Cardiac Arrest? Someday, Drones May Come to Save You

Amy Norton wrote . . . . . . . . .

A good Samaritan can save the life of someone in cardiac arrest if a portable defibrillator is nearby. Now, a pilot study suggests a new way to get the devices into bystanders’ hands: drones.

The study, done in Sweden, found that drone delivery was a feasible way to get automated external defibrillators (AEDs) to the scene of a cardiac arrest. In fact, the drones typically beat ambulances by a couple of minutes.

Since those minutes can mean the difference between life and death, the early findings are encouraging, researchers said.

However, drone-delivered AEDs are far from prime time.

“This points to a non-traditional route for addressing a problem we’ve had for a long time,” said Dr. Jennifer Silva, a member of the American College of Cardiology’s Health Care Innovation Council.

“In general, I love the concept of using technological advances to improve the way we practice medicine,” said Silva, who was not involved in the study.

In this case, she said, the findings suggest it’s possible to deliver AEDs by drone. But the big question, Silva stressed, is whether that can ultimately make a difference in cardiac arrest victims’ outcomes.

Cardiac arrest occurs when the heart’s normal rhythm stops suddenly, making the muscle incapable of delivering blood and oxygen to the body. It causes unconsciousness within seconds and is fatal within minutes — unless a bystander performs chest compressions or uses an AED until paramedics arrive.

AEDs are portable versions of the defibrillators doctors use to “shock” the heart back into a normal rhythm. The devices automatically analyze a person’s heart rhythm to gauge whether a cardiac arrest is in progress.

“They are incredibly user-friendly,” Silva explained. “They literally talk you through the steps, and tell you when a shock should be delivered.”

AEDs are often available in public places, she noted, including schools, airports, sports venues, retail stores and office buildings.

But most cardiac arrests happen at home, where AEDs are rarely available, said Dr. Sofia Schierbeck, of Karolinska University Hospital, in Stockholm, Sweden.

That’s a particular dilemma if an ambulance cannot arrive quickly.

So Schierbeck and her colleagues wondered whether drones could step in.

In a pilot study, they had three AED-equipped drones integrated into a regional medical system covering about 80,000 people. When a suspected cardiac arrest was reported to emergency services, both an ambulance and, if possible, a drone were dispatched.

Over three months, 53 possible cardiac arrests were called in. A drone was dispatched to 12. In the other cases, drones couldn’t be sent because of weather or darkness or because the emergency struck in a “no-fly zone” — near high-rise buildings, for instance.

When a drone could be sent, the study found, it beat the ambulance 64% of the time, typically by 2 minutes.

The findings were published Aug. 27 in the European Heart Journal and presented virtually at the European Society of Cardiology’s annual meeting.

In a news release from the meeting, Schierbeck acknowledged that weather and other logistics limited the drones’ use.

But, she said, “by 2022 we should have drones capable of flying in darkness and in moderate rain. Longer battery life could increase the flight range and the number of inhabitants covered by one drone.”

An editorial published with the study points out another issue: None of the AEDs delivered by the drones were actually used by bystanders.

“We also need to work on educating bystanders regarding AED use,” wrote Dr. Nicole Karam and colleagues at the University of Paris, in France.

Silva agreed that the study leaves open the crucial issue of what happens after the AED arrives. The “chain of survival,” she said, has to include lay people ready and willing to use the device.

“Drones can deliver an AED, which is all well and good,” Silva said. “But we need to know how it impacts patient care.”

According to Karam’s team, one possible solution is to have emergency dispatchers stay on the phone with bystanders as the AED arrives. Another, they say, is to take advantage of existing smartphone apps that alert people who are trained in CPR of a nearby cardiac arrest. Those alerts could also tell users that an AED is being delivered to the scene.

For now, Silva said people can learn more about responding to cardiac arrest through the American Heart Association’s website and others like it, or through classes (often free) at a local hospital.

Source: HealthDay

Soft Skin Patch Could Provide Early Warning for Strokes, Heart Attacks

Liezel Labios wrote . . . . . . . . .

Engineers at the University of California San Diego developed a soft and stretchy ultrasound patch that can be worn on the skin to monitor blood flow through major arteries and veins deep inside a person’s body.

