This is an interactive model of the heart's two main pumping chambers: the ventricles. Spin, zoom, drag, and open the heart using the gestures shown at the bottom. Vary the heart rate using the slider on the right.

The heart pumps blood around the body to provide all the organ systems with oxygen and nutrients.

The ECG trace (top right) represents the electrical waves in the heart that stimulate contraction and generate pressure (middle right) to pump blood.

Click through the tabs below to learn about various heart diseases.

The heart pumps blood to itself through blood vessels called the coronary arteries (not shown in the 3D model). A heart attack occurs when blood flow is obstructed by a narrowing of these arteries.

Good lifestyle choices help to keep the coronary arteries healthy and prevent heart attacks. Learn more about how lifestyle factors can affect the heart in the following movie clips.

Click on the tabs below to learn more about minor or severe heart attacks.

Electrical waves (coloured yellow) pass through the heart to trigger contraction of the muscular walls. The heart needs coordinated electrical waves and smooth contraction to pump effectively.

The electrical waves in the heart can be measured by placing electrodes on the chest. This is called an electrocardiogram (ECG) recording, as shown at the right.

Click on fibrillation below to see what happens when this smooth electrical activity is disrupted.

Long term problems such as high blood pressure or untreated heart attacks can eventually cause the heart to fail.

In heart failure, the heart needs to work harder than normal to meet the demands of the body. This can lead to changes in the heart's shape and stiffness, and its ability to contract and relax.

Click on the tabs below to learn more about the different types of heart failure.

In a heart attack, fatty deposits build up inside the coronary arteries. This obstructs blood flow to the heart muscle and causes tissue damage.

Less pressure is generated by hearts with damaged tissue (yellow trace) compared to healthy hearts (green trace).

Medications such as statins and aspirin help to clear coronary blockages. They must be combined with healthy lifestyle choices to help prevent further heart attacks.

In compensated heart failure the muscular walls of the heart get thicker in response to prolonged high blood pressure. Open the heart (double-click) to see the thicker heart walls.

In compensated failure, during each beat less blood is able to enter the heart, because of thicker walls, increased stiffness, and/or delayed relaxation.

At rest, the heart can cope with these problems, and patients may not show any symptoms. However, during exercise or stress, they may find that their hearts cannot effectively respond to the increased demand to pump blood.

Researchers are still seeking effective treatment options for patients with compensated heart failure. Some suggest that it may lead on to decompensated heart failure, described in the tab below.

If a minor heart attack is left untreated, or if medication is stopped too early, then the coronary artery blockage can become more severe.

A severe heart attack can cause permanent damage to a large portion of heart tissue. This prevents the heart from generating enough pressure to pump blood around the body (red trace).

Muscle damage due to a heart attack can lead to problems with electrical activity of the heart. Untreated heart attacks can eventually lead to heart failure.

Chaotic electrical waves (red ECG trace) cause uncoordinated contraction of the heart muscle. This reduces the heart's ability to generate pressure (red trace).

This is a serious medical condition that needs to be treated immediately. An automated external defibrillator (AED) is able to restore the smooth electrical waves in the heart by applying a large electrical shock across the chest.

AED devices can be found in many public places. Click on the standard AED logo below to defibrillate the virtual heart!

In decompensated heart failure the muscular walls of the heart become thinner and the heart balloons out. See these changes by opening the heart (double-click).

A heart with decompensated failure is weak and has problems with contraction and pumping of blood.

Patients with decompensated heart failure will have symptoms, even at rest. These symptoms include dizziness, breathing difficulties, inability to exercise, and chest pains.

Treatments for this disease include ACE inhibitors, beta blockers, and diuretics, which work to lower blood pressure and decrease the load on the heart.