Complete Heart Block and Massive Pericardial Effusion as the Presenting Manifestations of Metastatic Colorectal Adenocarcinoma

Abstract

Background

Colorectal cancer is the most prevalent gastrointestinal cancer in Asia. Cardiac metastasis is exceedingly rare, and clinical detection during life is low as most cases remain clinically silent.

Case Summary

A 41-year-old woman with a history of locally advanced rectal adenocarcinoma, who previously underwent upfront surgery and adjuvant chemotherapy, presented with progressive dyspnea and recurrent syncope. Evaluation revealed complete heart block and a large pericardial effusion. Pericardial fluid drainage was immediately performed, and a permanent pacemaker was subsequently implanted, resulting in clinical improvement.

Discussion

This case highlights extensive cardiac infiltration manifesting 2 life-threatening cardiac manifestations in a recurrent rectal adenocarcinoma, underscoring the importance of immediate interventions.

Take-Home Messages

In retrospect, the absence of total neoadjuvant therapy in the initial management may have contributed to early recurrence of rectal cancer. Prompt and coordinated multidisciplinary interventions are crucial in a critical cardiac metastatic disease to improve survival and quality of life.

Graphical Abstract

History of Presentation

A 41-year-old female patient presented with progressive dyspnea and episodes of syncope over the previous 5 months.

Two years earlier, the patient was diagnosed with mid-to-low rectal adenocarcinoma, poorly differentiated stage IIIC (pT4aN2bM0) at another institution. She underwent upfront total mesorectal excision, colostomy, and total abdominal hysterectomy with bilateral salpingo-oophorectomy followed by adjuvant chemotherapy (capecitabine and oxaliplatin) for 6 months. She was apparently well with good functional capacity. Surveillance scans were performed, showing no recurrence of disease.

With the present symptoms, the following initial tests were performed: 1) electrocardiogram which showed a complete heart block (CHB) with incomplete left bundle branch block pattern (Figure 1); 2) 2-dimensional echocardiogram (2DE) which revealed a large pericardial effusion with cardiac tamponade (Figure 2, Video 1); and 3) chest radiograph which showed a large cardiac silhouette and a small amount of left-sided pleural effusion (Figure 3). Immediately, the patient was advised get admitted for urgent pericardial fluid drainage. At the emergency department, the patient was complaining of shortness of breath and dizziness with the following vital signs: blood pressure of 110/70 mm Hg without pulsus paradoxus, heart rate of 44 beats/min, respiratory rate of 23 breaths/min, and oxygen saturation of 98% on room air.

Figure 1.

12-Lead Electrocardiogram Demonstrating Third-Degree Atrioventricular Block With Incomplete Left Bundle Branch Block

Figure 2.

2-Dimensional Echocardiogram 4-Chamber View Demonstrating a Large Pericardial Effusion (Red Arrow) With Right Ventricular Diastolic Collapse (Yellow Asterisk) During Diastole (Red Arrowhead)

LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.

Figure 3.

Chest Radiograph Anteroposterior (AP) View Demonstrating Large Pericardial Effusion Indicated by a Flask-Shaped Cardiac Silhouette and Left-Sided Pleural Effusion

Differential Diagnosis

Tuberculosis commonly manifests with large pericardial effusion, cardiac tamponade, or constrictive pericarditis in chronic stages; however, CHB through tuberculous myocarditis is uncommon. Sarcoidosis typically involves granulomatous infiltration of the conduction system, particularly the atrioventricular node and His-Purkinje system, leading to conduction abnormalities; pericardial effusion is usually mild, with large effusions or tamponade being uncommon.

Intervention

The initial preoperative plan was to place a temporary pacemaker wire via the right femoral vein before a pleuropericardial window procedure under general anesthesia, but this was not performed. Intraoperatively, the patient developed pulseless ventricular tachycardia requiring 2 cycles of cardiopulmonary resuscitation, epinephrine, and 200 J of biphasic cardiac defibrillation. The patient responded to dobutamine drip at 60-70 beats/min in intermittent sinus rhythm. Because of the emergent situation, a tube pericardiostomy was performed as a safer alternative. Pericardial fluid drainage was successfully performed, with a total amount of 1,397 mL of blood-tinged fluid drained. Pericardial fluid tests performed using GeneXpert were negative, and there was no growth on culture. A pericardial tissue biopsy was obtained, revealing a metastatic adenocarcinoma (Figure 4). The pericardial fluid cell block cytology was positive for tumor cells.

