A 47 year old male smoker was brought to the emergency room after
having experienced chest discomfort and shortness of breath, followed by
a syncopal episode. He had been investigated two weeks earlier for chest
pain on exertion (this included a negative exercise stress test which reached
11 mets).
In the emergency room, he was short of breath (breathing at 40/min. and
requiring 100% oxygen to maintain an adequate saturation) and had a depressed
level of consciousness. He was pale and diaphoretic, with a pulse of 120
bpm and a blood pressure of 70 mmHg systolic. His respiratory, cardiac,
and abdominal exam were all within normal limits with the exception of the
increased heart and respiratory rates. There was no obvious swelling of
his lower extremities. An ECG revealed a RBBB not present on previous ECGs . A CXR revealed no failure or other pathology.
With resuscitative measures underway, the patient was immediately brought
to the cardiac catheterization suite with a working diagnosis of cardiogenic
shock secondary to an acute myocardial infarction or acute pulmonary embolism.
In the cath lab, the patient became asystolic and ACLS protocol was begun.
The patient was intubated and a transvenous pacemaker was inserted. The
patient's blood pressure remained low despite maximum infusion of pressors,
and thus an intra-aortic balloon pump was inserted. A coronary angiogram
was then performed, which revealed completely normal coronary arteries.
It was decided at this point to immediately perform a pulmonary angiogram.
This revealed massive bilateral pulmonary emboli.
One hundred milligrams of rTPA and heparin were given intravenously,
with minimal resolution of the emboli. After attempts to mechanicaly break
up the emboli were unsuccessful, it was decided to bring the patient to
the OR.
On the way to the OR, the patient again became asystolic. A median sternotomy
was performed, open cardiac massage was begun, and the patient was placed
on cardiopulmonary bypass, using right atrial dual caval and ascending aortic
cannulation. The heart subsequently began to contract, but the right ventricle
was severely hypokinetic. The SVC and IVC were snared, and a longitudinal
incision was made in the pulmonary artery (PA). Large amounts of fresh clots
were removed from the right PA and multiple small clots were removed from
the left PA. Embolectomy catheters were placed down each main PA, but no
further clot was obtained. The arteriotomy was closed and attempts at weaning
from cadiopulmonary bypass where made. At this point, the RV was massively
dilated and severely hypokinetic. Despite maximum inotropes and the intra-aortic
balloon pump, the patient was unable to be weaned from bypass. The patient
expired due to right ventricular failure, 4 hours after presentation.
An autopsy done revealed four chamber cardiac failure, massive pulmonary
edema, and endocardial hemorrhages in the RA, RV, and LV, as well as residual
organizing thrombus in the left and right PA. |