Extended Abstract
1. Introduction
Tuberculosis (TB) cases has considerably declined in industrialized countries in recent years; however, Asia, Africa, and Latin America, with 86% of the world's population, account for 95% of active TB cases. TB pericarditis, caused by mycobacterium TB, has been detected in almost 1% of all dissected TB cases [1]. Pericardial effusion is a fluid in the space between the heart and the pericardial membrane that fills the pericardial sac. It could be generated by issues, such as heart attack, heart failure, kidney failure, infection and malignancy, and myocardial infarction. The thickness of >4 mm of pericardial fluid should be considered abnormal. This is because due to the limited space of pericardium, if not managed promptly and timely, it could impose pressure on the heart and cause tamponade [3]. The prompt treatment of TB pericarditis could be life-saving. Therefore, effective treatment requires a quick and accurate diagnosis for the disease, i.e. often difficult. The presented case was a patient with TB pericarditis whose condition had led to severe pericardial effusion.
2. Case report
The patient was an 85-year-old man who complained of weakness, lethargy, dizziness, and shortness of breath for >5 days. He reported no vomiting, sweating, or nausea; however, in the last few days, he experienced fever and shortness of breath. No specific case was reported in his family history, and there was no history of TB. Clinical findings were as follows: Pulses were full and symmetrical, organs lacked edema and cyanosis, vague heart was sound, there was a swelling of the jugular vein, as well as a wheezing sound in the right lung. Vital signs of the patient at the time of referral included blood pressure: 11.8 mmHg, pulse: 78 bpm, and body temperature: 38° C. Test results were as follows: Hemoglobin 12.5 gr/dL, RBC : 4.91 M/uL, WBC: 11.6 thousand per mL, platelet: 328 thousand, and ESR: 50 mm/h. A sinus tachycardia was observed on the patient's ECG and a cardiomegaly was detected on his chest (Figure 1). Initially, we performed an echocardiogram and received a report of severe pericardial effusion of 28 mm. Then, the patient was nominated for emergency pericardiotomy and the evacuation of pericardial effusion. Surgical incisions were conducted in the subxiphoid region and pericardial fluid was drained at 500 CC. The patient was implanted with a drain and transferred to the Cardiac Intensive Care Unit (CICU). The patient was prescribed cefazolin 1 g every 6 hours and clindamycin 600 g every 8 hours. Then , he was discharged after his symptoms of shortness of breath, fever, and white blood cell decreased and his general condition improved. The pericardial fluid and tissue sample was provided for pathology; accordingly, the response to the pericardial fluid sample was transferred for TB diagnosis and a Polymerase Chain Reaction (PCR) test was performed. 
3. Discussion
Tuberculous pericarditis is the most frequent cause of pericarditis in Africa and other countries where TB remains a major problem. According to reports, TB accounts for 4% of acute pericarditis and 7% of cardiac tamponades. Moreover, the rate of TB mortality ranges between 14% and 40% [4]. Chest radiography suggested heart enlargement in 90% of cases, and the ECG is abnormal in tuberculous pericarditis. Heart enlargement was detected in the patients’ chest CT scan; however, no sinus tachycardia was observed in the patient's ECG [1]. The pericardial effusion of >2 cm could lead to fatal cardiac tamponade; therefore, it is necessary to take emergency action in a timely manner in this regard. According to the echocardiography report which mentioned 28 mm thickness of the pericardial effusion, as well as the clinical history, the presented patient had severe tamponade; however, his life was saved by a quick and effective operation. 
Pericarditis usually presents with the symptoms of shortness of breath and sharp chest pain, and decreases with leaning forward while sitting. Pericardial abrasion may also be heard; however, this condition becomes non-obvious when fluid accumulates. The clinical manifestations of TB pericarditis are varied and unexplained. Besides, fever, fatigue, and weight loss are among the disease symptoms; however, the most common symptoms include cough, chest pain, and dyspnea [1].
Cardiac tamponade occurs when fluid accumulates in the pericardial space faster than its absorption rate in the pericardial sac. Subsequently, it could dilate and put a lot of pressure on the heart. This condition could be caused by a heart attack, heart failure, kidney failure, infection and malignancy, and myocardial infarction. The symptoms of tamponade include hypotension, swelling of the jugular vein, and a vague and complicated heart sound; the last two of which were present in our case [3].
In addition to the patient's clinical symptoms, echocardiography, and chest X-ray, PCR is applied to diagnose pericardial effusion. The rates of >40 U/L is considered active [4], i.e. positive in our case due to this level (ADA: 58.4 IU/L). However, an early and accurate diagnosis of this disease reduced the patient’s symptoms and improved his condition. Medications used for TB pericarditis include 4 standard anti-tuberculous drugs for a period of 6 months. Furthermore, daily prednisolone for at least two to three weeks is suggested, which was also prescribed for our patient.

4. Conclusion
Tuberculous pericarditis is a rare manifestation of TB. Given that it remains a deadly disease with high morbidity, early diagnosis and immediate action could prevent its symptoms and complications. Thus, PCR testing may be necessary for patients with pericardial effusion. Furthermore, some TB medications, like isoniazid, alone could cause pericarditis without fever.
Ethical Considerations
Compliance with ethical guidelines
All ethical principles were considered in this article. 
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or non-profit sectors.
Authors' contributions
All authors contributed in designing, running, and writing all parts of the research.
Conflicts of interest
The authors declared no conflict of interest