Temporary Transvenous Cardiac Pacing

Abstract

• For detailed descriptions of the anatomy of the neck, please refer to Surgical Anatomy chapters on Central Venous Access and Pulmonary Artery Catheterization.

1 Surgical Anatomy

• For detailed descriptions of the anatomy of the neck, please refer to Surgical Anatomy chapters on Central Venous Access and Pulmonary Artery Catheterization.

2 General Principles

• Consent from the patient or family member should be obtained whenever possible. Risks include:

  • (a) Arterial puncture

  • (b) Pneumothorax

  • (c) Infection

  • (d) Bleeding

  • (e) Venous obstruction or thrombosis

  • (f) Air embolism

  • (g) Cardiac perforation

  • (h) Cardiac tamponade

  • (i) Pulmonary embolism

  • (j) Cardiac arrhythmias

• Elective procedures should be done under sterile precautions, including body draping, gown, mask, and sterile gloves. Skin disinfection with chlorhexidine is superior to alcohol or iodine-based solutions. Cover the skin entry site with dry gauze or transparent breathable dressing. When ultrasound is used, the probe should be covered with a sterile probe cover.

• Catheters placed emergently, under suboptimal sterility, should be removed or replaced within 24 h.

3 Indications

• Temporary transvenous pacing is indicated for symptomatic bradyarrhythmia or bradyarrhythmia associated with hemodynamic impairment that occurs from an acute event. These include sinus arrest, sinus bradycardia, symptomatic second-degree block (Mobitz type II), and third-degree block.

• These indications assume less invasive means (pharmacologic agents) have been unsuccessful, and the patient is experiencing significant symptomatology (chest pain, altered level of consciousness, dyspnea, shock, hypotension, pulmonary edema, acute myocardial infarction).

• A temporary pacemaker may also be indicated to treat a supraventricular tachycardia refractory to medical management with overdrive pacing or to increase the heart rate (improve cardiac output) in patients in cardiac failure.

• Temporary transvenous pacing is indicated when dysrhythmia can cause significant deterioration, and there is no time to place a permanent pacemaker.

• Temporary transvenous pacing is used as a bridge to permanent pacing for conditions where prolonged pacing is indicated (second- or third-degree atrioventricular (AV) nodal block or bundle branch block).

• Temporary transvenous pacing is indicated when there is unclear indications for permanent pacing in a hemodynamically decompensating patient or when there is imminent risk of asystole.

• Temporary transvenous pacing is used when patients that are pacemaker-dependent must undergo pacemaker revision (lead revision or replacement).

4 Contraindications

• Stable bradyarrhythmias with minimal symptoms.

• Bradyarrhythmias with an escape rhythm (complete heart block or sick sinus syndrome with short infrequent pauses) where the patient is only mildly symptomatic.

• Tricuspid valve mechanical prostheses.

• Right atrial thrombus.

5 Patient Preparation and Positioning

• Preferred cannulation sites for transvenous pacing include the right internal jugular vein (best site) and the left subclavian vein having demonstrated the highest rates of proper placement with best captures from insertion at these sites.

• Femoral cannulation should generally be avoided except in the patient who is anticoagulated or undergoing thrombolysis where bleeding is a concern. Femoral insertion is less likely to result in good placement in the absence of fluoroscopy and carries a higher venous thromboembolism and infection risk.

• Choose the correct pacing lead—transvenous pacing (TVP) catheters are usually balloon-tipped and come with intrinsic curvature at sizes 2, 5, 6, and 7 French.

6 Equipment (Fig. 20.1)

Multiple commercially available transvenous pacemaker kits exist. The operator should ensure familiarity with the specific product prior to use. General equipment includes:

• Mask, cap, sterile gown, sterile gloves, sterile drapes.

• Portable ultrasound with vascular probe.

• Pacemaker generator with battery and cable.

• Temporary pacing catheter.

• Electrocardiographic (ECG) machine/cardiac monitor.

• Sheath with integral hemostasis valve/side port and transcutaneous pacer and tissue dilator (Pacing Cordis Kit).

