Various arrhythmias can complicate the procedure of pulmonary arterial catheterisation, with the time of greatest risk being the period of insertion of the catheter. Two manoeuvres have been described which may reduce the incidence of arrhythmias. These are:

1. Not advancing the Seldinger wire past the superior vena cava during insertion of the introducer sheath: (ie < ~ 20cms) ¹. In practice, this is not as easy as it sounds because many Seldinger wires, unlike catheters, have no distance markings. Andrews et al ², have recently measured the distance from skin entry site to atrio-caval junction in 100 patients undergoing central venous cannulation by various routes. These distances were:

2. Positioning the patient 5 degrees head up with slight right lateral tilt during flotation of the catheter: - This facilitates rapid transit of the catheter through the right ventricular outflow tract. Even if this posture is not used, the catheter should never be passed while the patient is still in a head-down position ³.

The 'prophylactic' administration of lignocaine prior to catheterisation has been used, but is of questionable benefit ⁴.

The arrhythmias which have been reported include: Atrial ectopic beats, ventricular ectopic beats, ventricular tachycardia, ventricular fibrillation, right bundle-branch block and complete heart block ^{5, 6}. Ventricular ectopic beats during insertion are by far the most commonly reported abnormal rhythm and may occur in about 50% of patients ⁷.

A transient right bundle branch block (RBBB) may occur in 1 - 3% ^{8, 9} of patients as the PAC passes through the right ventricular outflow tract (RVOT). It is probably due to pressure on the bundle at the point where it is in close proximity to the out flow tract (Figure 1).

If the patient has a pre-existing, chronic left bundle branch block (LBBB), complete heart block may be precipitated during catheter passage through the RVOT (Figure 2). The risk of precipitating CHB in such patients appears to be less than 1% ^{10, 11} and for this reason the 'prophylactic' use of temporary pacemakers is probably not warranted. Nevertheless, it is advisable to have an external pacemaker and resuscitation drugs (including isoprenaline) immediately available when catheterising patients with LBBB.

Patients with new AV or fascicular block occurring in the setting of acute myocardial ischaemia are at far greater risk of CHB and should be protected from this complication by the use of a catheter with a pacemaking facility (Refer to the section entitled 'Special Purpose PA Catheters') or by the insertion of a separate temporary pacemaker.

Overall, from large series of patients, the incidence of complete heart block during insertion of a PAC is in the order of 0.015% ¹¹.

The incidence of arrhythmias is highest in patients who have suffered recent myocardial infarction.

Cardiac arrhythmias associated with PAC removal:

Baldwin and Heland ¹² have examined the incidence and nature of cardiac dysrhythmias which occur on removal of PACs in patients who have undergone recent cardiac surgery. About 20% of patients experienced some form of dysrhythmia of which self-terminating ventricular tachycardia (with hypotension) was the most serious. This occurred in 2 out of 100 cases.

1. Royster RL, Johnston WE, Gravlee GP, Brauer S, Richards D. Arrhythmias during venous cannulation prior to pulmonary artery catheter insertion. Anesth Analg 64:1214-1216, 1985.

2. Andrews RT, Bova DA, Venbrux AC How much guidewire is too much? Direct measurement of the distance from subclavian and internal jugular vein access sites to the superior vena cava-atrial junction during central venous catheter placement. Crit Care Med 2000 Jan;28(1):138-42

3. Keusch DJ, Winters S, and Thys DM The patient's position influences the incidence of dysrhythmias during pulmonary artery catheterization. Anesthesiology 70:582-584, 1989.

4. Salmenpera M, Peltola K, and Ronsenberg P. Does prophylactic lidocaine control cardiac arrhythmias associated with pulmonary artery catheterization? Anesthesiology 56:210, 1982.

5. Thomson IR, Dalton BC, Lappas DG, Lowenstein E Right bundle-branch block and complete heart block caused by the Swan-Ganz catheter. Anesthesiology 51(35):9, 1979.

6. Abernathy WS: Complete heart block caused by a Swan-Ganz catheter. Chest 65:349, 1974.

7. Patel C; Laboy V; Venus B; Mathru M; Wier D Acute complications of pulmonary artery catheter insertion in critically ill patients. Crit Care Med, 14(3):195-7 1986 Mar

8. Roizen MF, Berger DL, Gabel RA et al Practice Guidelines for pulmonary artery catheterization. A report by the American Society of Anesthesiologists task force on pulmonary artery catheterization. Anesthesiology 78:380-394, 1993

9. Sprung CL, Elser B, Schein RMH, et al Risk of right bundle-branch block and complete heart block during pulmonary artery catheterization. Crit Care Med 17:1-3, 1989.

10. Risk SC, Brandon D, D'Ambra MN et al Indications for the use of pacing pulmonary artery catheters in cardiac surgery. J Cardiothorac Vasc Anesth, 1992:275-279

11. Shah KB, Rao TL, Laughlin S, El-Etr AA A review of pulmonary artery catheterization in 6245 patients. Anesthesiology 61:271 - 275, 1984

12. Baldwin IC, Heland M Incidence of cardiac dysrhythmias in patients during pulmonary artery catheter removal after cardiac surgery. Heart Lung 2000 May-Jun;29(3):155-60

Last edited on: 26/11/2000