Repetitive
yawning associated with cardiac
tamponade
Mori J. Krantz, Jenny K. Lee, David H.
Spodick
From the Department of
Medicine, Cardiology Division, Denver Health
Medical Center and the University of Colorado
Health Sciences Center, Denver,
Colorado
Cardiac tamponade is a clinical syndrome
caused by the accumulation of fluid in the
pericardial space that limits ventricular
filling and subsequently reduces stroke volume
and cardiac output.1 The principal abnormality
is an increase in intrapericardial pressure that
leads to a reduction in diastolic compliance and
equalization of diastolic pressure in each
chamber.
Neoplastic disease, infection, uremia,
idiopathic pericarditis, and trauma are among
the most common causes of tamponade in the
United States. Although dyspnea is the most
frequent presenting complaint, patients may also
complain of chest discomfort, cough, air hunger,
anorexia, and fatigue. We report a case of
cardiac tamponade temporally associated with
repetitive yawning, a phenomenon not previously
described.
A 59-year-old Latino man with a
history of stage IV non-small cell lung
carcinoma presented to the emergency department
with a 3-day history of progressive dyspnea and
malaise. The patient's family reported that he
had been yawning repeatedly over the preceding
24 hours. The patient also complained of
increasing chest discomfort for 2 weeks. Two
months before admission, a transthoracic
echocardiogram revealed a smallto- moderate
sized pericardial effusion with a suggestion of
epicardial tumor studding, but no evidence of
tamponade physiology. In the emergency
department, the patient's blood pressure was
105/69 mm Hg with a 16 mm Hg pulsus
paradoxus.
His heart rate was 112 beats/min and
respiratory rate was 25 breaths/min with an
oxygen saturation of 92% while breathing room
air (normal in Denver is 90% to 95%). He was
mildly agitated and displayed repetitive,
exaggerated yawning every few minutes. Neck
examination demonstrated jugular venous
distension to the angle of his jaw when he was
sitting upright. Cardiac auscultation revealed
tachycardia with severely diminished heart
sounds. Pulmonary examination was remarkable for
basilar crackles and diminished breath sounds at
the right lung base. Dullness to percussion and
bronchial breathing were also noted over the
angle of the left scapula (Ewart's sign).
The patient's lower extremities had mild
pitting edema bilaterally. Chest x-ray showed a
markedly enlarged cardiac silhouette with
obliteration of the retrosternal airspace,
absence of pulmonary vasculature in the hilum,
and a right-sided pleural effusion.
Electrocardiography revealed sinus tachycardia,
low QRS voltage, and electrical alternans. A
transthoracic echocardiogram confirmed the
presence of a massive pericardial effusion with
fluid surrounding both atria. In addition, there
was evidence of right ventricular diastolic
collapse and marked dilation of the inferior
vena cava.
Emergency pericardiocentesis with catheter
placement was performed at the bedside under
echocardiographic guidance and 2 liters of
serosanguinous fluid was removed. Immediately
after drainage, the patient's repetitive yawning
resolved completely. Computed tomography of the
brain showed no cerebral metastases. Follow-up
electrocardiography demonstrated resolution of
electrical alternans and an increase in QRS
voltage. Repeat echocardiography showed minimal
residual effusion and resolution of right
ventricular diastolic collapse. The drainage
catheter was removed within 24 hours, and the
patient was discharged home 2 days after
hospital admission.
The pathophysiology and purpose of
yawning are not known. The existing reports on
this subject are sparse, consisting almost
entirely of letters, case reports, and small
series. Although generally attributed to boredom
and fatigue, yawning has been observed in a
limited number of neurologic conditions,
including migraine, hemiplegia, coma,
encephalitis, brain hypoxia, pontine and fourth
ventricle tumors, progressive supranuclear
palsy, and multiple sclerosis. In addition,
psychiatric disorders such as schizophrenia,
psychosis, and involutional depression have been
associated with yawning.5 Yawning has also been
observed in patients who have overdosed on
naloxone and imipramine, as well as in
opioid-dependent patients withdrawing from
heroin.
The mechanism underlying the frequent
yawning observed in our patient with
tamponade is unknown. Inhalation to total lung
capacity during a yawn may reverse the
microatelectasis associated with breathing at
low lung volumes as might occur when the lung is
compressed by the expanded pericardial sac
(explaining the pathophysiology of Ewart's
sign). Alternatively, repetitive yawning in
tamponade may be secondary to phrenic nerve
irritation.
The yawning center is a complex neuronal
reflex system located at the level of the
reticular brainstem, close to the ascendant
activatory reticular system with connections to
the phrenic nerves.5 The right phrenic nerve
passes along the pericardium over the right
atrium, whereas the left phrenic nerve runs
along thefrequent yawning observed in our
patient with tamponade is unknown. Inhalation to
total lung capacity during a yawn may reverse
the microatelectasis associated with breathing
at low lung volumes as might occur when the lung
is compressed by the expanded pericardial sac
(explaining the pathophysiology of Ewart's
sign). Alternatively, repetitive yawning in
tamponade may be secondary to phrenic nerve
irritation.
The yawning center is a complex neuronal
reflex system located at the level of the
reticular brainstem, close to the ascendant
activatory reticular system with connections to
the phrenic nerves. The right phrenic nerve
passes along the pericardium over the right
atrium, whereas the left phrenic nerve runs
along the resolution of yawning and pericardial
drainage links it to some effect of the rapid
change in volume of the pericardial sac, cardiac
chambers, or lung.