• Introducer needle (18G) and 0.035 guidewire.

• 10 mL syringe.

• 3 mL syringe for pacemaker balloon.

• Chlorhexidine solution/swab.

• Ampule 1% lidocaine no epinephrine.

• Catheter contamination sleeve.

• Alligator clip for attachment to EKG lead.

• Scalpel #11.

• Stopcock with three-way high flow.

• Suture.

• Sterile dressings including Tegaderm and Biopatch.

Fig. 20.1

Equipment necessary for temporary transvenous pacing

7 Surgical Technique

• Apply sterile prep and drape to the desired cannulation site.

• Remove protective sheath on pacing wire end, test balloon on pacing wire (1.5 mL) (Fig. 20.2), apply contamination shield (compressed) to pacer wire, and hand the end off of the sterile field.

• Perform ultrasound-guided venous cannulation of desired location (Figs. 20.3a–b and 20.4), place guidewire through needle (Fig. 20.5), advance Cordis catheter over wire using Seldinger technique (Fig. 20.6a–c), and remove the dilator.

• Prepare to insert the pacing wire by orienting it along its intrinsic curvature to optimize the probability of passing through the tricuspid valve and into the right ventricle (Fig. 20.7).

Fig. 20.2

Test the balloon on the transvenous pacemaker

Fig. 20.3

Perform ultrasound-guided venous cannulation of the desired site (right internal jugular vein shown). Visualize the vessel in the transverse orientation (a) and cannulate under direct visualization (b)

Fig. 20.4

Cannulation of the site is confirmed by aspiration of dark red venous blood

Fig. 20.5

Advance the guidewire carefully through the needle, confirm with ultrasound both in transverse and longitudinal orientation that the guidewire is in the vein

Fig. 20.6

Assemble the Cordis catheter and dilator as a single unit as shown (a and b). Make a small incision in the skin (through the dermis) at the percutaneous entry site. Insert the Cordis catheter and dilator over the guidewire in Seldinger fashion

Fig. 20.7

Align the transvenous pacemaker catheter along its natural curvature, medially toward the heart. This will maximize the chance of passing through the tricuspid valve into the right ventricle

8 A. Blind Insertion Technique

• Connect wires to pulse generator, (+) lead to (+) channel, (−) lead to (−) channel.

• Configure initial settings for pacer—output 20 mA (or maximum), sensitivity to asynchronous, rate 60–80 (or higher if higher heart rate desired goal).

• Next place the transvenous lead through the introducer sheath, and if patient has a pulse and the catheter has a balloon, it should be inflated once it has passed through the introducer, approximately at the 20 cm mark on the catheter (Figs. 20.8 and 20.9).

• Continue to advance the pacemaker wire with the balloon up. As it is advanced, the EKG will show pacer spikes. When the catheter enters the right ventricle and contacts the ventricular wall, a left bundle branch pattern (wide QRS complex) should be seen after every pacer spike (usually 40–50 cm) (Fig. 20.10).

• The balloon can now be deflated and the catheter secured in place.

• If during advancement you reach the 60–70 cm mark with no capture, deflate the balloon, pull the lead back to about 20 cm, and start over as you have almost certainly gone down the IVC instead of through the tricuspid valve.

Fig. 20.8

Insert the transvenous pacer catheter through the sheath to 20 cm

Fig. 20.9

Once the balloon tip has passed the distal end of the Cordis catheter (at approximately 20 cm), inflate the balloon

Fig. 20.10

As the balloon successfully enters the right ventricle, pacer spikes will appear on the ECG tracing

9 Final Manipulations Following Pacing Catheter Insertion

• When the lead hits the apex feel for a “slack” pressure—the lead is in the right place and the bend of the lead is passing through the tricuspid valve. The bend will allow for small motions of the heart and prevent dislodgement and loss of capture. Secure the lead in place.

• Stretch and affix the contamination shield to catheter hub at this location, and secure the catheter to the skin with suture and apply a sterile dressing (Figs. 20.11, 20.12 and 20.13).

• Connect the leads to the pulse generator (screw tightly and securely) (Fig. 20.14a–c).

