Atrial Tachycardia Clinical Presentation

Updated: Mar 13, 2017
  • Author: Adam S Budzikowski, MD, PhD, FHRS; Chief Editor: Jeffrey N Rottman, MD  more...
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Presentation

History

Focal atrial tachycardia is usually episodic or paroxysmal. Typically, atrial tachycardia manifests as a sudden onset of palpitations. Atrial tachycardia due to enhanced automaticity may be nonsustained but repetitive or it may be continuous or sustained, as in reentrant forms of atrial tachycardia.

Atrial tachycardia may gradually speed up soon after its onset (warm-up phenomenon). However, the patient may be unaware of this. In a patient with supraventricular tachycardia (SVT), the presence of warm-up phenomenon on an electrocardiogram (eg, on Holter monitoring) suggests that the SVT is atrial tachycardia.

If the tachycardic episodes are accompanied by palpitations, patients also may report dyspnea, dizziness, lightheadedness, fatigue, or chest pressure. In patients with frequent or incessant tachycardias, a decline in effort tolerance and symptoms of heart failure may represent early manifestations of tachycardia-induced cardiomyopathy.

Lightheadedness may result from relative hypotension, depending on the heart rate and other factors, such as the state of hydration and particularly the presence of structural heart disease. The faster the heart rate, the more likely a patient is to feel lightheaded. A rapid rate and severe hypotension may lead to syncope.

Reentrant atrial tachycardia is not uncommon in patients with a history of a surgically repaired atrial septal defect. The scar tissue in the atrium may give rise to the formation of a reentrant circuit.

The history should include questions regarding possible causes, such as the following:

  • Medical history, especially history of tachycardia or other cardiac problems
  • Medications: Amphetamines, cocaine, caffeine, ephedrine, antihistamines, phenothiazines, antidepressants, theophylline, appetite suppressants, albuterol, digoxin
  • Family history of sudden death, deafness (Jervell-Lange Nielsen syndrome), or cardiac disease

Underlying disorders in multifocal atrial tachycardia

In patients with multifocal atrial tachycardia (MAT), the history may disclose an underlying illness that is causing the tachycardia. Such illnesses include pulmonary, cardiac, metabolic, and endocrinopathic disorders.

Chronic obstructive pulmonary disease (COPD) is the most common underlying disease process (60%). The arrhythmia is commonly precipitated by exacerbation of COPD, sometimes due to infection or exacerbation of heart failure. Increasing hypoxemia with respiratory acidosis and advanced disease also leads to increased bronchodilator usage, thereby increasing catecholamine levels, which may contribute to development of MAT.

Patients with MAT frequently have structural heart disease, mainly coronary artery disease and valvular heart disease, often in conjunction with COPD. Heart failure is often present when the diagnosis of MAT is first made. Metabolic disorders may also lead to MAT. In various series, 24% of patients with MAT were found to have diabetes mellitus, 14% had hypokalemia, and 14% had azotemia.

Twenty-eight percent of patients with MAT are recovering from major surgery, while others have postoperative infections, sepsis, pulmonary embolism, and heart failure. The link between pulmonary embolism and MAT is weak (ie, 6-14% of such patients have been said to have MAT), but the methods of diagnosing pulmonary embolism in these cases have not been well documented.

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Physical Examination

The primary abnormality noted on physical examination is a rapid pulse rate. In most atrial tachycardias, the rate is regular. However, in rapid atrial tachycardias with variable atrioventricular (AV) conduction and in MAT, the pulse may be irregular.

Blood pressure may be low in patients presenting with fatigue, lightheadedness, or presyncope. The cardiovascular examination should be aimed at excluding underlying structural heart diseases such as valvular abnormalities and heart failure.

Depending upon comorbid conditions or general health status, the patient may be hemodynamically unstable. However, determining whether this is due to the underlying condition or to the arrhythmia may be difficult.

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