Supraventricular arrhythmias refer to irregular heart actions or rapid heart rhythms. The actions may be a sudden recurrence or intensification of a condition of cardiac arrhythmia in which the contractions may be rapid (120 to 350 per minute) but, regular or irregular. There are several supraventricular arrhythmias, with atrial fibrillation being the most common arrhythmia. Definitions of selected supraventricular arrhythmias are as follows:

• Atrial fibrillation - This occurs when small areas of the atrial myocardium are in various uncoordinated stages of depolarization and repolarization. The atria quiver continuously in a chaotic pattern, causing a totally irregular and often rapid ventricular rate, instead of intermittently contracting. The atrial rate is 400 to 600 per minute, and the ventricular response is irregular, ranging from 80 to 180 beats per minute.

• Atrial flutter - It occurs when the atrial contractions are much faster than usual from 250 to 350 per minute, but regular. The ventricles are unable to respond to each atrial impulse, so that at least a partial atrioventricular block develops and the ventricular rate is usually approximately 150 beats per minute, but may also vary.

• Atrial premature beat - It occurs when the atria fires before the next sinus node impulse or a reentry circuit is established.

• Paroxysmal supraventricular tachycardia - It occurs when the heart rate may be 140 to 240 beats per minute, usually 160 to 220 per minute, and is regular despite exercise or change in position. The term paroxysmal refers to the fact that this rhythm suddenly starts and stops.

Other supraventricular arrhythmias that may occur include: supraventricular tachycardias due to accessory atrioventricular pathways (preexcitation syndrome); multifocal, chaotic atrial tachycardia; and atrioventricular junctional rhythm.

Physical- or disease-related disturbances in the release of cardiac impulses from the sinoatrial node or their transmission through conductive tissue of the heart cause the arrhythmias. Etiologic factors related to selected supraventricular arrhythmias are as follows:

• Atrial fibrillation - It may occur in the absence of apparent heart disease. The underlying causes may be rheumatic fever, coronary artery disease (CAD), pericarditis, chest trauma or surgery, hypertension, specific medications, and hyperthyroidism. Binge-drinking or chronic, heavy alcohol intake may also be causative factors.

• Atrial flutter - It may occur as a result of hypertension, valvular heart disease (see Diagnostic Code: 7000 Valvular heart disease), coronary heart disease, congestive heart failure (CHF), pulmonary embolism, and digitalis or postoperative revascularization.

• Paroxysmal supraventricular tachycardia - It often occurs in patients without structural heart disease. It may result from digitalis toxicity, and is commonly associated with atrioventricular block.

Symptoms vary depending on the resultant ventricular rate. They range from no symptoms to palpitations or skipped beats; chest discomfort; decreased cardiac output; dizziness; and syncope. There may also be weakness, faintness, and breathlessness. In atrial fibrillation, the electrocardiogram (EKG) shows chaotic, continuous rapid series of multiple interlacing waves. The EKG in atrial flutter typically shows flutter waves which may look like discrete P waves or a "sawtooth pattern." The EKG in paroxysmal supraventricular tachycardia shows multiple intermittent irregular waves with dramatic changes in both rate and regularity.

Diagnosis is made by EKGs that demonstrate the arrhythmias, and differentiate between aberrantly conducted supraventricular beats and ventricular beats. Use of a Holter monitor, loop monitor, and an echocardiogram may also be carried out.

Treatment of the conditions is directed toward terminating the arrhythmias, quickly if cardiac failure, syncope or anginal pain develops, or if there is underlying cardiac or cornary disease. Drug therapy, electrical cardioversion, and radiofrequency ablation are used in the treatment. Treatment, specific to the particular arrhythmia, may also be included. Paroxysmal supraventricular tachycardia may be treated by drug therapy, cardioversion, and mechanical measures such as the Valsalva's maneuver, and vagal stimulation if the person does not have carotid bruits or a history of transient cerebral ischemic attacks. Treatment is also directed toward prevention of the arrhythmias with antiarrythmic drug therapy and radiofrequency ablation for persons with recurrent symptomatic reentry supraventricular tachycardia.

Atrial fibrillation is a major risk factor for strokes due to the increase in thromboembolic phenomena. Drug therapy may be required to reduce the risk of a stroke. There may be repeated episodes of the arrhythmias. If a pacemaker is required, the person is informed of environmental hazards such as avoiding airport metal detectors, a magnetic resonance imaging (MRI), automobile anti-theft devices, and high-voltage electric wires. Exercise tolerance may be limited. Residuals will vary from individual to individual, from no residuals to any combination of the signs and symptoms.

• If a Veteran is a former prisoner of war, this disease shall be service connected if manifest to a degree of disability of 10% or more at any time after discharge or release from active military, naval, or air service even though there is no record of such disease during service, provided the rebuttable presumption provisions of 38 CFR 3.307 and/or 38 CFR 3.309 (c) are satisfied [Disease subject to service connection by presumption].

Notes

• Examples of supraventricular tachycardia include, but are not limited to: Atrial fibrillation, atrial flutter, sinus tachycardia, sinoatrial nodal reentrant tachycardia, atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, atrial tachycardia, junctional tachycardia, and multifocal atrial tachycardia.

• For the purposes of this diagnostic code, a treatment intervention occurs whenever a symptomatic patient requires intravenous pharmacologic adjustment, cardioversion, and/or ablation for symptom relief.

• For DCs 7009, 7010, 7011, and 7015, a single evaluation will be assigned under the diagnostic code that reflects the predominant disability picture.

• The rating criteria for cardiovascular conditions underwent full-scale revision effective on November 14, 2021 and January 12, 1999.  A regulatory change was effective August 13, 1998, updated criteria for cold injury residuals under 38 CFR 4.104, DC 7122.  The changes are not considered liberalizing and should not be used as the basis for reduction unless the disability has actually improved.