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Transarterial pacemaker lead implantation results in acute myocardial infarction

Ziad F. Issa, John B. Gill
DOI: http://dx.doi.org/10.1093/europace/euq189 1654-1655 First published online: 2 July 2010

Abstract

We report a case of inadvertent transarterial implantation of dual-chamber pacemaker leads; the ventricular lead positioned across the aortic valve into the left ventricle and the atrial lead curving in the aortic root with the tip positioned into the left circumflex artery, resulting in acute myocardial infarction. The diagnosis was made based on the finding on the chest X-ray, surface ECG, and coronary angiography.

Case report

A 96-year-old woman with symptomatic severe sinus node dysfunction underwent implantation of a dual-chamber pacemaker (St Jude Medical, Zephyr XL DR, model 5826) using active-fixation atrial (St Jude Medical, Tendril SDX 1688TC) and passive-fixation ventricular (St Jude Medical, Isoflex S 1646T) leads. The procedure was performed in the operating theatre utilizing a portable C-arm fluoroscopy machine. Vascular access was obtained with a 21-gauge needle and a micropuncture introducer set (Cook, Inc., Bloomington, IN, USA). The ventricular lead had an electrogram amplitude of 25 mV and pacing threshold of 0.5 V at 0.5 ms; the atrial lead had an electrogram amplitude of 2.5 mV and pacing threshold of 4 V at 1 ms. Attempts at repositioning the atrial lead failed to improve the pacing threshold.

Shortly after the procedure, the patient developed severe chest discomfort. A chest X-ray (CXR) was performed and suggested an abnormal course of the pacemaker leads (Figure 1A and B). Surface ECG demonstrated atrial pacing with intact AV conduction and right bundle branch block pattern, without new changes compared with old ECGs. However, polarity of the paced P-wave was negative in leads I and aVL, and upright in lead V1 and the inferior leads, consistent with pacing from the anterolateral left atrium. Cardiac enzymes were elevated (peak CK level was 1550 IU/L). Cardiac catheterization was performed emergently. The atrial lead was in the aortic root with the tip positioned into a marginal branch of the left circumflex artery (Figure 1C and D), whereas the ventricular lead was positioned in the left ventricle (LV).

Figure 1

Top panels: CXR [posteroanterior (A) and lateral (B) views]. Bottom panels: left coronary angiography [caudal left anterior oblique (C) and cranial right anterior oblique (D) projections]. See text for details.

The pacemaker leads were immediately explanted from the left side of the heart, and new leads were implanted into the right atrium and ventricle. Coronary angiogram performed concomitantly revealed no coronary perforation and no obstructive coronary artery disease. The patient recovered well with no further adverse events. Follow-up echocardiography demonstrated normal LV systolic function.

A rare cause of endocardial LV pacing is the erroneous introduction of the pacing lead into the subclavian artery and passage into the LV across the aortic valve.13 Transthoracic or transoesophageal echocardiography will usually delineate the trajectory of the leads from the right to the left heart chambers. Unique to our case is the malposition of the atrial lead in the aortic root with the tip screwed into the left circumflex artery, resulting in a non-ST elevation myocardial infarction. The lack of pulsatile arterial blood return through the small micropuncture needle used for vascular access in this case and the poor quality of the portable fluoroscopy images might have been among the factors that led to the inadvertent transarterial access.

Several precautions need to be undertaken to obviate such a complication. An unusual course of the guidewire on the anteroposterior fluoroscopy projection should prompt utilizing the right or left oblique fluoroscopy projections, which typically show posterior orientation of the wire for left heart positions and anterior orientation for right heart positions. Furthermore, the 12-lead ECG is a simple and readily available tool for verification of right vs. left heart position of the pacing leads based on the morphology of the paced P-wave and QRS complex. Additionally, an unexpectedly high pacing capture threshold should prompt careful reexamination of all previous steps before conclusion of the procedure.

Conflict of interest: none declared.

References

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