Mbuli died of pulmonary embolism

It reported that this was the outcome of a post mortem conducted on Monday.

Previous reports that Mbuli suffered a heart attack were untrue, family spokeswoman Rowena Baird told the SABC.

"His blood had clotted and he had two relatively large clots," she told the broadcaster. "The clots tend to move around the body, and they moved to his chest, hence he complained of chest pains."

Mbuli, 46, collapsed while watching the Cheetahs' 27-13 Vodacom Super Rugby win over the Reds at the Free State Stadium on Saturday night.

He was treated on the scene before being taken to the Mediclinic hospital in Bloemfontein, where he died.

An embolus is a “travelling clot” and pulmonary embolism (PE) is a complication of deep venous thrombosis (DVT) clot formation in a vein elsewhere in the body.

The clot or clots break off (now called an embolus) and travel through the veins and the right side of the heart, and blocks one or several lung arteries, preventing blood flow to parts of the lung. This results in less oxygen  reaching the rest of the body.

There are many known risk factors for this condition. Diagnosis may be missed or delayed due to non-specific symptoms, but special tests can be done and specific treatment started.

What causes pulmonary embolism?

The causes of pulmonary embolism can be divided into three categories:

 damage to the venous endothelium (lining of the vein) due to indwelling catheters, injection of irritating substances into the vein, sepsis, etc.

 increased coagulability (e.g. blood disorders, cancers, oral contraceptives, etc.)

venous stasis (postoperative, after child birth, varicose veins, etc.)

Who is at risk?

The risk factors for developing thrombosis and thus PE can be divided into major (where the risk is greater than 5-20 times normal) and minor (where the risk is 2-4 times normal).

Major risk factors include the following:

• trauma (including fractures, especially of the femur, hip and pelvis)
• surgery within the last three months (especially of the hip, knee and abdomen or pelvis)
• malignancy/cancer (especially of lung, pancreas or colon)
• prolonged immobilisation/inactivity (in bedridden patients, e.g. strokes, spinal cord injury, severe burns, etc.)
• pregnancy & Caesarean section (especially post-delivery)
•  varicose veins
•  previous DVT or PE-existing respiratory disease.

Minor risk factors include:

•  oestrogen-containing contraceptive pills and hormone replacement therapy (HRT)
• general medical illness (e.g. heart disease, lung disease, hypertension, TB, kidney disease causing nephrotic syndrome)
• obesity (BMI > 29kg/m²)
• travel (long distance sedentary, especially by air: “Tourist Class Syndrome”)
• advanced age
• heavy cigarette smoking (>25/day)
• indwelling venous lines.

Some patients develop PE without obvious risk factors and these may have unsuspected abnormalities which favour the development of DVT and PE, e.g. increased levels of clotting factors in their blood.