Wildfire smoke is an unfortunate reality in Los Angeles. The Palisades and Eaton fires in early 2025 showed even more of the dangers of smoke exposure on the heart for residents who had to bear the brunt of so many seasonal fires in recent years. For patients living in Westwood, Brentwood, Beverly Hills, Santa Monica, and throughout the LA area, wildfire smoke is a growing concern and an ongoing cardiovascular threat.

As a Westwood cardiac surgeon at the Ronald Reagan UCLA Medical Center, Dr. Maria Tehrani hears patients describing chest tightness, palpitations, and shortness of breath, and a decreased ability to enjoy physical fitness and sports. These symptoms are completely valid. The evidence for the effects of wildfire smoke on the heart is undeniable and the solutions to reduce the threat are equally clear.

How Wildfire Smoke Impacts Your Heart

Wildfire smoke is made up of gases, soot, and a lot of small particles. The component that impacts your heart the most is PM2.5. PM2.5 is a small particulate matter of 2.5 microns, or smaller. Because PM2.5 is so small, it can pass directly into the blood stream after crossing the lung barrier, and cause a lot of problems for the body.

– Inflammation

– Dysfunction of the endothelium (inner lining of the blood vessel)

– Clotting

– Blood pressure increases

– Heart rate increases

– Heart rhythm becomes irregular

– Less oxygen gets to the heart muscle

Research has shown that people who live near wildfires have more heart attacks, AFib, and heart attacks and strokes that go out to the ER when wildfires happen. Wildfire smoke is the most dangerous for people with heart disease, but can cause problems for people who are healthy too.

Who is Most Affected by Smoke Events

The Cardiac risks during wildfire smoke for several groups are shown here:

– Individuals with prior coronary artery disease, stents or open heart surgery

– Individuals with heart failure

– Individuals with AFib or arrhythmias

– Individuals with high and clinically significant hypertension

– Individuals with diabetes

– Individuals 65 and older

– Individuals that are currently pregnant

– Individuals with asthma, COPD, sleep apnea, or other similar respiratory disorders

If you belong to any of these categories, during a smoke event, you should be more alert and responsive than the remainder of the population. Issues that you might not be concerned about during normal clearing of the air, such as palpitations, increased chest pressure, fatigue, and shortness of breath, should be a cause for concern and prompt a visit to the er during heavy smoke.

The Air Quality Index: What You Should Know

The Air Quality Index (AQI) is a popular way for LA residents to track their exposure to air pollutants. For real time data, residents can download AirNow, IQAir, or PurpleAir for free. The following guidelines for AQI readings can be helpful to cardiac patients:

– AQI 0-50 (green): normal activity

– AQI 51-100 (yellow): generally safe, but sensitive patients may have symptoms

– AQI 101-150 (orange): outdoor activity should be limited

– AQI 151-200 (red): All outdoor exercise should be avoided and outdoor activity should be limited

– AQI 201-300 (purple): Stay indoors with filtered air. Outdoor activity should be postponed

– AQI 301 + (maroon): indoor air may be better than filtered air outdoors, stay indoors, air may be better than filtered air outdoors, stay indoors, air may be better than filtered air outdoors, stay indoors, and contact your physician if you are experiencing symptoms.

Thanks to LA’s unique topography and climate, AQI reports can be very different even in nearby neighborhoods. For example, the Santa Monica beach is often very different from the Pacific Palisades or the eastern parts of the city. Make sure to check the AQI for your specific zip code rather than a general LA report.

Your Best Defense: Indoor Air Quality

The goal during a smoke event should be to make indoor air cleaner than outdoor air. Here are some ways to accomplish that:

– Run a true HEPA air purifier. These should be sized for individual rooms and should be placed in every room.

– Close all windows and doors to help minimize smoky air from coming in.

– Set your HVAC system to recirculate rather than draw outside air into the system.

If your HVAC System can support it, upgrade your filters to at least MERV 13.

During smoke events, do not use gas stoves, light candles or incense, or smoke indoors. These do not replace outdoor sources of pollution.

If you are unable to filter air throughout your house, air filter purifiers can be placed in a clean room. This is a bedroom with a closed and sealed door, and an air filter purifier.

Indoor air quality concerns during heavy smoke events is not something that can be ignored. The levels of PM2.5 become dangerous in a matter of hours if there is no filtration.

Protection from Smoke

Cloth and surgical masks are nearly useless against smoke. Wildfire smoke is full of particles that are too small to be stopped. The only options that work are:

— N95s

— KN95s

— P100s

N95s and P100s are recommended for people who will experience high smoke exposure. If you have a chronic respiratory or heart condition, you should see your doctor before using these, as they do increase your breathing effort. For most people, using these briefly is better than no protection at all.

### Exercise and Activity During Smoke Events

Cardiac patients have a lot to worry about when exercising outside when there is heavy smoke. Outside of the usual worries related to cardio, breathing in heavily during smoke draws in a concerning level of particulates that can enter the bloodstream. Some practical activity adjustments that can be generalized are:

– Move your workouts inside on orange-or-higher AQI days

– Symptoms may appear during workouts. In that case, reduce the intensity of the workout.

– Do not try to make up for workouts once the smoke clears. Exposure during a smoke event still counts.

– Runners and cyclists should plan workouts based on AQI, not their habits.

After the Smoke Clears

Cardiac events are known to happen, but also can occur days or even weeks after the smoke has cleared. Changes to inflammation and clotting can last days after the smoke event. Smoke event symptoms like chest pain, irregular but rapid heartbeat and breathlessness, and extreme fatigue should not be ignored, even if they occur after.

The fires that occur every year create more smoke events that are a constant risk to the cardiovascular system. The longer this cycle lasts, the worse the risk. Your daily decisions also matter during this season.

When to Call the Heart Doctor

You should see a cardiologist or cardiac surgeon if you have any of the following:

– Serious heart disease, and your symptoms are worsening when you’re smoking.

– New heart palpitations, chest pressure, or shortness of breath after wildfires.

– A past heart issue and you’re concerned about what activities you can do to stay safe during the fires.

– High blood pressure and it’s getting harder to control when there’s smoke.

– You are planning on getting heart surgery and are concerned about your exposure.

Severe chest pain, fainting, and stroke symptoms (facial drooping, arm/leg weakness, slurred speech) should be treated as an emergency. Call 911.

Smoke from wildfires is dangerous for your heart. If you have heart problems, serious risk factors, or new health issues during the fires, you should see Dr. Maria Tehrani. These are the services provided for patients across Los Angeles.