Cardiologists are involved with the treatment and diagnosis of congenital heart problems, and they also help patients understand and avoid the risks that heart abnormalities can have on the risk for stroke. Surprisingly, stroke is the third leading cause of death in the United States, and patients who are not treated promptly can go on to suffer debilitating after-effects such as the loss of use of various parts of their bodies. Risk factors for stroke include high blood pressure, high cholesterol, diabetes, and inactivity. The cardiac abnormalities that can increase the risk of stroke include atrial fibrillation left ventricular hypertrophy, among others.

Most simply put, atrial fibrillation is a type of abnormal heartbeat that causes the heart rhythm to be both fast and irregular. When it happens, this type of irregular beat causes the two upper chambers of the heart (known as the atria) to beat chaotically and irregularly such that they are no longer synchronized with the lower chambers of the heart (called the ventricles). This type of irregular heartbeat can cause shortness of breath, heart palpitations, and weakness. Although the condition is not normally life-threatening in and of itself, it is associated with a greater risk for stroke. Some risk factors for atrial fibrillation include high blood pressure (which is an independent risk factor for stroke), diabetes, hyperthyroidism, alcohol consumption, and diabetes. The total lifetime risk that a patient will suffer from atrial fibrillation is about 26% for men and 23% for women.

The relationship between atrial fibrillation and stroke risk is somewhat complex, because each disease shares some common risk factors, and each can predispose the patient to developing the other condition. Patients with atrial fibrillation have anywhere between two and three times the risk of developing stroke as compared to patients without the disorder. Likewise, patients with the condition are more likely to die than are those without this type of abnormal heartbeat.

Another risk factor for stroke is left ventricular hypertrophy, a condition in which the muscle tissue that comprises the wall of the heart's main pumping chamber enlarges. Normally, this condition develops as a result of a response to another factor, such as high blood pressure. If the wall of the heart becomes enlarged too extensively, it can lose the elasticity necessary to efficiently pump blood to the rest of the body. A cardiologist can diagnose and help develop treatment strategies for left ventricular hypertrophy.

In the United States, for patients over 55 years of age, the risk for developing stroke is greater than the risk for developing Alzheimer's disease. Furthermore, due to the potential for lasting effects if a stroke is not treated quickly enough, all patients should know their risk factors for stroke and be treated to correct these. Maintaining a healthy weight, avoiding cigarette smoke, reducing blood pressure, and treating diabetes are all good starting points. For patients with cardiac abnormalities, the advice and care of a cardiologist are also prudent.