Unexplained cardiac arrest

Five in 10,000 people around the world develop unexplained cardiac arrest and rarely does any of them survive. This condition is hereditary, happens to any race, but is more common among those with Asian ancestry, particularly among Japanese and Southeast Asians. Ten times more common among men, this mysterious killer is called Brugada Syndrome. Not that well-known, even to most physicians, this stealth “assassin” must be exposed and dealt with early on to save lives.

My daughter, Rachel, an Obstetrician-Gynecologist in Lake Charles, Louisiana, relayed to me recently the story of a young black 12-year-old boy who developed a heart attack while playing basketball during a school game, and two weeks later, his father also developed a heart attack. Luckily, both were attended to immediately and they survived. Without electrophysiologic and genetic studies, we cannot confirm that these are cases of the Brugada syndrome.

What is Brugada Syndrome?

Brugada Syndrome is a baffling condition where a person, who appears to be healthy, unexpectedly develops cardiac arrest, for no apparent reason. Most victims do not survive the episode. This condition is now believed to be responsible for countless sudden deaths among young people— athletes, students, etc.,—who suddenly dropped dead while performing a sports activity. They could develop syncope (fainting spell) with irregular heart beats, followed by a heart attack. The mechanism here is the disruption of the heart’s abnormal rhythm and the event usually happens before age 40. The Sudden Infants Death Syndrome (SIDS) is suspected to be Brugada in nature.

Did the victims have any prior symptoms?

No, the majority of victims did not have any prior symptoms.  They were “in good health” when suddenly they collapsed, went into coma, and later died, or instantly died on the spot. There were some individuals who were lucky enough to have responded to prompt cardiopulmonary resuscitation. Patients like these, with aborted cardiac arrest and death, inspired the three Doctors Brugada (R, P & J) and their colleagues at the Unitat d’Aritmies, Hospital Clinic, in Barcelona, Spain, to pioneer in the study of this baffling condition, and became the first to describe the syndrome in the medical literature as a functional cardiac disorder with unique EKG findings. To honor them for this astute discovery, their peers around the world named the entity Brugada Syndrome.

What were their findings?

The study conducted by the Doctors Brugada in 1992 included 8 patients with a history of aborted sudden death with a distinct and specific EKG tracings that were abnormal (in medical lingo, there were right bundle branch block, ST segment elevation in the right precordial leads, and prolonged QT interval), in the absence of any structural or anatomical heart defect. The physical and clinical examination, biochemical tests, echocardiographic and angiographic tests among these patients yielded normal findings. In 4 of them, a family history of unexplained sudden cardiac arrest was present. The occurrence of ventricular fibrillation (beginning cardiac arrest) in the absence of any structural defect classifies this as a “primary electrical disease.” These specific and characteristic EKG findings among these patients discovered by the Doctors Brugada, together with the family history of unexplained cardiac arrest, are today the paradigms for the diagnosis of the Brugada Syndrome.

When was this syndrome first discovered?

In science, it is usually hard to accurately date the very first actual discovery of anything, because many scientists/physicians/researchers work simultaneously all around the world. Many of them do not even report their findings right away. But the first officially reported EKG findings, which later was to be known as Brugada Syndrome, was made in the late 1980 by other physicians, where 6 patients with sudden cardiac arrest were resuscitated successfully and found to have these characteristic and unique EKG tracings to be described in 1992 by the Doctors Brugada as a distinct disease entity, which heretofore was undiscovered and unexplained.

How many cases of this syndrome are there?

This entity is increasingly recognized. The Doctors Brugada reported 63 cases by 1998 and a Japanese multicenter reported an additional 63. The past few years, another 163 cases were discovered that satisfy the Brugada criteria, 76 (73%) of whom had actual cardiac arrest and 28 (27%) with syncope (unconciousness). Ninety five (58%) of them were Asians, with mean age from 22-65. In 36 of them (22%) had a strong family history of syncope, cardiac arrest or sudden death, without prior symptoms or apparent illness. In some cases, the typical abnormal Brugada EKG findings were noted during a routine screening medical exam performed because of a family history of sudden death.

How does one prevent Brugada Syndrome?

Since this disease entity has now been “described,” which makes diagnosis of this entity possible, everyone, especially those with a family history of unexplained sudden cardiac arrest, should be tested, starting with an EKG, and some “provocative” tests (with disopyramide, flecainide, ajmaline, procainamide) done to reproduce the characteristic Brugada EKG findings.

Can genetic testing help?

Since this disease is secondary to a mutation of SCN5A gene of chromosome 3 that has a dominant autosomic transmission pattern, with genetic defect in the alpha subunit of the sodium channel, genetic testing may be in order. However, 30% to 80% of patients will have negative (normal) gene screening in spite of overt or latent clinical Brugada Syndrome. Someday, perhaps, this test could be more sensitive, with less false negatives.

What’s the treatment for Brugada Syndrome?

If one is diagnosed to have Brugada Syndrome, an automatic implantable cardiac-pacemaker defibrillator (AICD) may be implanted, which will pace the heart and increase the heat rate if the rate goes down (awake or when asleep, 24/7), and shocks and jolts the heart back to normal rhythm, when the heart goes to ventricular fibrillation (cardiac arrest). Hundreds of thousands of people worldwide have AICD to prevent sudden death. None of the available drugs today are effective against Brugada Syndrome.

The more people know about this preventable killer, the more lives could be saved.

***

Philip S. Chua, MD, FACS, FPCS, Cardiac Surgeon Emeritus in Northwest Indiana and chairman of cardiac surgery from 1997 to 2010 at Cebu Doctors University Hospital, where he holds the title of Physician Emeritus in Surgery, is based in Las Vegas, Nevada. He is a Fellow of the American College of Surgeons, the Philippine College of Surgeons, and the Denton A. Cooley Cardiovascular Surgical Society. He is the chairman of the Filipino United Network – USA,  a 501(c)(3) humanitarian foundation in the United States. Email: [email protected]

Dr. Philip S. Chua

Philip S. Chua, MD, FACS, FPCS, Cardiac Surgeon Emeritus in Northwest Indiana and chairman of cardiac surgery from 1997 to 2010 at Cebu Doctors University Hospital, where he holds the title of Physician Emeritus in Surgery, is based in Las Vegas, Nevada. He is a Fellow of the American College of Surgeons, the Philippine College of Surgeons, and the Denton A. Cooley Cardiovascular Surgical Society. He is the chairman of the Filipino United Network – USA, a 501(c)(3) humanitarian foundation in the United States.

The Filipino-American Community Newspaper. Your News. Your Community. Your Journal. Since 1991.

Copyright © 1991-2024 Asian Journal Media Group.
All Rights Reserved.