Aspecte imagistice în sindroamele compresive pericardice – tamponada cardiacă în patologia oncologică

Introduction

Cardiac tamponade represents a life-threatening condition characterized by impaired ventricular filling with decreased cardiac output and hemodynamic instability caused by fluid accumulation in the pericardial sac or cardiac tumor compression^(1,2,3). It can occur as initial presentation of an unknown malignancy or in patients with established tumoral pathology⁽⁴⁾. Pericardial effusion in oncologic patients can be secondary to tumor extension/metastases^(5,6), may develop as a complication to radiation and chemotherapy⁽⁴⁾, or in case of opportunistic infections⁽⁵⁾. CT imaging features of cardiac tamponade in oncologic patients include: anterior heart compression by a mediastinal tumor or loculated/large pericardial effusion⁽⁵⁾, angulation and bowing of the interventricular septum⁽²⁾, enlargement of SVC and IVC (with diameter larger than the one of thoracic aorta)⁽⁶⁾, reflux of contrast material into the IVC or azygos vein, periportal edema⁽¹⁾, compression of the coronary sinus⁽⁷⁾. CT evaluation can provide valuable information regarding the tumoral pericardial involvement and extension, and the type of pericardial effusion⁽²⁾.

Materials and method

We made a retrospective study for a period of six years (between January 2015 and April 2021), and we selected 119 oncologic patients with signs of pericardial disease, five patients with clinical, hemodynamic and CT imaging findings suggestive for cardiac tamponade. CT imaging was performed on 16 or 64 multidetector (MD) CT scanners in all cases, with one non-enhanced CT phase (NECT), to measure attenuation values of the pericardial colection and two phases in arterial (25 seconds) and delayed phase (100 seconds) post iodinated contrast material injection, at the injection ratio of 2-3 ml/s, in a quantity of approximately 1-1.5 ml/kg b.w., to evaluate pericardial thickness and enhancement, neoplastic pericardial involvement and heart structural anomalities. The physical parameters used for CT consisted in axial thickness slices of 5 mm, with 1.25 or 1.5 mm reconstruction interval. Different planes reconstructions (coronal, sagittal, oblique views) have been performed in order to have an optimal visualization of the cardiovascular structures.

Results

We selected five cases of oncologic patients (two females and three males), with ages between 14 and 50 years old, all patients with clinical, hemodynamic and CT imaging findings suggestive for cardiac tamponade. Among our patients, one female patient was diagnosed with breast cancer and the other four patients were diagnosed with hematologic malignancies (one case with acute myeloid leukemia, one case with acute lymphoblastic leukemia, one case with Hodgkin lymphoma, and one case with non-Hodgkin lymphoma). Large pericardial effusion with attenuation values between 12 and 24 UH caused cardiac compression and consecutive cardiac tamponade in three patients, and in one case pericardiocentesis revealed hemopericardium – Case 1, Figure 1. Structural heart compression by a large mediastinal tumor was found in two patients (Case 2, Figure 2, and Case 3, Figure 3), with anterior heart compression, deformity and concave appearance of the anterior cardiac wall (Case 2, Figure 2, curved arrow – a, b) and small heart sign (Case 3, Figure 3). Indirect signs of cardiac tamponade with the enlargement of SVC and IVC (with diameter larger than the one of thoracic aorta) were found in all cases. In three cases, reflux of contrast material into the IVC or hepatic veins was noted (Case 2, Figure 2, arrowhead – c). Bowing of the interventricular septum and marked coronary sinus compression, although considered important imaging signs in cardiac tamponade, were not seen in our patients. In one case, we found associated the superior vena cava syndrome.
 

Discussion

Cardiac tamponade represents a life-threatening con­di­tion, the oncologic patients with cardiac tamponade caused by malignant disease having death rates exceeding 75% within 12 months⁽⁸⁾. In oncologic patients, cardiac tamponade can be secondary to heart compression by a large pericardial effusion^(4,5) or by an invasive cardiopericardial tumor with no evidence of pericardial ef­fusion⁽²⁾. Pericardial effusion in oncologic patients can be secondary to tumoral invasion of the pericardium, as side effect to the radiation and chemotherapy, or to opportunistic infections⁽⁹⁾. Dyspnea, cough and chest pain are the most frequent symptoms of impending cardiac tamponade⁽⁴⁾. Beck’s triad, with increased jugular vein distension, small and silent heart and hypotension, is rarely encountered in case of tumoral pericarditis^(9,10). In our patients, moderate to severe dyspnea was the most frequent symptom. Electrocardiography most often reveals ST-T changes and low QRS voltages^(4,11); in our patients, three of them presented ST-T changes and tachycardia. CT imaging signs suggestive for an impending cardiac tamponade are: cardiac compression by pericardial effusion, more common with fast fluid accumulation⁽¹⁾ (Case 1, Figure 1), flattened heart – anterior heart compression by a mediastinal tumor (Case 3, Figure 3), deformity with reduction of the anteroposterior cardiac diameter (Case 2, Figure 2) loculated/large pericardial effusion – in three of our patients (Case 1), angulation and bowing of the interventricular septum⁽²⁾, enlargement of SVC and IVC (with diameter larger than the thoracic aorta)  – seen in all our patients, reflux of contrast material into the IVC or azygos vein (Case 2, Figure 2; Case 3, Figure 3). According to literature, compression of the coronary sinus⁽⁷⁾ and bowing of the interventricular septum⁽²⁾, described as another signs of impending cardiac tamponade, were not seen in our patients’ CT examinations. Based on attenuation measurement, CT provides information about the posible nature of the pericardial effusion⁽²⁾; high density values and a density greater than that of skeletal muscle suggest haemorragic pericarditis⁽¹²⁾. All these imaging findings, in the presence of a large pericardial effusion, can strongly suggest an impending cardiac tamponade⁽²⁾, therefore timely therapeutic intervention is mandatory in oncologic patients in proper clinical scenarios.

Conclusions

Although a rapid assessment of patients with clinical signs of impending cardiac tamponade is best made with echocardiography, in malignancies CT examinations provide valuable and supplementary information regarding the tumoral pericardial involvement and extension, the type of pericardial effusion and cardiac structural changes, with implications for the therapeutic choice regarding the opportunity of pericardiocentesis or pericardiectomy.