question thanks to the test
However, sens and spec values are highly dependent on disease prevalence in the population being studied. The measures of test performance that are independent of population disease prevalence are likelihood ratios, which tell us how many times more likely a diagnosis is after applying a test.
September 19, 2025 at 1:15 AM
However, sens and spec values are highly dependent on disease prevalence in the population being studied. The measures of test performance that are independent of population disease prevalence are likelihood ratios, which tell us how many times more likely a diagnosis is after applying a test.
In Apple’s white paper on their Hypertension Notification Feature for Apple Watch, they report low sensitivity (41.2%) and high specificity (92.3%). They rightfully chose a threshold for notification while seeking to keep the false positive rate low.
The white paper: www.apple.com/health/pdf/H...
The white paper: www.apple.com/health/pdf/H...
www.apple.com
September 19, 2025 at 1:15 AM
In Apple’s white paper on their Hypertension Notification Feature for Apple Watch, they report low sensitivity (41.2%) and high specificity (92.3%). They rightfully chose a threshold for notification while seeking to keep the false positive rate low.
The white paper: www.apple.com/health/pdf/H...
The white paper: www.apple.com/health/pdf/H...
Read on if you are interested in (the Apple Watch) diagnostic test performance.
It's all about the likelihood ratios.
It's all about the likelihood ratios.
September 19, 2025 at 1:15 AM
Read on if you are interested in (the Apple Watch) diagnostic test performance.
It's all about the likelihood ratios.
It's all about the likelihood ratios.
I still applaud Apple and think the Hypertension Notification feature will be useful for the individual and society. Any nudge that can help early identification of hypertension is valuable, especially when it is passively integrated into everyday use of a consumer device as implemented by Apple.
September 19, 2025 at 1:15 AM
I still applaud Apple and think the Hypertension Notification feature will be useful for the individual and society. Any nudge that can help early identification of hypertension is valuable, especially when it is passively integrated into everyday use of a consumer device as implemented by Apple.
In other words, you should NOT rest on your laurels and assume that you don't have hypertension. Get your blood pressure tested regularly regardless, because hypertension is very common, deadly in the long term, and highly treatable.
September 19, 2025 at 1:15 AM
In other words, you should NOT rest on your laurels and assume that you don't have hypertension. Get your blood pressure tested regularly regardless, because hypertension is very common, deadly in the long term, and highly treatable.
If you do NOT get a Hypertension Notification despite using your watch, then you are NO MORE LIKELY to be free of hypertension than before you used your watch (inverse negative likelihood ratio 1.6, which is inconclusive).
September 19, 2025 at 1:15 AM
If you do NOT get a Hypertension Notification despite using your watch, then you are NO MORE LIKELY to be free of hypertension than before you used your watch (inverse negative likelihood ratio 1.6, which is inconclusive).
If you get an Apple Watch Hypertension Notification, then you are 5 TIMES MORE LIKELY to have hypertension than if you didn't use your watch (LR+ 5.4). This is moderately useful test information. You should definitely get your blood pressure tested.
A thread..
#CardioSky
#MedSky
#Apple
#AppleWatch
A thread..
#CardioSky
#MedSky
#Apple
#AppleWatch
September 19, 2025 at 1:15 AM
If you get an Apple Watch Hypertension Notification, then you are 5 TIMES MORE LIKELY to have hypertension than if you didn't use your watch (LR+ 5.4). This is moderately useful test information. You should definitely get your blood pressure tested.
A thread..
#CardioSky
#MedSky
#Apple
#AppleWatch
A thread..
#CardioSky
#MedSky
#Apple
#AppleWatch
Very much so, in a way that has surprised me. We are currently studying this prospectively.
September 13, 2025 at 7:17 PM
Very much so, in a way that has surprised me. We are currently studying this prospectively.
Not at all. I rather like the approach, which can be done without compromising scientific rigor, as in the following paper from our group.
PubMed.gov/39846063
PubMed.gov/39846063
Advanced electrocardiography heart age: a prognostic, explainable machine learning approach applicable to sinus and non-sinus rhythms - PubMed
An explainable A-ECG Heart Age gap applicable to both sinus and non-sinus rhythm associates with cardiovascular risk, cardiovascular morbidity, and survival.
PubMed.gov
September 13, 2025 at 8:55 AM
Not at all. I rather like the approach, which can be done without compromising scientific rigor, as in the following paper from our group.
PubMed.gov/39846063
PubMed.gov/39846063
Different roles, often overlapping, all there hopefully to help.
#mentor
#coach
#supervisor
#boss
#rolemodel
#advocate
#sponsor
#MedSky
#AcademicSky
#mentorship
#mentor
#coach
#supervisor
#boss
#rolemodel
#advocate
#sponsor
#MedSky
#AcademicSky
#mentorship
August 27, 2025 at 8:25 AM
Different roles, often overlapping, all there hopefully to help.
#mentor
#coach
#supervisor
#boss
#rolemodel
#advocate
#sponsor
#MedSky
#AcademicSky
#mentorship
#mentor
#coach
#supervisor
#boss
#rolemodel
#advocate
#sponsor
#MedSky
#AcademicSky
#mentorship
In our experience, "accelerated aging" measured in years of healthy human aging is a unit of measurement that has unsurpassed clarity of understanding among the general public (patients). We need to be more 'tabloid' to get our message across, imho.
August 22, 2025 at 6:19 AM
In our experience, "accelerated aging" measured in years of healthy human aging is a unit of measurement that has unsurpassed clarity of understanding among the general public (patients). We need to be more 'tabloid' to get our message across, imho.