Knowing how fast and how much blood flows through a patient’s blood vessels is important because it can help clinicians diagnose various cardiovascular conditions, including blood clots; heart valve problems; poor circulation in the limbs; or blockages in the arteries that could lead to strokes or heart attacks.

The new ultrasound patch developed at UC San Diego can continuously monitor blood flow—as well as blood pressure and heart function—in real time. Wearing such a device could make it easier to identify cardiovascular problems early on.

A team led by Sheng Xu, a professor of nanoengineering at the UC San Diego Jacobs School of Engineering, reported the patch in a paper published in Nature Biomedical Engineering.

The patch can be worn on the neck or chest. What’s special about the patch is that it can sense and measure cardiovascular signals as deep as 14 centimeters inside the body in a non-invasive manner. And it can do so with high accuracy.

“This type of wearable device can give you a more comprehensive, more accurate picture of what’s going on in deep tissues and critical organs like the heart and the brain, all from the surface of the skin,” said Xu.

“Sensing signals at such depths is extremely challenging for wearable electronics. Yet, this is where the body’s most critical signals and the central organs are buried,” said Chonghe Wang, a former nanoengineering graduate student in Xu’s lab and co-first author of the study. “We engineered a wearable device that can penetrate such deep tissue depths and sense those vital signals far beneath the skin. This technology can provide new insights for the field of healthcare.”

Another innovative feature of the patch is that the ultrasound beam can be tilted at different angles and steered to areas in the body that are not directly underneath the patch.

This is a first in the field of wearables, explained Xu, because existing wearable sensors typically only monitor areas right below them. “If you want to sense signals at a different position, you have to move the sensor to that location. With this patch, we can probe areas that are wider than the device’s footprint. This can open up a lot of opportunities.”

How It Works

The patch is made up of a thin sheet of flexible, stretchable polymer that adheres to the skin. Embedded on the patch is an array of millimeter-sized ultrasound transducers. Each is individually controlled by a computer—this type of array is known as an ultrasound phased array. It is a key part of the technology because it gives the patch the ability to go deeper and wider.

The phased array offers two main modes of operation. In one mode, all the transducers can be synchronized to transmit ultrasound waves together, which produces a high-intensity ultrasound beam that focuses on one spot as deep as 14 centimeters in the body. In the other mode, the transducers can be programmed to transmit out of sync, which produces ultrasound beams that can be steered to different angles.

“With the phased array technology, we can manipulate the ultrasound beam in the way that we want,” said Muyang Lin, a nanoengineering Ph.D. student at UC San Diego who is also a co-first author of the study. “This gives our device multiple capabilities: monitoring central organs as well as blood flow, with high resolution. This would not be possible using just one transducer.”

The phased array consists of a 12 by 12 grid of ultrasound transducers. When electricity flows through the transducers, they vibrate and emit ultrasound waves that travel through the skin and deep into the body. When the ultrasound waves penetrate through a major blood vessel, they encounter movement from red blood cells flowing inside. This movement changes or shifts how the ultrasound waves echo back to the patch—an effect known as Doppler frequency shift. This shift in the reflected signals gets picked up by the patch and is used to create a visual recording of the blood flow. This same mechanism can also be used to create moving images of the heart’s walls.

A Potential Game Changer in the Clinic

For many people, blood flow is not something that is measured during a regular visit to the physician. It is usually assessed after a patient shows some signs of cardiovascular problems, or if a patient is at high risk.

The standard blood flow exam itself can be time consuming and labor intensive. A trained technician presses a handheld ultrasound probe against a patient’s skin and moves it from one area to another until it’s directly above a major blood vessel. This may sound straightforward, but results can vary between tests and technicians.

Since the patch is simple to use, it could solve these problems, said Sai Zhou, a materials science and engineering Ph.D. student at UC San Diego and co-author of the study. “Just stick it on the skin, then read the signals. It’s not operator dependent, and it poses no extra work or burden to the technicians, clinicians or patients,” he said. “In the future, patients could wear something like this to do point of care or continuous at-home monitoring.”

In tests, the patch performed as well as a commercial ultrasound probe used in the clinic. It accurately recorded blood flow in major blood vessels such as the carotid artery, which is an artery in the neck that supplies blood to the brain. Having the ability to monitor changes in this flow could, for example, help identify if a person is at risk for stroke well before the onset of symptoms.

