Heart Beat: January 2015
Risk for Silent Stroke is Twice as High With Atrial Fibrillation
The common heart rhythm disorder atrial fibrillation (AF) is associated with a twofold higher risk for silent cerebral infarctions (SCIs), known as “silent strokes,” according to research published online in Annals of Internal Medicine. A silent stroke is an injury to the brain usually caused by the temporary blockage of blood flow to the brain by a blood clot in an artery. Unlike a typical stroke, an SCI has no outward symptoms. A person having a silent stroke may not even be aware that it’s happening. An individual may have several SCIs before the effects of the events become obvious. Damage caused by SCIs can be cumulative. Cognitive difficulties later in life may be due to the loss of brain cells due to repeated SCIs. AF is a condition in which the heart’s upper chambers (atria) beat in an erratic manner, uncoordinated with the lower chambers (ventricles). AF is associated with silent strokes and regular strokes because when the heart isn’t beating properly, blood can pool in the atria and form a clot. When that clot breaks free of the heart it can travel to the brain and cause a stroke. The research published in Annals was actually an analysis of nine major studies. Researchers noted that exploring the prevalence of SCIs in patients with AF is important because it may help doctors better understand the link between AF and cognitive impairment. Silent strokes may also be predictors of clinical symptomatic strokes and death.
Common Antibiotic May Raise Risks in Patients Taking ACE Inhibitors
The risk of sudden death climbed by more than a third in older adults taking ACE inhibitors or angiotensin-receptor blockers (ARBs) who were then put on the antibiotic medication cotrimoxazole (Bactrim ®), compared with those prescribed amoxicillin, according to a study published in BMJ. The findings were independent of other health problems and other medications taken by study participants. The risk appears linked to cotrimoxazole’s capacity for raising potassium levels in the blood. Combining that particular antibiotic with the antihypertensive medications ACE inhibitors and ARBs may put people at risk of hyperkalemia, an unsafe level of potassium in the body. Researchers noted that people with type 2 diabetes are at especially high risk, because they are particularly vulnerable to hyperkalemia. The risk depends on the dosage and the duration of use. Cotrimoxazole is commonly prescribed for 10-day treatments of uncomplicated urinary-tract infections. A three-day regimen of the drug may suffice in many cases, the researchers noted. The safest approach, the researchers added, is simply to prescribe amoxicillin or another antibiotic rather than run the risk of prescribing cotrimoxazole to patients already on ACE inhibitors or ARBs. Be sure to tell your doctor all the medications you take, to avoid interactions.
Blood Pressure Control May be Improved With a Second Doctor’s Visit
Individuals who visit their doctor at least twice a year were 3.2 times more likely to have better blood pressure control than those who see their physician once a year or less, according to study findings published in the American Heart Association journal Circulation. Researchers also found that having health insurance and getting treatment of high cholesterol also increases the likelihood of better blood pressure management. Interestingly, obese people in the study were more likely to keep their blood pressure under control. Researchers suggested that the doctors of obese patients may be quicker to put those patients on anti-hypertensive medications because the need to control risk factors appeared to be more urgent. The study didn’t explain why twice-yearly visits had such an impact on blood pressure control, but there are several possible explanations. Individuals who see their doctors more often may be more inclined to engage in other heart-healthy behaviors, such as exercising frequently or eating a balanced diet. Also, having to be “accountable” to your doctor more often may make you follow a good blood pressure-control regimen. Research shows that 20 percent of adults in the U.S. with high blood pressure don’t even know they have it. But of those who do know they have hypertension, only 75 percent are treated, and only half have it controlled. If you’re trying to get your blood pressure under control, talk with your doctor about strategies you can use.