Pulmonary Thrombo Embolism (PTE) is the third leading cause of sudden death worldwide. Around 10 per cent of symptomatic pulmonary embolism (PE) is fatal in the first hour. Risk factors include prolonged immobilization, advanced age, diabetes, smoking, obesity, recent surgeries.

Patients with genetic predisposition together with precipitating factors lead to overt PTE. Main genetic determinants are resistance to activated protein C, mutations in factors V and prothrombin deficiency, according to Lt Gen. Dr BN Shahi, New Delhi.

Clinical features depend on the size of emboli, cardiopulmonary status and right ventricular status. Dyspnoea is the most common symptom followed by tachycardia, chest pain and cough. Investigations include ECG, chest X-ray, V:Q scan and spiral CT scan. MR angiography is non invasive and informative, but costly. Pulmonary angiography is a diagnostic modality, and echocardiography is done for risk stratification.

If thrombolytic therapy is contraindicated or failed, catheter based embolectomy or surgical embolectomy is done.