May 16, 2008
It strikes without warning
The symptoms came on suddenly as Mike, a middle-aged man with a passion for a
well-manicured lawn and flowerbeds, pushed the mower across the thick spring grass. The pain quickly expanded from his chest to his left arm. Although the day was cool, Mike dripped with perspiration and grew increasingly anxious about his shortness of breath and nausea.
A heart attack? Most likely. Radiating chest pain, difficulty breathing, profuse sweating, nausea or vomiting, and anxiety are all classic symptoms of acute myocardial infarction (AMI).
During a heart attack, one of the keys to preventing irreversible heart damage is to re-establish blood flow to the heart before the heart muscle begins to experience oxygen starvation. In many of these cases, using a balloon to reopen a narrowed blood vessel is considered the most effective method for restoring blood flow.
At UPMC hospitals, multidisciplinary teams focus on lowering “door-to-balloon times (D2B),” the window of care that begins with the patient’s arrival at the Emergency Department door and continues until balloon inflation.
New tools for EMS
Minutes after his wife calls 911, paramedics perform a 12-lead electrocardiogram (EKG) on Mike. These paramedics have completed 12-lead EKG training under the direction of the UPMC Prehospital Care Program. Each lead gathers data about activity in specific sections of the heart wall and how oxygen deprivation is affecting it.
The paramedics place a clear overlay, provided by UPMC Prehospital Care, on the EKG printout. The overlay assists them in locating the pattern of the myocardial injury so they may begin appropriate treatment.
Getting data to the hospital earlier than ever
While Mike is en route to the hospital, the ambulance crew uses cellular technology built into the heart monitor to send a copy of his EKG to the Medical Command Center at UPMC Presbyterian, where a physician reviews it. The paramedics also fax the EKG to the Emergency Department preparing to treat Mike.
The EKG reveals an ST-segment elevation acute myocardial infarction (STEMI). ST elevation implies an ongoing acute myocardial infarct (a heart attack where heart cells are dying). The command center places the EKG in a secure electronic folder, which Mike’s own cardiologist can access from a home or office computer.
The clock is ticking
Once a patient has been diagnosed with STEMI, both the American College of Cardiology and the American Heart Association call for primary percutaneous coronary intervention (PCI) within 90 minutes of arrival at the hospital. Typically, PCI is performed by threading a slender balloon-tipped tube (a catheter) from an artery in the groin to a trouble spot such as a buildup of plaque in an artery of the heart. The balloon is then inflated, compressing plaque and widening the narrowed coronary artery so blood can flow more easily.
“The goal is to restore blood flow to the heart muscle within 90 minutes of hitting the ED door, because evidence-based medicine has shown that patients truly benefit from door-to-balloon times of 90 minutes or less,” says Joon Sup Lee, MD, clinical director, UPMC Cardiovascular Institute.
In Mike’s case, early review of the EKG at the Medical Command Center and by the ED physicians pays off. Upon arrival, Mike is stabilized and given medication to relax his coronary arteries and allow more oxygen to reach the heart muscle. Meanwhile, a team of UPMC cardiac specialists and technicians has been assembled and begins preparing the cardiac catheterization lab for Mike’s procedure.
Restoring the flow
About 30 minutes after passing through the ED door, the balloon reaches Mike’s obstructed coronary artery, where it is inflated to restore blood flow. An expandable metal stent is inserted to prop open the artery. Mike is taken to a recovery area. He’ll have to take it easy for a while, and his progress will be monitored closely. However, with proper diet changes, regular exercise, and medications to lower his cholesterol, Mike can look forward to many years of tending his lawn and flowers.