Cardiology > Cardiac Metastases

 Background 

1. I) Definition

Cardiac metastases are secondary tumors that involve the heart as a result of the spread of malignancies from distant primary sites. Unlike primary cardiac tumors, which are rare, cardiac metastases are relatively common and often signify advanced-stage disease. These metastases can involve any cardiac layer—pericardium, myocardium, endocardium—or present as intracavitary masses. They may be clinically silent or cause serious complications such as pericardial effusion, arrhythmias, or heart failure. 

1. II) Classification/Types

By Cardiac Layer Involvement: 

• Pericardial involvement (most common): Leads to effusion or tamponade 

• Myocardial infiltration: Can cause arrhythmias or conduction blocks 

• Endocardial involvement: Rare; may form intracavitary masses 

• Intracavitary extension: Tumor protrudes into chambers, mimicking primary tumors 

By Mechanism of Spread: 

• Direct extension: From adjacent structures (e.g., lung, breast) 

• Lymphatic spread: Common in breast and lung cancers 

• Hematogenous spread: Seen in melanoma, renal cell carcinoma, sarcomas 

• Transvenous extension: e.g., renal cell carcinoma via inferior vena cava 

By Primary Tumor Type: 

• Most common sources: 

• Lung carcinoma 

• Breast carcinoma 

• Lymphoma/leukemia 

• Melanoma 

• Esophageal and renal cell carcinoma 

Pathophysiology 

Cardiac metastases cause symptoms through mechanical compression, electrical disruption, or inflammatory effects. Pericardial metastases lead to effusions and tamponade. Myocardial infiltration disrupts electrical conduction, causing arrhythmias or heart block. Endocardial involvement may create masses mimicking thrombi or primary tumors, and embolization may occur. Systemic symptoms are more prominent with aggressive or inflammatory tumors (e.g., lymphomas, melanoma). 

Epidemiology 

• Found in ~10% of patients dying of cancer 

• Pericardial involvement is most common 

• Melanoma has the highest predilection for cardiac spread (~50% of cases) 

• More common than primary cardiac tumors by a factor of 20–40 

• Often asymptomatic and detected post-mortem 

Etiology 

1. I) Causes (Primary Sites of Origin)

• Lung carcinoma (most frequent due to proximity) 

• Breast carcinoma 

• Malignant melanoma (high metastatic potential) 

• Lymphomas and leukemias 

• Esophageal, renal cell, hepatocellular carcinomas 

• Gastrointestinal tract tumors 

1. II) Risk Factors

• Advanced malignancy 

• Highly vascular tumors (e.g., melanoma, renal cell carcinoma) 

• Tumors with thoracic proximity 

• Immunosuppressed state (increased lymphoma risk) 

Clinical Presentation 

1. I) History (Symptoms)

• Often asymptomatic until late-stage 

• Dyspnea, orthopnea: From pericardial effusion or tamponade 

• Chest pain: Pericardial or myocardial infiltration 

• Palpitations: Arrhythmias from myocardial invasion 

• Syncope: Conduction abnormalities or outflow obstruction 

• Systemic signs: Weight loss, fatigue, fever 

• Embolic events: Rare, from endocardial or intracavitary masses 

1. II) Physical Exam (Signs)

• Distant heart sounds, jugular venous distention, hypotension: Tamponade 

• Friction rub: Pericardial involvement 

• Muffled heart sounds: Large effusion 

• Signs of right/left heart failure 

• New arrhythmias or conduction blocks 

Differential Diagnosis (DDx) 

• Primary cardiac tumors (e.g., myxoma, angiosarcoma) 

• Pericarditis (viral, autoimmune) 

• Intracardiac thrombus 

• Infective endocarditis 

• Cardiac amyloidosis or sarcoidosis 

• Constrictive pericarditis 

Diagnostic Tests 

Initial Evaluation 

• ECG: Low-voltage QRS (effusion), arrhythmias, conduction blocks 

• Chest X-ray: Cardiomegaly, pulmonary congestion, pleural effusion 

• Transthoracic echocardiography (TTE): First-line to detect effusion, masses 

• Transesophageal echocardiography (TEE): Superior for posterior or small lesions 

Advanced Imaging 

• Cardiac MRI: Tissue characterization, infiltration pattern 

• Cardiac CT: Anatomic definition, involvement of adjacent structures 

• PET-CT: Detects metabolically active lesions; helpful in systemic staging 

• Pericardiocentesis with cytology: For pericardial effusion 

• Biopsy: Histologic confirmation (often guided by imaging) 

Treatment 

1. I) Acute Management

• Pericardiocentesis: Immediate relief of tamponade 

• Hemodynamic stabilization 

• Symptomatic control of heart failure or arrhythmias 

1. II) Chronic Management

• Oncologic therapy: 

• Chemotherapy for lymphoma, leukemia, metastatic disease 

• Targeted therapy/immunotherapy depending on primary tumor 

• Radiation therapy: For radiosensitive tumors (e.g., lymphoma) 

• Surgical resection: Rarely indicated, reserved for isolated masses or obstruction 

• Pericardial window or drain: For recurrent effusions 

Medications 

Device Therapy 

• Pacemaker/ICD: For conduction block or malignant arrhythmias 

• Pericardial drain or window: For recurrent tamponade 

• Mechanical support: Rare; temporary bridge in advanced cases 

Patient Education, Screening, Vaccines 

• Educate about signs of tamponade and arrhythmias 

• Emphasize importance of oncologic follow-up 

• Palliative care discussions if prognosis is poor 

• Recommend influenza and pneumococcal vaccines in immunocompromised patients 

Consults/Referrals 

• Cardiology: For cardiac evaluation and imaging 

• Oncology: Management of primary malignancy 

• Cardiothoracic Surgery: If surgical intervention required 

• Radiation Oncology: For radiotherapy planning 

• Palliative Care: For symptom management in terminal cases 

Follow-Up 

Short-Term 

• Monitor for effusion recurrence post-drainage 

• Surveillance imaging for treatment response 

• Management of heart failure or arrhythmias 

Long-Term 

• Periodic cardiac imaging if cardiac involvement remains stable 

• Long-term cancer surveillance based on primary tumor 

• Monitor for therapy-related cardiac toxicity (e.g., anthracyclines) 

Prognosis 

• Poor overall prognosis; cardiac metastases indicate advanced disease 

• Median survival varies by tumor type: 

• Melanoma and sarcoma: <6 months 

• Lymphoma with treatment: Better outcomes 

• Symptom palliation and quality of life are key goals 

• Early detection may allow for targeted treatment and improved function