What comes to mind when you hear the words “heart disease?” It’s likely to be the Hollywood heart attack … a man clutching his chest, a rush to the emergency room. That does happen, but this scene is not the whole picture. Heart disease includes a range of treatable conditions.
Dr. Robert Palac, a cardiologist at Dartmouth-Hitchcock Medical Center in Lebanon, says, “Think of the heart as a pumping system, with arteries and valves,” he says.
“Then think of the heart as a muscle system that has an electrical system to coordinate contraction of the heart. A problem can occur within any of these systems. Careful diagnosis is critical.”
It is usually a complaint or symptom that brings the patient to the attention of the cardiologist. That might be shortness of breath, chest discomfort and light-headedness. A patient with risk factors for coronary artery disease (atherosclerosis) — hypertension, high blood fat, obesity, diabetes, smoking and a family history of heart disease among them — should also be evaluated.
In today’s world, patients often expect sophisticated medical technology to play a role, and indeed it may. But diagnosis begins with basic techniques, says Dr. Palac. A thorough history (family and personal) is a first step. “We will listen to the heart and lungs with a stethoscope; we will listen for turbulent blood flow, check blood pressure, often in both arms and legs, and feel pulse strength.”
Beyond these basic techniques, there are many sophisticated, noninvasive tests that may be used to evaluate the heart structurally and functionally. Ultra sound is one example. A hand-held transducer emits a sound wave that penetrates the skin, giving a moving picture of cardiac structure. A cardiac Doppler uses sound waves to evaluate blood flow in the heart and identify heart valve leakage. Such tests, perhaps combined with exercise modalities, such as walking on a treadmill, will give a great deal of information.
Ultra sound now can give a three-dimensional image of the heart, which improves quantitative measures of heart chamber sizes and evaluation of the heart valve. Magnetic resonance imaging (MRI) is another technique that gives a moving picture of the heart and high-resolution images of structures in and around the heart. It can also be used to characterize tissue content (scar fat or healthy muscle). Coronary CTA (computed tomograph angiogram) is a noninvasive alternative to the well-established catheter-based procedure of coronary angiography. Coronary CTA is very accurate in excluding coronary blockages in carefully selected patients.
Dr. Palac gives examples of possible problems, relating them to the blood flow through the heart, the electrical and the muscular functions of the heart. Arrhythmias (irregular beating or changes in rhythm) can be a serious or benign problem with the electrical system. Various forms of monitoring are available to determine the pattern and frequency of the arrhythmia. These range from holters (a computerized monitoring system) to small implantable chips that a patient wears for extended recording of the patterns of the heartbeat.
Coronary artery disease is a problem with the blood flow in the arteries supplying the heart muscle and is the most common type of heart disease. Blockages limit blood flow, and as a result, the patient experiences chest pain or may have a heart attack (regional heart muscle death from a complete block in blood flow). Heart failure is also a flaw in the pumping system; blood isn’t pumped in sufficient amounts to nourish and oxygenate the organs. Cardiomyopathy is a heart muscle disease where the muscle becomes weak and does not work properly.
Given the three systems within the heart, each with several possible conditions, accurate diagnosis must precede treatment.
“We have many non-invasive diagnostic tools,” says Dr. Palac, “and they make it possible to have an accurate diagnosis without invasive techniques. We are also seeing hybrid technologies, which co-register more than one imaging modality. Two images can be superimposed with computer aided techniques to improve visualization.”
“At Dartmouth-Hitchcock, we are working to create a set of guidelines as to the best way to use these powerful, noninvasive tests,” Dr. Palac explains. “In what sequence should they be done? How can we get the best results and still be mindful of health care costs?” A better job of risk profiling is also needed, he says, so that sophisticated tests are used earlier and are targeted to the patients most at risk.
Heart disease is frightening, but it is important to remember that millions of people with heart disease are living satisfying, productive lives. Better diagnosis, expanded choice of medication and new options in surgery are making a difference.
Asked if he sees trends in the public perception of heart disease, Dr. Palac responds, “I think we are getting somewhere with public education.” Lifestyle changes are a constant battle, he says, but more people are making the effort to exercise and eat healthy. They are more aware of risk factors and more likely to seek early intervention if there is a problem. NH