Emergency cardiac pacing can be accomplished by several methods.
These include epicardial, esophageal, transcutaneous, transthoracic,
and transvenous pacing. pacing can be a temporizing and lifesaving
technique that should be familiar to physicians working in an Emergency
Department. It will allow the patient to maintain a cardiac rhythm
while providing oxygen and nutrients to the vital organs.
The earliest use of electricity to stimulate the heart can be
found in an essay written in the late 1700s.1 It discusses
the use of electric current and artificial ventilation to revive
victims of drowning. Transvenous pacing was first attempted on dogs
in 1905 by Floresco.The technology and technique have
since been developed to allow successful transvenous pacing in humans.
It involves the placement of a pacing wire through the central venous
circulation and into direct contact with the myocardium of the right
The heart is the only muscle of the body that generates its own
electric impulses. Its automaticity and subsequent rhythmic contractions
propel blood to the tissues of the body. The initial cardiac impulse
starts in the right atrium of the heart at the sinoatrial (SA) node.
The sympathetic and parasympathetic nervous systems control the
rate of impulse generation at the SA node. Once the electric stimulus
is generated, it is conducted along the internal conduction pathways
of the heart to the muscular atrial and ventricular walls. A delicate
balance between electrolyte flux to create action potentials, myocardial
integrity to allow impulses to become contractions, and an intact conduction
system must be maintained. Conduction system problems are often
the result of inadequate blood flow to the heart due to ventricular
infarction and coronary artery occlusion. The blood supply to the
conduction system of the heart originates from the right coronary
artery. Occlusion of the right coronary artery can result in arrhythmias
and conduction delays.
A transvenous pacing catheter may be introduced through the femoral,
internal jugular, or subclavian vein. In
the Emergency Department, the right internal jugular vein or left
subclavian vein are the primary sites (Figure 22-1). These routes
allow a more direct and easy access for the pacing catheter to enter
the right ventricle. The right internal jugular vein is preferred,
as it allows a relatively straight line of access through the superior
vena cava and right atrium into the right ventricle.2 The
other routes are technically more difficult to use and often require
fluoroscopy for proper placement of the pacing catheter.
Common sites for introducing a transvenous pacing catheter. A. The right internal jugular vein. B. The left subclavian vein.
In children, the femoral vein is often used to insert a transvenous
cardiac pacing catheter (Figure 22-2). The child’s relatively
large head and short neck makes access to the internal jugular vein difficult.
The subclavian vein in a ...