Guarding Against Syncope

 

Changing of the guard ceremonies take place in many countries, including the United States (Arlington Cemetery), the United Kingdom (Buckingham Palace), China (Tiananmen Square), Greece (Syntagma Square), Canada (Parliament Hill), India (palace of the President) and Monaco (the Prince’s Palace). Typically, these ceremonies involve military personnel with one group switching place with another and taking over the protection of a significant national monument. The guard changes are elaborate, precisely choreographed and viewed by tourists. Many times, the soldiers stand motionless for hours in the hot sun. Sometimes, they pass out. Passing out, fainting, blacking out or losing consciousness is called syncope. What causes syncope and how can it be diagnosed efficiently?

 

Syncope is an abrupt and transient loss of consciousness due to lack of blood flow to the brain followed by a quick recovery. Syncope must be distinguished from seizure, low blood sugar, drug or alcohol intoxication or psychiatric conditions all of which may cause a person to pass out but are not due to lack of brain blood flow. Syncope is extremely common, accounting for 3% to 6% of all emergency room visits. In people over 45 years of age, 25% have reported an event. The incidence of syncope has three peaks, ages 20, 60 and 80. Women are more likely than men to pass out. 

 

The causes of syncope can be divided into nonlife-threatening processes and severe, potentially life-limiting diseases. Benign causes include the following. 

Vasovagal syncope: passing out due to an unpleasant stimulus (pain, sight of blood, stress, medical procedure)

Situational syncope: passing out after coughing, sneezing, swallowing, urinating

Orthostatic hypotension: passing out after standing, blood pressure falls on standing

Dehydration

Even though these causes usually are not life-threatening, there is significant morbidity such as falls and fractures.

Potentially life-threatening etiologies include:

Bradyarrhythmias: slow heart rate (heart rate less than 40 beats per minute or no heart beat for 3 or more seconds) or heart block (electric pathway between upper and lower chambers disrupted).

Tachyarrhythmias: ventricular tachycardia (irregular heart rhythm from the lower chambers)

Heart attack

Blood clot in the lungs

Structural heart disease, obstruction to the blood flow from the lower chamber: thickened heart muscle or blockage in the aortic valve  

The prognosis in cardiac related syncope is much worse than the other types. With vasovagal syncope, the prognosis is the same as the general population. In both groups, 60% are alive 15 years after the event. In patients with a cardiac cause, only 20% are alive at 15 years. Therefore, it is important to determine whether the cause of syncope is due to a heart related issue.

 

Syncope is a symptom and finding an accurate diagnosis is imperative. However, trying to determine the cause of a syncopal episode is notoriously difficult. Even in the best of circumstances a diagnosis can be attributed in only about 50% of cases. There are many diagnostic tests that can be ordered including, CT scan, MRI, ambulatory external monitor (one to three days or one to four weeks), implantable cardiac monitor, stress test, catheterization, ultrasound of the neck arteries, electrophysiology study, tilt table test. One or more of these tests may be appropriate in the right situation, but not every patient with syncope needs multiple tests.  The items with the greatest diagnostic yield are the history, the physical exam, an electrocardiogram (EKG) and an echocardiogram (ultrasound of the heart). These should be done on all patients and further tests can be ordered as needed.  The history, the circumstances surrounding the event, is the key.

If the syncope occurs:

With an unpleasant stimulus (for example, a needle stick), think vasovagal.

With coughing, swallowing, urinating, defecating, think situational.

In any position (especially while sitting or lying down), think cardiac.

With standing up, think orthostatic hypotension.

With nausea, sweating or flushing, think vasovagal.

With palpitations or chest pain, think cardiac.

With history of heart disease or male or older age, think cardiac.

With blood pressure drop on standing, think orthostatic hypotension.

With associated head or facial trauma, think cardiac.

With normal physical exam, EKG and echocardiogram (structural heart disease less likely), think noncardiac cause.

After evaluating these four items, a risk assessment can be made, further testing ordered tailored to the situation and appropriate treatment begun.

 

So, if you find yourself watching a changing of the guard in the hot mid-day sun and you pass out, take it seriously. Head to the nearest emergency room immediately, even if you are low risk and even if you feel perfectly normal after recovering.  

The Chaos of Atrial Fibrillation

 

Chaos is defined as a state of disorder, disarray, a lack of organization. Atrial fibrillation (Afib) is a disorganized, chaotic heart rhythm. Chaos theory is a branch of science and mathematics that seeks to find connections and repetitive patterns in chaotic systems (for example weather patterns, stock market trends, or understanding complex medical systems). It seeks to bring order to the chaos. This review will try to bring some order to the chaotic world of Afib. 

