Facts About the Heart Condition Known as Supraventricular Tachycardia

Connel Patrick loves to swim, ride his bike, and run laps around the driveway. He is a typical six-year-old boy...and he has a heart condition called Supraventricular Tachycardia.

Tachycardia means a fast heart rate. Supraventricular means coming from above the ventricle. Commonly referred to as SVT, this irregularity causes his heart to beat very fast. In a normal heart, there are electrical connections called conduction tissue. These connections carry the electrical current through the heart muscle and cause it to beat. SVT happens when a heart has an extra electrical connection. When this connection is turned on, the heart beats much faster than normal. It's not usually dangerous and can be treated with medication, but it can be very scary - especially when it happens for the first time.

Source: Children's Memorial Hospital, Chicago Illinois. Resources for Parents and Families. February 2005

At noon on a snowy day in March 2007, Connel, a dinosaur fanatic since the age of two, was living out his dream. He had traveled from his home in Michigan to Chicago and was finally at the Field Museum of Natural History, examining Tyrannosaurus Sue (the most complete T-Rex skeleton in the world) in person. But, in a split second his mood changed from excited to exhausted. "My tummy feels funny," he told his mother, Jennifer, as he hugged his stomach and hunched over . "I need to go to the bathroom."

"I took him to the restroom," recalls Jennifer, " but it didn't help him." He complained of being really thirsty, but several drinks from the water fountain didn't help quench his thirst. According to Jennifer, Connel looked very pale and felt clammy. "We found a seating area and rested while my husband took our younger son to look at the dinosaur exhibit. Connel, who had been looking forward to this trip to the museum for years, was on my lap with his eyes closed," Jennifer recounts.

While resting, Jennifer noticed that Connel's pulse was very visible on his neck and that his heart was beating fast. These are warning signs of an SVT episode, but not having experienced this before Jennifer didn't think much of it. But, when she got Connel up so that he could look at the dinosaur exhibit, he could hardly walk. The Patricks rented a stroller from the museum and placed Connel in it, however, he vomited soon after.

The family went back to their hotel, where, from 3 p.m. until 11 p.m., Connel vomited once every twenty minutes. "Since our whole family had been sick with the stomach flu and other viruses throughout the winter, we played down Connel's condition all day and evening as another minor illness," says Connel's father, Brian.

At 11 p.m, Jennifer and Connel went to the nearest hospital, Northwest Memorial, in a cab. When the triage nurse in the emergency room couldn't get a blood pressure reading on Connel with a machine, she checked his pulse manually and immediately called back to the emergency room doctors and told them to clear a bed immediately.

Connel was rushed to a bed in the emergency room and a doctor was with him quickly. Connel kept vomiting. He was hooked up to machines. They took an X-Ray of his chest to see if he had a chest infection that may be causing these symptoms. His lungs were clear, so they ruled out that possibility. The doctor read Connel's heart rate at 240 beats per minute (bpm) -a normal heart rate is between 80 - 120 bpm. The doctor told Jennifer that Connel's heart needed to be slowed down before his heart was damaged - if it wasn't already. The doctors administered a medicine called Adenosine that blocked the electrical impulses in his heart and got it beating at a normal rate.

Connel was then sent by ambulance to Children's Memorial Hospital around 3 a.m., where he was examined by a doctor who specializes in the heart's electrical currents. The specialist examined Connel's heart with an echocardiogram (a type of ultrasound) and determined that Connel has AV Node Tachycardia. This means that he was born with an extra electrical connection. It may not have been noticed before because often this extra connection isn't turned on until years after a child is born. Triggers can be exercise, excitement, stress, caffeine and certain medications. Blood tests showed that there had been some damage to Connel's heart during this episode because it had gone on for so long. The specialist said that this episode was equivalent to Connel running a marathon for 18 hours.

Connel stayed at Children's Memorial Hospital for three more days. They tried out different medications to control his SVT, such as Propranolol and Atenolol. These medications are also used to treat migraines and aggressive behavior. His partents were given a stethoscope and instructed to use it to check Connel's heart rate once in the morning and once at night. Further blood tests showed that his heart was healing and that there would most likely not be any permanent damage.

Connel was on Atenolol for a month. While he was on the medication, he was very quiet and lethargic. He was referred to a well-known pediatric cardiologist at the University of Michigan Mott's Children's Hospital named Dr. MacDonald Dick. After examining Connel, Dr. Dick decided to take him off the Atenolol. If Connel starts to feel funny in his stomach again, he is supposed to use a valsalva maneuver. This means that he is to pretend to blow up a balloon on his thumb or bear down as if having a bowel movement. These maneuvers may slow his heart rate down. If his heart rate doesn't slow down within an hour, he must be taken to an emergency room.

If SVT becomes more of a problem for Connel in the future, his parents may consider him undergoing a procedure called Radiofrequency Ablation. During the procedure, which usually requires only an overnight stay in the hospital, a doctor burns a small piece of heart muscle where the tachychardia occurs. It's becoming more common now and can result in the tachycardia being destroyed.