The researchers point out that the patch still has a long way to go before it is ready for the clinic. Currently, it needs to be connected to a power source and benchtop machine in order to work. Xu’s team is working on integrating all the electronics on the patch to make it wireless.

Source: UC San Diego

Flu May Play Part in Plaque-rupturing Heart Attacks

Thor Christensen wrote . . . . . . . . .

Getting a flu vaccine can reduce the risk of a common type of heart attack in people 60 and older, according to new research that suggests the virus plays a role in rupturing plaque.

In a study published Thursday in the Journal of the American Heart Association, researchers in Spain used data from five consecutive flu seasons and zeroed in on 8,240 people who had Type 1 heart attacks. They found flu and cold temperatures were each independently associated with an increased risk of that kind of heart attack, and flu shots could reduce that risk among people 60 and up.

“Our results suggest influenza viruses play a major role in plaque rupture,” said study author Dr. J Alberto García-Lledó, head of cardiology at Hospital Universitario Príncipe de Asturias in Madrid. “The study reinforces the need to conduct prevention campaigns during cold waves and influenza seasons. The most important prevention tool we have is influenza vaccination.”

García-Lledó said health experts usually aim for a 60%-70% flu vaccination rate for people over 60 as well as people with high-risk conditions and health care workers.

“Sadly, these targets are not met in Europe or the U.S. It’s important to try to reach this target and, if possible, exceed it,” he said. “Influenza is not a trivial disease. It causes many preventable deaths for reasons other than the respiratory disease itself.”

A 2018 study found the risk of heart attack was six times higher within a week of confirmed flu infection. The findings were most pronounced for older adults and those experiencing their first heart attack. A study published last year of more than 80,000 U.S. adults hospitalized with flu over eight flu seasons found that sudden, serious heart complications were common and occurred in 1 in 8 patients.

The American College of Cardiology and American Heart Association have long recommended the flu vaccine to protect against cardiovascular disease complications. The Centers for Disease Control and Prevention recommends annual flu vaccination for everyone 6 months and older.

In late March, the CDC said weekly flu infections in the U.S. were “unusually low.” But the agency cautioned that COVID-19 has made measuring flu cases more difficult, and it warned flu activity could rise in coming months.

While flu season typically peaks between December and February, it can last as late as May, which is why the CDC still urges people to get a flu shot this spring.

Dr. Daniel Muñoz said the new study in Madrid was limited by being done in a single metro area with a temperate climate.

“It would be interesting to see whether these data can be replicated across a diverse array of geographic locations,” said Muñoz, an associate professor of cardiology at Vanderbilt University Medical Center in Nashville who was not involved in the research.

But he said it was “a smart, thoughtful study that shines further light on the notion that the flu is an infection that affects the whole body. It contributes to the growing body of evidence that flu vaccinations save lives.”

The research also underscores the need for medical professionals “to think outside of our clinical comfort zone,” Muñoz said.

“As cardiologists, we learn the traditional tried-and-true risk factors, like smoking, diabetes, high blood pressure and high cholesterol. But we also have to keep our eyes wide open about other risk factors. We have to ask our patients, ‘Have you gotten your flu vaccination?’ And when necessary, educate them about the benefits of getting one.”

Source: American Heart Association

Instant Death from Heart Attack More Common in People Who Do Not Exercise

An active lifestyle is linked with a lower chance of dying immediately from a heart attack, according to a study published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).1

Heart disease is the leading cause of death globally and prevention is a major public health priority. The beneficial impact of physical activity in stopping heart disease and sudden death on a population level is well documented. This study focused on the effect of an active versus sedentary lifestyle on the immediate course of a heart attack – an area with little information.

The researchers used data from 10 European observational cohorts including healthy participants with a baseline assessment of physical activity who had a heart attack during follow-up – a total of 28,140 individuals. Participants were categorised according to their weekly level of leisure-time physical activity as sedentary, low, moderate, or high.

The association between activity level and the risk of death due to a heart attack (instantly and within 28 days) was analysed in each cohort separately and then the results were pooled. The analyses were adjusted for age, sex, diabetes, blood pressure, family history of heart disease, smoking, body mass index, blood cholesterol, alcohol consumption, and socioeconomic status.