Figure 4.

Histopathologic Findings of Pericardial Biopsy

Pericardial biopsy specimen obtained during the tube pericardiostomy. (A) Low-power view showing tumor cells admixed with abundant inflammatory infiltrates and red cells; (B) high-power view demonstrating a poorly differentiated metastatic adenocarcinoma, characterized by acinar formation with luminal mucoid secretions (red arrow) and signet-ring tumor cells (green arrow).

Dual-chamber pacemaker implantation was planned; however, the patient opted for a single-chamber pacemaker to be implanted after 2 weeks because of financial difficulty. The patient was discharged with significant improvement in dyspnea.

Five days post discharge, the patient underwent ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), which revealed soft tissue fullness within the pericardium anterior to and compressing the right atrium (Figure 5). Hypermetabolic bilateral pleural and pulmonary nodules were also noted. Carcinoembryonic antigen was elevated at 11.52 ng/mL (normal range: 0.14-6.5 ng/mL), which suggested tumor recurrence.

Figure 5.

¹⁸F-Fluorodeoxyglucose Positron Emission Tomography

(A) Transaxial image showing soft tissue fullness within the pericardium anterior to and compressing the right atrium (red arrow) with noted hypermetabolic pericardial effusion; (B) transaxial image demonstrating hypermetabolic lesions at the precarinal (red arrow) and para-aortic (white arrow); and (C) paratracheal regions (red arrow).

A day before the scheduled single-chamber ventricular pacemaker implantation, the patient went into a witnessed transient, self-terminating generalized tonic-clonic seizure, preceded by an approximately 10-second sinus pause. A single-chamber ventricular pacemaker was implanted the following day, achieving hemodynamic and rhythm stability as shown in Figure 6. Three weeks later, the patient received the first cycle of folinic acid, 5-fluorouracil, and irinotecan. Molecular biomarker testing for NRAS, KRAS, MSI/MMR, and HER2 was requested; however, it was not performed.

Figure 6.

12-Lead Electrocardiogram Demonstrating Ventricular Pacemaker Rhythm With Good Capture

Outcome and Follow-Up

Five months later, the patient completed 6 cycles of folinic acid, 5-fluorouracil, and irinotecan. The patient reported occasional exertional dyspnea and hoarseness, remaining physically active but limited in strenuous activity. A repeat FDG-PET was performed, demonstrating persistent hypermetabolic pericardial soft tissue fullness compressing the right atrium. A new hypermetabolic mass lesion was found at the left lower lung lobe, epigastric abdominal wall, right anterior subdiaphragmatic space, and a cortical lytic lesion in the left femur. A 2DE showed scanty pericardial effusion (Figure 7, Video 2), and chest radiograph revealed a smaller cardiac silhouette and worsening of left pleural effusion (Figure 8) as compared with Figure 3. These findings indicate progressive metastasis with relatively stable cardiac-related clinical symptoms.

Figure 7.

2-Dimensional Echocardiographic 4-Chamber View Demonstrating Scant Pericardial Effusion Without Cardiac Tamponade 5 Months Post Pericardiocentesis

LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.

Figure 8.

Chest Radiograph Anteroposterior View Showing Smaller Cardiac Silhouette and Worsening Left-Sided Pleural Effusion 5 Months Post Pericardiocentesis

Discussion

Cardiac metastasis from colorectal adenocarcinoma is exceptionally rare, with only 31 cases reported in the literature.¹ This case is notable for 2 reasons: First, it involves a relatively young 41-year-old female patient, whereas cardiac metastases more commonly occur in older, predominantly male patients.² Second, it demonstrates extensive cardiac involvement, presenting with a large symptomatic pericardial effusion and CHB, highlighting the associated mortality risk.

Although more than 90% of metastatic cardiac tumors are clinically silent, symptom onset depends on the site of involvement.³ In this case, FDG-PET demonstrated extensive pericardial metastases with compression of the right atrium and involvement of the pericardial fluid. Notably, the presence of widespread metastatic deposits in the para-aortic, paratracheal, and precarinal lymph nodes suggests a lymphatic route as the primary mechanism for this condition. The large pericardial effusion reflects malignant cell exfoliation with associated inflammation. The occurrence of CHB indicates myocardial invasion of the conduction system; a wide QRS complex escape rhythm localizes the block to an infrahisian level, suggesting infiltration of the interventricular septum and bundle branches. This progression from pericardial to myocardial involvement is consistent with the pattern described by Lichtenberger et al⁴ where epicardial and myocardial metastases often occur secondary to pericardial disease.

