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Johns Hopkins Pediatric

Uncovering the Cause of Unrelenting Syncope

Cardiovascular Report
November 1, 2013

Nancy Strahan was determined to find the underlying reason for Tammie Riblett’s repeated fainting episodes.

Growing up, Tammie Riblett had experienced dizziness during gym classes but later, at age 27, she began having frequent fainting episodes.

“My heart would start racing. I’d feel a fluttering sensation in my chest, and then I’d pass out,” she says. Sometimes the early warning signs lasted for a few minutes; at other times, only a few seconds.

Riblett went to the local emergency department several times and had many tests, none of which helped pinpoint the underlying problem. Her primary care doctor, Bimal Ashar, referred her to cardiologistNancy Strahan for recurrent syncope.

“At first, the cause of her fainting wasn’t clear,” says Strahan. “Was it a heart rhythm disturbance? A seizure disorder or maybe abnormally low blood pressure?”

Her stress test and echocardiogram were normal. Wearing a Holter monitor for a month didn’t reveal the underlying cause of her problem. Next, Strahan asked Riblett to see electrophysiologist Jeffrey Brinker for a tilt table test.

“At 23 minutes into the study, she became limp with tonic-clonic movements and no detectable blood pressure,” says Strahan. “But then, as soon as she was moved to a Trendelenburg position, her blood pressure and heart rate came up and her seizure activity stopped. That clearly pointed us to the reason behind the fainting episodes— neurally mediated hypotension.”

The condition is caused by abnormal pooling of blood in the leg veins coincident with a drop in BP and lack of compensatory increase in the heart rate, according to Strahan. 

She adds, “Tammie’s condition is not rare, but the severity of it certainly is. It’s usually benign and most patients can be managed with simple lifestyle modifications. But her severe drops in blood pressure have caused seizures and sudden fainting episodes resulting in fractures and lacerations, which are extremely uncommon with neurally mediated hypotension.” 

Further complicating Riblett’s condition was an irregular heart rhythm. Strahan referred her for a cardiac ablation procedure, which took away the fluttering symptoms in her chest.

Strahan says numerous drugs have been recommended for the condition. Riblett has responded to two of the more common drugs to prevent her blood pressure from dropping: florinef and midodrine. However, it’s sometimes necessary to try a variety of medications at different doses to find out what works best for individual patients. She also advised Riblett to increase the salt in her diet and stay well-hydrated.

In spite of the ablation, medications and dietary changes, Riblett continued to have fainting episodes, although they were becoming less frequent than before. Strahan then decided to recommend that she have a pacemaker.

“Placing a permanent pacemaker is not the usual treatment for this condition since it does not cure the underlying problem, but it will prevent severe bradycardia, which can contribute to the symptoms,” Strahan says. 

It’s not surprising that her symptoms have continued, according to Strahan. While the pacemaker is now keeping her heart rate from dropping, her autonomic nervous system still causes her blood pressure to drop and venous pooling of blood in the standing position. There is currently no cure for the condition.

Today, Riblett is 38 and says she does what she can to manage her condition. “I found that I need to be very aware of how I’m feeling and be sure to take care of myself and get plenty of rest,” she says. “Feeling stress can increase the risk that I’ll pass out. I have to remain calm and drink enough water, especially in warm weather.”

“Also,” Riblett says, “I eat a lot of pretzels and pickles.”

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