Navigating Post-COVID Cardiac Issues: What Your ECG Might Reveal

The COVID-19 pandemic has brought many challenges to our health, and its effects go far beyond the lungs. More and more research shows that it can leave a lasting impact on the heart, even in people who had only mild symptoms at first. Many are still feeling heart-related symptoms months later.

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COVID-19 and the Heart

COVID-19 is primarily known as a respiratory illness, but it can affect nearly every organ system in the body, including the heart. The virus can directly infect heart muscle cells, leading to myocarditis (inflammation of the heart muscle), or it can trigger an exaggerated inflammatory response that indirectly damages the heart. Blood clots, which are a common complication of severe COVID-19, can also lead to heart attacks or strokes.

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Long COVID and Persistent Symptoms

Even after the acute infection has cleared, some individuals experience a range of persistent symptoms, often referred to as "Long COVID" or "Post-Acute Sequelae of SARS-CoV-2 infection (PASC)." Heart-related symptoms are quite common in Long COVID, and they can include things like palpitations, chest discomfort, shortness of breath, and feeling unusually tired with activity. Your ECG can offer helpful clues about what’s going on and guide you in getting the right care.

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Common Post-COVID ECG Findings

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Palpitations

One of the most commonly reported cardiac symptoms in Long COVID is palpitations, often described as a racing, pounding, or fluttering sensation in the chest. These can be due to various arrhythmias, some of which may be detectable on your ECG. Common findings include:

• Sinus Tachycardia: A persistently fast heart rate (over 100 beats per minute) that originates from the heart's natural pacemaker. This is very common in Long COVID and can be a sign of autonomic nervous system dysfunction, where the body's "fight or flight" response remains overactive.
• Postural Orthostatic Tachycardia Syndrome (POTS): A condition characterized by an abnormal increase in heart rate upon standing, often accompanied by dizziness, fatigue, and brain fog. While not always visible on a single ECG, a series of ECGs showing significant heart rate increases upon positional changes can be suggestive.
• Premature Atrial Contractions (PACs) and Premature Ventricular Contractions (PVCs): These extra heartbeats are often benign but can become more frequent and bothersome after COVID-19. Your ECG can capture these isolated irregular beats.
• Atrial Fibrillation (AFib): While less common in mild cases, some individuals, particularly those with pre-existing heart conditions or severe COVID-19, may develop new-onset AFib or experience worsening of pre-existing AFib. AFib is characterized by an irregularly irregular rhythm on the ECG.

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Chest Pain

Chest pain is another frequent complaint in Long COVID. While it's crucial to rule out a heart attack, many cases of post-COVID chest pain are non-cardiac or related to inflammation. However, your ECG can help differentiate. Potential ECG findings related to chest pain include:

• Myocarditis: Inflammation of the heart muscle can cause chest pain and may lead to ECG changes such as diffuse ST segment elevation (though often less pronounced than in a heart attack), T wave inversions, or arrhythmias. While a definitive diagnosis of myocarditis requires other tests (like cardiac MRI), an abnormal ECG can raise suspicion. However, it's important to note that ST segment changes may not be clearly visible on smartwatch ECGs, so follow-up with a medical-grade ECG is often necessary.
• Pericarditis: Inflammation of the sac surrounding the heart can also cause sharp chest pain, often worse when lying down or breathing deeply. ECG in pericarditis typically shows widespread ST segment elevation and PR segment depression.

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Shortness of Breath and Exercise Intolerance

Shortness of breath and exercise intolerance are also common post-COVID symptoms. While often related to lung issues, cardiac involvement can contribute. Your ECG, especially during or after exertion, might reveal:

• Persistent Sinus Tachycardia: As mentioned, a persistently elevated heart rate can contribute to feeling breathless, especially with activity.
• Arrhythmias during exertion: Some individuals may develop arrhythmias only during physical activity, which can be captured by a wearable ECG or during an exercise stress test.
• Signs of Heart Failure: In rare but severe cases, COVID-19 can lead to new or worsened heart failure. An ECG might show signs of ventricular hypertrophy (enlargement of heart chambers) or conduction abnormalities, though these are non-specific and require further investigation.

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Recommended Follow-Up

If you've had COVID-19 and are experiencing persistent cardiac symptoms, it's important to consult your healthcare provider. They may recommend a comprehensive cardiac evaluation, which could include:

• Blood Tests: To check for markers of inflammation (e.g., CRP, D-dimer) or heart muscle damage (e.g., troponin).
• Echocardiogram: An ultrasound of the heart to assess its structure and function.
• Holter Monitor or Event Recorder: For continuous monitoring of heart rhythm over days or weeks to capture intermittent arrhythmias.
• Cardiac MRI: Considered the gold standard for detecting myocarditis and other structural heart changes.
• Exercise Stress Test: To evaluate your heart's response to physical exertion and identify exercise-induced arrhythmias or ischemia.

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Role of Smartwatches and Wearables

Your ECG, whether from a medical device or your smartwatch, plays a crucial role in this diagnostic process. It can provide the initial clues that prompt further investigation or help monitor the effectiveness of treatments.

Modern wearable devices with ECG capabilities, like the Apple Watch, have become invaluable tools for individuals monitoring their heart health post-COVID. These devices allow you to:

• Track Heart Rate Trends
• Detect Irregular Rhythms
• Record On-Demand ECGs
• Monitor Heart Rate Recovery

While these devices are not diagnostic, the data they collect can be incredibly helpful for your healthcare team  - and for you  - in understanding your symptoms and guiding further testing. For example, they can allow you to capture events as they happen -like palpitations, dizziness, or a racing heart -so you can share a real-time snapshot with your doctor. Over time, consistent monitoring can help you spot patterns, such as whether certain symptoms are triggered by activity, stress, or posture. This kind of insight can be hard to get during a single doctor's visit, making wearable devices a valuable part of your heart health toolkit.

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Conclusion

That wraps up our guide on how COVID-19 can affect your heart and what your ECG might reveal along the way. Whether you’re dealing with ongoing palpitations, unusual fatigue, or chest discomfort, know that you’re not alone - and that what you’re feeling is real and worth exploring.

If you’re ever uncertain about what your smartwatch ECG is showing or just want a second set of eyes, that’s exactly why we created the Qaly app. On Qaly, human experts review your ECG recordings and help you make sense of what’s going on with your heart. It’s about bringing clarity, confidence, and peace of mind back to your health journey.

To get started, download the Qaly app from the App Store or Play Store. And if you ever have questions or need support, we’re always here at support@qaly.co.

From all of us at Qaly, take care of your heart - and yourself ❤️