FDG-PET is a highly sensitive imaging modality for detecting metastatic disease, offering valuable whole-body assessment in patients with cancer.⁵ However, its interpretation in cardiac metastasis remains challenging because of variable physiological myocardial uptake, which can obscure true lesions and often necessitates correlation with other imaging modalities for confirmation. In this case, the definitive diagnosis was achieved through pericardial tissue biopsy and pericardial fluid cytology, which confirmed metastatic adenocarcinoma, a method with a reported diagnostic sensitivity of 70%-90%.⁶

When an isolated metastasis or oligometastatic disease is identified, several treatment approaches, however, require careful evaluation of multiple factors, including the extent of disease, tumor burden, coexisting medical conditions, genetic profile, and a personalized assessment of potential risks and benefits. The initial plan for a pleuropericardial window, a more definitive procedure to prevent possible reaccumulation of pericardial effusion, was abandoned in this case because of concomitant CHB, without prior temporary pacing. Furthermore, a significant clinical challenge was the delay in permanent pacemaker implantation because of financial constraints, causing vulnerability to syncope, seizure, or asystole, which led to sudden cardiac death.

The planned pleuropericardial window and dual-chamber permanent pacemaker implantation were not performed, and the patient was likewise unable to undergo molecular biomarker testing because of financial constraints. These limitations underscore how socioeconomic barriers can restrict access to optimal treatment interventions, which may influence clinical outcomes.

The new standard of care for locally advanced rectal cancer is total neoadjuvant therapy (TNT), which includes systemic chemotherapy and concurrent chemoradiation. A recent clinical trial, PRODIGE-23, assessed TNT in comparison with adjuvant treatment in locally advanced rectal cancer, showing a 7.6% absolute increase in 5-year disease-free survival and a 9.9% increase in metastasis-free survival compared to adjuvant therapy.⁷ Having upfront rectal surgery without neoadjuvant treatment may have contributed to early recurrence of malignancy.

The prognosis for patients with cardiac metastasis remains poor, reflective of widespread, aggressive disease. A recent retrospective analysis by Lin et al⁸ reported a 12-month survival rate of only 38% for patients with metastatic cardiac tumors. The same study emphasized that continued antitumor therapy after the diagnosis of cardiac metastasis can significantly improve outcomes, with a median survival of 55.6 months compared to 13.4 months for those without further treatment. Therefore, although the development of cardiac metastasis is an ominous sign, active and tailored systemic therapy offers the best chance for prolonging survival.

Conclusions

Cardiac metastasis, though uncommon, should always be considered in patients with known malignancy who present with new or unexplained cardiac symptoms, even in cases of rectal adenocarcinoma where cardiac involvement is exceedingly rare.

Metastatic cardiac infiltration involved multiple regions of the heart, leading to 2 life-threatening manifestations: massive pericardial effusion with cardiac tamponade and CHB. The coexistence of these complications highlights the aggressive nature of metastatic disease and significantly increases the risk of mortality. In retrospect, the absence of TNT in the patient's initial management may have contributed to early recurrence.

Overall, management of complex, concurrent life-threatening cardiac manifestations necessitates a multidisciplinary approach integrating cardiology, surgery, oncology, and anesthesiology, particularly in the context of limited patient resources and the need for proactive risk anticipation. With timely diagnosis and a well-coordinated treatment plan, patient survival and quality of life may still be improved, even in cases that initially present in a critically ill state.

Funding Support and Author Disclosures

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

Take-Home Messages

• •In retrospect, the absence of total neoadjuvant therapy in the initial management may have contributed to early recurrence of rectal cancer.
• •Prompt and coordinated multidisciplinary interventions are crucial in a critical cardiac metastatic disease to improve survival and quality of life.

Appendix

Video 1

Two-Dimensional Echocardiogram 4-Chamber View Showing a Massive Pericardial Effusion Indicating Cardiac Tamponade at Presentation

Video 2

Two-Dimensional Echocardiogram 4-Chamber View Showing Scanty Pericardial Effusion Without Cardiac Tamponade Five Months Post Pericardiocentesis