Acute ST-Segment Elevation Myocardial Infarction as a Rare Postoperative Complication of Biventricular Implantable Cardioverter-Defibrillator Placement.

We present a rare case of an 84-year-old woman who suffered an acute ST-segment elevation myocardial infarction as a postoperative complication of biventricular implantable cardioverter-defibrillator placement, caused by the left ventricular lead impinging onto the second obtuse marginal artery. (Level of Difficulty: Intermediate.).

History of Presentation

An 84-year-old White woman came to the hospital as an elective admission for implantable cardioverter defibrillator (ICD) placement. On presentation, her heart rate was 75 beats/min, respiratory rate was 16 breaths/min, blood pressure was 109/68 mm Hg, and oxygen saturation was 96% on room air. On physical examination, S1 and S2 were heard. No S3, S4, murmurs, rubs, or gallops were appreciated. The lungs were clear to auscultation bilaterally. No jugular venous distension or pedal edema was appreciated.

Learning Objective

To recognize an acute myocardial infarction as a rare postoperative complication of biventricular ICD placement.

She successfully underwent a biventricular ICD placement with no intraoperative complications (Medtronic lead, model number 479888, placed in the posterolateral cardiac vein). However, postoperatively, while in the postanesthesia care unit, the patient started to complain of a vague left-sided chest discomfort with nausea.

Past Medical History

The patient’s past medical history was notable for heart failure with reduced ejection fraction of 31%, atrial fibrillation with uncontrolled ventricular response, prior episodes of nonsustained ventricular tachycardia, hypertension, and coronary artery disease.

Differential Diagnosis

The differential diagnosis included myocardial infarction, anxiety/panic attack, arrythmias, and incision site pain.

Investigations

Electrocardiogram showed ST-segment elevations in the lateral precordial leads along with reciprocal ST-segment depressions in V1 through V4 (Figure 1).

Figure 1

Electrocardiogram Showing Acute ST-Segment Elevation Myocardial Infarction Post–Implantable Cardioverter-Defibrillator Placement

An electrocardiogram obtained for acute chest pain after placement of the implantable cardioverter-defibrillator showing ST-segment elevation in leads I, aVL, V5, and V6, with reciprocal ST-segment depressions in V1 through V4.

Management

The patient underwent an emergent left heart catheterization, which showed a 100% distal occlusion of the second obtuse marginal artery (OM2) at the site, which corresponded to an anchoring mechanism of the left ventricular (LV) lead of the biventricular ICD (Figure 2). The lesion in the OM2 was negotiated with a coronary wire and a microcatheter. Without further intervention, an angiogram demonstrated restoration of flow distally (Figure 3). It was believed that there may have been a small thrombus that had resolved. Given the concern for potential injury to both the artery and the adjacent cardiac vein, balloon angioplasty was not performed initially. The patient’s troponins continued to rise after the cardiac catheterization. She then underwent a hybrid procedure involving unscrewing of the LV lead along with a left heart catheterization. Angiography showed complete reocclusion of OM2 (Figure 4). Flow through the OM2 improved as the fixation mechanism on the LV lead was released and the lead was pulled back. An area of focal stenosis on OM2 was dilated at low pressures with a 2-mm balloon for a sustained period of time. A repeat angiogram done immediately postangioplasty showed no residual stenosis (Figure 5). The patient suffered no immediate complications postprocedure.

Figure 2

First Angiogram Showing Completely Occluded Second Obtuse Marginal Artery

(A) Right anterior oblique caudal view. (B) Right anterior oblique cranial view. These images show the results of the first angiography after acute ST-segment elevation myocardial infarction post-implantable cardioverter-defibrillator placement in 2 different views. There is a 100% distal occlusion of the second obtuse marginal artery (red arrows), which corresponded to an anchoring mechanism of the left ventricle lead (orange arrows). The white arrow points to the right ventricular lead.

Figure 3

First Angiogram Showing Restoration of Flow in the Second Obtuse Marginal Artery

The results of the first coronary angiography after the second obtuse marginal artery lesion was negotiated with a coronary wire and a microcatheter. Without further intervention, an angiogram demonstrated restoration of flow distally in the obtuse marginal artery (red arrow). The orange arrow points to the left ventricle lead.

Figure 4

Second Angiogram Showing Completely Reoccluded Second Obtuse Marginal Artery

Second angiogram as a part of the hybrid procedure before the unscrewing of the left ventricle lead (orange arrow) showed a complete reocclusion of the second obtuse marginal artery (red arrow).

Figure 5

Post-Hybrid Procedure Angiogram Showing No Residual Stenosis in the Second Obtuse Marginal Artery

Flow through the second obtuse marginal artery improved as the fixation mechanism on the left ventricle lead (orange arrow) was released and the lead was pulled back. An area of focal stenosis in the second obtuse marginal artery was dilated with a balloon. A repeat angiogram immediately postangioplasty showed no residual stenosis in the second obtuse marginal artery (red arrow).

Discussion

Cardiac implantable electronic devices have come a long way from the first clinically successful cardiac pacemaker invented in 1960. The first implantations of an automatic internal defibrillator in humans began in 1980, followed by U.S. Food and Drug Administration approval in 1985, initially only for secondary prevention in survivors of cardiac arrest. Implantable defibrillators were initially developed to prevent sudden cardiac death from ventricular arrythmias; however, their scope has now expanded. Most ICDs now offer 3-tiered therapy for the termination of a programmed tachycardia: antitachycardia pacing, cardioversion, and defibrillation.

Building on the decreased mortality afforded by ICDs and pacemakers, cardiac resynchronization therapy (CRT) was developed. CRT is indicated in patients with an LV ejection fraction of <36%, sinus rhythm with left bundle branch block morphology, QRS interval duration more than 149 ms, and New York Heart Association functional class II, III, or IV symptoms. There was a Class IIa recommendation for ICD in our patient given the history of heart failure with a reduced ejection fraction of 31%, left bundle branch block with a QRS interval duration of 134 ms and New York Heart Association functional class III symptoms on optimal medical therapy. The ideal placement of the LV lead for CRT is technically demanding because of the high degree of variability in the anatomy of the coronary sinus (CS). To achieve maximal hemodynamic benefit from CRT, appropriate positioning of the LV lead is essential in the region of viable myocardium that has delayed electrical activation and mechanical dyssynchrony. The LV lead is usually implanted in the lateral and posterior branches of the CS, which can be variable in number, tortuosity, dimensions, and angulation. Various techniques and adaptations have been used for successful LV lead placement. The anchoring mechanism of the LV lead in the CS can theoretically compress the adjacent coronary arteries, causing stasis and thrombosis. Endothelial injury to the coronary arteries can also be caused by traumatic and difficult placement of the LV lead. In our case, the etiology for the ST-segment elevation myocardial infarction was believed to likely be the anchoring mechanism of the LV lead compressing the adjacent OM2 or the invasion of the screw mechanism.

ICD placement carries an inevitable risk of complications. The majority of reported complications arose from lead displacement, hematoma, and pneumothorax., However, to our knowledge, acute myocardial infarction has not been previously reported as a complication of ICD placement. Thus, this case highlights a rare complication of ICD LV lead placement.

Follow-Up

The patient tolerated the procedure well and was discharged home. She has been regularly following up with our cardiology clinic.

Conclusions

Mechanical obstruction of a coronary artery is possible from the adjacent LV lead, leading to an acute myocardial infarction. This rare complication has not been documented as a known complication of biventricular ICD placement. Awareness about this rare complication can lead to its earlier identification and, thus, an overall decreased morbidity and mortality.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.