Spontaneous pneumopericardium due to exertion. (Case Report).

Abstract: We report the unique case of a patient with an idiopathic pneumopericardium due to heavy lifting and discuss Valsalva's maneuver as a rare cause in the pathogenesis of pneumopericardium. Our patient recovered without treatment and had no recurrence of pneumopericardium during follow-up. All physicians should be aware of pneumopericardium as a possible cause of chest pain, especially when no trauma is visible. Pneumopericardium may also be an occasional complication of pneumothorax and pneumomediastinum.

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Pneumopericardium can be an occasional complication of pneumothorax and pneumomediastinum. In reviewing the literature, we found no mention of physical exertion involving manual labor as a cause of pneumopericardium. We report the case of a patient who had pneumopericardium and discuss the role of Valsalva's maneuver in the pathogenesis.

Case Report

A 30-year-old man came to the emergency room because of a sudden onset of left-sided chest pain without radiation after carrying heavy furniture. He also had dyspnea. There was no bradycardia or tachycardia, cyanosis, pulsus paradoxus, fever, hypotension, or shock. His history was completely uneventful, and he had never had asthmatic attacks. He took no medications and denied drug abuse. Auscultation and electrocardiogram were unremarkable. Laboratory values including complete blood count were within normal limits, with a creatine kinase level of 89 U/L. A chest x-ray film disclosed pneumomediastinum and pneumopericardium (Fig. 1), which was confirmed by computed tomography (Fig. 2). There was no evidence of other abnormalities. Gastrografin swallow, esophagogastroscopy, and a bronchoscopy showed no leak or any other abnormality. No special supportive measures such as sedation, analgesics, or antibiotics and no interventions such as pericardiocentesis were necessary. Repeated chest films showed progressive re solution of the air in the pericardial sac and the mediastinum, and the patient was discharged. There was no recurrence of pneumopericardium during follow-up.

Discussion

Pneumopericardium is defined as a collection of air or gas in the pericardial cavity and was first described by Bricheteau in 1844. (1) Many cases have since been reported, mostly due to blunt or penetrating chest injuries in adults (1,2) and due to respiratory distress syndrome combined or not with mechanical positive pressure ventilation in infants. (1,3,4) Other reported causes are pyopneumopericardium due to infected fluid in the pericardial sac, (1-3) perforated benign or malignant ulcers with bronchopericardial, esophagopericardial, and gastropericardial fistulae, (1-3,5,6) foreign body aspiration, (3) and amebic abscess of the liver. (1) Iatrogenic causes have included sternal bone marrow puncture, (1,7) thoracic surgery, (2,3) thoracocentesis and pericardiocentesis, (1,3,7) dental extraction, (2) endoscopic procedures, (2) and laparoscopy. (2) Symptoms of pneumopericardium include chest pain, dyspnea, cyanosis, hypotension, bradycardia or tachycardia, and pulsus paradoxus. (1-3,5,7) On auscultation, a mill wheel murmur (bruit de moulin) is characteristic, caused by the movement of the heart with fluctuation of air and fluid. (1,3) In the absence of fluid, a metallic sound of high frequency is heard, (3,6) and muffled heart sounds have also been described. (4,5) On percussion, precordial tympany shifting with position is characteristic but not found in all cases. (1-3) Hamman's sign with mediastinal crepitation caused by an accompanying pneumomediastinum can occur occasionally. (2,6,7)

Electrocardiogram can show elevated ST segments and low voltage. (1,2,8) An echocardiogram is valuable to demonstrate accompanying pericardial effusion and can show intra-pericardial spontaneous contrast echoes. (6,8,9) In some reports on pneumopericardium, inability to view the heart through echo-cardiographic windows was noted. (6,9) In our case, echocardiography was not useful in evaluating the heart because of interfering air.

Gas surrounding the heart may be confused with pneumomediastinum. (1) Therefore, studies other than posteroanterior roentgenograph are helpful to distinguish pneumopericardium from pneumomediastinum: A left-side-down decubitus radiograph will show a rapid shift of air in the pericardial sac, while air in the mediastinum will not move in the short interval between films. (1,2,7,10) The transverse band of air sign (air in the transverse sinus of the pericardium) (2,10) and the triangle of air sign (a hyperlucency behind the sternum, anterior to the cardiac base and the aortic root) (2,10) are useful in distinguishing pneumopericardium from pneumomediastinum. A radiolucent band of air partially or completely surrounding the heart in pneumopericardium (halo sign) does not extend above the upper limit of the pericardial reflection in the erect position, and thus the air is confined to below the aortic arch. (2,10) In usual pneumopericardium, an enlarged cardiac shadow can be found, whereas in tension pneumopericar dium; the small heart sign with a decreased cardiothoracic ratio on serial chest films can be seen. (2,6)

Computed tomography (CT) can also demonstrate pneumopericardium. (3,5) In infants, transillumination is reported to be useful in the diagnosis. (4) Endoscopic and contrast examinations are useful when an ulcer or a fistula is supposed. (11)

Clinical differential diagnoses include angina pectoris, myocardial infarction, aortic dissection, pericarditis, pneumonitis, pneumothorax, and pulmonary embolism. (9) A life-threatening tension pneumopericardium can be a complication that can be caused by a valve mechanism that allows the air to enter the pericardial sac but not to exit it. (6) Cardiac tamponade then results in decreased cardiac output and circulatory failure. (1,4,7) Pneumopericardium can be accompanied by subcutaneous emphysema, pneumomediastinum, pneumothorax, and pncumoperitoneum. (1,4,5,9,12)

