Uncommon Cardiac Perforation and Lead Displacement After Pacemaker Implantation: A Case Study and Diagnostic Insights

Introduction

With the advances in medicine and improved accessibility in recent years, more patients are undergoing permanent pacemaker implantation. A worldwide cardiac pacing and implantable cardioverter-defibrillator survey (2009) found that 1 002 664 pacemakers were inserted in 61 countries across Europe, Asia Pacific, the Middle East, Africa, and the United States, of which 737 840 were new implants, and 264 824 were replacements [1]. Over the past 10 years, the growth in the pacemaker implantation rate has increased by more than 100%, with the highest growth rate in non-European (80%) and Eastern European (60%) countries [2]. While pacemaker implantation is generally perceived as a low-risk intervention, it is imperative to acknowledge that short- and long-term complications, as well as technical oversights during surgery, can still occur. Although the incidence of complications from pacemaker implantation is low, estimated at around 7%, it is crucial to recognize that some complications can pose life-threatening risks [3]. For instance, pneumothorax resulting from cardiac perforation, albeit rare, has the potential to escalate to conditions like tension pneumopericardium and cardiac tamponade [4]. Among these complications, tension pneumopericardium, although rare, can result in significant respiratory distress, elevated central venous pressure, and hypotension in severe cases. Similarly, cardiac tamponade can lead to reduced cardiac output. If left untreated, these conditions can ultimately culminate in cardiac arrest [4].

This report highlights a case of myocardial perforation and left-sided pneumothorax resulting from the passage of the right ventricular lead through the heart after dual-chamber pacemaker implantation, even in the absence of typical symptoms of complications. It is imperative that frontline healthcare providers remain vigilant regarding the occurrence of complications following pacemaker implantations, despite their low incidence rates. The dangers associated with these complications are underestimated, especially among high-risk groups, thereby emphasizing the importance of prompt recognition and intervention.

Case Report

An 87-year-old man was sent to the Emergency Department with dizziness and progressive dyspnea. He had a medical history of hypertension, peptic ulcer, sigmoid cancer, and anemia. Physical examination showed a height of 168 cm, weight of 42.8 kg, body mass index (BMI) of 15.16, blood pressure of 130–140/55–80 mmHg, heart rate of 45 beats per min, and no neurological abnormalities. An electrocardiogram revealed complete atrioventricular block, and a chest X-ray showed cardiomegaly and pulmonary edema. Blood test disclosed hemoglobin: 13.8 gm/dL; BUN/Cr: 26/1.51 mg/dL; sodium: 131 mmol/L; potassium: 4.0 mmol/L; and NT-proBNP: 4770 pg/mL. Daily medications were as follows: amlodipine 5 mg daily, mosapride 5 mg daily, famotidine 20 mg daily, and vitamin B1 twice daily. There was no previous medical history of medication aimed at controlling the heart rate.

After initial evaluation, dizziness related to vertigo, gastrointestinal bleeding, and stroke were excluded. Therefore, a temporary pacemaker was inserted, and he was transferred to Coronary Care Unit. Diuretics were administered for pulmonary edema. His echocardiogram showed an ejection fraction of 52%, mild left ventricle chamber dilation (left ventricular size was 55/36 mm). The right ventricular anterior wall dimension measured 5.4 mm, without abnormal thinning. There was mild tricuspid regurgitation. Following the resolution of pulmonary edema, a dual-chamber permanent pacemaker implantation was scheduled. The leads were advanced into the heart via the left subclavian vein and passively positioned in the right atrium (tined lead; Figure 1A) and actively fixed (screw-in lead; Figure 1B) at the right ventricular apex, considering the better lead stability. After the implantation, the pacemaker settings were as follows: atrial lead parameters included a threshold of 0.4 V/ms and sensitivity to P waves at 8.5, while ventricular parameters included a threshold of 0.7 V/ms and sensitivity to R waves at 5.5. The lowest programmed heart rate was set to 50 beats per min, with an upper limit not exceeding 120 beats per min. Fluoroscopy immediate after the procedure showed normal lead positioning. The post-procedural pacemaker check confirmed normal pacemaker function; meanwhile, the electrocardiogram showed a left bundle branch block paced QRS pattern. Subsequently, the patient was returned to the Cardiac Care Unit for further monitoring after the reconfirmation of the pacemaker’s normal function.

The patient’s condition was uneventful the next morning, with a blood pressure of 120–140/75–85 mmHg and heart rate of 60–80 beats per min. The patient did not report any symptoms suggestive of complications, such as chest pain or dyspnea. Later that day, the patient developed bradycardia of 45–50 beats/min, and capture failure was observed on the electrocardiogram (ECG)/telemetry (Figure 2A). Despite attempts to adjust pacing output, there was no response, and the ECG showed persistent complete heart block with right bundle branch block (Figure 2B).

Physical examination remained unremarkable, and vital signs were relatively stable, aside from slower heart rates and reduced breath sounds in the left lower lobe. Chest X-ray disclosed ventricular lead displacement and pneumothorax. Bedside echocardiography revealed a small amount of pericardial effusion, with no features of cardiac tamponade. Given these findings, lead displacement causing the capture failure and pericardial effusion was suspected. Consequently, computed tomography was conducted, revealing the lead traversed the right ventricle, and left-sided pneumothorax was present (Figures 3, 4, indicated by arrows). Consultation from a thoracic specialist was sought, and a chest drain was inserted.

