Ask The Doctors: December 2014
Q. Are there any vitamins or other supplements that are proven to help the heart? Are there any that you recommend or any that we should avoid if we have hypertension or other heart conditions?
A. It is known that heart disease happens more frequently when certain nutritional deficiencies are present. For example, people with low levels of vitamin D are more likely to develop coronary artery disease (CAD) and experience a heart attack than those with normal levels. However, such information in itself does not prove that low vitamin D levels are causing these patients’ heart problems. In order to support a cause-and-effect relationship, one must treat with either vitamin D or placebo, and determine if raising vitamin D levels reduces risk of heart disease over time. Several clinical trials have studied this, finding no significant cardiovascular benefit or harm. However, the studies lasted only for five to seven years, and longer-term treatment may yield benefit. If one takes vitamin, mineral, or other dietary supplements in hopes of preventing cancer or cardiovascular disease (CVD), the U.S. Preventive Services Task Force has a message for you: There is insufficient evidence to recommend for or against supplementation with beta-carotene, vitamins A, C, and E, antioxidant combinations, or multivitamins with folic acid. Also, the following supplements can cause or worsen pre-existing high blood pressure: ephedra, Siberian ginseng, bitter orange, and licorice. Deficiency in the mineral selenium has been linked closely to CAD and heart attack, but supplementation studies have have not shown cardiac benefit (one showed lower cancer risk).
Finally, the standard multivitamin is the most commonly used dietary supplement. Does it prolong life or help prevent CVD or cancer? Analyses of multiple studies have shown no evidence for harm. Depending on the type of study, a mild, nonsignificant trend towards decreased cancer risk and decreased CVD risk has also been seen, which could accrue further with time. Overall, the best goal would be to consume a balanced diet that is replete with essential vitamins and minerals. A standard multivitamin can be taken without fear of harm, and it may improve health, especially if one’s diet is not balanced.
Q. I’m 71 and have paroxysmal atrial fibrillation. The episodes, which started about five years ago, usually last a day or two. Will these episodes increase in duration and frequency? How long can a heart beat at that unhealthy rate before damage is done?
A. Atrial fibrillation (AF) is a condition in which the atria, the upper chambers of the heart, quiver uncontrollably rather than contracting, in an orderly fashion. When the abnormal electrical activity of the atria passes to the ventricles (lower chambers which pump to the body), the heart tends to beat rapidly and irregularly, as you describe. Unfortunately, studies have indicated that intermittent, episodic AF such as yours has about a five-percent chance per year of becoming permanent. Factors which tend to increase likelihood of progression include older age, an enlarged heart, a history of heart failure, and a prior heart attack.
Regarding your other question, it usually takes at least a week of rapid AF to decrease cardiac pump function. Typically, such changes are reversible once normal (sinus) rhythm has been re-established. However, as doctors say, “AF begets AF,” meaning that episodes tend to cause a self-sustaining cycle, inducing longer and more frequent periods of arrhythmia. In order to decrease your risk of stroke and heart failure, your best bet is to find a cardiac electrophysiologist with whom you feel comfortable, and discuss your options. In the meantime, anticoagulation with warfarin (Coumadin ®) or one of the other, newer drugs should be strongly considered for stroke prevention, if you are not already receiving such treatment.