Heartbeat insights: Normal vs. concerning palpitations

Palpitations, a term often used by patients to describe abnormal sensations in the heartbeat, can range from a flutter to a racing sensation. Understanding the nature of these palpitations is crucial in distinguishing between normal variations and potential signs of a serious heart problem. In her latest online article, Dr Anne Griguer explores the key differences between normal and abnormal palpitations, the underlying causes, and when to seek medical attention.

Normal palpitations:

The human heart operates on its internal electrical system, controlled by the sinus node. This is the natural pacemaker of the heart which generates electrical impulses that cause the heart's chambers to contract. Normal palpitations, known as 'sinus rhythm or sinus tachycardia’, occur when the heart rhythm remains within the control of the sinus node. These palpitations are typically stronger or faster heartbeats that come and go gradually, triggered by specific circumstances like stress, exercise, or infection. This natural response to stressors involves the release of stress hormones such as adrenaline and cortisol. In some cases, standing up may trigger palpitations, indicating a condition called 'POTS,' necessitating specialised investigation and management.

Abnormal palpitations:

Abnormal palpitations present as a sudden sensation of a very fast or irregular heartbeat, often accompanied by symptoms like dizziness, light-headedness, shortness of breath, chest pain, or blackout.

When palpitations are felt as missed beats or isolated extra beats, they can be attributed to ectopic beats, where extra electrical impulses originate from outside of the sinus node, either in the heart's atria (top chambers) or ventricles (bottom chambers). While atrial or ventricular ectopics are common and usually benign, certain criteria, such as a high frequency, a prolonged duration, or underlying structural heart issues, can make them concerning.

Ectopic beats that persist for an extended period can lead to arrhythmias, signalling a loss of control by the sinus node. Supraventricular arrhythmias, originating in the atria, may include conditions like atrial fibrillation, requiring medication such as blood thinners to manage associated risks of stroke, or interventions like cardioversion or ablation to restore the normal heart rhythm. Ventricular arrhythmias, arising in the ventricles, can lead to life-threatening conditions such as ventricular tachycardia or fibrillation, necessitating urgent medical attention, often involving defibrillation (external or internal cardiac electric choc).

Diagnosis and monitoring:

To differentiate between normal and abnormal palpitations, recording a trace of the heart rhythm (ECG) during symptoms is crucial. Simple ECGs or prolonged recordings using Holter monitors can provide valuable insights. Home devices, including smartwatches or 'home ECG event recorders,' offer convenient options for ongoing monitoring. Blood tests and echocardiograms are also essential to rule out extra-cardiac problems and assess the heart's structure and function.

When to seek medical attention:

Frequent, prolonged, or lifestyle-impacting palpitations warrant a visit to a healthcare professional for a thorough examination and diagnostic tests. Emergency services should be contacted if palpitations persist for over an hour, accompanied by significant chest pain, shortness of breath, dizziness, or blackout, especially in individuals with cardiac risk factors.

Dr Anne Griguer is an esteemed consultant general and imaging consultant. You can schedule an appointment with Dr Griguer on her Top Doctors profile.