Arrhythmias in Post-COVID-19 Syndrome: Incidence and Management

Post-COVID-19 syndrome can involve persistent palpitations, episodic tachycardia, exercise intolerance, dizziness and apparent rhythm irregularity months after the acute infection. These symptoms may reflect a documented arrhythmia, autonomic dysfunction, inappropriate sinus tachycardia, postural orthostatic tachycardia syndrome (POTS), deconditioning, or a combination of factors. Clear clinical assessment is therefore more useful than assuming every palpitation represents recurrent atrial fibrillation or myocarditis.

The reported incidence of rhythm disorders varies substantially between studies because cohorts use different definitions, follow-up periods and monitoring methods. Hospitalised patients, people with severe acute disease and those with previous cardiovascular disease appear to carry the greatest risk, while community-based studies often identify a larger burden of intermittent symptoms than of sustained arrhythmia. For Australian clinicians, the practical task is to identify significant rhythm disease without exposing patients to unnecessary testing or attributing persistent symptoms solely to anxiety.

What Current Evidence Shows

Early in the pandemic, atrial fibrillation and atrial flutter were frequently reported during acute COVID-19, particularly in older patients with inflammation, hypoxia, fever, electrolyte disturbance or critical illness. Ventricular arrhythmias were less common but clinically important in patients with myocardial injury, shock or severe systemic disease. During recovery, palpitations and elevated resting heart rate remain common, although the proportion attributable to a confirmed supraventricular or ventricular rhythm is less consistent.

Observational studies suggest an increased risk of new cardiovascular diagnoses after SARS-CoV-2 infection, but they do not establish that every post-infectious symptom is caused by direct cardiac injury. Incidence estimates are influenced by access to electrocardiography, the use of wearable devices and whether researchers count sinus tachycardia as an arrhythmia. A careful distinction between symptoms, ECG findings and clinically consequential rhythm disorders is essential when interpreting the literature.

In Australia, local case numbers and healthcare access have changed across successive waves, making international incidence figures difficult to apply directly. A patient seen in a metropolitan cardiology clinic in Sydney may undergo prolonged ambulatory monitoring quickly, whereas someone in regional Queensland or Western Australia may first require telehealth review and remote testing. These differences affect detection as much as biology.

Why Rhythm Disturbances May Persist

Several mechanisms can overlap. Autonomic imbalance may produce an excessive heart-rate response to standing or modest activity, while reduced physical conditioning, altered sleep, anaemia and ongoing inflammation can amplify symptoms. Some patients experience sinus tachycardia without structural heart disease; others develop ectopic beats, atrial tachycardia or recurrent atrial fibrillation in the setting of pre-existing substrate.

Myocardial inflammation and microvascular dysfunction remain possible contributors, particularly when palpitations occur with chest pain, exertional breathlessness or reduced exercise capacity. Fibrosis or scar could create a substrate for re-entry, although the presence and clinical importance of such changes vary considerably. Medication effects, including bronchodilators, decongestants, stimulants and corticosteroids, should also be reviewed.

The relationship between autonomic dysfunction and atrial arrhythmia deserves particular attention. A rapid pulse after standing may be mistaken for paroxysmal supraventricular tachycardia, while frequent ectopy can be experienced as a sustained racing heartbeat. Advanced electrophysiology techniques may help define mechanisms in selected patients; a review of ultra-high-density mapping illustrates how detailed substrate assessment can inform treatment of complex atrial fibrillation, although such mapping is not a routine test for post-viral palpitations.

Clinical Assessment And Triage

Assessment begins with a detailed symptom history. Clinicians should document onset after infection, triggers, posture, duration, associated syncope or presyncope, exertional pattern and recovery time. A medication review, family history of sudden cardiac death, previous atrial fibrillation and thromboembolic risk factors can quickly change the level of concern. Resting blood pressure and heart rate should be supplemented by orthostatic measurements when symptoms are posture-related.

A 12-lead ECG is appropriate for persistent or recurrent symptoms, while ambulatory monitoring should match the symptom frequency. A 24-hour Holter may capture frequent ectopy or daily tachycardia, whereas a seven- to fourteen-day patch or event monitor is more useful for intermittent episodes. Consumer wearables can flag an irregular pulse, but they do not replace diagnostic ECG confirmation and may generate false alerts in people with ectopy or motion artefact.

Red flags warrant urgent evaluation or referral. These include syncope during exertion, sustained ventricular tachycardia, persistent chest pain, marked breathlessness, new heart failure signs, high-grade atrioventricular block, a significant family history of sudden death, or a rapid rhythm with haemodynamic compromise. Troponin, echocardiography and cardiac magnetic resonance imaging should be considered when the history, ECG or examination raises concern for myocarditis or structural disease.

Australia’s public system often requires prioritisation of investigations through general practice, emergency departments and outpatient cardiology services. Clear referral information can reduce delays: include the acute COVID-19 history, rhythm strips, orthostatic observations, medication list and relevant pathology. For patients using private services, the availability and cost of extended monitoring can differ from public pathways, so test selection should be clinically justified.