On the second postoperative day, the patient was scheduled for a percutaneous lead revision. The extraction and replacement of perforated leads was performed under fluoroscopic guidance. Repeated transthoracic echocardiography was performed for surveillance of pericardial effusion. Open heart preparation was made in advance, and a cardiothoracic surgery team was on standby in case of severe tamponade during lead repositioning. The right ventricular lead was safely repositioned to the ventricular septum (Figure 5). The following day, the patient exhibited stable vital signs, and the electrocardiogram confirmed pacemaker pacing response (Figure 6). A subsequent chest X-ray revealed no obvious pneumothorax, prompting the removal of the chest tube. Upon achieving stability, the patient was transferred to the general ward and discharged safely from the hospital. Subsequent follow-up visits revealed no complications.

Discussion

Various factors can contribute to complications following pacemaker implantation, including artificial factors, technical factors, and patient constitution. Early detection and prompt treatment are crucial, as they can significantly reduce the risk of life-threatening situations. It is also essential to emphasize the role of routine postoperative assessments and investigations, such as electrocardiography, chest X-rays, and pacing checks, in detecting potentially silent complications [5].

Drawing from the insights gained in this case study, the following 3 points are proposed for further discussion. First, except for monitoring clinical symptoms and pacemaker function, close monitoring of the ECG is crucial, as it facilitates the detection of pacing errors or absence of pacing following pacemaker implantation [6,7]. Typically, the ECG after right ventricular pacing should exhibit a left bundle branch block pattern. However, the occurrence of right bundle branch block after pacing serves as an important indicator that the implanted lead may have shifted [8]. In addition, ventricular lead perforation can be diagnosed through various examinations, including fluoroscopy, cardiac ultrasound, and computed tomography [5]. Especially for high-risk groups or those with inconspicuous symptoms of complications, it is crucial to closely perform physical examination and monitor ECG, point-of-care ultrasound (POCUS), and serial chest radiography [9]. These diagnostic methods aid clinicians in performing comprehensive assessments and confirming the presence of lead perforation.

Second, the risk of complications is influenced by medical factors and patient constitution. Regarding medical factors, pacemaker leads are categorized into passive and active fixation leads. The method of active fixation lead has gained popularity because of various merits, such as ease of placement, higher fixation stability, and lower dislodgement rate [10]. However, literature indicates that active fixation leads, due to their frontal structure, can pose a higher risk of pericardial perforation than can passive fixation leads [9,10]. Of note, factors such as old age, lean body, and thin myocardial walls can also pre-dispose active fixation leads to developing myocardial perforation as a complication [11]. The possible mechanism is that the active fixation lead, due to its screw-shaped electrode that requires rotation to anchor within the myocardial layer, can exert localized pressure on the myocardium. If the myocardial wall is thin, or if there is excessive rotation during the lead fixation process, it can result in myocardial perforation [11]. Therefore, when using active fixation leads, careful selection of the lead tip structure is essential to avoid an overly rigid tip with a small diameter to reduce pressure on the heart wall, especially in high-risk patients. Additionally, literature has suggested that the lead should be fixed in the septum of the right ventricle rather than the apex [9].

In terms of patient’s constitution factors, as per a study conducted by Yale University, Massachusetts General Hospital, and Harvard Medical School, an analysis of pacemaker implantation safety in the elderly population revealed that age alone is not the sole predictor of poor prognosis. It is imperative to also take other comorbidities into account [12]. Other research stated that old age, female sex, underweight (BMI <20 kg/m2), myocardial wall thinning, dilated cardiomyopathy or myocardial atrophy, and the use of anticoagulant or steroid medication within 7 days after implantation can increase the risk of lead perforation [11,13]. Nevertheless, the patient in this case study, aged 87 years, with a BMI of 15.16, an enlarged heart, and the utilization of an active pacing lead in the ventricle, met the high-risk factors outlined in the aforementioned studies/reports.

Third, regarding treatment, the readjustment of lead placement is commonly recommended as an essential measure. Some experts argue that for asymptomatic, incidental lead-induced cardiac perforation, lead removal may not be necessary. However, in cases of cardiac tamponade, pericardiocentesis becomes essential. Failure to catch this complication could eventually lead to cardiac arrest and death. Thoracotomy serves as an alternative, albeit more aggressive, treatment option and should be considered only as a last resort [9,14].

Conclusions

This case study underscores the complexity and potential severity of complications following pacemaker implantation, particularly in high-risk patients. It highlights the critical importance of early detection and prompt intervention to prevent life-threatening outcomes. Key takeaways include the necessity for vigilant postoperative monitoring using ECG, chest X-rays, and advanced imaging techniques to identify lead displacement and cardiac perforation. Additionally, the findings emphasize that while the patient’s age is not the only significant factor, other comorbidities (such as low body weight and thin myocardial walls) and the type of pacing lead used also play crucial roles in determining risk levels. For high-risk groups, it is crucial to maintain heightened vigilance and keep a strong suspicion for lead perforation. When using active fixation leads, it is preferable to prioritize implanting the lead in the ventricular septum rather than the apex. This approach helps mitigate the risk of perforation. Effective management, including timely lead repositioning and thoracic drainage, as demonstrated in this case, can lead to favorable outcomes even in the presence of severe complications.