Lung Ultrasound

During Stress Echocardiography

Atul Jaidka | TGH Echo Rounds

Index

Background

Why

Lung US

Picano E, et al. (2018) Lung Ultrasound for the Cardiologist. JACC Cardiovasc Imaging 11:1692-705.

• Simple, noninvasive, radiation-free and semi-quantitative tool

Why Lung Ultrasound

Lichtenstein DA; Mezière GA. (2008) Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest 134:117-25.

Lichtenstein D. (2014) Lung ultrasound in the critically ill. Curr Opin Crit Care 20:315-22.

A lines:

• Horizontal repetitions of the pleural lines

Profiles

B lines:

• Comet tail artifact
• Arise from pleura
• Move with respirations
• Erase A-lines

C Profile (Consolidation):

• Non-aerated, fully consolidated lung has the appearance of liver
• "Hepatization"

Jaidka, AK. https://echoguide.ca/.

• Artifact generated in alveolar-interstitial syndromes
• Etiology depends on associated features and whether they are focal or bilateral

B-lines

Arntfield R, et al. (2021). BMJ Open 11:e045120.

Kagami K, et al. (2023). Eur Heart J Cardiovasc Imaging 24:553-61.

• B-lines measured by LUS have been shown to correlate with NT-proBNP, PCWP, and MPAP
• B-lines have prognostic value in patients with HF

Pulmonary Congestion + B Lines

Szabó IA, et al. (2022) Prognostic Value of Lung Ultrasound in Aortic Stenosis. Front Physiol 13:838479.

Imanishi J, et al. (2023) Association between B-lines on lung ultrasound, invasive haemodynamics, and prognosis in acute heart failure patients. Eur Heart J Acute Cardiovasc Care 12:115-23.

ASE/ESC Guideline:

• In both patients with preserved or reduced LVEF, the presence and the amount of B-lines (lung comets) likely correlate with the estimated LV filling pressure and the presence of pulmonary interstitial edema.
•  The demonstration of B-lines during exercise SE seems a feasible way for demonstrating that exertional dyspnoea is related to pulmonary congestion.

Stress Echo + B Lines

Lancellotti P, et al. (2016) The clinical use of stress echocardiography in non-ischaemic heart disease: recommendations from the European Association of Cardiovascular Imaging and the American Society of Echocardiography. Eur Heart J Cardiovasc Imaging 17:1191-229.

Stress Echo + B Lines

Lancellotti P, et al. (2016) The clinical use of stress echocardiography in non-ischaemic heart disease: recommendations from the European Association of Cardiovascular Imaging and the American Society of Echocardiography. Eur Heart J Cardiovasc Imaging 17:1191-229.

Protocols

• No consistency in protocols, ranging from 4-28 points

Non-Stress Protocols

• 135 patients referred for CAD or HF
• Comparing different protocols
• Top 3 "wet" spots all 3rd IS
• Good agreement with 4-S and 28-S but reduced scan time from 140s to 20s

Stress Protocol

Scali MC, et al. (2020) Lung Ultrasound and Pulmonary Congestion During Stress Echocardiography. JACC Cardiovasc Imaging 13:2085-95.

• Used in subsequent Stress Echo 2020/2030 studies
• Cardiac transducer
• Perpendicular to ribs
• 18cm depth
• 6s clips

Simplified Protocol

Scali MC, et al. (2020) Lung Ultrasound and Pulmonary Congestion During Stress Echocardiography. JACC Cardiovasc Imaging 13:2085-95.

Acquisition

Example Acquisition

Jaidka A, Myslik J. POCUS Rapid Review: Lung Blue Protocol. Available at https://www.youtube.com/watch?v=FS9FztSI460

Example Acquisition

Picano E, et al.. Stress lung Ultrasound stress echo2020.2019. Available at https://www.youtube.com/watch?v=BwzgoG15E_A

Scoring Patients

Scali MC, et al. (2020) Lung Ultrasound and Pulmonary Congestion During Stress Echocardiography. JACC Cardiovasc Imaging 13:2085-95.

