Echocardiographic Pattern of Acute Pulmonary Embolism: Analysis of 511 Consecutive Patients

Katarzyna Kurnicka, MD, PhD, Barbara Lichodziejewska, MD, PhD, Sylwia Goliszek, MD,
Olga Dzikowska-Diduch, MD, Olga Zdonczyk, MD, Marta Kozlowska, MD, Maciej Kostrubiec, MD, PhD,
Micha1 Ciurzynski, MD, PhD, Piotr Palczewski, MD, PhD, Katarzyna Grudzka, MD, Marcin Krupa, MD,
Marcin Koc, MD, and Piotr Pruszczyk, MD, PhD, Warsaw, Poland

Abstract

Background: There is no comprehensive analysis of transthoracic echocardiographic findings of pulmonary embolism (PE). The aim of this study was to assess the frequency of right ventricular (RV) dysfunction (RVD), typical echocardiographic signs of acute PE (TES), and incidental abnormalities.

Methods: A single-center, retrospective analysis was conducted of 511 consecutive patients (281 women; mean age, 64.0 6 18.6 years) with PE confirmed by contrast-enhanced multidetector computed tomography who underwent transthoracic echocardiography for the assessment of left ventricular and RV alterations. The McConnell sign, the ‘‘60/60’’ sign, and right heart thrombus were regarded as TES. RVD included RV free wall hypokinesis and RV to LV end-diastolic ratio>0.9. Incidental echocardiographic alterations were also reported.

Results: RV enlargement, RV free wall hypokinesis, and interventricular septal flattening were found in 27.4%,26.6%, and 18.4% of patients, respectively. Tricuspid regurgitation peak systolic gradient > 30 mmHg and pulmonary ejection acceleration time < 80 msec were measured in 46.6% and 37.2% of patients, respectively. RVD was found in 20.0% of patients, while normal RV function was present in 33.4% of patients. The McConnell sign, 60/60 sign, and right heart thrombus were found in 19.8%, 12.9%, 1.8% of subjects, respectively. All 16 hemodynamically unstable patients with PE presented enlarged hypokinetic right ventricle and at least one TES. However, in three of them, RV to LV end-diastolic ratio was <0.9. Incidental abnormalities were found in 9.6% of 364 stable patients with PE without RVD and TES.

Conclusions: Transthoracic echocardiography showed no significant abnormalities suggestive of PE in 71% of patients with PE, while in approximately 10%, transthoracic echocardiography revealed incidental findings. The coexistence of an enlarged hypokinetic right ventricle with the McConnell sign together with the 60/60 sign seems to be the most useful echocardiographic criterion for RVD. (J Am Soc Echocardiogr 2016;29:907-13.)

Review

by Frederick Conlin M.D.

It has long been said that echo can suggest the diagnosis of PE but should not be relied upon unless a mobile thrombus in transit is visualized. Here the authors retrospectively sought to investigate the likelihood of having a suggestive echocardiographic sign of PE in patients who experienced documented PE. In 71% of subjects with PE, TTE may provide no clues for PE, or even approximately 10% of them may show potentially deceiving comorbidities, which could falsely redirect the diagnostic process and make the proper diagnosis of PE more difficult or even lead to its being overlooked. This confirms these long held beliefs. Echocardiography, be it in the OR, the PACU, or on the floor, may be a helpful adjunct but should not be relied upon as the only tool for the diagnosis of acute PE.

It was interesting to note that the authors stated all hemodynamically unstable patients with PE had an enlarged and hypokinetic right ventricle with at least one typical echocardiographic sign of PE suggesting that these may be late and ominous signs in the progression of PE although that was not validated with any outcomes in the study.

While this was a retrospective post hoc analysis at only one center the number of 511 is impressive. It should be noted that some of the echocardiograms (94) occurred more than 24 hours after admission or diagnosis. While it is possible that some of the acute signs of PE may not be present this far out from the event, given the low frequency of echocardiographic signs of PE overall it is unlikely this would change the result of the study significantly.