• Obtain a post-procedure CXR to rule out pneumohemothorax and to assess for pacer wire location in or near the right ventricular apex (Fig. 20.15).

• Pacing (output) and sensing thresholds need to be tested after placement.

• The pacing threshold is the minimum current needed to obtain capture. To obtain the pacing threshold, set the pacer rate at least 10 beats/min higher than the patient’s intrinsic rate, set the sensitivity to asynchronous, and set the pacing output to its highest level. Then slowly reduce the output until capture is lost which represents the pacing threshold. Set the output to double (two times) the threshold to ensure capture. The ideal pacing threshold is 1–3 mA, and the catheter should probably be repositioned if the threshold is above 6–8 mA.

• The sensing threshold need be tested only if the pacemaker will be used in a demand mode (if the patient has an underlying rhythm to be “sensed”) which is unusual in the emergency setting.

• To test the sensing threshold, set the rate 10 beats/min slower than the patient’s intrinsic rate and the sensitivity to its lowest level; the pacemaker should show sensing at this level. Slowly dial up the sensitivity (raise the level) until the pacer stops sensing, that is, the sensing threshold. Now lower the sensitivity level to below the sensing threshold to ensure adequate sensing (usually by half).

Fig. 20.11

Stretch and affix the contamination shield to catheter hub

Fig. 20.12

Suture the catheter to the skin

Fig. 20.13

With the catheter secured by suture, apply a sterile dressing

Fig. 20.14

(a) At the distal end of the transvenous pacer, assemble the pacer leads and connect the pulse generator leads to the ventricular port. (b) Verify that the pacing leads are corrected to the appropriate polarity. (c) With the leads inserted correctly, turn on the pacemaker and set as desired (mode, rate, output, and sensitivity). With appropriate capture, the light will flash signifying the patient is being paced

Fig. 20.15

Post-procedure X-ray demonstrating cannulation of the right internal jugular vein with appropriate placement of the transvenous pacemaker at the right ventricular apex. Appropriate placement is also confirmed by capture on the ECG monitor

10 B. Placement with Electrocardiogram (EKG) Guidance

• If placing with EKG guidance, attach the negative (distal) electrode from the pacing catheter to any precordial (V) EKG lead using an alligator clip. This allows the pacing catheter to serve as an intracardiac EKG lead so the physician can monitor the progression of the catheter as it approaches the right ventricle by analyzing the various EKG wave forms (Fig. 20.16a–f).

• Place the transvenous lead through the introducer sheath and if patient has a pulse and the catheter has a balloon, it should be inflated once it has passed through the introducer, approximately at the 20 cm mark on the catheter.

• Continue to advance the catheter with the balloon up. A superior vena cava location results in low amplitude and negative polarity P waves (since it is above the right atrium) and negative polarity QRS complexes.

• As the catheter tip enters the right atrium, the P wave becomes larger and is negative (as is the QRS), but it becomes biphasic and positive as it moves down (below) the atrium and reaches the tricuspid valve. If the catheter exits the right atrium into the IVC, the P wave will remain positive, but the QRS will become smaller as the catheter moves away from the heart (Fig. 20.17a, b). This positive P wave would be what was seen first with a femoral approach as the catheter approached the right atrium from below.

• Right ventricular entry by the lead is signaled by a small positive P wave and a deeply negative QRS. When the catheter tip engages the right ventricle, it will show a current of injury (ST segment elevation) with a large QRS.

• If the catheter transverses the right ventricle into the pulmonary artery, the P wave will again become negative as the catheter moves above the right atrium and the QRS smaller (Fig. 20.18a–e).

• To prevent this, it is often helpful to deflate the balloon once the catheter passes through the tricuspid valve to help guide the tip into the right ventricle apex instead of being carried into the pulmonary artery.

• Frequent premature ventricular beats or ventricular tachyarrhythmia also signifies the lead has advanced into the right ventricle myocardium. If available fluoroscopy will allow direct visualization of the lead to the proper location.

