Feeling an irregular heartbeat can be unsettling, especially when settling down to rest. This sensation, often described as a skipped beat or a flutter, might be bigeminy. Bigeminy occurs when a normal heartbeat is followed by an extra, premature beat, creating a distinctive pattern. This article explores why this specific heart rhythm might become noticeable when lying down and what it could signify.
Understanding Bigeminy
Bigeminy is a heart rhythm where every normal heartbeat is followed by a premature contraction, creating a paired beat sequence. This can manifest as a sensation of a skipped beat, a flutter, a thud, or a pause followed by a stronger beat. While some individuals have no symptoms, others are acutely aware of these changes in their heart rate. These extra beats are typically premature ventricular contractions (PVCs) originating from the lower chambers of the heart, or less commonly, premature atrial contractions (PACs) from the upper chambers.
In bigeminy, an electrical impulse fires from an unusual location, interrupting the typical sequence of coordinated beats. This can cause the premature beat to feel different because less blood may be pumped out during that early beat. While occasional premature beats are common and often harmless, the consistent pattern of bigeminy defines this specific rhythm.
Why Lying Down Can Trigger Bigeminy
Physiological factors can contribute to bigeminy becoming more apparent when lying down. One reason involves the vagus nerve, which can be stimulated when lying down, particularly on your left side. This nerve influences heart rate, and its stimulation can sometimes trigger arrhythmias.
Lying flat can lead to diaphragmatic pressure, where abdominal contents press against the diaphragm. This pressure can irritate the heart or vagus nerve, potentially contributing to irregular heartbeats. When lying down, more blood returns to the heart. This fluid redistribution slightly increases the heart’s volume and pressure, which can sometimes make the heart more sensitive and prone to irritability.
Increased awareness when still and quiet in bed can play a role. During daily activities, subtle heart rhythm changes might go unnoticed, but in a calm environment, these sensations become more prominent. Acid reflux or gastroesophageal reflux disease (GERD) is another contributing factor. Lying down can worsen acid reflux, and esophageal irritation has been linked to triggering heart palpitations, including bigeminy.
Recognizing When to Seek Medical Attention
While bigeminy is often benign, medical evaluation is necessary if it is frequent, persistent, or causes distressing symptoms. These concerning symptoms include dizziness, lightheadedness, fainting spells, chest pain, or shortness of breath.
Medical evaluation is warranted if you have a history of heart disease, high blood pressure, or other cardiovascular conditions. A family history of sudden cardiac death is an important factor to discuss. Any new onset of bigeminy or a noticeable change in its pattern should prompt a medical consultation.
Diagnosis and Treatment Approaches
Diagnosis typically begins with a thorough medical history and physical examination. An electrocardiogram (ECG or EKG) is a standard test that records the heart’s electrical activity and can identify the bigeminy pattern. Since bigeminy might not occur during a brief ECG, a Holter monitor or event recorder may be used. These wearable devices capture heart activity over extended periods to detect intermittent bigeminy.
An echocardiogram, an ultrasound of the heart, may be performed to assess heart structure and function. Blood tests might be ordered to check for underlying issues like electrolyte imbalances or thyroid problems that can contribute to bigeminy.
Treatment approaches for bigeminy vary depending on the underlying cause and the severity of symptoms.
Lifestyle modifications are often the first step and can include reducing caffeine and alcohol intake, managing stress, ensuring adequate sleep, and maintaining hydration. Addressing any identified underlying conditions, such as acid reflux, sleep apnea, or thyroid issues, is an important part of treatment.
In some cases, medications like beta-blockers or calcium channel blockers may be prescribed to help regulate heart rhythm and lower heart rate. For very symptomatic or severe cases unresponsive to other treatments, catheter ablation may be considered. This procedure targets and modifies specific heart tissue responsible for abnormal electrical signals.