Isolated atrial standstill

What it is

From: Orphanet

A rare cardiac rhythm disease characterized by a transient or permanent absence of electrical and mechanical atrial activity. Electrocardiographic findings include bradycardia, ectopic supraventricular rhythms, lack of atrial excitability and absent P waves.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal P wave · Very frequent (99-80%)

Any anomaly of the P wave of the EKG, which results from atrial depolarization. The P wave occurs when the sinoatrial node creates an action potential that depolarizes the atria.

Atrial standstill · Very frequent (99-80%)

Atrial standstill or silent atrium is a rare condition presenting with the absence of electrical and mechanical activity in the atria. It presents with the absence of P waves, bradycardia, and wide QRS complex in the electrocardiogram.

Cardiac conduction abnormality · Very frequent (99-80%)

Any anomaly of the progression of electrical impulses through the heart.

Palpitations · Very frequent (99-80%)

A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia.

Ventricular escape rhythm · Very frequent (99-80%)

A ventricular escape rhythm occurs whenever higher-lever pacemakers in AV junction or sinus node fail to control ventricular activation. Escape rate is usually 20-40 bpm, often associated with broad QRS complexes (at least 120 ms).

Abnormal heart morphology · Frequent (79-30%)

Any structural anomaly of the heart.

Arrhythmia · Frequent (79-30%)

Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both.

Dyspnea · Frequent (79-30%)

Difficult or labored breathing. Dyspnea is a subjective feeling only the patient can rate, e.g., on a Borg scale.

Fatigue · Frequent (79-30%)

A subjective feeling of tiredness characterized by a lack of energy and motivation.

Increased circulating troponin T concentration · Frequent (79-30%)

An increased concentration of tropnin T in the blood, which is a cardiac regulatory protein that controls the calcium mediated interaction between actin and myosin. Raised cardiac troponin concentrations are now accepted as the standard biochemical marker for the diagnosis of myocardial infarction.

Left ventricular noncompaction · Frequent (79-30%)

Left ventricular noncompaction (LVNC) is defined by 3 markers: prominent left ventricular (LV) trabeculae, deep intertrabecular recesses, and the thin compacted layer.

Muscular dystrophy · Frequent (79-30%)

The term dystrophy means abnormal growth. However, muscular dystrophy is used to describe primary myopathies with a genetic basis and a progressive course characterized by progressive skeletal muscle weakness and wasting, defects in muscle proteins, and histological features of muscle fiber degeneration (necrosis) and regeneration. If possible, it is preferred to use other HPO terms to describe the precise phenotypic abnormalities.

Postexertional malaise · Frequent (79-30%)

Post-exertional symptom exacerbation (PESE), also referred to as post-exertional malaise (PEM), is defined as the worsening of symptoms that can follow minimal cognitive, physical, emotional, or social activity, or activity that could previously be tolerated. Symptoms typically worsen 12 to 72 hours after activity and can last for days or even weeks, sometimes leading to a relapse.

Reduced left ventricular ejection fraction · Frequent (79-30%)

A diminution of the volumetric fraction of blood pumped out of the ventricle with each cardiac cycle.

Other findings in the same source

From: Orphanet

Additional reported features include Right bundle branch block (Frequent (79-30%)); Sick sinus syndrome (Frequent (79-30%)); Aphasia (Occasional (29-5%)); Bradycardia (Occasional (29-5%)); Cardiomyopathy (Occasional (29-5%)); Congestive heart failure (Occasional (29-5%)); Dysarthria (Occasional (29-5%)); Flexion contracture (Occasional (29-5%)); Headache (Occasional (29-5%)); Hemiplegia (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Adult

Inheritance in the source

From: Orphanet

Autosomal dominant; Not applicable

Which doctor should you see?

The suggested department for discussing Isolated atrial standstill is Cardiology, with a cardiologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Is the main concern heart structure, rhythm, circulation or another cause?
• Which symptoms should change the timing of follow-up?
• How would a proposed investigation change the care plan?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Isolated atrial standstill. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.