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esuscitation (2007) 74, 559—562

ASE REPORT

cute myocardial infarction complicated byentricular standstill terminated by thrombolysisnd transcutaneous pacing�

ick Castlea,b,∗, Crispin Porterc, Beverley Thompsonc

Department of EMC&R, Durban University of Technology, South AfricaFrimley Park Hospital, Portsmouth Road, Frimley, Surrey GU16 7UJ, UKEmergency Department, Frimley Park Hospital, Surrey, UK

eceived 10 November 2006; received in revised form 25 January 2007; accepted 26 January 2007

KEYWORDS Summary Although the overall need for emergency pacing following AMI has

Transcutaneous pacing;Thrombolytic therapy;Acute Myocardial

reduced with the wide spread use of thrombolysis the availability of transcutaneouspacing offers an emergency non-invasive strategy to optimise circulation followingCHB or ventricular standstill. Transcutaneous pacing also facilitates the safe insti-gation of thrombolytic therapy to achieve reperfusion of the conduction system

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infarctionfollowing AMI.© 2007 Elsevier Ireland

39-year-old female collapsed at home. As shead a chronic history of diabetes her children triedo give her chocolate for what they believed toe a hypoglycaemic episode. When she failed toecover, they summoned the emergency medicalervices (EMS).

On arrival of the EMS, her GCS was 6 (E1, V1, M4),he was hypotensive (90/60 mmHg) and in com-

lete heart block (CHB) with evidence of an anteriorcute myocardial infarction (AMI).

On arrival at the emergency department the CHBad resolved but right bundle branch block with

� A Spanish translated version of the summary of thisrticle appears as Appendix in the final online version at0.1016/j.resuscitation.2007.01.034.∗ Corresponding author.

E-mail address: Nicholas.castle@ntlworld.com (N. Castle).

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300-9572/$ — see front matter © 2007 Elsevier Ireland Ltd. All rightoi:10.1016/j.resuscitation.2007.01.034

. All rights reserved.

eft axis deviation (Figure 1) and evidence of annterior AMI persisted. Her GCS had improved to 13E/3, V/4, M/6) but obtaining a clinical history wasifficult. However with persistent questioning sheenied the presence of chest pain or breathlessnessut did complain of ‘pins and needles in her head’.

The patient’s long standing medical historyavailable from her medical notes), which includedoorly controlled diabetes since age 7, hyper-holesterolemia and heavy cigarette smoking,ndicated that AMI was the most likely cause forer current clinical condition. However the risk ofn intra-cerebral event (particularly subarachnoidaemorrhage) needed to be excluded prior to thedministration of reperfusion therapy. The patient

as transferred with an escort (consultant emer-ency physician) for a CT scan performed by aonsultant radiologist. The CT scan was reporteds normal.

s reserved.

560 N. Castle et al.

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Figure 1 Demonstrating RBB

During transfer back to the emergency depart-ment the patient’s cardiac rhythm deteriorated toventricular standstill. Chest compressions wherestarted immediately whilst transcutaneous pacingpads where applied in the standard defibrillationposition. Atropine and adrenaline (epinephrine)

were prepared but withheld as mechanical cap-ture was achieved immediately at 110 mA at ademand rate of 70 paces per minute (ppm).The pacing pads were placed in the standard

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Figure 2 Pausing of external pacing demonstrating pacing sp

axis and anterior infarction.

efibrillation position as opposed to the pre-erred anterior-posterior position due to ease ofccess.

Weight-adjusted tenecteplase and 30 mg ofnoxaparin was administered intravenously fol-owed by subcutaneous enoxaparin (1 mg/kg).1

spirin (300 mg) and clopidogrel (300 mg) were pre-ared but withheld due to the patients reducedevel of consciousness and associated risk of aspi-ation.

ikes and underlying rhythm of ventricular standstill.

Acute myocardial infarction complicated by ventricular standstill terminated 561

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igure 3 At 60 min ECG demonstrating resolution of ventBBB.

The patient’s GCS improved to 15 and she com-lained of pain associated with transcutaneousacing. Her discomfort was managed by givingmg of morphine and a reduction in the pacing

hreshold to 80 mA and pacing rate to 60 ppm.his was achieved without affecting blood pres-ure or mechanical capture. The improvement inhe patient’s GCS allowed her to swallow her anti-latelet therapy safely.

Over the next 30-min the under-lying rhythmemained as ventricular standstill (Figure 2) butpontaneous sinus tachycardia occurred at 40-in which terminated the demand pacing. A

2-lead ECG confirmed sinus tachycardia with ante-ior AMI and right bundle branch block (RBBB).epeat ECG (Figure 3) at 90-min demonstratededuction of ST-elevation although RBBB persisted.he patient was now haemodynically stable andhe was transferred to the coronary care unithilst transfer to our regional cardiac centre wasrranged.

iscussion

nterior AMI, complicated by CHB, has a high mor-ality as it results from ischaemia/necrosis of thentra-ventricular septum/bundle branch following

cclusion of the left anterior descending artery.2

he over-all incidence of CHB requiring pacing fol-owing AMI has fallen since the introduction ofhrombolysis.3

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ar standstill, reduction in ST elevation but with persistent

Transcutaneous pacing is simple to instigate andnlike the transvenous route does not require cen-ral venous access which following thrombolysisnd the associated administration of heparin andnti-platelet therapy may result in significant riskf haemorrhage. Furthermore, transcutaneous pac-ng, unlike the use of atropine or adrenaline, willot induce tachycardia which may adversely affectn limited myocardial oxygen supply.4,5 Althoughemporary pacing may stabilise cardiac rhythmt will not reperfuse the occluded artery andherefore immediate reperfusion therapy remainsandatory.Our case study demonstrates the combined

enefits of thrombolysis whilst maintaining car-iac circulation with transcutaneous pacing asvidenced by the restoration of conduction andhe resolution of ST-elevation indicating myocar-ial salvage.6 This patient also serves to highlighthe incidence of atypical/pain-free presentationf AMI particularly in diabetic patients and inemales.7

onclusion

lthough the overall need for emergency pacingollowing AMI has reduced with the wide spread

se of thrombolysis, the availability of transcu-aneous pacing offers an emergency non-invasivetrategy to optimise circulation following CHB orentricular standstill. Transcutaneous pacing also

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facilitates the safe instigation of thrombolytic ther-apy to achieve reperfusion of the conduction systemfollowing AMI.

Conflict of interest

None

References

. Antman EM, et al. Enoxaparin versus unfractionated heparinwith fibrinolysis for ST-elevation myocardial infarction. N Engl

J Med 2006;354:1477—88.

. Gersh BJ, Rahimtoola SH. Conduction disturbances: tempo-rary and permanent pacing in patients with acute myocardialinfarction. In: Acute myocardial infarction, 2nd ed. New York:Chapman & Hall, 1996. p. 354—67 (chapter 15).

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. Antman EM, Anbe DT, Armstrong PN, et al. ACC/AHA guide-lines for the management of patients with ST-segmentmyocardial infarction; A report of the American College ofCardiology/American Heart Association. J Am Coll Cardiol2004;44(3):E1—211.

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. Taher T, Yuling F, Wagner GS, et al. Aborted myocar-dial infarction in patients with ST-segment elevation. JACC

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. Canto JG, Shlipak MG, Rogers WJ, et al. Prevalence, clin-ical characteristics, and mortality among patients withmyocardial infarction presenting without chest pain. JAMA2000;283:3223—9.