Treatment in symptomatic pneumopericardium include immediate needle aspiration and insertion of a tube for continuous pericardial drainage. (1,2,12) In some cases, an emergency thoracotomy and pericardiotomy has been described. (2) Surgical interventions are necessary in cases of an underlying ulcer or fistula. (7) Oxygen therapy at high concentration can support the resorption of the air. (13) Furthermore, treatment can include bed rest, observation, sedation, analgesics, antibiotics, (5,9) and in ventilated patients a reduction of positive end-expiratory pressure (PEEP) and peak inflation pressure (PIP). (4,12,13) A small pneumopericardium without signs of tamponade and with low risk of recurrence needs close observation but usually no specific treatment, because the air will be absorbed spontaneously within 2 weeks, as in our case. (7,9)

The pathogenesis of pneumopericardium is probably an increase in intra-alveolar pressure with alveolar overdistention that results in rupture of alveolar walls, allowing air to travel through the pulmonary interstitium along perivascular sheaths to the lung hilum and mediastinum and to the pericardial reflection. (1,2,8) Pericardial connective tissue is discontinuous at the reflection of parietal onto visceral pericardium near the ostia of the pulmonary veins so that there is a site of potential weakness where a microscopic dissection of air into the pericardial sac is possible. (1-3,7,9) Thus, it can be assumed that in the patient described here an increase in intra-alveolar pressure due to Valsalva's maneuver with forced expiration against a closed glottis in heavy lifting was the cause of pneumopericardium. Other cases without an obvious or detectable cause of air leakage suggest Valsalva's maneuver associated with exertion as a reason for increased intrabronchial and intra-alveolar pressure resulting in a lveolar rupture and idiopathic pneumopericardium, as well as asthmatic attacks, (7) childbirth, (9) dancing, (5) diving, (14) morning sickness during pregnancy, (14) cocaine inhalation by special positive-pressure sniffing techniques, (8) and marijuana smoking. (8) Moreover, congenital defects can be an explanation for pneumopericardium: The absence of the left pericardium is more common than that of the right side or of the entire pericardium. (15) Our case elucidates the role of Valsalva's s maneuver in the pathophysiology of pneumopericardium and increases physicians' awareness of pneumopericardium as a possible cause of chest pain and to rule out tension pneumopericardium as a possible reason of hemodynamic shock, especially when no trauma is visible. (2,7) Pneumopericardium must also be considered as a possible complication, with a high risk of recurrence, (4,12) in every patient with pneumothorax and pneumomediastinum. (1,4,9,12)

Accepted January 15, 2002.

References

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(3.) Katzir D, Klinovsky E, Kent V, Shucri A, Gilboa Y. Spontaneous pneumopericardium: Case report and review of the literature. Cardiology 1989;76:305-308.

(4.) Emery RW, Foker J, Thompson TR. Neonatal pneumopericardium: A surgical emergency. Ann Thorac Surg 1984;37:128-132.

(5.) Ahmed JM, Salame MY, Oakley GD. Chest pain in a young girl. Post-grad Med J 1998;74:115-116.

(6.) Costa IV, Soto B, Diethelm L, Zarco P. Air pericardial tamponade. Am J Cordial 1987;60:1421-1422.

(7.) Toledo TM, Moore WL Jr, Nash DA, North RL. Spontaneous pneumopericardium in acute asthma: Case report and review of the literature. Chest 1972;62:118-120.

(8.) Leitman BS, Greengart A, Wasser HJ. Pneumomediastinum and pneumopericardium after cocaine abuse. AJR Am J Roentgenol 1988;151:614.

(9.) Luby BJ, Georgiev M, Warren SG, Capito R. Postpartum pneumopericardium. Obstet Gynecol 1983;62(3 Suppl):46s-50s.

(10.) Van Gelderen WF. Stab wounds of the heart: Two new signs of pneumopericardium. Br J Radiol 1993;66:794-796.

(11.) Breatnach E, Han SY. Pneumopericardium occurring as a complication of achalasia. Chest 1986;90:292-293.

(12.) Cohen DJ, Baumgart S, Stephenson LW. Pneumopericardium in neonates: Is it PEEP or is it PIP? Ann Thorac Surg 1983;35:179-153.

(13.) Pomerance JJ, Weller MH, Richardson CJ, Soule JA, Cato A. Pneumopericardium complicating respiratory distress syndrome: Role of conservative management. J Pediatr 1974;84:883-886.

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(15.) Glover LB, Barcia A, Reeves TJ. Congenital absence of the pericardium: A review of the literature with demonstration of a previously unreported fluoroscopic finding. Am J Roentgenol Radium Ther Nucl Med 1969;106:542-549.

RELATED ARTICLE: Key Points

* Physical exertion and Valsalva's maneuver are rare causes of pneumopericardium.

* Pneumopericardium can be a cause of chest pain, and tension pneumopericardium may lead to hemodynamic shock.

* Pneumopericardium can be an occasional complication of pneumothorax and pneumomediastinum.

* Pneumopericardium without signs of tamponade needs close observation but usually no special treatment.

From Innere Medizin D, Mcdizinische Poliklinik, Westfalische Wilhelms Universitat Munster, Munster, Germany

Reprints requests to Gerald W. Westermann, MD, Medizinische Poliklinik D, Westfalische Wilhelms-Universitat Munster, Albert-Schweitzer-Stra[beta]e 33 D-48149 149 Munster, Germany

Copyright [c] 2003 by The Southern Medical Association 0038-4348/03/9601-0050