• As in the blind technique, the pacing catheter should now be connected to the pacemaker generator and capture demonstrated. If there is no capture, the catheter should be repositioned.

• Perform “Final Manipulations” as detailed at the end of the Blind Insertion Technique above.

Fig. 20.16

Transvenous catheter progression from mid-SVC (a) → high right atrium (RA) (b) → mid RA (c) → low RA (d) → right ventricle (RV) (free) (e) → RV (against wall) (f). (a) Mid-SVC position of transvenous catheter. ECG tracing demonstrates low amplitude and negative deflection of P and QRS waves. (b) High right atrium position of transvenous catheter. ECG tracing consists of enlarging negative P and QRS wave deflections. (c) Mid-right atrial position of transvenous catheter. ECG tracing demonstrates negative deflection QRS wave. (d) Low right atrial position of transvenous catheter. ECG demonstrates decreasing negative P wave deflection. On occasion the P wave in the low atrial position can appear biphasic. (e) Floating transvenous catheter in the right ventricle. As opposed to an abutted right ventricular position (large ST elevation), the floating transvenous catheter is characterized by a small positive P wave and strong negative QRS wave. (f) Right ventricular position with transvenous catheter engaged on the ventricular wall. Characteristic findings on ECG are a large QRS with strong positive deflection

Fig. 20.17

Aberrant ECG waveforms in the IVC. As the catheter transitions from the mid-SVC to the IVC (bypasses the heart, conduction is inverted), the waveform is characterized by formation of positive P wave deflection and low QRS amplitude. (a) Mid-SVC position of transvenous catheter. ECG tracing demonstrates low amplitude and negative deflection of P and QRS waves. (b) IVC ECG waveform characterized by positive P wave and low QRS amplitude

Fig. 20.18

As the catheter is advanced through the heart into the pulmonary artery, the P wave will become increasingly negative as the catheter moves above the atrium (away from normal electrical conduction) and the QRS smaller. (a) Mid-SVC position of the transvenous catheter. (b) High right atrial position of the transvenous catheter. (c) Low right atrial position of the transvenous catheter. (d) Floating transvenous catheter in the right ventricle. (e) Transvenous catheter advanced into the pulmonary artery

10.1 Tips and Pitfalls

• The blind insertion technique is often preferred by inexperienced operators or in an emergency since it is faster and technically less complex. However the operator receives virtually no feedback as the catheter is advanced making this a major drawback of this technique.

• If possible avoid the left subclavian vein if you anticipate the patient will need a permanent pacemaker as this is the preferred location for its insertion.

• The right internal jugular vein results in the highest successful placement in the right ventricle.

• Ultrasound can be very helpful in placing the pacing catheter if the operator has experience in bedside ultrasonography. The subxiphoid four-chamber view is preferred. The pacing wire appears as a bright linear hyper-echogenic structure as it enters the heart and can be followed as it transverses the tricuspid valve into the right ventricle and contacts the ventricular apex (Fig. 20.19).

• Failure to connect the lead to the pulse generator securely can lead to life-threatening asystole in the event the lead becomes disconnected.

• Never forget to have a new battery (or at least to check the battery) in the pulse generator prior to insertion.

• Avoid inappropriate initial settings—low mA output or low sensitivity.

• Failure to achieve capture or high mA (> 20 mA) needed to achieve capture (lead not in the right place or wire not functional) means the lead must be repositioned.

• Pacing the diaphragm indicates the pacing lead is near the IVC, and not in the heart.

• Overinflation of balloon can result in rupture that can instill air into the heart resulting in an air embolus.

• Failure to inflate the balloon increases the chance of vascular or cardiac damage and makes placement more difficult.

• Failure to adequately secure lead can allow pacing lead movement, and dislodgment (pacer won’t fire anymore) can lead to life-threatening bradycardia and cardiovascular collapse.

• Failure to monitor for changes in sensitivity threshold or capture (pacing) threshold (needs to be checked every nursing shift) can lead to sudden pacemaker non-function.

Fig. 20.19

Illustration demonstrating transvenous pacemaker advanced into the apex of the right ventricle