A total of 4,976 (17.7%) participants died within 28 days of their heart attack – of these, 3,101 (62.3%) died instantly. Overall, a higher level of physical activity was associated with a lower risk of instant and 28-day fatal heart attack, seemingly in a dose–response-like manner. Patients who had engaged in moderate and high levels of leisure-time physical activity had a 33% and 45% lower risk of instant death compared to sedentary individuals. At 28 days these numbers were 36% and 28%, respectively. The relationship with low activity did not reach statistical significance.

Study author Dr. Kim Wadt Hansen of Bispebjerg Hospital, Copenhagen, Denmark said: “Almost 18% of patients with a heart attack died within 28 days, substantiating the severity of this condition. We found an immediate survival benefit of prior physical activity in the setting of a heart attack, a benefit which seemed preserved at 28 days.”

He noted: “Based on our analyses, even a low amount of leisure-time physical activity may in fact be beneficial against fatal heart attacks, but statistical uncertainty precludes us from drawing any firm conclusions on that point.”

The authors said in the paper: “Our pooled analysis provides strong support for the recommendations on weekly physical activity in healthy adults stated in the 2016 European Guidelines on cardiovascular disease prevention in clinical practice;2 especially as we used cut-off values for physical activity comparable to those used in the guidelines.”

The guidelines recommend that healthy adults of all ages perform at least 150 minutes a week of moderate intensity or 75 minutes a week of vigorous intensity aerobic physical activity or an equivalent combination thereof.

Dr. Hansen concluded: “There are many ways to be physically active at little or no cost. Our study provides yet more evidence for the rewards of exercise.”

Source: European Society of Cardiology

Drinking Green Tea, Coffee Lowers Risk of Death for Stroke and Heart Attack Survivors

Stroke and heart attack survivors can reduce multiple causes of death and prevent further cardiovascular events by drinking green tea, according to new research published today in Stroke, a journal of the American Stroke Association, a division of the American Heart Association. The study also found daily coffee consumption helps heart attack survivors by lowering their risk of death after a heart attack and can prevent heart attacks or strokes in healthy individuals.

Previous research has examined the benefits of green tea and coffee on heart health in people without a history of cardiovascular disease or cancer. Researchers in the study “Green tea and coffee consumption and all-cause mortality among persons with and without stroke or myocardial infarction” sought to determine the effects of green tea and coffee consumption after surviving a stroke or heart attack.

“There is a strong need for scientific evidence on the lifestyles among survivors of stroke and heart attack considering the rapidly aging population and the need to improve life expectancy following these cardiovascular events,” says Hiroyasu Iso, M.D., a professor of public health at Osaka University in Suita, Japan, and the study’s corresponding author.

Researchers analyzed data of more than 46,000 participants (ages 40 to 79, 60% female) from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC study), a study conducted in 45 communities across Japan. Participants were asked to complete self-administered questionnaires that included information about demographics, lifestyle, medical history and diet. People were then divided into three groups: history of stroke; history of myocardial infarction (MI); and no history of stroke or MI. Researchers then analyzed the amount and frequency of green tea and coffee consumption. Researchers noted that a typical cup of green tea contains approximately 100mL (about 3.4 ounces) of liquid, and a typical cup of coffee contains approximately 150mL (about 5 ounces) of liquid.

Results include:

  • When compared with participants who rarely drank green tea, stroke survivors who consumed at least seven cups of green tea daily lowered their risk of all-cause mortality by approximately 62%. Researchers did not observe a statistically significant association among participants without a history of stroke or heart attack.
  • Heart attack survivors who drank one cup of coffee a day reduced their overall risk of death by approximately 22% when compared to those who did not regularly drink coffee.
  • People without a history of stroke or heart attack who consumed one or more cups of coffee a week had approximately a 14% lower risk of all-cause mortality compared to non-coffee drinkers.
  • Green tea consumption can prevent further cardiovascular events in survivors, while drinking coffee can prevent such events in healthy individuals.

“An important distinction to make is that in Japanese culture, green tea is generally prepared with water and without sugar. Additionally, coffee is prepared with water and occasionally milk and sugar,” said Iso. “The healthiest way to prepare these beverages is without an unnecessary amount of added sugars.”

Researchers note that this study was observational, and the reason why drinking green tea and coffee lowered the risk of heart attack and stroke cannot be determined. Further research is needed to understand the details in the different effects of green tea and coffee.

Source: American Heart Association