Temporary Cardiac Pacing

Temporary Cardiac Pacing
David D. Spragg
Daniel A. Kim
I. GENERAL PRINCIPLES
A. Background.
1. The purpose of temporary cardiac pacing is to reestablish circulatory integrity and normal hemodynamics in acutely compromised bradyarrhythmia or tachyarrhythmia by maintaining an appropriate heart rate until it resolves or until long-term therapy can be initiated.
2. Algorithm for managing patients with bradycardia (Fig. 37-1).
B. Pacing options.
1. Transcutaneous.
a. Primary use: prophylaxis in patients at risk for high-grade atrioventricular (AV) block.
b. Pros: multifunctional capabilities including sensing; can be used for overdrive pacing.
c. Cons: patient discomfort, adequate ventricular capture may be challenging.
2. Transvenous: has commonly supplanted transcutaneous pacing given ease of use and less patient discomfort.
II. INDICATIONS
A. Overview.
1. Indications for temporary pacing in the setting of acute myocardial infarction (MI) have been well defined and outlined in a consensus guideline from American Heart Association and the American College of Cardiology (AHA/ACC) (see Table 37-1).
2. No similar guidelines available for other conditions causing bradycardia (i.e., electrolyte abnormalities, drug reactions, or infections).
3. Of patients needing temporary pacing, about half require permanent pacing before discharge.
B. Specific indications.
1. MI (Table 37-1).
a. Bradycardia/AV block related to ischemia or infarction of conduction system.
i. Revascularization is the primary management—in particular when AV nodal or fascicular blood supply is compromised.
Figure 37-1. Algorithm for management of bradycardia unresponsive to pharmacologic therapy. *High-grade block includes the Class I indications on Table 37-1. PPM, permanent pacemaker.
(a) Inferior ischemia (disruption of AV nodal blood supply).
(b) Anterior ischemia (disruption of fascicular blood supply).
ii. Prognosis.
(a) Depends on extent of underlying ischemia and LV function.
(b) Death is rare from complete heart block.
2. Bradyarrhythmias (Table 37-2: Section I).
a. The most common indication is symptomatic bradycardia that is unresponsive to pharmacologic therapy.
b. Classifications.
i. Disordered impulse formation (i.e., sinus node dysfunction).
ii. Disordered impulse propagation (i.e., conduction block).
3. Tachyarrhythmias (Table 37-2: Section II).
a. Temporary pacing rarely used in clinical practice due to efficacy of medications and increased prevalence of implantable defibrillators.
b. Pacing can play a role in prevention or termination of arrhythmia.
c. Many reentrant rhythms are susceptible to pace termination.
i. Supraventricular tachycardia (SVT) (AV nodal reentrant tachycardia, accessory pathway-mediated tachycardia).
ii. Ventricular tachycardia (VT) (scar mediated).
TABLE 37-1 Indications of Pacing in Acute Myocardial Infarction

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Jun 11, 2016 | Posted by in CRITICAL CARE | Comments Off on Temporary Cardiac Pacing

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Placement of transcutaneous patches and active (demand) transcutaneous pacing

Class I

Sinus bradycardia (<50 bpm) with systolic BP < 80 mm Hg unresponsive to drug therapy

Mobitz type II second-degree AV block

Third-degree heart block

BBBB (alternative RBBB and LBBB)

Newly acquired or age-indeterminate LBBB, RBBB and LAFB, or RBBB and LPFB

RBBB or LBBB with first-degree AV block

Class IIa

Stable bradycardia with systolic BP > 90 mm Hg or hemodynamic compromise responsive to drug therapy

Newly acquired or age-indeterminate RBBB

Class IIb

Newly acquired or age-indeterminate first-degree AV block

Class III

Uncomplicated acute MI without evidence of conduction system disease

Temporary transvenous pacing

Class I

Asystole

Symptomatic bradycardia

Sinus bradycardia with hypotension

Type I second-degree AV block with hypotension unresponsive to atropine

Mobitz type II second-degree AV block

BBBB (alternating BBB or RBBB with alternating LAFB/LPFB) of any age

New or indeterminate-age bifascicular block (RBBB with LAFB or LPFB or LBBB) with first-degree AV block

Class IIa

Recurrent sinus pauses (>3 s) not responsive to atropine

RBBB with first-degree AV block

New or age-indeterminate RBBB and LAFB or LPFB

New or age-indeterminate LBBB

Incessant VT for atrial or ventricular overdrive pacing

Class IIb

Bifascicular block of indeterminate age

New or age-indeterminate isolated RBBB

Class III