"Atrial Fibrillation": Different Symptoms and Multiple Diagnostic Methods
Dr. Wala’a Hafez – Some people may occasionally feel a rapid or irregular heartbeat, and these symptoms are often transient. However, their recurrence, especially if accompanied by episodes of fluttering or palpitations in the chest, along with dizziness and shortness of breath, may be a distinctive sign of atrial fibrillation. Nevertheless, about a quarter of those affected feel no symptoms at all, a condition known as “silent atrial fibrillation.” Dr. Shan Khurshid, Assistant Professor at Harvard Medical School and specialist in cardiac electrophysiology at Massachusetts General Hospital, notes that doctors do not know precisely why some patients with atrial fibrillation experience clear symptoms while others do not. He explained that some patients may suffer only from cardiac symptoms, while others exhibit symptoms such as dizziness or shortness of breath, and some may experience both types. Khurshid adds, “I have heard from some patients that they can pinpoint the exact moment atrial fibrillation begins and ends, while others say they feel absolutely nothing.”
◄ What is atrial fibrillation? Dr. Khurshid explained that atrial fibrillation occurs due to an electrical disorder in the heart. Instead of the heart’s natural pacemaker generating regular beats, the upper chambers of the heart (the atria) quiver rapidly, at rates that can reach hundreds of times per minute. Most of these electrical impulses do not reach the lower chambers of the heart (the ventricles) to stimulate contraction, while some do, leading to irregular and accelerated heartbeats that may exceed 175 beats per minute. He noted that a normal heart rate is considered regular, ranging between 60 and 100 beats per minute. Therefore, episodes of atrial fibrillation may occur in short, intermittent bursts or for much longer periods, and may even be permanent in some individuals. Approximately one in 11 people aged 65 and older develops atrial fibrillation, which is more common among those with high blood pressure, heart disease, obesity, and sleep apnea.
◄ Common symptoms during an episode of atrial fibrillation: Patients often feel heart palpitations, fluttering, or irregular heartbeats. Because the ventricles do not fill with blood normally, the amount of oxygen-rich blood reaching the muscles and tissues decreases, which may cause feelings of fatigue and weakness. Blood may also accumulate in the lungs, leading to shortness of breath. Reduced blood flow to the brain can result in dizziness, vertigo, or even fainting. Additionally, a rapid heart rate can strain the heart, worsening feelings of tiredness. Dr. Khurshid says, “Many patients with atrial fibrillation simply report feeling extremely tired, while others describe a vague sense that something is wrong, without being able to pinpoint it precisely.” Another less common symptom that some people may experience during atrial fibrillation episodes is the frequent need to urinate. Dr. Khurshid explains, “When the atria quiver, they stretch and release a hormone called atrial natriuretic peptide, which sends a signal to the kidneys to eliminate excess fluid from the body.” He added that symptoms of atrial fibrillation may become more noticeable during exercise or even during daily activities, such as walking or climbing stairs. However, some patients may feel irregular heartbeats even while at rest.
◄ Episodes of atrial fibrillation: These episodes are often unpredictable and may be transient or last for much longer periods. Over time, atrial fibrillation may become a chronic condition. Experts classify this disorder into four categories based on the duration of the episodes:
• Paroxysmal atrial fibrillation: Episodes come and go, lasting minutes or hours over several days. They usually resolve on their own or with medical intervention within seven days of onset.
• Persistent atrial fibrillation: The episode lasts more than seven days and requires some form of treatment to restore the heart to its normal rhythm.
• Long-standing persistent atrial fibrillation: Atrial fibrillation lasts for more than one year.
• Permanent atrial fibrillation: Atrial fibrillation lasts for more than one year and no longer responds to treatment.
◄ How is it diagnosed? Because episodes of atrial fibrillation are often short-lived and may occur without symptoms, diagnosis can be difficult. Electrocardiography (ECG) is the primary diagnostic test to confirm the condition, as it records the heart’s electrical activity. However, a routine ECG performed during an annual check-up lasts only about 10 seconds, so it may not detect atrial fibrillation that occurs intermittently. Consequently, diagnosing atrial fibrillation often requires the use of a heart monitor, which uses electronic sensors placed on the chest to continuously monitor heart rhythm. One option is the Holter monitor, a device carried in a pocket or attached elsewhere on the body, connected by wires to several electrodes on the chest. This device records an ECG for one to two days. However, cardiologists are increasingly using wireless patch monitors, roughly the size of a large bandage, which can record an ECG for up to 14 days.
