Sudden Death

Sudden death is commonly the first presenting symptom indicative of coronary heart disease. Some published reports suggest that over 50% of patients have as their first cardiac episode, an episode of sudden death. Unfortunately, most do not survive.

It is called sudden death or sudden cardiac death, because as the name may imply it occurs completely unexpected. Despite the suddenness of this condition, it is by no means rare. In the United States last year for example, an estimated 310,000 people suffered from an episode of sudden death.

The latest example of what may be sudden death occurred to Michael Jackson. Since the tragic and unexpected news of Mr. Jacksons passing, my office phone has been ringing off the hook, with patients who are naturally alarmed and concerned.  It seems that it takes a tragedy of significant proportion to rattle us into noticing what should have been obvious all along. We get caught up in our own mostly insignificant situations, which we may tend to blow out of proportion and ignore the important issues the most important of which is our health.

As of this day, the public is unaware of whether Mr. Jackson had some pre-existing medical condition, history of coronary artery disease(C.A.D.), a weak heart muscle (cardiomyopathy), any other heart disease, or was taking medications either prescribed or otherwise etc.

By the shocking and unexpected nature of his passing for his family though, it suggests that at least for most people who were close to him, no obvious sign of any significant medical condition existed.

If this is the case, then more than likely it can be categorized as an episode of sudden death. In younger aged patients without known medical conditions, common causes of sudden death include arrhythmias (heart beat irregularity), specifically arrhythmias that originate from the lower heart chamber or ventricles. The most common forms of ventricular arrhythmias include ventricular fibrillation or ventricular tachycardia. Another important cause of sudden death is diseases of the ventricular muscle itself, or what we call a cardiomyopathy. There are many potential cardiomyopathies that can result in sudden death, and most have in common a thickened or altered ventricular muscle architecture.

But by far the leading cause of sudden death is CAD. Coronary disease is the condition of narrowed, atherosclerotic arteries. Arteries that with time have become clogged with cholesterol and fat deposits. These are a ticking time bomb just waiting to go off and explode. For sudden death to result from a blocked artery, the artery that is blocked or occluded has to be a main/principal coronary artery, and must be completely and acutely blocked off. It’s not fat or cholesterol that causes the acute, total blockage, it is rupture of a plaque that produces that occlusion.

Plaque is an accumulation of lipids, fats, blood cell products and other circulating cells, which with time builds up. By use of intra-vascular ultrasound we know that many times this build up of debris if you will in addition to encroaching and reducing the size of the blood vessel lumen, also extends outwards away from the lumen of the artery. This explains why some people may have a normal stress test or cardiac catheterization, yet have a heart attack days later.

So an inflammatory process is occurring under the surface cells that line the coronary arteries. This cell lining is called the endothelium. Slowly and continuously material, junk, accumulates and forms a little volcano-like structure. No one knows all the triggers or causes, but at some point the surface of this plaque is eroded, its contents makes contact with circulation platelets, the body’s coagulation system is triggered and as a result a huge clot forms which blocks the artery completely. All this occurs with seconds to minutes and the result is sudden death.

We cardiologists now know that many patients may have mini episodes of plaque rupture that do not produce sudden death. With the use of ultrafast CT scans, we can quantify calcium located within the coronary arteries. It’s not normal to see calcium in the coronary arteries as its presence is indicative of blood.  But with CT angiography we can quantify the amount of calcium found, score it and provide another risk assessment for patients. The higher the calcium score, the higher the risk for a future cardiac event.

Typically we need to wait on autopsy reports to determine the specific cause, including reports of toxicology as there may be medications and substances that can contribute to sudden death.