• 4 zone protocol
• Score each zone from 0-10 B-lines and sum 4 zones
• Report total at rest and stress and interval change
• Stress B-lines are categorized as:
  • absent (score points 0 to 1), mild (2 to 4), moderate (5 to 9), and severe (≥10 points)

Case

Case

• RFR: dyspnea
• 58-year-old female
• PHT 141 ms, MVA 1.6 cm2
• Mild to moderate regurgitation

Wiley BM, et al. (2020) Lung Ultrasound During Stress Echocardiography Aids the Evaluation of Valvular Heart Disease Severity. JACC Cardiovasc Imaging 13:866-72.

Case

Wiley BM, et al. (2020) Lung Ultrasound During Stress Echocardiography Aids the Evaluation of Valvular Heart Disease Severity. JACC Cardiovasc Imaging 13:866-72.

Case

Wiley BM, et al. (2020) Lung Ultrasound During Stress Echocardiography Aids the Evaluation of Valvular Heart Disease Severity. JACC Cardiovasc Imaging 13:866-72.

Case

• B-lines are a result of dynamic elevation in LA pressure due to mixed MR/MS
• MV disease causing exercise induced pulmonary edema, in combination with increase in MG and RVSP, helps classify valve as hemodynamically severe
• Patient underwent MVR post stress test

Wiley BM, et al. (2020) Lung Ultrasound During Stress Echocardiography Aids the Evaluation of Valvular Heart Disease Severity. JACC Cardiovasc Imaging 13:866-72.

Disease States

• Pulmonary congestion during Exercise stress Echocardiography in Hypertrophic Cardiomyopathy
• 128 patients with non-obstructive HCM
• B-lines present in 10% at rest and 30% at stress
• Patients with stress B-lines had higher rest/peak E/e', rest/peak SPAP, and increased increment in MR
• B-lines at rest and during stress in HCM may help to identify a pulmonary congestion phenotype
  • Possibly direct diuretic usage

Hypertrophic Cardiomyopathy

Pálinkás ED, et al. (2022) Pulmonary congestion during Exercise stress Echocardiography in Hypertrophic Cardiomyopathy. Int J Cardiovasc Imaging 38:2593-604.

Hypertrophic Cardiomyopathy

Pálinkás ED, et al. (2022) Pulmonary congestion during Exercise stress Echocardiography in Hypertrophic Cardiomyopathy. Int J Cardiovasc Imaging 38:2593-604.

• Prognostic Value of Lung Ultrasound in Aortic Stenosis
• 75 patients with mod-severe AS
• B-lines were significantly correlated with NYHA functional class, LV ejection fraction, and pulmonary artery systolic pressure
• Patients were followed for 13.4 ± 6 months and a higher number of B-lines was associated with HF-related adverse events and death

Valvular Disease

Szabó IA, et al. (2022) Prognostic Value of Lung Ultrasound in Aortic Stenosis. Front Physiol 13:838479.

• Incremental diagnostic value of post-exercise lung congestion in heart failure with preserved ejection fraction
• 134 patients with HFpEF and 121 controls
  • Stress echo with B-line assessment at each stage
• B-lines were most prominent during early recovery
• This and other recent studies have shown improved diagnostic accuracy when B-lines are paired with HFpEF scores (H2FPEF and HFA-PEFF)

HFpEF

Coiro S, et al. (2023) Exercise-induced B-lines for the diagnosis of heart failure with preserved ejection fraction: a two-centre study. Clin Res Cardiol.

Kagami K, et al. (2023) Incremental diagnostic value of post-exercise lung congestion in heart failure with preserved ejection fraction. Eur Heart J Cardiovasc Imaging 24:553-61. 

Wrap-up

• B-lines are not specific to pulmonary congestion
  • ie. cannot use in patients with ILD
• No consensus on protocol or interpreting results
  • No defined cutoff for abnormal LVEDP

Limitations

• Consider lung ultrasound when pulmonary congestion during stress is a consideration
• 4 zones - all in the 3 intercostal space
  • Only adds 20 seconds
• Sum B-lines and stress B-lines >10 is likely significant

Take Home Points

THANK YOU

Happy to answer any questions!