 

During normal heart rhythm, the atria (the upper chambers of the heart) beat smoothly and rhythmically. In Afib, the atria fibrillate and beat chaotically, like a bag of squirming worms. Afib is triggered by extra beats (premature atrial contractions) that arise in the pulmonary veins (there are 4 pulmonary veins bringing blood from the lungs into the left atrium). The extra beats start the rhythm, then multiple electrical wavelets travel in a random, chaotic way through the atria. The wavelets disrupt the normal, organized contraction of the atria, leading to disorganization and “squirmy atria”.

 

Afib is the most common arrhythmia encountered in cardiology. About 3 to 6 million people in the US currently have Afib and that number is expected to rise in the coming years (to about 12 million by 2030). The prevalence of Afib rises with age. About 1% to 3% of 60-year-olds have Afib while 10% to 11% of 80-year-olds have it. Afib causes serious medical problems, increasing the risk for stroke by 5 times, the risk for congestive heart failure by 3 times and the risk of death by 2 times. 

 

Risk factors for developing Afib include: high blood pressure, valvular heart disease, congestive heart failure, heart attack, sedentary lifestyle, obesity, alcohol, smoking, sleep apnea, and thyroid disease. However, it is not just the old and the sick who have Afib. Famous people who have had Afib include: George HW Bush, Dick Cheney, Tony Blair, Barry Manilow, Elton John, Roger Moore (aka, James Bond), Kareem Abdul-Jabbar, Larry Bird, Jerry West, Billie Jean King, Mark Spitz, and Mario Lemieux.  The athletes on this list might be surprising, but there are many Olympic athletes who have had Afib. In fact, studies have shown that high volume exercisers, professional and amateur, are prone to Afib. Elite, Olympic rowers are seven times more likely to develop Afib compared to the average person. 

 

Afib is diagnosed on an electrocardiogram (EKG) or on a rhythm strip. Often, Afib is fleeting and short- and long-term monitors have been developed to try to catch Afib. An example of a short-term monitor is a Holter monitor, which assesses the heart’s rhythm for one to three days. An event monitor is a patch that provides more long-term evaluation and is worn for one to four weeks. Wearable devices (such as an Apple watch) can detect Afib and the detection algorithms are getting better and better. Still, wearable devices are only about 70% accurate in determining Afib. The diagnosis must be confirmed by a medical-grade device. 

 

The treatment for Afib occurs on several levels. Almost everyone is put on a blood thinner to prevent blood clots and strokes. If the heart rate is fast, beta blockers (such as metoprolol) or calcium channel blockers (for example diltiazem) are used to slow the heart rate. If appropriate, cardioversion is recommended. Cardioversion is performed with the patient under light anesthesia. An electric shock is given via pads placed on the chest. This resets the heart rhythm and, in many cases, returns the patient to normal sinus rhythm. In addition, antiarrhythmic agents may be employed (for example, amiodarone, sotalol or flecainide). Antiarrhythmics are powerful medications with many side effects. In addition, they are only moderately effective. The best agent, amiodarone, can only keep a patient in normal rhythm 60% of the time. What else can be done to bring order to Afib?

 

Catheter ablation is an invasive procedure to try to cure Afib. Cardiologists who specialize in arrhythmias (electrophysiologists) place a catheter around each of the four pulmonary veins and create a scar (using radiofrequency or pulsed field energy). The scar acts as an electrical barrier, preventing the wavelets in the pulmonary veins from escaping and precipitating Afib in the atria. The ablationists can eliminate Afib about 80% of the time; so let’s call them the chaos crushers. What can the average person do to avoid Afib and an ablation? Several lifestyle modifications can be initiated to prevent Afib. Being sedentary is a huge risk factor for Afib. Moderate exercise will decrease the risk substantially. If obese (BMI > 27), losing 10% or more of body weight almost cures Afib. Treating sleep apnea decreases the risk of Afib by 40%. Lastly, stopping or cutting back on alcohol consumption lowers the risk of Afib.

 

Life can be chaotic. Your heart rhythm doesn’t have to be.  Take care of the factors that you can control. See your doctor and treat any medical issues that might lead to Afib (bring blood pressure down or treat sleep apnea, for example). Initiate the lifestyle changes noted earlier to decrease the risk of Afib. This is the theory on how to control the chaos king of cardiology, Afib.