Managing Tachycardia And Autonomic Symptoms

Management should target the documented rhythm and the factors sustaining it. Pacing activity, regular sleep, gradual reconditioning and adequate nutrition may help people with post-exertional symptoms, although exercise should be individualised rather than imposed through a rapid escalation programme. Patients with orthostatic intolerance may benefit from fluid and electrolyte strategies, compression garments and slow transitions from lying to standing, subject to assessment for hypertension, renal disease and heart failure.

For inappropriate sinus tachycardia or POTS-like presentations, specialist-directed treatment can include low-dose beta blockers, ivabradine or other selected agents. These medicines require attention to blood pressure, asthma, conduction disease, pregnancy and drug interactions. A normal echocardiogram does not make symptoms irrelevant, but it can support a conservative approach when there is no evidence of dangerous rhythm disease.

People in Australia may receive advice influenced by climate and lifestyle. Heat exposure in Brisbane or Perth can worsen orthostatic symptoms through vasodilation and fluid loss, while long travel distances in remote communities can make frequent clinic-based monitoring impractical. Plans should be realistic, culturally safe and coordinated with the patient’s GP, with telehealth and local pathology services used where suitable.

Rehabilitation should stop short of dismissing symptoms as simple deconditioning. A graded plan that respects delayed symptom worsening is preferable to a fixed target that repeatedly provokes relapse. Sleep disorders, postural symptoms, migraine, gastrointestinal complaints and cognitive fatigue may need parallel management because they can intensify awareness of palpitations and reduce treatment tolerance.

Treating Atrial And Ventricular Arrhythmias

When atrial fibrillation or flutter is documented, management follows established principles while accounting for the patient’s recovery status. Stroke prevention should be based on validated risk assessment and bleeding risk rather than on the assumption that the infection itself creates a permanent indication for anticoagulation. Rate control, rhythm control, cardioversion and ablation are selected according to symptoms, duration, structural heart disease and patient preference.

A short episode recorded by a wearable should be confirmed before committing a patient to long-term anticoagulation or antiarrhythmic therapy. Conversely, clinicians should not overlook brief but recurrent episodes in people with substantial thromboembolic risk. Triggers such as alcohol, acute illness, sleep apnoea, thyroid dysfunction, obesity and uncontrolled blood pressure remain relevant after COVID-19.

Ventricular ectopy is often benign when the heart is structurally normal, but a high burden, non-sustained ventricular tachycardia or exertional symptoms requires further assessment. Echocardiography, exercise testing, cardiac MRI and electrophysiology consultation may be appropriate. Antiarrhythmic drugs and catheter ablation should be considered within a documented risk-benefit framework rather than used solely to suppress an unexplained sensation of a skipped beat.

Cardiac devices may be relevant when infection has unmasked conduction disease or worsened pre-existing pacing dependence. ECG interpretation can also be complicated by changes that persist after the original rhythm problem has resolved. The discussion of cardiac memory changes is useful when assessing repolarisation patterns after pacing or tachycardia, helping clinicians avoid interpreting every post-rhythm ECG abnormality as acute ischaemia.

Follow-Up, Research And Patient Communication

Follow-up should be proportionate to the findings. A patient with brief palpitations, a normal ECG, no red flags and improving exercise tolerance may need reassurance, symptom tracking and review rather than repeated imaging. Persistent tachycardia, abnormal biomarkers, reduced ventricular function or documented arrhythmia requires a more structured pathway involving cardiology or electrophysiology services.

Communication is part of treatment. Explain what has been found, what remains uncertain and which symptoms require urgent attention. Patients often arrive with smartwatch recordings and extensive online information; reviewing these records respectfully can improve trust while clarifying the limits of consumer technology. Advice should include when to call emergency services, especially for syncope, severe chest pain, sudden neurological symptoms or sustained breathlessness.

Research still needs better prospective cohorts, standardised definitions and longer follow-up. Studies should distinguish sinus tachycardia, autonomic syndromes, ectopic beats and confirmed atrial or ventricular arrhythmias rather than combining them under a single cardiovascular endpoint. Australia can contribute valuable data through linked health records, regional networks and collaboration between public hospitals, private cardiology practices and primary care.

For clinicians and researchers seeking peer-reviewed work on electrophysiology, devices and arrhythmia care, the Journal of Arrhythmia provides an open-access setting for current evidence, clinical guidance and educational material. Continued reporting of real-world outcomes will help determine which patients need advanced investigation and which can recover safely with supportive care and monitoring.

Clinicians should document rhythm evidence carefully, use risk-based referral pathways and review post-COVID symptoms without minimising them or overmedicalising every palpitation. Researchers can strengthen the evidence base through standardised definitions and inclusive Australian cohorts, while patients should record episodes, attend follow-up and seek urgent care for red-flag symptoms. The Journal of Arrhythmia’s research and educational resources offer a practical platform for advancing informed management of rhythm disorders after COVID-19.