Heart Block Associated with Pulmonary Artery Catheter Placement
Osborne Williams, MD
Resident in Anesthesiology
New York University Medical Center
New York, NY USA
Introduction
Pulmonary artery catheter placement may lead to a numbef of
complications, including pulmonary artery rupture, carotid artery
puncture, hematoma, and pneumothorax. Cardiac dysrhythmias, however,
are the most common complication related to pulmonary artery catheter
placement. Most dysrhythmias resulting from pulmonary artery
catheter placement are transient and resolve spontaneously, and include
atrial and ventricular premature contraction, and short runs of
ventricular tachycardia. These usually occur as a result of contact of
the tip of the catheter with the heart. PA catheter placement may,
however, result in bundle branch block or even complete heart block,
which may be life-threatening. This review discusses the epidemiology,
prevention, and treatment of conduction blockade in patients undergoing
PA catheter placement.
Occurrance
Shah et al reviewed 6245 patients undergoing pulmonary artery
catheterization, and reported an incidence of complications of 72%.
Transient dysrhythmias resolving with advancement or withdrawal of the
catheter included PVCs, which occurred in 68% of patients and PACs,
which occurred in 1.3%. 3.1% of the patients had PVCs which persisted
despite catheter advancement or withdrawal, and required treatment
with lidocaine. Transient right bundle branch block (RBBB) was
reported in 0.048%. 113 patients developed left bundle branch block
(LBBB), one of whom developed complete heart block and required pacing.
Sprung et al reported a 3% incidence of RBBB with no higher risk in
patients with pre-existing conduction defects. (e.g., LBBB)
Morris et al evaluated 82 PA catheterizations in 47 patients with
LBBB. No complete heart block was associated with PA catheter
placement.
Pathophysiology
RBBB is presumed to occur because of direct mechanical trauma to the
right bundle branch (RBB). The RBB is particularly vulnerable because
of its relatively superficial location in the ventricular endocardium.
In earlier reports, RBBB was felt to be more likely in the setting of
acute MI or severe CAD. (i.e. the conduction system was compromised
by ischemia). The soft, flexible nature of the balloon-tipped
catheter does not alleviate the potential for trauma.
Patients with LBBB present additional concerns when undergoing PA
catheter placement. Because these patients depend on their right
bundle branch to carry impulses to the ventricles, RBBB produced
as a result of catheter placement may result in complete heart block.
It was previously thought that prior placement of a transvenous
pacemaker was necessary prior to PA catheter insertion. The recent
data demonstrating a low incidence of complete heart block suggests
that this is probably not necessary as a routine precaution.
Precautions
Pacing equipment should be immediately available when inserting a
PA catheter in a patient with pre-existing left bundle branch block.
The patient can be paced with either an external pacer or a PA
catheter with pacing capability and pacing cables. Pacing wires
passed through a catheter will be positioned in the right ventricle
only when the catheter has been placed correctly. A pacing catheter
may therefore not allow pacing if complete heart block occurs before
the tip of the catheter is in the pulmonary artery.
References
1. Thompson IR et al: Right bundle branch block and complete heart
block caused by Swan-Ganz catheter. Anesthesiology 51:359-362, 1979.
2. Sprung CL et al: Risks of right bundle branch block and complete
heart block during pulmonary artery catheterization. Crit Care Med
17:1-3, 1989.
3. Shah KB et al: A review of pulmonary artery catheterization in 6245
patients. Anesthesiology 61:271-275, 1984.
4. Morris D et al: Risk of developing complete heart block during
bedside pulmonary artery catheterization in patients with left bundle
branch block. Arch Intern Med 147:2005-2010, 1987.