Disturbed Right Ventricular Ejection Pattern as a New Doppler Echocardiographic Sign of Acute Pulmonary Embolism

Kurzyna. Am J Cardiology 2002;90:507-511

Clinical Question

• In patients with suspected acute pulmonary embolism, do echo features of disturbed right ventricular ejection allow accurate diagnosis?

Background

• In patients with acute pulmonary embolism (APE), right ventricular (RV) pressure overload often occurs which can be detected by echocardiography. In patients with pre-existing cardiorespiratory disease the presence of RV overload may be chronic
• A retrospective study suggested that in patients with pre-existing pulmonary hypertension the 60/60 sign may be able to aid in the correct diagnosis of APE
• This study investigated whether the 60/60 sign and McConnell’s sign are useful diagnostic tools in the assessment of suspected APE in patients with and without pre-existing cardiorespiratory disease

Design

• Prospective observational diagnostic cohort
• Consecutive patients
• Not stated if assessors of test of interest were blinded to results of gold standard investigation
• Statistical analysis
  • Differences between groups compared with Student’s t test or Mann’s U test
  • Differences between categorical variables assessed with Pearson’s chi-square test with Yates’ correction when required

Setting

• Single tertiary pulmonary medicine referral centre, Poland
• Dates of data collection – not documented

Population

• Inclusion criteria: Clinical suspicion of acute pulmonary embolism following clinical assessment including history, examination, arterial blood gases, chest x-ray and ECG
• Exclusion criteria:
  • Time from onset or aggravation of symptoms to study enrolment >14 days
• 100 patients included
  • 57 male, 43 female
  • Age (mean): 61 years ±15 years
  • 54 patients had known previous cardiorespiratory disease, including 23 patients with diagnosed/suspected COPD, and 17 patients with congestive heart failure
  • 62 patients assessed in the intensive care unit

Tests of Interest

• Trans-thoracic ECHO
  • 60/60 sign
    • Pulmonary valve acceleration time ≤60ms and tricuspid regurgitation pressure gradient ≤60mmHg
  • McConnell sign
    • Normokinesia +/or hyperkinesia of the apical segment of the RV free wall despite hypokinesia +/or akinesia of the remaining parts of the RV free wall
  • Signs of RV pressure overload, defined as 1 or more of the following signs
    • Right sided cardiac thrombus
    • RV diastolic dimension on parasternal view of >30mm or a ratio of RV to left ventricle of >1
    • Systolic flattening of the interventricular septum
    • Pulmonary valve acceleration time <90ms or tricuspid regurgitation pressure gradient >30mmHg in absence of RV hypertrophy

Gold Standard Investigation

• APE diagnosed with
  • Spiral CT, n=63 (5mm thick sections, 5mm/s table feed, secondary reconstruction of overlapped images at 3mm intervals)
  • High-probability lung perfusion scan, n=1
  • Pulmonary angiography, n=1
  • Surgery, n=1
  • Autopsy, n=1
• APE excluded based on
  • Negative CT and negative venous compression ultrasound, n=20
  • Negative lung perfusion scan, n=10
  • Autopsy, n=3
• Mortality assessed at 1 month

Outcome

• APE confirmed in 67 patients
  • 60/60 sign
    • Diagnosed 17/67 patients correctly with APE
    • 2 false positives (lung fibrosis n=1, ARDS post bi-lobectomy, n=1)
  • McConnell Sign
    • Diagnosed 13/67 patients correctly with APE
    • No false positives
  • RV pressure overload
    • Diagnosed 54/67 patients correctly with APE
    • 18 false positives

• In patients without known previous cardiorespiratory diseases, the 60/60 sign and McConnell’s sign were 100% specific for the diagnosis of APE

• In patients with APE, comparing patients with a +ve 60/60 sign vs. a –ve 60/60 sign, significant difference in:
  • Hypoxaemia: PaO2: 51mmHg vs. 60mmHg, p=0.01
  • Collapsibility of inferior vena cava: 19% vs. 33%, p=0.02
• ECHO features in patients with vs. without APE
  • RV diameter (mm) measured in parasternal long axis view: 31 vs. 28, p=0.01
  • RV:LV ratio: 0.72 vs. 0.63, p=0.04
  • Septal flattening: 36% vs. 12%, p=0.02
  • Tricuspid regurgitation pressure gradient (mmHg): 41 vs. 28, p=0.01
  • Pulmonary valve acceleration time: 73ms vs. 95ms, p<0.0001
  • Inferior vena cava expiratory diameter: 18mm vs. 16mm, p=0.06
  • IVC collapsibility index: 28% vs. 36%, p=0.22

Authors’ Conclusions

• The 60/60 sign and McConnell signs are reliable but not sensitive signs of APE

Strengths

• Consecutive patients
• Prospective
• Appropriate gold standard

Weaknesses

• Population studied from single tertiary pulmonary referral centre with very high prevalence of APE. This limits the external validity
• Not stated if assessors of test of interest blinded to gold standard investigation
• No sample size calculation

The Bottom Line

• In patients seen at a tertiary referral centre with a high pre-test probability of acute pulmonary embolism, the McConnell Sign had a very high positive likelihood ratio. In patients without previous cardiorespiratory disease the 60/60 sign also demonstrated a very high positive likelihood ratio. A negative McConnell or 60/60 sign added little diagnostic information
• In patients presenting to the ED/ICU with a high probability of acute pulmonary embolism who cannot immediately undergo CT, I will use bedside echo to assess the 60/60 and McConnell’s signs. A positive test result will give me greater confidence for the diagnosis of acute pulmonary embolism, where as a negative result will neither help confirm or repute the diagnosis of acute pulmonary embolism

External Links

• [article] Disturbed right ventricular ejection pattern as a new Doppler echocardiographic sign of acute pulmonary embolism
• [further reading] ECHOPRAXIS – An Echo in PE
• [further reading] Echocardiographic Pattern of Acute Pulmonary Embolism: Analysis of 511 Consecutive Patients
• [further reading] Ultrasound of the week: Pulmonary embolism

Metadata

Summary author: Dave Slessor
Summary date: 10/09/2017
Peer-review editor: Steve Mathieu