Correspondence

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American Journal of Emergency Medicine

journal homepage: www. elsevier. com/ locate/ajem

A handy echocardiographic marker in Acute pericarditis: echo probe sign

To the Editor,

Five percent of all causes of chest pain in the emergency service is related with acute pericarditis [1]. A clinical diagnosis of acute pericardi- tis can be made according to the 2015 European Society of Cardiology (ESC) guidelines [2]. Because of ST-segment elevation or T inversion in electrocardiogram (ECG), acute pericarditis can be confused with acute myocardial infarction with ST elevation, early repolarization, and myocarditis [3-6]. Especially in young patients, differential diagnosis of acute pericarditis can be extremely difficult, and different practical methods or tools may sometimes be necessary in the differential diagnosis. This study suggests a handy echocardiographic tool in acute pericarditis at emergency admission in addition to the presence or absence pericardial effusion in echocardiography.

Among 102 patients admitted to the emergency department, 52 pa- tients were diagnosed with acute pericarditis (group I) according to the ESC guidelines of pericardial diseases. Fifty patients were in the normal control group (group II). The control group had Atypical chest pain (myalgia). The patients with painful chest skin lesions, those with chest trauma history, and those patients older than 50 years (osteoporosis pos- sibility) were excluded. Both groups were evaluated by Transthoracic echocardiography in the emergency department at the bedside. TTE was performed by 2 blinded cardiologists. Both groups were investi- gated in terms of impaired segmental wall-motion abnormalities, pericar- dial effusion, and the sensitivity to echo probe-induced chest pain by TTE.

1. Definition of echo probe sign

The pressure effect of echocardiographic probe used in TTE was taken into consideration during echocardiography procedure, in which the patients felt the pain only in the fifth left intercostal space at the midclavicular line (Fig. 1).

When the probe-induced chest pain occurred in the fifth intercostal space, echo probe sign was accepted as positive. We assume that this pain occurred in this region only for this region is the closest point to the outer surface of the chest. We called this echo probe sign because of its resemblance to sonographic Murphy sign in acute cholecystitis [7,8]. To standardize the amount of pressure, double-blind technique was used. When cardiac cellular damage or death occurs in acute pericarditis, pain fibers (visceral afferents) are stimulated. These visceral sensory fibers fol- low the course of sympathetic fibers. At T1 and T4 levels, both types of af- ferents (visceral and somatic) synapse with interneurons and then ascend to the somatosensory areas of the brain that represent the T1 to T4 levels.

When inflammation develops in pericardium, tenderness occurs in the

fifth intercostal space during the examination with echo probe sign.

Patient characteristics and outcomes of the patients were investigated. Continuous variables and categorical variables were

compared by Mann-Whitney U test. All the data were analyzed using SPSS 17.0 statistical software. Significance level was set at P b .5.

The pericardial friction rub was detected in 26 patients with acute peri- carditis (50%). ST-elevation in ECG was observed in 52 patients in group I (9 patients in inferior derivations [D2, D3, aVF], 30 patients in anterior deri- vations [V2-V6], 7 patients in lateral derivations [D1, aVL]). Six patients had only PR depression or elevation in ECG (stage II acute pericarditis). In both groups, cardiac enzyme follow-ups (creatine kinase [CK], CK-MB, and tropo- nin) were followed. The etiology of the acute pericarditis was thought to be viral infection because no viral serology test was administered.

Pericardial effusion sensitivity was found to be 81%, and pericardial effusion specificity was 65.5% in acute pericarditis.

The echo probe sign was observed in acute pericarditis patients only. The presence of echo probe sign was both sensitive (90%) and specific (86.7%) in acute pericarditis. Positive predictive rate was 88.3% (Fig. 2). Acute pericarditis is a common disease caused by inflammation of the pericardium, a generally benign progress [5]. Acute pericarditis diagnosis should have at least 2 of the 4 criteria according to the 2015 ESC guide- lines of pericardial diseases, which are characteristic chest pain (sharp pain), pericardial friction rub, pericardial effusion in echocardiography, and typical electrocardiogram changes (concave ST-segment elevation and PR-segment depression or elevation) [2]. Inflammatory markers to support diagnosis include leukocyte count, C-reactive protein level, and

test of myocardial injury (cardiac troponin levels and CK level).

The present study showed a handy sign for acute pericarditis diagnosis in addition to absence or presence pericardial effusion. This handy sign is based on inflamed organ tenderness. The heart apex is directed downward, forward, and to the left, and is overlapped by the left lung and pleura. The anterior facies of the heart lies behind the fifth left intercostal space. Similarly, when echocardiographic probe contacts the patient in the fifth intercostal space in the midclavicular line, if pain occurs, echo probe sign is accepted as positive.

In conclusion, the pressure effect of echocardiographic probe used in TTE can be taken into consideration during echocardiography procedure. This sign can be considered as a clinically handy method in the differential diagnosis of acute pericarditis.

Ersin Saricam, MD? Yasemin Saglam, MD

Cag Hospital and Medicana International Ankara Hospital, Cardiology

Clinic, Ankara, Turkey

?Corresponding author. Medicana International Ankara Hospital Sogutozu District 2165 St No. 6, Sogutozu, Ankara, Turkey Tel.: +90 5324066440; fax: +90 3122203170

E-mail addresses: [email protected],

[email protected]

http://dx.doi.org/10.1016/j.ajem.2016.06.053

0735-6757/(C) 2016

Fig. 1. Locating the point of pain during the echocardiographic procedure (Echo probe sign).

Fig. 2. ROC Curve for echo probe sign sensitivity and specifity.

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