A Man with Chest Pain and Shortness of Breath

Posted by • June 19th, 2015

In the latest Case Record of the Massachusetts General Hospital, a 71-year-old man presented with sudden chest pain, diaphoresis, shortness of breath, and hypotension. An electrocardiogram showed new ST-segment elevations. Ten days earlier, an implantable cardioverter–defibrillator had been placed. Diagnostic procedures were performed.

Complications of ICD placement are well described, and ICD lead migration or dislodgment occurs within a few days after implantation in approximately 0.14 to 1.2% of patients. Early clinical signs of lead perforation can be subtle and nonspecific, so a rapid and focused evaluation is required, even in the absence of signs of tamponade on physical examination.

Clinical Pearls

Are there known risk factors for perforation of an ICD lead?

A few risk factors for lead perforation, including female sex and a low body-mass index, have been described. Some data suggest that myocardial fibrosis, which is frequently observed in patients with ischemic cardiomyopathy, may be protective against perforation. Ventricular hypertrophy and diabetes, both of which are associated with fibrosis, may be associated with reduced rates of perforation.

What is the typical time course for ICD lead dislodgement, and what risk does it carry for a related major adverse event?

The overall incidence of ICD lead dislodgment is highest in the first weeks after implantation, before myocardial fibrosis occurs at the insertion site. Perforations that occur 1 month or more after implantation are rare but have been reported. In nearly 11% of patients with lead dislodgment, another related major adverse event (e.g., cardiac perforation and tamponade, pneumothorax, or cardiac arrest) or in-hospital death occurs.

Morning Report Questions

Q: Is lead perforation challenging to diagnose?

A: During the diagnostic evaluation of a patient who has had any recent medical or surgical procedure, the clinician should consider and rule out periprocedural complications. The manifestations of ICD lead migration are protean and may be surprisingly subtle. However, the events after a lead perforation may evolve rapidly, and a normal overall examination or ultrasound examination at any one point in time cannot rule out a perforation. To make a diagnosis of lead perforation, a high index of suspicion is required, and the diagnostic strategy must expeditiously rule out other lethal possibilities, including aortic dissection and pulmonary embolism. It is important to note that chest radiography is not very sensitive in the detection of lead migration. It is also important to remember that changes in lead measurements can reveal lead migration even in the absence of definitive imaging findings.

Figure 3. CT Images of the Chest.

Q: How should you manage perforation of an implantable cardioverter-defibrillator lead?

A: Lead perforation must be addressed promptly, because it can precipitate life-threatening cardiac tamponade within minutes. The key issue in the management of a lead perforation is to be prepared for decompensation or a disaster at the time the lead is extracted. Extraction of a migrated lead is performed in the operating room; the patient should receive general anesthesia and be monitored with transesophageal echocardiography. In the majority of cases, a lead associated with a perforation can be withdrawn without substantial bleeding into the pericardium. Even when the presence of the ventricular lead tip outside the myocardial wall is confirmed by CT scan, management of lead migration cannot be based on imaging findings alone. Careful correlation between the imaging findings and repeat device interrogation is required before a treatment strategy can be formed. It is possible to see a lead tip located beyond the myocardial border on CT without finding any evidence of change in lead measurements or pericardial effusion; this is frequently termed an asymptomatic lead perforation and does not necessarily require revision of the lead.

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