August 15, 2025 at 6:58 AM
August 14, 2025 at 6:45 AM
Reposted by Martin Ugander
Imaging of aortic regurgitation presented eloquently by @JoaoLCavalcante #CSANZ2025
🤝poor agreement b/t echo & CMR
💰big price to pay when AR labelled moderate
🧲use CMR to accurately assess AR
#ANZCMR #whyCMR @scmrorg.bsky.social
🤝poor agreement b/t echo & CMR
💰big price to pay when AR labelled moderate
🧲use CMR to accurately assess AR
#ANZCMR #whyCMR @scmrorg.bsky.social
August 14, 2025 at 1:24 AM
Imaging of aortic regurgitation presented eloquently by @JoaoLCavalcante #CSANZ2025
🤝poor agreement b/t echo & CMR
💰big price to pay when AR labelled moderate
🧲use CMR to accurately assess AR
#ANZCMR #whyCMR @scmrorg.bsky.social
🤝poor agreement b/t echo & CMR
💰big price to pay when AR labelled moderate
🧲use CMR to accurately assess AR
#ANZCMR #whyCMR @scmrorg.bsky.social
Reposted by Martin Ugander
Thursday #CSANZ2025 is packed with so many great meetings! I’ll be going between the imaging, heart failure and genetics meetings. Which one will you attend? @anastasiasmihaili.bsky.social @mugander.bsky.social
August 10, 2025 at 9:51 PM
Thursday #CSANZ2025 is packed with so many great meetings! I’ll be going between the imaging, heart failure and genetics meetings. Which one will you attend? @anastasiasmihaili.bsky.social @mugander.bsky.social
We don’t yet have definitive data on it, but the non-LAVI (c) formula is likely best for short-term changes in PAWP, whereas (b) is just as good in stable hemodynamics, and (a) is good enough if you haven’t acquired PV velocities.
July 20, 2025 at 12:47 PM
We don’t yet have definitive data on it, but the non-LAVI (c) formula is likely best for short-term changes in PAWP, whereas (b) is just as good in stable hemodynamics, and (a) is good enough if you haven’t acquired PV velocities.
We have actually have three formulas for estimating PAWP.
From Lindow 2024 using:
a) E + LAVI
b) E + PVs + LAVI
and from Lindow 2025 using
c) E + PVs + PVd
Their accuracy, precision and prognostic association are presented in each paper.
From Lindow 2024 using:
a) E + LAVI
b) E + PVs + LAVI
and from Lindow 2025 using
c) E + PVs + PVd
Their accuracy, precision and prognostic association are presented in each paper.
July 20, 2025 at 12:47 PM
We have actually have three formulas for estimating PAWP.
From Lindow 2024 using:
a) E + LAVI
b) E + PVs + LAVI
and from Lindow 2025 using
c) E + PVs + PVd
Their accuracy, precision and prognostic association are presented in each paper.
From Lindow 2024 using:
a) E + LAVI
b) E + PVs + LAVI
and from Lindow 2025 using
c) E + PVs + PVd
Their accuracy, precision and prognostic association are presented in each paper.
Both HFpEF and HFrEF were included. However, it was limited to those with at most mild mitral regurgitation or stenosis, and sinus rhythm.
More details are in the paper.
academic.oup.com/ehjimp/artic...
More details are in the paper.
academic.oup.com/ehjimp/artic...
Echocardiography can accurately estimate pulmonary artery wedge pressure without left atrial volume information—diagnostic and prognostic performance
AbstractAims. A quantitative estimate of pulmonary artery wedge pressure (PAWP) can be obtained using echocardiography, but including left atrial (LA) volu
academic.oup.com
July 5, 2025 at 4:13 PM
Both HFpEF and HFrEF were included. However, it was limited to those with at most mild mitral regurgitation or stenosis, and sinus rhythm.
More details are in the paper.
academic.oup.com/ehjimp/artic...
More details are in the paper.
academic.oup.com/ehjimp/artic...
Beware the Four Fallacies of (Dis)Loyalty.
In providing career guidance, mentoring and coaching to academics, aspects of loyalty and holding grudges (disloyalty) often come up. This has provided structure to some of these conversations.
#AcademicSky
#PhDSky
#LeadershipSky
#MentorSky
#CoachSky
In providing career guidance, mentoring and coaching to academics, aspects of loyalty and holding grudges (disloyalty) often come up. This has provided structure to some of these conversations.
#AcademicSky
#PhDSky
#LeadershipSky
#MentorSky
#CoachSky
June 22, 2025 at 12:16 AM
Beware the Four Fallacies of (Dis)Loyalty.
In providing career guidance, mentoring and coaching to academics, aspects of loyalty and holding grudges (disloyalty) often come up. This has provided structure to some of these conversations.
#AcademicSky
#PhDSky
#LeadershipSky
#MentorSky
#CoachSky
In providing career guidance, mentoring and coaching to academics, aspects of loyalty and holding grudges (disloyalty) often come up. This has provided structure to some of these conversations.
#AcademicSky
#PhDSky
#LeadershipSky
#MentorSky
#CoachSky
Reposted by Martin Ugander
Tirzepatide reduces LV mass and paracardiac adipose tissue, a potential mechanism for reduced HF events in SUMMIT @jaccjournals.bsky.social @chriskramermd.bsky.social www.jacc.org/doi/10.1016/...
Tirzepatide Reduces LV Mass and Paracardiac Adipose Tissue in Obesity-Related Heart Failure: SUMMIT CMR Substudy
www.jacc.org
June 18, 2025 at 1:00 PM
Tirzepatide reduces LV mass and paracardiac adipose tissue, a potential mechanism for reduced HF events in SUMMIT @jaccjournals.bsky.social @chriskramermd.bsky.social www.jacc.org/doi/10.1016/...